WO2010025090A1 - Tissue and object retrieval device and system - Google Patents

Abstract

The invention described herein provides a device for tissue and/or object retrieval constructed for use with minimally invasive medical procedures. By virtue of its construction and operation, the device of the invention can obtain a relatively large amount of tissue (or object) while reducing or minimizing the amount of trauma to the patient. The device of the invention further maintains reduced or minimal dimensions during insertion and access stages and utilizes a greater freedom of movement at the retrieval site environment. The invention further provides a system comprising the device in combination with an elongated sheath component. The invention can be used as part of, or in conjunction with, other minimally invasive surgical devices.

Description

TISSUE AND OBJECT RETRIEVAL DEVICE AND SYSTEM

Description

BACKGROUND OF THE INVENTION

[1] A wide variety of surgical instruments which are used in biopsy and tissue retrieval procedures are known in the medical field. Biopsy and tissue retrieval procedures are typically used in circumstances wherein a partial sample of a tissue mass is needed for histological analysis, or wherein an entire mass of tissue is to be removed altogether. Structural features of such devices and their configurations vary according to the contemplated procedure and dynamics of the tissue sampling or removal site involved.

[2] Endoscopic surgical instruments having improved performance and advantageous features have long been of interest in the surgical field. Of increasing interest in the medical field are instruments and techniques that are minimally invasive and which reduce the extent of trauma to the patient's body and tissues at the surgical site.

[3] A variety of biopsy devices and tissue removal/retrieval instruments have been developed for use in conjunction with minimally invasive procedures. By virtue of their design requirements and dimensions as well as operative requirements, some devices have been problematic to construct or design to be suitable for minimal or relatively reduced dimensions as desirable for minimally invasive access or operation within narrow or small surgical sites. Device design dimensions are further limited by the size of the working channel of the endoscope or the port of entry of such devices. Often, a compromise is needed between reducing dimensions and mechanical performance, which poses challenges to instrument design.

[4] A variety of devices employing a V-jaw grasping tools and their mechanisms are known. For example, devices having elongated shaft and distal tissue retrieval tools are described in U.S. Patent No. 4,971,067; U.S. Patent No. 5,389,104; U.S. Patent No. 5,683,359; U.S. Patent No. 5,643,307 and U.S. published patent application No. 2008/0009858, for example. One significant disadvantage of current V-jaw or split cup devices is that multiple repetitions of tissue retrieval are often required in order to obtain tissue samples of adequate size. Another disadvantage associated with conventional devices is that because of the repetitions needed, tissue samples are retrieved in small, severed pieces, thereby requiring compromise of the sample integrity. Compromise of tissue sample integrity can lead to errors in histological analysis. Furthermore, many grasping or sampling mechanisms are incompatible with minimally invasive design and are suited for wide access tissue sites.

[5] Other known biopsy structures include coaxial sliding cannula assemblies wherein sample size retrieval relies upon tissue encroachment into a recess, cavity or channel followed by coaxial sliding of an outer or inner cannula to sever the tissue and capture the sample. Some of these devices employ vacuum or aspiration forces to induce tissue into the device, which can be difficult to control with precision and aggravate trauma. [6] This is especially true in biopsy and some tissue removal and retrieval procedures requiring a grasp-sever-retain-transport sequence of functions. Certain endoscopic procedures involve restricted access routes in conjunction with enlarged cavity tissue sites, such as ureteroscopic surgery. Such procedures in order to be minimally invasive present a surgical dynamic wherein the devices used must have minimal dimensions during insertion and access stages, but permit larger freedom of movement and increased dimensions at the surgical site. Many existing devices do not adapt or accommodate, or take advantage of, the change in space. Other devices, although of minimally invasive dimensions, are limited in their performance in terms of force and strength as a compromise to the confines of the reduced dimensions and parameters.

[7] Thus, there exists in the surgical field a need for improved endoscopic biopsy and tissue removal instruments for devices which reduce trauma, obtain an adequate or sufficient sample size, are efficient and thorough in tissue removal, preserve the integrity of samples (important for, e.g., subsequent histological analysis), maintain instrument structural integrity and performance, and are constructed to be compliant with minimally invasive procedures and maneuverability within surgical sites.

