WO2009125397A2

WO2009125397A2 - Device and method for foot drop analysis and rehabilitation

Info

Publication number: WO2009125397A2
Application number: PCT/IL2009/000384
Authority: WO
Inventors: Omer Einav; Derick Glenn Puckett
Original assignee: Motorika Limited
Priority date: 2008-04-08
Filing date: 2009-04-06
Publication date: 2009-10-15
Also published as: WO2009125397A3

Abstract

A foot drop rehabilitation system comprises a frame configured for at least partially supporting a patient in an upright position, a mechanical ankle joint associated with the frame and configured for being fitted on a patient's foot and for assisting movement of the patient's foot at the ankle, at least one sensor configured or sensing at least one lower extremity parameter of the patient, and a controller configured for sampling the at least one sensor output and for controlling timing or angle of dorsiflexion during gait based on output from the at least one sensor output.

Description

DEVICE AND METHOD FOR FOOT DROP ANALYSIS AND REHABILITATION

FIELD OF THE INVENTION

The present invention, in some embodiments thereof, relates to devices and methods for foot drop diagnosis and rehabilitation and, more particularly, but not exclusively, to systems and methods for foot drop rehabilitation during gait and balance.

BACKGROUND OF THE INVENTION

Strokes, accidents and other medical conditions can cause a person to lose balance control and/or the ability to control gait, for example, how to walk or run. Loss of balance and/or gait control may be full or partial lose of control. During a lengthy rehabilitation process, a patient is taught anew how to control the body parts that contribute to patient gait and locomotion.

Drop Foot and Foot Drop are interchangeable terms that primarily describe a deficit in turning the ankle upward, e.g. raising the foot at the ankle. Drop foot is further characterized by an inability to point the toes toward the body (dorsiflexion) or move the foot at the ankle inward or outward.

Walking becomes a challenge due to the patient's inability to control the foot at the ankle. The foot may appear floppy and the patient may drag the foot and toes while walking. Patients with foot drop usually exhibit an exaggerated or high-stepping walk called Steppage Gait or Footdrop Gait.

One system for providing gait rehabilitation is described in U.S. Pat. No.

6,666,831 assigned to The Regents of the University of California and to California

Institute of Technology, the disclosure of which is hereby incorporated by reference in its entirety. U.S. Patent No. 6,666,831 describes a robotic exoskeleton and a control system for driving the robotic exoskeleton, including a method for making and using the robotic exoskeleton and its control system. The robotic exoskeleton has sensors embedded in it which provide feedback to the control system. Feedback is used from the motion of the legs themselves, as they deviate from a normal gait, to provide corrective pressure and guidance. The position versus time is sensed and compared to a normal gait profile. Various normal profiles are obtained based on studies of the population for age, weight, height and other variables. Another system for providing rehabilitation is described in U.S. Pat. No. 6,689,075 assigned to HealthSouth Corp. the disclosure of which is hereby incorporated by reference in it entirety. U.S. Pat. No. 6,689,075 describes a support structure which supports powered lifting means for lifting a patient from a wheelchair and moving the patient over a powered treadmill where the patient is lowered onto the treadmill. A control panel with a mirror thereon is supported at one end of the support structure, and a touch screen data entry/display device is supported by the panel. Two similar housings are disposed at opposite sides of the treadmill. Each housing pivotally supports a support arm which can swing away from the treadmill to facilitate access to the treadmill. Each support arm pivotally supports a first depending arm, and a second depending arm is pivotally supported therefrom. A pair of servo motors are supported by each support arm and are drivingly connected to the first and second depending arms to independently move the depending arms about the pivot axes thereof. A first attachment cuff is connected to the first depending arm for attachment to a patient's leg just above the knee. A second attachment cuff is connected to the second depending arm for attachment to a patient's ankle. The support arms are vertically adjustable, and the attachment cuffs are horizontally adjustable. The first attachment cuff is vertically adjustable, and the second attachment cuff floats vertically relative to its depending arm. Control means is connected to the drive means for the treadmill and the servo motors which move the depending arms to cause the treadmill and the depending arms to operate in a coordinated manner to cause the legs of the patient to move in a desired gait. Sensor means is also provided for sensing the home position as well as possible over-travel of the knee joint of the device.

One other system for providing rehabilitation is described in International Patent Application Publication No. WO 2005/074370 and whose inventor is common with one of the inventors of the present application, the disclosure of which is hereby incorporated by reference in its entirety. WO 2005/074370 describes a system and method for gait rehabilitation, comprising, identifying at least one deficient gait element, e.g. a foot; exercising said deficient gait element individually using a rehabilitation apparatus; and exercising said deficient gait element in concert with at least one other gait element using said rehabilitation apparatus. Products developed by companies such as Bioness Inc. and Innovative Neurotronics, address foot drop and use functional electrical stimulation to replace the typical nerve-to-muscle signals in the leg and foot, effectively lifting the foot at the appropriate time during the gait cycle. An overview of these products may be found on the following internet sites www.bionessinc.com/products/1300.htm and www.walkaide.com/products/medicalcommunity/index.html as of December 2007.

SUMMARY OF THE INVENTION

An aspect of some embodiments of the present invention is the provision of a device and method for analysis and rehabilitation of foot drop during gait and balance including analysis and coordination of ankle movement and ankle muscle control together with movement and control of the entire lower extremity.

An aspect of some embodiments of the present invention is the provision of a foot drop rehabilitation system comprising a frame configured for at least partially supporting a patient in an upright position, a mechanical ankle joint associated with the frame and configured for being fitted on a patient's leg and for assisting movement of the patient's foot at the ankle, at least one sensor configured or sensing at least one lower extremity parameter of the patient; and a controller configured for sampling the at least one sensor output and for controlling timing or angle of dorsiflexion during gait based on output from the at least one sensor output.

Optionally, the mechanical ankle joint includes an actuator configured for controllably driving rotation of the ankle joint and wherein the controller is configured for controlling motion of the actuator.

Optionally, the system comprises a stimulation unit configured for stimulating a muscle associated with movement of the patient's foot at the ankle based on the at least one lower extremity movement control parameter.

Optionally, the at least one sensor is a pair of electro-myogram electrodes for sensing activation of at least one muscle associated with ankle movement control.

Optionally, the pair of electro-myogram electrodes is configured to detect the electro-myogram signals from a healthy leg of the patient.

Optionally, the at least one muscle is the tibialis muscle. Optionally, the at least one sensor is sensor configured for sensing at least one lower extremity movement control parameter of a healthy leg of the patient during a rehabilitation session.

Optionally, the sensor is integrated on a passive mechanical ankle joint, wherein the passive mechanical ankle joint is fitted on the patient's healthy leg.

Optionally, the system comprises at least one of a mechanical knee joint or a mechanical hip joint, wherein the controller is configured for coordinating movement of the at least one of a mechanical knee joint or a mechanical hip joint with ankle joint rotation. Optionally, the at least one of a mechanical knee joint or a mechanical hip joint comprises an actuator configured for controllably driving rotation of the joint and wherein the controller is configured for controlling motion of the actuator in coordination with the mechanical ankle joint.

Optionally, the at least one sensor is a rotational sensor configured for sensing rotation of the at least one of the mechanical knee joint and the mechanical hip joint.

Optionally, the at least one sensor includes a torque sensor configured for sensing torque exerted on the mechanical ankle joint.

Optionally, the system comprises a standing platform above which a patient stands when engaged on the rehabilitation system. Optionally, the standing platform is configured for being tilted in a forward or backwards direction with respect to a patient's foot standing on the standing platform.

Optionally, the standing platform is configured for being tilted in a sideway direction with respect to a patient's foot standing on the standing platform.

Optionally, the controller is configured for controlling the tilting angle of the standing platform.

Optionally, the standing platform is configured for being vibrated or jolted.

Optionally, the controller is configured for controlling vibration or jolting of the standing platform.

Optionally, the at least one sensor is configured to detect a pressure exerted by a patient's foot on a standing platform associated with the system.

Optionally, the sensor is a pressure pad integrated on to the standing platform.

Optionally, the sensor is an insole pressure pad. Optionally, the sensor is a pressure sensor plate comprising a first plate and a second plate, one over the other and separated by at least two load cells and two springs and wherein the load cells are configured to detect pressure.

Optionally, the system comprises a foot position detector configured for detecting a position of a foot at and/or near a standing platform.

Optionally, the foot position detector comprises at least one light emitter array and at least one light detector array positioned on opposite sides of a standing platform, wherein the light detector array is configured for detecting light from the light emitter.

Optionally, the foot position detector comprises a second set of light emitter and light detector array positioned on opposite sides of a standing platform one sides other than the sides occupied by the at least one light detector and emitter array, wherein the foot position detector is configured for detecting two dimensional position of a patient's foot.

Optionally, the foot position detector is configured for detecting an orientation of the foot based on output from the light detector array.