[8] SUMMARY OF THE INVENTION

[9] The invention provides a surgical instrument structured for use in conjunction with endoscopic visualization and dimensioned for minimally invasive techniques which, by virtue of its construction and operation, can obtain a relatively large amount of tissue while reducing or minimizing the amount of trauma to the patient. It has been discovered that a biopsy or tissue removal device can be structured to operate in two general states: a first folded compact state during insertion into the surgical site; and a second operative tissue retrieval state while exerting sufficient force to perform while at the same time affording minimal dimension design. The invention involves a device which, by virtue of its design and construction, maintains reduced or minimal dimensions during insertion and access stages, and utilizes a greater freedom of movement at the tissue retrieval site environment. Thus, the device of the invention accommodates minimally invasive access but can be structured to obtain a tissue sample size that is about 20% to about 46% as compared to some minimally invasive biopsy and grasper devices given the same access and delivery cannula dimensions of about 3.0 mm to about 3.2 mm, for example. Thus, comparatively larger sample sizes can be obtained and removed from the sampling site as compared to conventional V- jaw-structured (e.g., split cup design) biopsy or grasper devices. It has further been discovered that by virtue of its structural features, significantly greater mechanical forces to obtain and sever the tissue can be applied despite reduced dimensions of the device and access cannula. Although the invention can be used in a variety of procedures such as simple tissue grasping, tissue engagement, object retrieval/removal, and the like, the benefits associated with the invention can be fully realized when used in conjunction with minimally invasive biopsy techniques, procedures and equipment, such as ureteroscopic-assisted tissue removal procedures.

[10] In one aspect, the invention provides a device structured for tissue and object retrieval comprising:

[11] an elongated shaft having a longitudinal axis, proximal region and distal region, said distal region terminating at a contiguous fixed trap located at the distal end of said shaft;

[12] said elongated shaft having a recessed bridge portion located proximal to said fixed trap;

[13] a movable trap element having a substantially elongated body and open cavity on one side and hingedly coupled to a proximal end of said fixed trap element;

[14] said movable trap residing adjacent to said recessed bridge portion when in the open position;

[15] both of said fixed trap element and said movable trap element having respective open cavities on one side;

[16] said movable trap element and said fixed trap pivotally coupled to one another so as to alternate between a) a first retracted non-actuated state, wherein the first trap element and second trap element are positioned along a shared longitudinal axis in linear sequence and in alignment with said longitudinal axis of said shaft, and b) a second final actuated state, wherein said open cavity of said first trap element and said open cavity of said second trap element are in opposing orientation to one another such that the first and second trap elements together form an encased chamber in a second final closed, actuated state. Relative to the hinged coupling between the movable trap element and the fixed trap element, the unhinged end of the movable trap element travels over about a 180 degree angle about a transverse axis and in alignment with the longitudinal axis of the shaft until the unhinged end of the movable trap element contacts the distal-most end of the fixed trap element.

[17] The device of the invention further comprises an actuation assembly that operates the movable element movable trap element in relation to the fixed trap element from an open non-actuated state to a closed final actuated state. By virtue of its construction and design, the actuation assembly can exert a significant force in its operation despite, or when initially introduced through, minimally invasive diametrical parameters. An important aspect of the invention is the fulcrum of the first class lever arrangement of the movable trap element as applied through the tension line-actuation assembly of the device.

[18] In a preferred embodiment, and in order to exert the desired greater force in operation of the trap elements, the actuation assembly is structured to comprise three points of pivotal movement between a tension line and the hinged portion of the trap elements, and wherein the three pivotal points are in addition to the hinged coupling between the trap elements. The three pivotal points of the actuation assembly function in relation to two pairs of components - a pair of rocking elements and a pair of linking elements - each member of the pair of rocking elements and each member of the pair of linking elements being located on opposite sides of the elongated shaft.

[19] In one embodiment, each member of a first pair of rocking elements can comprise two legs in angular relation to one another and can be hingedly coupled at the vertex between said legs to the recessed portion of the shaft. One leg of each rocking element can be indirectly and pivotally coupled via a linking element to the hinged region of the movable trap element, one end of the linking element being pivotally coupled to one leg of the rocking element, and further pivotally coupled at its other end to the hinged region of the movable trap element through an additional hinge that is separate and distinct from the hinged coupling shared by both trap elements. In an alternative embodiment, each of the rocking element components can have an overall planar or plate configuration having the same pivot and articulating points present as needed for the operation of the actuation assembly.

[20] The device of the invention further comprises a tension line running along the longitudinal axis of the shaft and which functions to transfer operational force exerted by the user or operator at the proximal end of the device by way of a longitudinal axis to the actuation assembly at the distal region of the device. The tension line resides within, and is bi-directionally and longitudinally movable in a linear motion within, a sheath. In one embodiment, the tension line is mechanically coupled to the actuation assembly via a bracket, such as a U-shaped bracket (referred to herein as a U-bracket) wherein each end of the legs of the 'U' is connected to the proximal portion (e.g., first and second rocking elements) of the actuation assembly. The tension line can be mechanically connected to a stem of the U-bracket.

[21] In one embodiment, movement of the tension line in the proximal direction causes movable trap element to pivot forward in the distal direction so as to ultimately place the open cavity of the movable trap element in opposition to the open cavity of the fixed trap element, and in corresponding alignment, forming an encased chamber. In use, this motion can contact, engage, sever, excise, and/or capture a tissue within the encased chamber. When severed, the tissue sample is contained and resides within the chamber throughout the withdrawal of the device from the tissue site.

[22] The invention further comprises a system comprising a device as described above together with an elongated sheath having a longitudinal axis, a proximal end and distal end, and having a lumen within running along said sheath longitudinal axis and terminating at a distal port;

[23] wherein said lumen accommodates at least a portion of the device.

[24] In one embodiment, the sheath is positioned between an external operating mechanism at its proximal end and the device at the distal portion of the sheath such that the tension line of the device resides within the sheath lumen. In a preferred embodiment of the invention, the distal portion of the device can reside within the distal portion of the lumen when the device is in initial non-actuated state, and the distal portion of the device can be extended beyond the distal end of the sheath and lumen in situ prior to tissue engagement.

[25] In a broader aspect, the system of the invention can be employed by itself as an independent instrument in combination with, for instance, an access portal, or alternatively in accompaniment to a secondary cannula that is part of a surgical instrument, for instance a ureteroscope.

[26] The invention is associated with a number of advantages. The device of the invention can be constructed in accordance with dimensions compatible with minimally invasive techniques, such as those associated with endoscopic or laparoscopic devices, e.g., ureteroscopes. The device and component structures are relatively simple and afford ease of manufacture and cost-effective manufacture. One degree of freedom is required for the device, e.g., a ureteroscope can be used to control device insertion and positioning with the device operation being manually controlled from outside patient's body. By virtue of the hinge pin joints of the preferred embodiment of the invention, the device can afford good manufacturability and functional reliability, as well as reduced likelihood of pinching by design.

[27] In another aspect, the invention provides a device comprising an actuation assembly structured to move a movable element relative to a fixed element in alignment with a longitudinal axis in response to linear movement of a tension line mechanically coupled to the actuation assembly, wherein the movable element is hingedly coupled to the fixed element, the actuation assembly comprising: a rocking element having two points of articulation in relation to a pivot point about which said rocking element moves, and one articulating point which is connected to a tension line; and a linking element, wherein the linking element is simultaneously connected at one end to said movable element adjacent the hinged coupling, and connected to one articulating point of the rocking element at the other end; wherein force exerted by linear movement of the tension line moves the movable element relative to the fixed element, the movement being effected through said rocking element and linking element.

[28] An important aspect of the invention is that linear movement of the tension line drives a 4-point or '4-bar' mechanical connection between actuation assembly components. By virtue of the actuation assembly construction, a tension line operates via the actuation assembly in relation to an ultimate fixed point at the distal region of the shaft (e.g., a fixed trap element) at a mechanical advantage to operate the tool(s) of the device. In this invention, the one such tool involves a fixed element and a movable element wherein the actuation assembly of the invention drives the movable element over an approximate 180 degree rotation pathway from a starting position having minimal height.