Optionally, the foot position detector comprises an additional set of light emitter and light detector array positioned at a height above the at least one light detector and emitter array, wherein the additional set of the light emitter and light detector array is configured for detecting position of a patient's foot at a height above the standing platform.

Optionally, the standing platform is integrated with a treadmill.

Optionally, the controller is configured for controlling operation of the treadmill.

Optionally, the system comprises a harness movably attached to the frame and configured for at least partially supporting a patient in an upright position. Optionally, the system comprises a force sensor engaged on an interface between the harness and the frame for sensing the weight supported by the harness.

Optionally, the system comprises a height adjustment mechanism for adjusting the height at which a patient is supported in an upright posture.

Optionally, the system comprises a visual display unit configured for providing feedback to the patient or health professional based on data sampled from the at least one sensor. Optionally, the visual display unit configured for instructing the patient to perform a defined task.

Optionally, the system comprises a data processing unit configured for processing data sampled by the controller and for defining at least one parameter for controlling foot drop.

Optionally, the at least one parameter for controlling foot drop is selected from a group including: driven rotation of the mechanical ankle joint, functional electrical stimulation of one or more muscles associated with dorsiflextion, visual feedback, percent of body weight supported, motion of a treadmill integrated with a standing platform, and motion of the standing platform.

An aspect of some embodiments of the present invention is the provision of a method for foot drop rehabilitation, the method comprising partially supporting a patient in an upright position, sensing at least one lower extremity movement control parameter of the patient with at least one sensor, determining a desired timing or angle of dorsiflexion of a first leg, and artificial initiating dorsiflexion of the first leg.

Optionally, dorsiflexion of the first leg is initiated by a mechanical ankle joint.

Optionally, the angle of dorsiflexion is controlled by the mechanical ankle joint.

Optionally, the timing of dorsiflexion is controlled by the mechanical ankle joint. Optionally, dorsiflexion of the first leg is initiated by a functional electrical stimulator configured for stimulating muscles associated with rotation of the ankle joint.

Optionally, the angle of dorsiflexion is controlled by the functional electrical stimulator.

Optionally, the timing of dorsiflexion is controlled by the functional electrical stimulator.

Optionally, the method comprises determining a pattern of motion of the first leg about a knee based on the sensing, and coordinating motion about the ankle with the determined pattern of motion about the knee.

Optionally, the method comprises determining a pattern of motion of the first leg about a hip based on the sensing, and coordinating motion about the ankle with the determined pattern of motion about the hip. Optionally, the method comprises determining a pattern of motion of a second leg of the patient based on the sensing, and coordinating motion about the ankle with the determined pattern of motion about the second leg.

Optionally, the at least one sensor is configured to sense rotation of at least one lower extremity joint.

Optionally, the at least one sensor is a pair of electro-myogram electrodes for sensing innervations of at least one muscle associated with lower extremity control.

Optionally, the at least one muscle is associated with ankle movement control.

Optionally, the pair of electro-myogram electrodes is configured to detect the electro-myogram signals from muscles controlling the ankle of the first leg.

Optionally, the at least one muscle is the tibialis muscle.

Optionally, the method comprises artificially initiating the movement about at least one of a knee joint and a hip joint.

Optionally, the at least one sensor is a torque sensor configured for sensing a torque about a lower extremity joint.

Optionally, the at least one sensor configured for sensing a pressure exerted by the foot on a standing platform. Optionally, the at least one sensor is configured for sensing a force exerted by the foot on a standing platform.

Optionally, the at least one sensor is configured for sensing a position of a foot on or near a standing platform.

Optionally, the at least one sensor is configured for sensing a two dimensional position of the foot.

Optionally, the at least one sensor is configured for sensing a foot on or near a standing platform.

Optionally, the at least one sensor is configured for determining a time period spent on each foot during gait. Optionally, the method comprises moving a standing platform on which the patient is standing and coordinating the pattern of foot motion about the ankle based on the motion of the standing platform. Optionally, the method comprises at least partially supporting a patient from the pelvis with telescopic pelvic support rods and adjusting a length of the pelvic support rods based on the motion of the standing platform.

An aspect of some embodiments of the present invention is the provision of a foot drop rehabilitation system comprising a frame configured for at least partially supporting a patient in an upright position over a standing surface, the standing surface associated with the frame, wherein the standing surface is configured for tilting sideways, at least one sensor configured or sensing at least ankle rotation or ankle muscle activation during tilt, and a controller configured for tilting the standing surface and for sampling output from the at least one sensor during tilt of the standing surface.

Optionally, the standing surface is configure for backwards tilting, forwards tilting, right tilting, and left tilting.

Optionally, the standing surface is a treadmill, wherein the treadmill is configured for tilting. Optionally, the system comprises a sensor configured for sensing position of the patients center of gravity.

Optionally, the system comprises a sensor configured for sensing weight distribution between the patients feet.

Optionally, the controller is configured for sampling output during a gait cycle. An aspect of some embodiments of the present invention is the provision of a foot drop rehabilitation system comprising a frame configured for at least partially supporting a patient in an upright position, a mechanical ankle joint associated with the frame and configured for being fitted on a patient's leg and for assisting movement of the patient's foot at the ankle, a light array detector system configured for detecting position of a patient's foot on or near a standing surface, and a controller configured for controlling timing or angle of dorsiflexion during gait based on output from the light array detector system.

Optionally, the light array detector system includes at least one array of light emitters positioned on one side of a standing platform and one array of light detectors position on an opposite side of the standing platform.

Optionally, the standing platform is for a single foot. Optionally, the light array detector system includes two array of light emitters positioned on two adjacent sides of a standing platform and two array of light detectors position on an opposite sides of the array of light emitters.

Optionally, the light array detector system is configured for determining position and orientation of the patient's foot.

Optionally, the light array detector system includes at least two arrays of light emitters positioned one over the other at a defined vertical distance from each other and two corresponding arrays of light detectors positioned one over the other at the defined vertical distance from each other. Optionally, the light array detector system is configured for determining position of the patient's foot as it approaches the standing surface.

An aspect of some embodiments of the present invention is the provision of a method for retrofitting an existing gait robot, the method comprising retrofitting an existing gait robot with a mechanical ankle joint, retrofitting the existing gait robot with at least one sensor configured for sensing ankle rotation or ankle muscle activation, upgrading a controller associated with the existing gait robot to accommodate control of the mechanical ankle joint and the at least one sensor, and installing new software on a computing device associated with the existing gait robot for upgrading the existing gait robot to provide ankle joint control and sensing. Optionally, the method comprises retrofitting the existing gait robot with a functional electrical stimulation, wherein the functional electrical stimulation is configured for stimulating ankle rotation.

Optionally, the retrofitting provides foot drop rehabilitation or foot drop rehabilitation capability. Optionally, the method comprises retrofitting an existing gait robot with a treadmill, wherein the treadmill is configured for sideways titling and wherein the controller is configured for controlling tilt of the treadmill.

Optionally, the method comprises retrofitting an existing gait robot with a light array detector system configured for detecting position of a patient's foot on or near a standing surface associated with the gait robot. Optionally, the light detector system includes at least one array of light emitters positioned on one side of a standing platform and one array of light detectors position on an opposite side of a standing surface associated with the gait robot.

Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

Implementation of the method and/or system of embodiments of the invention can involve performing or completing selected tasks manually, automatically, or a combination thereof. Moreover, according to actual instrumentation and equipment of embodiments of the method and/or system of the invention, several selected tasks could be implemented by hardware, by software or by firmware or by a combination thereof using an operating system.

For example, hardware for performing selected tasks according to embodiments of the invention could be implemented as a chip or a circuit. As software, selected tasks according to embodiments of the invention could be implemented as a plurality of software instructions being executed by a computer using any suitable operating system. In an exemplary embodiment of the invention, one or more tasks according to exemplary embodiments of method and/or system as described herein are performed by a data processor, such as a computing platform for executing a plurality of instructions. Optionally, the data processor includes a volatile memory for storing instructions and/or data and/or a non-volatile storage, for example, a magnetic hard-disk and/or removable media, for storing instructions and/or data. Optionally, a network connection is provided as well. A display and/or a user input device such as a keyboard or mouse are optionally provided as well.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced. In the drawings:

Figure 1 is an exemplary lower extremity movement control robot shown with and without a patient according to some embodiments of the present invention;

Figure 2A and 2B is a back view and a sectional view of an exemplary lower extremity movement control robot including mechanical joint adapted for controlling foot motion about the ankle according to some embodiments of the present invention;

Figure 3 is an exemplary simplified block diagram describing a stimulation system for stimulation muscles to control movement about the ankle according to some embodiments of the present invention;

Figures 4A-4C is an exemplary system for measuring pressure and/or force of the foot on a standing surface according to some embodiments of the present invention;

Figures 5A-5D is an exemplary system for detection foot position at and/or near the standing surface according to some embodiments of the present invention;

Figure 6 is an exemplary flow chart describing a method of foot drop rehabilitation according to some embodiments of the present invention; Figure 7 is an exemplary flow chart describing a method for lower extremity movement control rehabilitation according to some embodiments of the present invention;

Figure 8 is an exemplary flow chart describing a method of balance rehabilitation according to some embodiments of the present invention; and Figure 9 is an exemplary flow chart describing a method of planning a foot drop rehabilitation session according to some embodiments of the present invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

The present invention, in some embodiments thereof, relates to devices and methods for foot drop diagnosis and rehabilitation and, more particularly, but not exclusively, to systems and methods for foot drop rehabilitation during gait and balance. According to some embodiments of the present invention there is provided a device including a support structure for supporting a patient in an upright position, a detecting unit for detecting at least one parameter while engaged in the support structure, e.g. a parameter associated with lower extremity movement control of the patient, and at least one robotic arm and/or mechanical ankle joint configured for directly controlling dorsiflexion during gait or during balance retention based on output from the detecting unit. In some exemplary embodiments, the timing for the onset of dorsiflexion is controlled by an actuated mechanical ankle joint attached to the patient's leg and foot. In some exemplary embodiments, the amount of dorsiflexion is controlled by the actuated mechanical ankle joint attached to the patient's leg and foot.

According to some embodiments of the present invention, the device includes a functional electrical stimulation (FES) unit for stimulating one or more muscles associated with dorsiflexion in response to a specified output from the detection unit. In some exemplary embodiments, the device is capable of initiating muscle activation of muscles associated with dorsiflexion at a specified time and/or controlling the amplitude of muscle stimulation. In some exemplary embodiments, movement at the ankle may be stimulated by stimulating the one or more nerves innervating muscles that facilitate dorsiflexion of the ankle, e.g. the tibialis, with electrodes positioned on the lower leg. According to some embodiments of the present invention, the device provides actuated movement of a lower extremity joint, e.g. hip, knee and/or ankle, in coordination with FES of one or more nerves innervating muscles that facilitate dorsiflexion of the ankle and/or toe lift. According to some embodiments of the present invention, actuated ankle movement with a mechanical ankle joint together with FES for electrically stimulating ankle movement enables controlled dorsiflexion and/or full dorsiflexion with toe lift. According to some embodiments of the present invention, the detecting unit includes at least one pressure sensor plate and/or force plate configured to detect pressure and/or forces applied by the foot on a standing surface. In some exemplary embodiments, a pressure sensor plate and/or force plate is positioned under a treadmill, e.g. a treadmill belt. In some exemplary embodiments, the detecting unit includes two sensing plates, e.g. one sensing plate for each foot. In some exemplary embodiments, the pressure sensor plate and/or force plate is used to determine the time and duration that each foot touches the standing surface during gait. In some exemplary embodiments, the pressure sensor plate and/or force plate is used to determine the pressure distribution between the patient's feet during standing and gait. According to some embodiments of the present invention, the treadmill is capable of being tilting forward/backwards and side to side during a rehabilitation session. According to some embodiments of the present invention, the detecting unit includes a position and/or orientation detector for detecting the position and/or angle of at least one lower extremity joints, e.g. hip, knee and ankle, and/or for detecting the position and orientation of the foot on a standing surface. In some exemplary embodiments, the position and/or orientation detector detects position and/or orientation of the foot during gait, standing and/or during transition between gait and standing.

In some exemplary embodiments, the position and/or orientation detecting unit includes a light array detector system for detecting the position and orientation of a patient's foot on and/or over a standing surface. The light array detector system includes an array of light emitters position on one side of a standing surface and a corresponding array of light detectors position on a opposite side of a standing platform. A foot positioned on the standing platform may block a portion of the light emitted from the array of light emitters so that the light detectors detect a pattern of light that correspond to a position of the foot on the standing platform. In some exemplary embodiments a two dimensional light array detector is used. For example an array of emitters may be position on two adjacent sides of a rectangular standing surface with detectors positioned on the two remaining sides so that each array of emitters is associated with an array of detectors on an opposite side. In some exemplary embodiments, a two dimensional light array detector is configured for detecting the position as well as orientation of the foot on and/or near the standing surface. In some exemplary embodiments, additional sets of light emitters and detectors are positioned one over the other in a vertical fashion so that position and orientation of a foot as it approaches a standing platform can also be detected.

According to some embodiments of the present invention, the detecting unit is configured for detecting a balance feature of the patient associated with foot drop. In some exemplary embodiments of the present invention the balance feature includes a balance feature during standing. In some exemplary embodiments of the present invention a balance feature includes balance feature during transition between standing and gait. Specifically, a balance feature associated with foot drop and/or with function of one or more muscles associated with foot drop is detected. Examples of balance features include positioning of the foot on a standing platform and activation of muscles associated with foot drop during balance retention. According to some embodiments of the present invention, the device includes a knee and/or hip mechanical joint actuated in coordination with the mechanical ankle joint and/or with FES of the patient's ankle, e.g. to correct for foot drop. In some exemplary embodiments of the present invention, the detecting unit includes one or more potentiometers and/or torque sensors positioned on at least one mechanical joint for tracking movement and force exerted on the mechanical joints during a rehabilitation session.

According to some embodiments of the present invention, the device provides compensation for foot drop while rehabilitating other parts of the lower extremity. In some exemplary embodiments, compensation is by actuated mechanical ankle joint movement and/or by FES stimulation during a rehabilitation session. The present inventors have found that foot drop often gets in the way of rehabilitation of knee and/or hip control exercises performed on gait robots. The device and methods described herein maybe used to fully and/or partially compensate for foot drop during gait rehabilitation sessions. According to some embodiments of the present invention, the device includes computing device including a processing unit, memory and a controller for sampling and processing output from the detecting unit and for controlling and/or updating function of the mechanical joints and/or the FES. In some exemplary embodiments, control and/or update of the mechanical joints and/or the FES is based on the sampled output. According to some embodiments of the present invention, the computing device is associated with a display unit for providing feedback to the patient and the health professional. In some exemplary embodiments, the display provides instructions, e.g. graphical instructions, regarding the exercise that the patient is to perform and provides feedback on his performance. According to some embodiments of the present invention, the detecting unit,

FES and a mechanical ankle joint are retrofitted on an existing gait robot. According to embodiments of the present invention, the retrofitted system is capable of compensating for foot drop and providing foot drop rehabilitation capability. According to embodiments of the present invention, software is installed on the computing device to accommodate the retrofit. In some exemplary embodiments, the controller is updated and/or replaced to provide capability of controlling the additional elements added to the existing gait robot.

Reference is now made to Fig. 1 showing an exemplary lower extremity movement control robot according to some embodiments of the present invention. According to some embodiments of the present invention, a gait and balance robot 100 facilitates diagnosis and rehabilitation of gait and balance function including diagnosis and rehabilitation of ankle joint control and/or lower extremity control including ankle joint control. According to some embodiments of the present invention, robot 100 typically includes a frame 110 from which a patient may be supported in an upright position, one or more mechanical joints 120 to assist and/or resist movement of one or more joints as required, one or more muscle stimulators 130 to electrically stimulate gait or balance, one or more sensors 140 to sense one or more gait and/or balance related parameters. A computing device 200 including controller 150, processor 199 and memory 198 is used to control function of robot 100.

According to some embodiments of the present invention, frame 110 may fully or partially support a patient in an upright posture, e.g. with harness 112. In some exemplary embodiment, frame includes a structure to assist a patient in supporting himself or herself in an upright posture, e.g. handle bars 117. According to some embodiments harness 112 may be removably engaged and/or attached to a frame 110 with a base 111. In some exemplary embodiments, base 111 can be removably engaged to frame 110. Frame 110 and/or elements of the frame may be adjustable to provide support at variable heights to accommodate different patient's heights (e.g. adult and children heights). In some embodiments of the invention, frame 110 is adjustable to provide varying levels of supporting force to the patient.

According to some embodiments of the present invention, harness 112 is supported by frame using one or more pistons to allow a patient to exercise without bearing the patient's full weight on the rehabilitating limbs. As strength and control return to the patient, weight can be gradually added until the patient is bearing full weight. A varying amount of support may be provided to each side of the patient, e.g. left and right side, depending on the patient's ability.

In some exemplary embodiments, the support system may include a force sensor 113, for monitoring the amount of supporting force provided to the patient. The height of the support system may be adjusted to accommodate a selected amount of supporting force. According to some embodiments, the support system includes one or more bars and/or handles 117 from which a patient may support himself or herself where the heights of the bars and/or handles may be adjusted to accommodate different patient heights. According to some embodiments of the present invention, frame 110 additionally provides structure for supporting one or more mechanical joints, sensors, and/or electrical stimulators included in robot 100.

According to some embodiments of the present invention, one or more pelvic support rods 121, e.g. typically two pelvic support rods, may be attached to harness 112 and/or a belt around a patient's waist to assist a patient in maintaining an upright position by supporting the patient in the pelvic area. In some exemplary embodiments, varying amounts of support may be provided by adjusting the length of pelvic support rods 121.