[29] Accordingly, the invention also provides a device comprising: a tension line, s shaft, a fixed element on the shaft and a movable element hingedly coupled to said fixed element structured for an approximate 180 degree movement pathway aligned with a longitudinal axis of the shaft; an actuation assembly operatively connecting the tension line and the movable element and the fixed element; the actuation assembly comprising a 4-bar mechanical connection.

[30] In a preferred embodiment, the actuation assembly comprises a '4-bar' pivotal articulation structure between the components, wherein the articulating connections between 1) the tension line and the rocking element(s); 2) the rocking element(s) and recessed bridge portion of the shaft; 3) the rocking element(s) and the linking element(s); and 4) the linking element(s) and movable (trap) element of the device, all include a pivotal hinge structure.

[31] In one embodiment, the actuation mechanism can comprise a single rocking element and linking element, or in the alternative, a pair of rocking elements and a pair of linking elements. The amount of force exerted upon the actuation assembly relative to the amount of force exerted by the movable element is an important aspect of the actuation assembly of the invention.

[32] The device of the invention and actuation assembly can be employed in a variety of instruments and procedures. One significant advantage associated with the invention is that it permits the use of a relatively large cavity size to be used for tissue engagement or collection, while simultaneously affording a reduced or minimal cross-sectional diameter of a sheath accommodating the device. These and other advantages will become apparent from the following disclosure.

[33] BRIEF DESCRIPTION OF THE DRAWINGS

[34] The invention is further illustrated by the following drawings and numerical references corresponding to components of the invention which remain consistent throughout the specification. None of the depicted embodiments is intended to be construed as necessarily limiting the invention.

[35] Figure 1 is an overall, angled view of the distal portion of a system containing the device and sheath in accordance with one embodiment of the invention.

[36] Figure 2 A is an angled side view of the distal region of the device shown in the first retracted non-actuated state according to one embodiment of the invention.

[37] Figure 2B is an angled side view of the distal region of the device shown in second actuated state of operation.

[38] Figures 3A, 3B and 3C together show the operative sequence of the distal region of the system including the device and sheath from a first retracted non-actuated position, an actuated transition state, and a final actuated state of operation, respectively, according to one embodiment of the invention.

[39] Figure 4A is an end view of the distal end of the system including the distal end of the device in a first retracted, non-actuated state and sheath according to one embodiment of the invention.

[40] Figure 4B is an end view of the distal end of the system including the distal end of the device in a final actuated state and sheath according to one embodiment of the invention.

[41] Figure 5 is a close-up angled side view of a section of the device showing the hinged structures of the device including the actuation assembly according to one embodiment of the invention.

[42] Figure 6 is an exploded view of the assembly showing individual components parts in separated state according to one embodiment of the invention.

[43] Figure 7 is an angled view of the distal portion of the elongated shaft and individual fixed trap without the remaining mechanism, according to one embodiment of the invention.

[44] Figure 8 is an angled view of a single rocking element of the actuation assembly according to one embodiment of the invention.

[45] Figure 9 is an angled view of a single linking element of the actuation assembly according to one embodiment of the invention.

[46] Figure 10 is an end view of the distal end of the system including the distal end of the device in non-actuated resting state and sheath having a dual lumen structure, according to one embodiment of the invention.

[47] DETAILED DESCRIPTION OF THE INVENTION

[48] As used herein, the term 'tissue retrieval¹ within the context of using the invention is meant to encompass tissue-interactive surgical techniques, including but not limited to, biopsy procedures, tissue detachment, tissue removal, tissue engagement, clamping, cauterization, and the like. The term is not intended to be restricted to biopsy procedures, or other tissue severance and capture functions. Though the invention can be appreciated within the context of tissue interaction, it will nevertheless be understood by one skilled in the surgical field that the device of the invention can be used for non-tissue object removal as well. Thus, although the term 'tissue' is used in association with the invention throughout the description, unless specified otherwise the term can apply to objects as well, as far as intended targets for the device.