According to some embodiments of the present invention, pelvic support rod 121 may be a telescopic rod whose length may be adjusted by an actuator and controlled by controller 150. In some exemplary embodiments, pelvic support rod 121 is implemented for initiating and/or controlling pelvic rotation, e.g. during gait and balance. In some exemplary embodiments, pelvic rotation may be coordinated with lower extremity joint movement to stimulate real gait. In some exemplary embodiments, a sensor may be associated with pelvic support rod to sense pelvic rotation during gait and/or balance exercise.

According to some embodiments of the present invention, robot 100 may include one or more mechanical joints 120 to assist in moving and/or control movement of the ankle joint. In some exemplary embodiments, movement of the ankle joint is coordinated with one or more joints of the lower extremities, e.g. hip and knee. According to some embodiments of the present invention, mechanical ankle joint 120A facilitates correctly timing lifting of the patient's foot at the ankle during a gait cycle, e.g. to compensate for foot drop or rehabilitate foot drop. According to some embodiments of the present invention, mechanical ankle joint 120A facilitates gauging the amount of dorsiflexion of the patient's foot during a gait cycle. According to some embodiments of the present invention, mechanical ankle joint 120A may provide resistance to movement during specific periods in a gait cycle and/or for exercising muscles controlling ankle movement. According to some embodiments of the present invention, ankle motion is coordinated with movement and/or position of the hip and/or knee joint.

According to some embodiments of the present invention, the mechanical joint includes an actuator, e.g. a servo-motor engaged to two arms that are rotatably connected. According to embodiments of the present invention, each of the two arms are strapped with straps 119 and/or otherwise attached to a patient's limb at either side of the patient's joint to drive controlled movement and/or to provide resistance to movement about the joint. Typically, the mechanical joint provides movement with one degree of freedom. According to some embodiments of the present invention, a plurality of mechanical joints may be linked, e.g. hip, knee and ankle mechanical joints. In some exemplary embodiments, the mechanical ankle joint is similar to the mechanical joints described in incorporated Patent Application Publication No. WO 2005/074370.

In some exemplary embodiment, a first arm 125 is rotatably supported by the frame to form a mechanical hip joint 120C. A second arm 126 is rotatably connected to the first arm to form a mechanical knee joint 120B. The third arm 127 is rotatably connected to the second arm. Third arm 127 be rigidly connected to a bar and/or platform strapped and/or otherwise rigidly connected to a patient's foot, e.g. forming a mechanical ankle joint 120A. The second arm may be supported on the lower leg, e.g. above the ankle. The height of the rotatable connection between the first and second arm and the second and third arm may be adjusted to the height of the patient's joints and arms 125, 126, and 127 may be coupled to the patients lower extremities with straps and/or brackets so that the patient's movement about the joints are coupled to movement of the mechanical joints.. The length of the arms may also be adjusted to conform to the length of the patient's limb so that the mechanical joints may be aligned to the patient's joints. A servo motor may be engaged to one or more rotatable connections of the arms, e.g. mechanical joints to provide driven movement. According to some embodiments of the present invention, robot 100 includes mechanical joints for both legs.

According to some embodiments of the present invention, a potentiometer 140A and/or other rotational sensor may be mounted on the mechanical joint to monitor rotation of one or more joints. According to some embodiments of the present invention, a torque sensor may be applied to monitor torque applied at one or more of the mechanical joints. In some exemplary embodiments, current output of a motor used to drive a mechanical joint may be measured to monitor torque. In some exemplary embodiments, one or more mechanical joints may be passive and may not include an actuator to drive motion about the joint. In some exemplary embodiments, one or more actuators may be passive and/or neutralized during use of robot 100. In some exemplary embodiments, a passive joint may include a sensor 140, e.g. a potentiometer 140A to sense movement of the passive joint, e.g. patient initiated movement. According to some embodiments of the present invention, a torque load may be applied at one of the mechanical joints to provide resistance to movement, e.g. an actuator may apply a torque in a direction opposite to the direction of movement. According to some embodiments of the present invention, one leg of a patient may be engaged to one or more mechanical joints that are actuator driven while a second leg of the patient may be engaged to one or more passive mechanical joints including sensors. According to some embodiments of the present invention, sensor output from one leg may provide input to actuators applied to the other leg. According to some embodiments of the present invention output from rotational sensors mounted on one or more joints may be used to coordinate and/or time driven motion of the ankle joint during gait and/or balance. According to some embodiments of the present invention, robot 100 may include one or more muscle stimulators 130 to perform FES to stimulate nerves innervating muscles at specific times in coordination with one or more gait parameters. In some exemplary embodiments of the present invention, one or more muscles associated with movement about the ankle may be stimulated in response to information obtained one or more sensors 140, e.g. obtained from sensors associated with the knee or hip joint and/or the ankle joint movement of the injured and/or healthy leg. In one exemplary embodiment, the stimulator may stimulate the common peroneal nerve, which innervates the tibialis anterior and other muscles that produce dorsiflexion. According to some embodiments of the present invention, FES may be implemented in place of actuated driven motion of one or more mechanical joints. In some exemplary embodiments, actuated driven motion of one or more mechanical joints may be implemented in place of FES. In some embodiments of the present invention, actuated driven motion of one or more mechanical joints, e.g. the ankle joint may be implemented together with FES. In one exemplary embodiments, in the beginning of rehabilitation both actuated movement of the ankle and FES of the ankle is used to provide dorsiflexion at the appropriate time, an appropriate amount and for an appropriate duration. As the patient gets stronger, the amount of help that a patient gets may be reduced by either reducing the amplitude of FES and/or the torque applied on the mechanical joint. In some rehabilitation sessions that ankle joint is applied to provide resistance of dorsiflexion to help strengthen the ankle muscles. In some exemplary embodiments, the tradeoffs between applying actuated movement of the mechanical joint and FES may be weighed and customized for each patient and during each rehabilitation session. Application of actuated movement of the mechanical joint and FES may be based on output from one or more sensors associated with robot 100 and may be adjusted during the rehabilitation session.

According to some embodiments of the present invention, FES of the ankle may be based on information detected from the other ankle, e.g. healthy ankle. According to some embodiments of the present invention, FES may be adjusted to the percent of the patient's weight that harness 112 is supporting. For example, amplitude of stimulation may be increased for a decrease in the percent of the patient's weight that harness 112 is supporting. According to some embodiments of the present invention, robot 100 may include one or more pairs of electromyography (EMG) electrodes 140B for detecting muscle activity related to gait and balance control. According to some embodiments of the present invention, one or more sets of EMG electrodes may be used to detect muscle activity of muscles associated with dorsiflexion. In some exemplary embodiments, activity of the tibialis anterior, extensor hallucis longus, and extensor digitorum longus muscles typically associated with clearing the foot during a swing phase and controlling plantar flexion of the foot on heel strike. According to some embodiments of the present invention EMG electrodes 140B may be used to detect a muscle activity pattern in a healthy limb and use that information to stimulate an injured limb. According to some embodiments of the present invention muscle activity on both limbs may be examined, e.g. during a gait cycle. According to some embodiments of the present invention, muscle activity on an injured leg may be recorded and changes in EMG occurring over time, e.g. over the course of the rehabilitation may be tracked. According to some embodiments of the present invention, information regarding activity of other muscles associated with gait and balanced is examined and implemented to diagnose and/or rehabilitate gait and/or balance control. In an exemplary embodiment of the invention, one or more muscle tension sensors and/or electromyography ("EMG") sensors are used to monitor a patient's electromotor responses to rehabilitation. Analysis of measurements taken from these sensors help identify which parts of the patient require further rehabilitation and allow planning of future rehabilitation strategy and also may be used to adjust FES and actuation of the mechanical ankle joint during a rehabilitation session. Optionally, pulse measurement or breathing rate sensors are used for monitoring physiological state of the patient.

According to some embodiments of the present invention, robot 100 may include a movable, tillable and/or vibrating platform 160 from which gait and/or balance control excerises can be initiated. In some embodiments platform 160 includes a treadmill. In one exemplary embodiment, the treadmill may be controllably inclined to form an uphill, downhill, or sideways tilting platform, e.g. left or right tilting, platform. In some exemplary embodiment, driven movement including dorisflexion and/or stimulation may be coordinated with movement and/or tilt of the treadmill. According to some embodiments of the present invention, platform 160 may be controllably vibrated, e.g. using one or more piezoelectric actuators. In one exemplary embodiment, vibration may be added to treadmill motion. Introducing vibration allows further diagnosis and rehabilitation of patient muscle and balance control in different situations that may replicate real life situations, e.g. walking down aisles of a plane in flight, and standing in an elevator.

According to some embodiments of the present invention, robot 100 may include one or more pressure and/or force sensor plates 140C to detect forces applied by one or each of the feet supported on the standing platform and/or position and/or orientation of the foot on and/or near the standing platform. According to some embodiments of the present invention, one, two or more force plates may be used to detect forces exerted by one or both of the feet standing on the platform. According to some embodiments of the present invention, the one or more force plates, e.g. two force plates, may be integrated with a treadmill to measure forces during gait. According to some embodiments of the present invention the one or more force plates may be integrated with a moving platform.

According to some embodiments of the present invention, robot 100 may include one or more sensors to detect position, orientation, and/or foot touch on the standing platform. In some embodiments of the present invention, one or more pressure pads may be implemented for this purpose. In some embodiments of the present invention, the pressure pads are integrated as insoles to the patient's shoes and are in electrical communication with controller 150. Output from the pressure sensor plates 140C may be sampled by controller 150 and implemented for coordinating movement, stimulation and/or for performing diagnosis. According to some embodiments of the present invention, one or more tilt sensors may be used to determine tilt of a joint, e.g. the ankle joint. Insoles used may be similar to insoles proved by Andante Medical Device Ltd. and described in www.andante.co.il as of April 3, 2008 which is hereby incorporated by reference.

According to some embodiments of the present invention, robot 100 may include light array detector system to detect foot touch, foot orientation on and/or near the standing platform. Details of the light array detector system is provided herein and in reference to Figs. 5A-5D. According to embodiments of the present invention, control or coordination of the one or more elements of robot 100 may be based on output from one or more of the sensors sensing gait or balance parameters, patient feedback, and/or pre-selected exercise routines. According to embodiments of the present invention, controller 150 may sample data from one or more sensors of robot 100 and may use the data to coordinate timing, duration, and angle of dorsiflexion. In some exemplary embodiments, FES₅ motion driving mechanical joints, pelvic rotation, percent body weight supported and/or feedback provided to the patient, e.g. visual, audio, and/or tactile feedback is used to coordinate timing, duration, and angle of dorsiflexion. Data processing device 199 may process data, e.g. sensor data, sampled by controller 150 to and perform analysis of the motion recorded. Optionally, based on an analysis, data processing device defines robot parameters and/or plans rehabilitation exercises. In some embodiments of the present invention, motion about the ankle joint, e.g. dorsiflexion, is coordinated in response to sensed sensor output. In some embodiments of the present invention, motion about the ankle is coordinated with one or more other joint motions, e.g. knee and hip motion. In some exemplary embodiments, a camera is used to track the patient's movements of the lower extremities. In an exemplary embodiment of the invention, patients' rehabilitation is assisted by feedback based on a target movement profile in view of their current movements. Feedback to the patient can be in the form of beeps and/or visual cues and other similar video and audio prompts. A target movement profile is particularly useful for patients with Parkinson's who have a gait problem because they cannot properly gauge step size. Through feedback, the proper step size can be taught. Feedback is optionally implemented with any of the methods and/or apparatuses described herein. For example, in an exercise where the patient imitates a movement seen on the display, or imitates a previously recorded movement profile, the patient can be guided through exercise via kinesthetic feedback as the controller senses patient movement, calculates deviation from the goal movement profile, and prompts the patient to move according to the goal profile. In some exemplary embodiment, a patient is prompted to shift their body weight from one foot to the other and control of ankle muscles is examined, diagnosed and/or exercised. Optionally prompting is achieved through vibration provided by the standing platform and a patient's response and response time is examined. Optionally, in an exercise for maintaining balance, patients view a calculated position of their center of gravity as well as a target center of gravity, e.g. moving target, and are requested to shift their center of gravity to correspond to the target center of gravity. Optionally, varying levels of feedback and exercise instruction are provided to the patient based on the patient's cognitive state. For example, for patients with low cognitive abilities, more simple instructions and/or more forceful feedback is optionally provided. According to embodiments of the present invention, providing fully lower extremity control, e.g. including ankle control, enables improved diagnosis and rehabilitation of balance.

Reference is now made to Fig. 2A and 2B showing a back view and a sectional view of an exemplary lower extremity movement control robot including mechanical joints according to some embodiments of the present invention. According to embodiments of the present invention, robot 100 may include lower extremity mechanical joints 120A-120C that may be applied to flex and/or extend one or more lower extremity joints. According to embodiments of the present invention, a mechanical ankle joint 120A may be formed between arm 126 that may be rigidly strapped to a patient's lower leg and pedal and/or strap 127 that may be rigidly strapped to a patient's foot. An actuator, e.g. a stepper motor may be used to drive motion of at least one of ankle joint 120A, knee joint 120B, and hip joint 120C. In some exemplary embodiments, one or more of the mechanical joints may be passive, e.g. not actively moved by an actuator, so that only the patient controls rotation of the joint and the actuator is neutral. According to some embodiments of the present invention, actuated control of the mechanical joint may be accompanied and/or replaced by FES of muscles associated with that joint during rehabilitation. In some exemplary embodiments, a health professional may choose to control and/or initiate movement of a patient's ankle by FES and/or actuated movement of the mechanical ankle joint. In some exemplary embodiments, selection of FES and actuated movement is performed by computing unit 200 based on processed information from robot 100. One or more sensors may be associated with mechanical joints 120, e.g. potentiometers, torque sensors, to determine working condition of each of the patient's joints. In some exemplary embodiments, one or more devices, e.g. EMG, FES, are tethered and the wires are run along arms 125-127 and/or frame 110 to computing device 200 and/or controller 150. In some exemplary embodiments wireless transceivers may be positioned on arms 125-127 or frame 110 for receiving data from one or more sensors.

Reference is now made to Fig. 3 showing an exemplary simplified block diagram describing a stimulation system for stimulating muscles to initiate and/or control movement about the ankle according to some embodiments of the present invention. According to embodiments of the present invention controller 150 activates the FES 130 and a mechanical joint 120 based on a plurality of inputs to controller 150. Optionally, the timing and/or pattern of FES may be controlled based on an EMG input 310 received by one or more EMG electrodes of corresponding muscles on the other leg and processed by data processing device 199. Optionally, the timing and/or pattern of FES may be controlled based on a movement pattern input 320 received from detection of movement pattern of the hip, knee and/or ankle joint. Optionally, the timing and/or pattern of FES may be controlled based on foot position input 330 from detection of the foot approaching the standing platform. Optionally, the timing and/or pattern of FES may be controlled based on forces detected on the standing platform. Optionally, the timing and/or pattern of FES may be based on a signal provided by a user, e.g. patient and/or health professional. Optionally, the timing and/or pattern of FES may be controlled based on the movement planned for the standing platform.

Reference is now made to Figs. 4A-4C showing an exemplary system for measuring pressure and/or force of the foot on a standing surface according to some embodiments of the present invention. According to some embodiments of the present invention, one or more pressure sensors and/or load cells 410 may be positioned between an upper surface 440, e.g. standing surface and lower surface 450 for measuring pressure exerted on the foot under a standing surface. One or more springs 460 may be positioned in parallel to the load cells to provide counter balance force on the standing surface. According to some embodiments of the present invention, robot 100 may include two separate pressure plates positioned side by side, to measure pressure that each of the feet exerts on a standing surface. According to some embodiments of the present invention, each plate includes a load cell and spring on two opposite ends of the plate, e.g. along a longitudinal axis of the plane. According to some embodiments of the present invention, the plate(s) is integrated with a treadmill so that measurements may be taken during gait and/or during movement of the treadmill. For example, the plate(s) may be positioned under a belt of the treadmill over which a patient stands. In some exemplary embodiments, one or more force plates may be used to measure a force distribution that one or both of the feet exerts on the standing platform. According to some embodiments of the present invention one or more pressure pads may be implemented to measure pressure distribution under the feet. In some exemplary embodiments, pressure pads may be implemented as insoles on the patient's shoes. In some exemplary embodiments, pressure pads or pressure insoles may be used together with pressure sensor plate 140C.

According to some embodiments of the present invention, output from one or more load cells 410 may be sampled by controller 150 and processed by data processing unit 199. Sampled output from load cell 410 may be used for diagnosis, providing feedback to the patient and/or health professional, and/or for designing the rehabilitation procedure of the patient.

Reference is now made to Fig. 4C showing a tiltable platform that may be associated with robot 100 according to some embodiments of the present invention. According to some embodiments of the present invention lower surface 450 may be tiltable forward and backwards and/or side to side. One or more actuators may be implemented for controlling the tilt of platform 160 and/or pressure sensor plate 140C, e.g. in conjunction with a treadmill. In some exemplary embodiments of the present invention, a direct drive ball screw motor 480 may be coupled to each of support rods 485 to control tilt of platform 450 about joint 490. In one exemplary embodiment, motors 480 may be individually controlled to provide sideways tilting as well as forward and backwards tilting. For example if rods 485 are raised to different heights, platform 160 will have a sideways tilt, e.g. left or right tilt. According to some embodiments of the present invention, during a rehabilitation session, the standing platform is tilted to rehabilitate ankle control and specifically foot drop when standing or walking on terrain is not flat. During diagnosis as well as during rehabilitation sessions, a patient's response to the tilting may be detected and feedback may be provided to the health care professional and/or to the patient. For example, muscle stimulation, ankle tilt during gait, and timing of foot lift may be detected. Reference is now made to Figs. 5A-5D showing an exemplary system for detecting foot position at and/or near the standing surface according to some embodiments of the present invention. According to some embodiments of the present invention, the light array detector system includes an array of light emitters 510 position on one side of a standing surface and a corresponding array of light detectors 540 position on a opposite side of a standing platform. As the foot 1000 approaches and/or touches platform 160, light 555 from one or more emitters, e.g. array emitters 510 may be blocked and may not reach detectors 540 in an area(s) 545 corresponding to an area where foot 1000 is positioned. In some exemplary embodiments a one dimensional array may be implemented (Figs. 5A-5B) and foot position may be detected in one dimension.