[49] As used herein, the term 'endoscopic' is meant to refer to the context of employing the invention under endoscopic visualization techniques employing a cannula and optic system. The term is also meant to include a variety of externally viewable optical techniques, such as magnetic resonance imaging, ultrasound, laparoscopic, or any other visualization technique that can be used to view or perceive the location of the instrument in relation to the surgical site.

[50] As used herein, the phrase 'minimally invasive' within the context of the device and system of the invention is meant to indicate that the device and system are compliant with the relatively reduced dimensional attributes and minimally traumatic function typically associated with such procedures. For example, 'minimally invasive' can refer to a device having a small diameter and reduced diameter introduction ranging from about 1.0 mm to about 3.5 mm. It will be understood that 'minimally invasive' is a subjective expression that can vary among the various types of surgical instru- mentation and contexts and requirements of procedures and usage.

[51] The terms 'proximal' and 'distal' as used herein to indicate positional relationships and movement of the invention and its components, are meant to indicate that the proximal direction is oriented toward the user and exterior of body in use. The distal direction is meant to refer to an orientation toward the tissue contacting region of the device and toward the end of the device opposite to the proximal end.

[52] As used herein, the term 'comprising' means the elements recited, or their equivalent in structure or function, plus any other element(s) which are not recited. The terms 'having' and 'including' are also to be construed as open-ended unless the context suggests otherwise. Terms such as 'about', 'generally', 'substantially' and the like are to be construed as modifying a term or value such that it is not an absolute, but does not read on the prior art. Such terms will be defined by the circumstances and the terms that they modify are understood by those of skill in the art. This includes, at the very least, the degree of expected experimental error, technique error, and instrument error for a given technique used to measure a value.

[53] As used herein, the term 'articulating,' and inflections thereof, are meant to include relational movement between at least two structures, wherein the articulating movement of one structure effects movement in the other associated structure(s). The term 'articulating' is meant to include, but not be limited to, 'pivotal' movement. The term 'pivotal,' and inflections thereof are meant to refer to relational movement about a shared axis, e.g., a hinge-type motion, between at least two structures.

[54] In general and as shown in Figure 1, the device of the invention comprises an elongated shaft 10 and a distal region 11 that includes the (tissue- or object-) interactive componentry of the device. The device can be part of a system that includes a sheath within which the device can reside and from which the device can be extended and operated by the user. In a preferred embodiment of the invention, the distal portion 11 of the device can reside within the distal portion of a sheath lumen 14 of an elongated sheath 12 (shown in Figures 1, 4 A and 4B) during the introduction and positioning stages of a surgical procedure, and subsequently be extended beyond the distal end 13 of the lumen 14 in the target tissue site, thereby affording the full range of operative freedom for the device. One contemplated usage for the invention is, for example, use in combination with a ureteroscopic procedure wherein minimally invasive dimensions of the urethra are used for introduction and the tissue site is within the urinary bladder. In such a procedure, it is desirable for a device to have a minimal diameter structure capability in conjunction with the ability to expand and convert into a larger field of engagement once at the tissue site. The device of the invention is structured to meet these criteria and capabilities

[55] The device is structured for tissue retrieval or tissue engagement and comprises an elongated shaft 10 having a longitudinal axis (Figure 1, symbol #), proximal region, and distal region 11. The distal region 11 of the shaft 10 terminates at a contiguous fixed trap element 20 located at the distal end 21 of the shaft 10. One advantage of the device of the invention is that it can be constructed such that the shaft and fixed trap element can be of contiguous one-piece construction, which can afford structural integrity and material consistency, as well as cost-effective manufacture by reducing the number of separate components to be fabricated. The elongated shaft 10 can also have a recessed bridge portion 30 located proximal to the fixed trap element 20.

[56] The movable trap element 22 can have a substantially elongated body and open cavity 25 on one side. The movable trap element 22 can be hingedly coupled to the proximal end 26 of the fixed trap element 20. The recessed bridge portion 30 of the shaft 10 can be structured to maintain a contiguous span between the fixed trap element 20 and the remainder of the shaft, and at the same time can be structured to accommodate the movable trap element 22 adjacent to the recessed bridge portion 30 (as shown in Figure 1, for example). This arrangement can correspond to the 'open' position, or non-actuated first position of the device. One of the advantages of the shaft including a recessed bridge portion is that by accommodating the movable trap element, the height of the non-actuated or resting state of the device can be minimized.