In some exemplary embodiments, a two dimensional array may be implemented (Figs. 5C-5D) and foot position may be detected in two dimensions. For example an array of emitters 510 may be position on two adjacent sides of a rectangular standing surface with detectors 540 positioned on the two remaining sides so that each array of emitters is associated with an array of detectors on an opposite side. In some exemplary embodiments, a two dimensional light array detector is configured for detecting the position of foot 1000 in two dimensions so that position and orientation of foot 1000 on and/or near the standing surface can be determined.

In some exemplary embodiments, additional sets of light emitters and detectors are positioned one over the other in a vertical fashion so that position and orientation of a foot can be determined at various heights above the platform, e.g. during lifting or lowering of the foot. According to some embodiments of the present invention, controller 150 may sample output of one or more light detector array(s) 540 and data processing unit 199 may determine position and/or touch of foot 1000 over time based on sampled output. According to some embodiments of the present invention, a separate system for detecting foot position at and/or near the standing surface may be implemented for each of the patient's feet. For example, an array of emitters and detectors may be positioned on opposite sides of platform 160 and also in the middle between the patients two feet. According to some embodiments of the present invention, foot position detector may be implemented to detect spatial position and/or orientation of foot during gait and/or balance. Position and/or orientation may be implemented to evaluate and/or coordinate lower extremity movement.

According to some embodiments of the present invention, a vision system is integrated with robot 100 for tracking movement of the lower extremities with one or more cameras. In some exemplary embodiments, one or more reflectors and/or markers are positioned on the lower extremities, e.g. on one or more joints and one or more cameras track movement of the reflectors and/or markers. In some exemplary embodiments, a marker is placed on the big toe of a patient to track toe lift, e.g. toe lift during dorsiflextion. According to embodiments of the present invention, the vision system may be similar to vision systems known in the art and used to track and analysis gait. According to some embodiments of the present invention, controller 150 may control operation of the vision system and/or may determine one or more parameters of the operation of robot 100 based on information obtained from the vision system. According to embodiments of the present invention processor 199 may process information obtained from the vision system.

Reference is now made to Fig. 6 showing an exemplary flow chart describing a method of foot drop rehabilitation according to some embodiments of the present invention. According to some embodiments of the present invention, foot drop rehabilitation on an injured leg may be designed based on reproducing learned gait and/or balance parameters detected from a healthy foot. According to embodiments of the present invention, during a rehabilitation and/or diagnosis procedure, joint rotation patterns from one or more joints of a healthy leg may be recorded during gait and/or in response to movement of a standing platform (block 610). Optionally, the relationship between movement of the different joints may be determined and repeated on the injured leg. Optionally, neuromuscular patterns associated with joint movement, e.g. ankle joint movement, of a healthy leg may be monitored, e.g. monitored by EMG measurements (block 615). Optionally, a touch pattern, e.g. timing of touch, pressure distribution, force distribution, foot orientation during touch, may be of a healthy leg may be monitored and/or detected, e.g. with pressure plate, force plate, pressure pads, in-sole pressure pads, foot position detector (block 620). According to some embodiments of the present invention, controller 150 together with data processing device 199 may implement information gathered from the healthy foot to design and/or teach a gait or balance pattern to an injured leg suffering from foot drop. Typically the gait and/or balance pattern taught is for an initiated task, e.g. movement of the treadmill initiating gait, vibrating of the standing platform, tilting the standing platform and includes coordination of ankle joint movement with movement of at least one other joint. According to some embodiments of the present invention, joint rotation pattern and/or coordination detected from a healthy leg may be mechanically repeated with an injured leg using one or more actuator driven mechanical joints (block 625). Optionally, weakened muscles resulting from foot drop may be detected and exercised with a mechanical actuator driven ankle joint. Optionally, neuromuscular patterns detected in the healthy leg may be used to stimulate corresponding muscles in the injured leg, e.g. using FES (block 630). Timing of FES may be coordinated with detected joint rotation of the hip, knee or ankle joint, and/or touch pattern based on the coordination detected on the healthy leg. Systems and method for reproducing learned motion of a healthy limb to rehabilitate a corresponding injured limb may be similar to the system and methods described in International Patent Application Publication No. WO 2005/105203 entitled Neuromuscular Stimulation, assigned to the common assignee and which is hereby incorporated by reference in its entirety.

Performance of the patient during rehabilitation may be monitored (block 635) and feedback may be presented to the patient and/or health professional (block 640). One or more sensors may optionally monitor the patient's gait and/or balance parameters including for example, position, acceleration, force, and/or velocity. The data output by the sensors is analyzed and thus, anomalies in the gait and/or balance performance are detected, either by the controller, data processing device or by a healthcare professional. From this data analysis of the gait and/or balance performance, it can be determined where improvements need to be made. Optionally, the data processing device may determine advisory instructions on how to improve the patient's performance. Optionally, the patient's movements are played back in slow motion for detailed review. Optionally, gait and/or balance performance analysis includes comparison of movement to measurements conducted by a neural network.

According to some embodiments of the present invention, based on detected performance, one or more parameters of robot 100 may be adjusted during the rehabilitation procedure (block 645). In some exemplary embodiments, results may be used to correct gait in subsequent gait cycle and/or provide feedback. According to some embodiments of the present invention, rehabilitation of foot drop may be performed for different conditions, e.g. walking on tilted platforms, balancing during movement of a standing platform, and different walking speeds. According to some embodiments of the present invention, normal control parameters and coordination between different parameters may be learned from a healthy leg and used to train an injured leg. According to some embodiments of the present invention, monitoring of one or more parameters of motion of an injured leg may be implemented to initiating control of ankle joint rotation. Reference is now made to Fig. 7 showing an exemplary flow chart describing a method for gait rehabilitation according to some embodiments of the present invention. According to some embodiments of the present invention, patient information may be obtained from the patient (block 710) so that diagnosis and rehabilitation of the patient may be geared toward the patient's abilities and needs. Patient information may be saved in a computing device 200 and used by processor 199 for computing parameters for operating robot 100 during diagnosis and rehabilitation. Patient information may include information regarding age, weight, physical condition of patient, and diagnosis information. According to embodiments of the present invention, evaluation and/or analysis of the current gait performance is carried out (block 720). Analysis of gait performance may include determining a patient's ability to support their body weight, determining stability of patient during initiation of gait and/or during gait, determining a patient's gait coordination, position and/or orientation of joints during a gait cycle, response to perturbation in gait environment, e.g. muscle stimulation pattern during a gait cycle. According to some embodiments of the present invention, evaluation of gait analysis may include sensing time a patient spends on each foot during gait, ability of a patient to lift the foot about the ankle during gait, the position and orientation of the foot during gait, A patient's reaction to a change in gait environment may be performed. In some exemplary embodiments, gait performance may be analyzed on an uphill platform, downhill platform, vibrating platform, sideways tilting platform, etc. In some exemplary embodiments, gait may be analyzed for different gait speeds, e.g. different treadmill speeds and for different terrains, e.g. uphill, downhill, and side-tilting.

One or more sensed parameters during gait evaluation may be sampled by controller 150 and saved on computing device 200 for analysis with processor 199 and/or for providing visual feedback to the patient (block 725). According to embodiments of the present invention, exercise routines and/or parameters may be defined based on acquired data from analysis and patient information (block 730). Sample parameters that may be defined include percent body weight to support with harness 112, selection of mechanical joints to activate, coordination and speed of actuated mechanical joints, resistance to movement to apply, selection of muscle nerves to apply FES, angle of platform, speed of treadmill, visual feedback, etc. Gait exercises may be performed as part of a rehabilitation session (block 740) and data sampled from one or more sensors may be monitored so that parameters of the robot may be updated in real time and/or during subsequent sessions.

Reference is now made to Fig. 8 showing an exemplary flow chart describing a method for balance rehabilitation according to some embodiments of the present invention. According to some embodiments of the present invention, patient information may be obtained from the patient (block 810) so that diagnosis and rehabilitation of the patient may be geared toward the patient's abilities and needs. Patient information may be saved in a computing device 200 and used by processor 199 for computing parameters for operating robot 100 during diagnosis and rehabilitation. Patient information may include information regarding age, weight, physical condition of patient, and diagnosis information.

According to embodiments of the present invention, evaluation and/or analysis of the current balance performance is carried out (block 820). Analysis of balance performance may include determining a patient's ability to support their body weight, determining stability of patient during initiation of gait and/or standing from a sitting position, determining time-up-and-go performance, determining weight exerted on each of the pelvic support rods 121, joint angle and EMG in response to perturbing balance with moving platform, ability to shift center of gravity in accordance with visual feedback, etc.

One or more sensed parameters during balance evaluation may be sampled by controller 150 and saved on computing device 200 for analysis with processor 199 and/or for providing visual feedback to the patient (block 725). According to embodiments of the present invention, exercise routines and/or parameters may be defined based on acquired data from analysis and patient information (block 730). Sample parameters that may be defined include percent body weight to support with harness 112, selection of pelvic supports and/or mechanical joints to activate at a specified time, resistance to movement to apply, selection of muscle nerves to apply FES, angle of platform, speed of treadmill, visual feedback, etc. Balance exercises may be performed as part of a rehabilitation session to strengthen control of ankle muscles (block 740) and data sampled from one or more sensors may be monitored so that parameters of the robot may be updated in real time and/or during subsequent sessions. One type of balance exercise may include providing visual feedback of a current position of the patient's center of gravity together with visual feedback of a target position for the center of gravity. A patient attempts to match the displayed center of gravity with the target center of gravity. Pelvic supports, mechanical joints, FES, and harness may aid the patient in maintaining balance.

Reference is now made to Fig. 9 describing an exemplary flow chart describing a method of planning a foot drop rehabilitation session according to some embodiments of the present invention. According to some embodiments of the present invention, at the start of a rehabilitation and/or diagnosis session, a patient strapped into robot 100 performs a series of gait cycles while the mechanical ankle joint is activated to actuate ankle movement during gait (block 910). During the gait cycles one or more parameters related to gait are measured. In some exemplary embodiments, ankle muscle activity, e.g. muscles associated with dorsiflexion, is detected using EMG electrodes (block 915). In some exemplary embodiments, torque exerted by the patient's ankle is detected using a torque sensor as described herein (block 920). During a second stage of the analysis, the mechanical ankle joint is neutralized (block 923) and a series of gait cycles are performed using FES to stimulate dorsiflexion during gait (block 925). During the second stage of the analysis one or more parameters related to gait are measured. In some exemplary embodiments, ankle rotation pattern during gait is detected using a potentiometer fitted on the mechanical ankle joint as described herein (block 930). In some exemplary embodiments, ankle muscle activity, e.g. muscles associated with dorsiflexion, is detected using EMG electrodes (block 940). In some exemplary embodiments, torque exerted by the patient's ankle is detected using a torque sensor as described herein (block 945). Based on data sampled from the various sensors diagnosis of foot drop is made and an exercise plan may be constructed (block 950). For example, based on the results obtained, the health professional and/or computing device 200 may suggest and/or build a rehabilitation exercise plan including FES and/or actuated movement of the ankle with a mechanical joint based on the detected results. In some exemplary embodiments, selection of FES and/or FES and actuated movement depend on the severity of the injury detected from output of the sensors. For example both FES and actuated movement may be required for sever injury while only one of FES and actuated movement may be required for injuries that are more mild. In some exemplary embodiments, selection of FES and/or actuated movement depends on the nature of the damage. For example, for some patients the ability for timing of dorsiflexion is damaged, for other patients the extent and/or angle of dorsiflexion are lacking, and yet for other patients the ability of toe lift during dorsiflexion is damaged. According to some embodiments of the present invention, selection of FES and/or actuated movement depends on the diagnosis.

According to some embodiments of the present invention, one or more modules described herein, e.g. sensors, ankle mechanical joints, treadmill, can be retrofitted on known gait rehabilitation robots to provide full lower extremity control and evaluation. Typically, processing unit 199 and controller 150 are adapted to accommodate the retrofitted modules. In one exemplary embodiment, a treadmill capable of being titled may be retrofitted on an existing gait evaluation device. In some exemplary embodiments, an ankle mechanical joint can be retrofitted on an existing gait robot with mechanical hip and knee joints. In some exemplary embodiments a FES may be retrofitted on an existing gait robot to provide muscle stimulation. According to embodiments of the present invention, the retrofit can be readily performed on existing gait robots without making major changes to the existing structure of the gait robot. The additional mechanical joint (ankle joint) can be attached to the lower arm of the knee joint of an existing gait robot. The other features are added without having to change the structure of the existing gait robot. Retrofitting can provide upgraded function to the gait robots that includes the ability of compensating, diagnosing and rehabilitating foot drop at relatively low expense compared to buying an upgraded new gait robot that includes these features.

Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

The terms "comprises", "comprising", "includes", "including", "having" and their conjugates mean "including but not limited to".

The term "consisting of means "including and limited to". The term "consisting essentially of" means that the composition, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure. It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

Claims

We claim:

1. A foot drop rehabilitation system comprising: a frame configured for at least partially supporting a patient in an upright position; a mechanical ankle joint associated with the frame and configured for being fitted on a patient's foot and for assisting movement of the patient's foot at the ankle; at least one sensor configured or sensing at least one lower extremity parameter of the patient; and a controller configured for sampling the at least one sensor output and for controlling timing or angle of dorsiflexion during gait based on output from the at least one sensor output.

2. The system according to claim 1 wherein the mechanical ankle joint includes an actuator configured for controllably driving rotation of the ankle joint and wherein the controller is configured for controlling motion of the actuator.

3. The system according to claim 1 or claim 2 comprising a stimulation unit configured for stimulating a muscle associated with movement of the patient's foot at the ankle based on the at least one lower extremity movement control parameter.

4. The system according to any of claims 1 to 3 wherein the at least one sensor is a pair of electro-myogram electrodes for sensing activation of at least one muscle associated with ankle movement control.

5. The system according to claim 4 wherein the pair of electro-myogram electrodes is configured to detect the electro-myogram signals from a healthy leg of the patient.

6. The system according to claim 4 or 5 wherein the at least one muscle is the tibialis muscle.

7. The system according to any of claims 1 to 6 wherein the at least one sensor is sensor configured for sensing at least one lower extremity movement control parameter of a healthy leg of the patient during a rehabilitation session.

8. The system according to claim 7 wherein the sensor is integrated on a passive mechanical ankle joint, wherein the passive mechanical ankle joint is fitted on the patient's healthy leg.

9. The system according to any of claims 1 to 8 comprising at least one of a mechanical knee joint or a mechanical hip joint, wherein the controller is configured for coordinating movement of the at least one of a mechanical knee joint or a mechanical hip joint with ankle joint rotation.

10. The system according to claim 9 wherein the at least one of a mechanical knee joint or a mechanical hip joint comprises an actuator configured for controllably driving rotation of the joint and wherein the controller is configured for controlling motion of the actuator in coordination with the mechanical ankle joint.

11. The system according to claim 9 wherein the at least one sensor is a rotational sensor configured for sensing rotation of the at least one of the mechanical knee joint and the mechanical hip joint.

12. The system according to any of claims 1 to 11 wherein the at least one sensor includes a torque sensor configured for sensing torque exerted on the mechanical ankle joint.

13. The system according to any of claims 1 to 12 comprising a standing platform above which a patient stands when engaged on the rehabilitation system.

14. The system according to claim 13 wherein the standing platform is configured for being tilted in a forward or backwards direction with respect to a patient's foot standing on the standing platform.

15. The system according to claim 13 or claim 14 wherein the standing platform is configured for being tilted in a sideway direction with respect to a patient's foot standing on the standing platform.

16. The system according to any of claims 13 to 15 wherein the controller is configured for controlling the tilting angle of the standing platform.

17. The system according to any of claims 13 to 16 wherein the standing platform is configured for being vibrated or jolted.

18. The system according to claim 17 wherein the controller is configured for controlling vibration or jolting of the standing platform.

19. The system according to any of claims 1 to 18 wherein the at least one sensor is configured to detect a pressure exerted by a patient's foot on a standing platform associated with the system.

20. The system according to claim 19 wherein the sensor is a pressure pad integrated on to the standing platform.

21. The system according to claim 20 wherein the sensor is an insole pressure pad.

22. The system according to claim 19 wherein the sensor is a pressure sensor plate comprising a first plate and a second plate, one over the other and separated by at least two load cells and two springs and wherein the load cells are configured to detect pressure.

23. The system according to any of claims 1 to 22 comprising a foot position detector configured for detecting a position of a foot at and/or near a standing platform.

24. The system according to claim 23 wherein the foot position detector comprises at least one light emitter array and at least one light detector array positioned on opposite sides of a standing platform, wherein the light detector array is configured for detecting light from the light emitter.