[57] The structure and configuration of the trap elements - the movable trap element 22, fixed trap element 20, or both - can vary according to the particular usage and procedure contemplated for the device. In one embodiment wherein the device is intended for use in a biopsy procedure, both the fixed trap element 20 and the movable trap element 22 have respective open cavities (27 and 25, respectively) on one side. Thus, each trap element can have a general cup-like shape that permits tissue encroachment therein.

[58] The movable trap element 22 and the fixed trap element 20 can be pivotally coupled to one another so as to alternate between a) a first retracted non-actuated state (see Figures 2 A and 3A), wherein the movable trap element 22 and fixed trap element 20 are positioned along a shared longitudinal axis # in linear sequence and in alignment with the longitudinal axis # of the shaft 10, and b) a second final actuated state (as shown in Figures 2B and 3C), wherein the open cavity 27 of the fixed trap element 20 and the open cavity 25 of the movable trap element 22 are in opposing orientation to one another such that the trap elements together form a combined relatively large encased chamber (not shown) in a second final closed, actuated state.

[59] Just as the overall size, shape and configuration of the trap elements can vary, the depth, size and configuration of the cavities of the trap element(s) can vary as well. For example, the cavity of the movable trap element can be shallower than the cavity of the fixed trap element, and vice versa. Additionally, the size of the cavity opening can be substantially consistent with the edge of the trap element, or alternatively, can be a smaller cavity opening. In another embodiment, one trap element can be dimensioned to superimpose over, or fit within, the other trap element.

[60] A variety of trap element designs can be used with the invention and can be modified to perform specifically contemplated procedures and/or objectives. In addition to variations in shape and size of the trap elements, their structure can vary as well. For example, the trap elements can be in the form of a cage or basket (not shown). One of more of the trap elements can comprise perforations through the trap wall, or openings or windows in the trap wall aside from the cavity opening.

[61] A portion of, or the entire edge 40 of each trap element 20 and 22 circumscribing the cavity opening 25 and 27 can be symmetrically or asymmetrically beveled or sharpened to facilitate tissue severance. Alternatively, or in addition to, a sharpened edge, the circumscribing edges 40 of the trap elements can be serrated or toothed to facilitate tissue grasp, retention and/or hold.

[62] Relative to the hinged coupling 33 between the movable trap element 22 and the fixed trap element 20, the unhinged end 28 of the movable trap element 22 travels over about a 180 degree angle in alignment with the longitudinal axis # of the shaft 10 until the unhinged end 28 of the movable trap element 22 contacts the distal end 21 of the fixed trap element 20 as shown collectively in Figures 3A, 3B and 3C. Although the mechanical advantages of the invention can be realized employing an approximate 180 degree rotational movement of the trap elements with respect to their outer points, variation in the degree of movement is possible depending upon the desired features of the particular device.

[63] The device of the invention further comprises an actuation assembly 50 that operates the movable trap element 22 in relation to the fixed trap element 20 from an open non-actuated state (see Figure 2A) to a closed final actuated state (Figure 2B). One embodiment of the actuation assembly 50 is shown in detail in Figure 5. By virtue of its construction and design, the actuation assembly can exert a significant force in its operation despite, or when initially introduced through, minimally invasive diametrical parameters. An important aspect of the invention is the fulcrum of the first class lever arrangement of the movable trap element as applied through the tension line-actuation assembly of the device.

[64] In a preferred embodiment, and in order to exert the desired greater force in operation of the trap elements, the actuation assembly 50 is structured to comprise three points of pivotal movement between a tension line 60 and the hinged portion 33 of the trap elements, and wherein the three pivotal points are in addition to the hinged coupling 33 between the trap elements and the tension line 60 and intervening structures as may be present between the tension line 60 and actuation assembly 50. In one embodiment and referring now to Figures 5 and 6, three pivotal points of the actuation assembly 50 function in relation to two pairs of components - a pair of rocking elements (7OA and 70B) and a pair of linking elements (80A and 80B) - each member of the pair of rocking elements 7OA and 7OB and each member of the pair of linking elements 80A and 80B being located on opposite sides of the elongated shaft 10 (see Figure 6). [65] In one embodiment and as shown in Figure 8, each unit of a pair of rocking elements 7OA and 7OB can comprise two legs 71 and 72 (A and B corresponding to the sides of the shaft 10) in angular relation to one another and can be hingedly coupled (see Figure 5) at the vertex (73A and 73B) between said legs (71A and 71B, 72A and 72B) to the recessed bridge portion 30 of the shaft 10. One leg of each end piece 70 can be indirectly and pivotally coupled via a linking element 80 (80A and 80B with A and B corresponding to opposing sides of the shaft 10) to the hinged region 33 of the movable trap element 22, one end (81A and 81B) of the linking element 80 being pivotally coupled to one leg (72A or 72B) of the end piece 70, and further pivotally coupled at its other end (82 A and 82B) to the hinged region 33 of the movable trap element 22 through an additional hinge 84 that is separate and distinct from the hinged coupling 33 shared by both trap elements 20 and 22. In motion, the linking element 80 moves the movable trap element 22 relative to hinged coupling 33 in response to actuation by the tension line 60.

[66] Referring now to Figure 6, the movable trap element 22 is hingedly coupled to the fixed trap element 20 using interfitting end structures such that, when interfit, a common aligned coaxial tunnel is created as would be formed by line # when assembled. A single pin 101 can be positioned through the tunnel to join the trap elements such that they can pivot relative to one another on a shared transverse axis (symbol # in Figure 1) running along the longitudinal axis of the pin 101 body. It is possible to employ a variety of hinge arrangements, provided they can effect the movement of the trap elements and do not interfere with the actuation assembly function. For example, a pair of short pins, or alternatively contiguous pivotal pegs (not shown) can be used in lieu of a single shared pin. For purposes of structural and functional strength, however, it is preferable to use a single shared pin at the trap element coupling.

[67] In one embodiment shown in Figure 6, the fixed trap hinge structure 93B and the corresponding interfitting movable trap hinge structure 93A can be hingedly coupled using a single shared long pin 101. Similarly, a single shared long pin 201 can be used to pivotally join the first and second rocking elements 7OA and 7OB of the actuation assembly 50 through a common aligned coaxial tunnel formed through the recessed bridge hinge structures 90 and 91, as would be formed by the line marked by symbol # when assembled.

[68] Although the actuation assembly 50 is described and illustrated as an angular and two-legged ¹V rocking element configuration having two pivot points and an articulating connection to the legs of a 'U' bracket, the structurally essential arrangement associated with the rocking element(s) component of the actuation assembly resides in the articulating triad arrangement wherein a pivot point can effectuate a 'rocking' motion of the rocking element relative to, and about, a fixed position on the shaft (e.g., a hinge structure on the recessed bridge portion). This being the case, it will be un- derstood that the overall configuration of the rocking element can vary, provided the triad articulation motion as described can occur. For example, other suitable rocking element configurations that can be used with the actuation assembly part of the invention include, but are not limited to, a triangular planar plate having the articulating triad arrangement. In this particular embodiment, the rocking element need not require the presence of 'legs' in angular relation in order to be operative in the actuation assembly.

[69] In the same embodiment as shown in Figure 6, the pivotal coupling arrangement between 1) U-bracket 112 and its legs 110 and 111, and the first and second rocking elements 7OA and 7OB; 2) the first and second rocking elements 7OA and 7OB and the first and second linking elements 80A and 80B; and 3) the first and second linking elements 80A and 80B and the movable trap element 22 - can be constructed using short pins or pegs about which the components can pivot (see Figures 5 and 6, for example, wherein short pegs share the numerical reference 300).