25. The system according to claim 24 wherein the foot position detector comprises a second set of light emitter and light detector array positioned on opposite sides of a standing platform one sides other than the sides occupied by the at least one light detector and emitter array, wherein the foot position detector is configured for detecting two dimensional position of a patient's foot.

26. The system according to claim 25 wherein the foot position detector is configured for detecting an orientation of the foot based on output from the light detector array.

27. The system according to any of claims 24 to 26 wherein the foot position detector comprises an additional set of light emitter and light detector array positioned at a height above the at least one light detector and emitter array, wherein the additional set of the light emitter and light detector array is configured for detecting position of a patient's foot at a height above the standing platform.

28. The system according to any of claims 13 to 27 wherein the standing platform is integrated with a treadmill.

29. The system according to claim 28 wherein the controller is configured for controlling operation of the treadmill.

30. The system according to any of claims 1 to 29 comprising a harness movably attached to the frame and configured for at least partially supporting a patient in an upright position.

31. The system according to claim 30 comprising a force sensor engaged on an interface between the harness and the frame for sensing the weight supported by the harness.

32. The system according to claim 31 comprising a height adjustment mechanism for adjusting the height at which a patient is supported in an upright posture.

33. The system according to any of claims 1 to 32 comprising a visual display unit configured for providing feedback to the patient or health professional based on data sampled from the at least one sensor.

34. The system according to claim 33 wherein the visual display unit configured for instructing the patient to perform a defined task.

35. The system according to any of claims 1 to 34 comprising a data processing unit configured for processing data sampled by the controller and for defining at least one parameter for controlling foot drop.

36. The system according to claim 35 wherein the at least one parameter for controlling foot drop is selected from a group including: driven rotation of the mechanical ankle joint, functional electrical stimulation of one or more muscles associated with dorsiflextion, visual feedback, percent of body weight supported, motion of a treadmill integrated with a standing platform, and motion of the standing platform.

37. A method for foot drop rehabilitation, the method comprising: partially supporting a patient in an upright position; sensing at least one lower extremity movement control parameter of the patient with at least one sensor; determining a desired timing or angle of dorsiflexion of a first leg; and artificial initiating dorsiflexion of the first leg based on the desired timing or angle of dorsiflexion.

38. The method according to claim 37 wherein dorsiflexion of the first leg is initiated by a mechanical ankle joint.

39. The method according to claim 38 wherein the angle of dorsiflexion is controlled by the mechanical ankle joint.

40. The method according to claim 38 or claim 39 wherein the timing of dorsiflexion is controlled by the mechanical ankle joint.

41. The method according to any of claims 37-40 wherein dorsiflexion of the first leg is initiated by a functional electrical stimulator configured for stimulating muscles associated with rotation of the ankle joint.

42. The method according to claim 41 wherein the angle of dorsiflexion is controlled by the functional electrical stimulator.

43. The method according to claim 41 or claim 42 wherein the timing of dorsiflexion is controlled by the functional electrical stimulator.

44. The method according to any of claims 37 to 43 comprising: determining a pattern of motion of the first leg about a knee based on the sensing; and coordinating motion about the ankle with the determined pattern of motion about the knee.

45. The method according to any of claims 37 to 44 comprising: determining a pattern of motion of the first leg about a hip based on the sensing; and coordinating motion about the ankle with the determined pattern of motion about the hip.

46. The method according to any of claims 37 to 45 comprising: determining a pattern of motion of a second leg of the patient based on the sensing; and coordinating motion about the ankle with the determined pattern of motion about the second leg.

47. The method according to any of claims 37 to 46 wherein the at least one sensor is configured to sense rotation of at least one lower extremity joint.

48. The method according to any of claims 37 to 47 wherein the at least one sensor is a pair of electro-myogram electrodes for sensing innervations of at least one muscle associated with lower extremity control.

49. The method according to claim 48 wherein the at least one muscle is associated with ankle movement control.

50. The method according to claim 48 or claim 49 wherein the pair of electro-myogram electrodes is configured to detect the electro-myogram signals from a healthy leg of the patient.

51. The method according to claim 48 or claim 49 wherein the pair of electro-myogram electrodes is configured to detect the electro-myogram signals from muscles controlling the ankle of the first leg.

52. The method according to any of claim 48 to 50 wherein the at least one muscle is the tibialis muscle.

53. The method according to any of claims 37 to 52 comprising artificially initiating the movement about at least one of a knee joint and a hip joint.

54. The method according to any of claims 37 to 53 wherein the at least one sensor is a torque sensor configured for sensing a torque about a lower extremity joint.

55. The method according to any of claims 37 to 54 wherein the at least one sensor configured for sensing a pressure exerted by the foot on a standing platform.

56. The method according to any of claims 37 to 55 wherein the at least one sensor is configured for sensing a force exerted by the foot on a standing platform.

57. The method according to any of claims 37 to 56 wherein the at least one sensor is configured for sensing a position of a foot on or near a standing platform.

58. The method according to claim 57 wherein the at least one sensor is configured for sensing a two dimensional position of the foot.

59. The method according to any of claims 37 to 57 wherein the at least one sensor is configured for sensing a foot on or near a standing platform.

60. The method according to any of claims 37 to 59 wherein the at least one sensor is configured for determining a time period spent on each foot during gait.

61. The method according to any of claims 37 to 60 comprising: moving a standing platform on which the patient is standing; and coordinating the pattern of foot motion about the ankle based on the motion of the standing platform.

62. The method according to claim 61 comprising: at least partially supporting a patient from the pelvis with telescopic pelvic support rods; and adjusting a length of the pelvic support rods based on the motion of the standing platform.

63. A foot drop rehabilitation system comprising: a frame configured for at least partially supporting a patient in an upright position over a standing surface; the standing surface associated with the frame, wherein the standing surface is configured for tilting sideways; at least one sensor configured or sensing at least ankle rotation or ankle muscle activation during tilt; and a controller configured for tilting the standing surface and for sampling output from the at least one sensor during tilt of the standing surface.

64. The system according to claim 63 wherein the standing surface is configure for backwards tilting, forwards tilting, right tilting, and left tilting.

65. The system according to claim 63 or claim 64 wherein the standing surface is a treadmill, wherein the treadmill is configured for tilting.

66. The system according to any of claims 63 to 65 comprising a sensor configured for sensing position of the patients center of gravity.

67. The system according to any of claims 63 to 66 comprising a sensor configured for sensing weight distribution between the patients feet.

68. The system according to any of claims 63 to 67 wherein the controller is configured for sampling output during a gait cycle.

69. A foot drop rehabilitation system comprising: a frame configured for at least partially supporting a patient in an upright position; a mechanical ankle joint associated with the frame and configured for being fitted on a patient's foot and for assisting movement of the patient's foot at the ankle; a light array detector system configured for detecting position of a patient's foot on or near a standing surface; and a controller configured for controlling timing or angle of dorsiflexion during gait based on output from the light array detector system.

70. The system according to claim 69 wherein the light array detector system includes at least one array of light emitters positioned on one side of a standing platform and one array of light detectors position on an opposite side of the standing platform.

71. The system according to claim 70 wherein the standing platform is for a single foot.

72. The system according to claim 69 or claim 70, wherein the light array detector system includes two array of light emitters positioned on two adjacent sides of a standing platform and two array of light detectors position on an opposite sides of the array of light emitters.

73. The system according to claim 72 wherein the light array detector system is configured for determining position and orientation of the patient's foot.

74. The system according to any of claims 69 to 73, wherein the light array detector system includes at least two arrays of light emitters positioned one over the other at a defined vertical distance from each other and two corresponding arrays of light detectors positioned one over the other at the defined vertical distance from each other.

75. The system according to claim 72 wherein the light array detector system is configured for determining position of the patient's foot as it approaches the standing surface.

76. A method for retrofitting an existing gait robot, the method comprising: retrofitting an existing gait robot with a mechanical ankle joint; retrofitting the existing gait robot with at least one sensor configured for sensing ankle rotation or ankle muscle activation; upgrading a controller associated with the existing gait robot to accommodate control of the mechanical ankle joint and the at least one sensor; and installing new software on a computing device associated with the existing gait robot for upgrading the existing gait robot to provide ankle joint control and sensing.

77. The method according to claim 76 comprising retrofitting the existing gait robot with a functional electrical stimulation, wherein the functional electrical stimulation is configured for stimulating ankle rotation.

78. The method according to claim 76 or claim 77 wherein the retrofitting provides foot drop rehabilitation or foot drop rehabilitation capability.

79. The method according to any of claims 76 to 78 comprising retrofitting an existing gait robot with a treadmill, wherein the treadmill is configured for sideways titling and wherein the controller is configured for controlling tilt of the treadmill.

80. The method according to any of claims 76 to 79 comprising retrofitting an existing gait robot with a light array detector system configured for detecting position of a patient's foot on or near a standing surface associated with the gait robot.

81. The method according to claim 80 wherein the light detector system includes at least one array of light emitters positioned on one side of a standing platform and one array of light detectors position on an opposite side of a standing surface associated with the gait robot.