[70] The device of the invention can further comprise a tension line 60 running along the longitudinal axis # of the shaft 10 and which functions to transfer operational force exerted by the user or operator at the proximal end of the device (not shown), by way of linear movement of the tension line 60 in a longitudinal direction, to the actuation assembly 50 at the distal region 11 of the device. The tension line 60 thus mechanically connects, directly or indirectly, the proximal end actuation or operative mechanism (not shown) of the device to the actuation assembly 50. The tension line 60 can reside within, and is bi-directionally and longitudinally movable within, a shaft lumen (not shown). In one embodiment, the tension line 60 is mechanically coupled to the actuation assembly via a bracket 112, such as a U-shaped bracket wherein each leg of the 'U' (110 and 111) is connected to a proximal portion of the actuation assembly 50.

[71] In one embodiment and as illustrated collectively in Figures 3 A, 3B and 3C, movement of the tension line 60 in the proximal direction causes movable trap element 22 to pivot forward in the distal direction so as to ultimately place the open cavity 25 of the movable trap element 22 in opposition to the open cavity 27 of the fixed trap element 20, and in corresponding alignment, forming an encased chamber (not shown). In use, this motion can contact, engage, sever, excise, and/or capture a tissue within the encased chamber. When severed, the tissue sample is contained and resides within the chamber throughout the withdrawal of the device from the tissue site.

[72] Actuation Assembly

[73] Although the actuation assembly part of the invention is illustrated and described herein in the device context of a tissue retrieval instrument (e.g., a pair of trap elements), another aspect of the invention is a broader application context of the benefits afforded to different and various devices by virtue of the advantageous actuation assembly itself described herein. Thus, the invention also includes a device comprising an actuation assembly structured to move a movable element relative to a fixed element in alignment with a longitudinal axis in response to linear movement of a tension line mechanically coupled to the actuation assembly, wherein the movable element is hingedly coupled to a fixed element.

[74] The invention affords a tool movement (movable element relative to fixed element) over an approximate 180 degree (hinged) pathway in alignment with the longitudinal axis of the shaft of the device. The device of the invention, and actuation assembly, can be constructed to conduct a movement as described slightly greater than 180 degrees, and less than 180 degrees. The full advantages associated with the invention, however, can be realized with a construction wherein the tool has a linear resting state configuration, which permits minimal cross-sectional diameter design and minimally invasive access to the target site.

[75] An important aspect of the invention is that linear movement of the tension line drives a 4-point or '4-bar' mechanical connection between actuation assembly components. By virtue of the actuation assembly construction, a tension line operates via the actuation assembly in relation to an ultimate fixed point at the distal region of the shaft (e.g., a fixed trap element) at a mechanical advantage to operate the tool(s) of the device. In this invention, the one such tool involves a fixed element and a movable element wherein the actuation assembly of the invention drives the movable element over a 180 degree rotation pathway from a starting position having minimal height.

[76] The actuation assembly can comprise a rocking element, or pair of rocking elements, each rocking element having three points of articulation including a pivotal attachment at a fixed position about which the rocking element moves, and a linking element, or pair of linking elements, wherein the linking element is simultaneously pivotally coupled at one end to the movable element adjacent the hinged coupling, and wherein the other end of the linking element is coupled to the rocking element.

[77] In other words, the actuation mechanism can comprise a single rocking element and single linking element, or in the alternative, a pair of rocking elements and a pair of linking elements. Furthermore, the exerted force advantages afforded by the actuation assembly structure can be applied to a variety of devices wherein a movable component hingedly moves in relation to a fixed component in response to linear movement of a tension line. Examples of moveable and fixed elements that can be operated using the actuation assembly of the invention include, but are not limited to, pliers, forceps, or scissor component structures, and the like. The device, therefore, need not be confined to biopsy or grasper device structures to realize the benefits associated with the actuation assembly per se or by itself.

[78] Referring now to Figure 8 and the rocking element 7OA (illustrated as a ¹V with two legs), the pivot point 303 is located at the vertex 73A in order to effect a rocking motion in response to a force exerted by the tension line (not shown) attached to articulating point 302 on leg 7 IA. The movement of the linking element (see Figure 9) is controlled by the articulating point 304 on the other leg 72A of the rocking element 7OA. While it is important that the pivot point 303 be fixed to rotate about the axis of a stationary joint, articulating points 302 and 304 need not include a hinged or pin structure. In other words, the tension line 60 can be attached, directly or indirectly, to articulating point 302, and other coupling structures that can effect the movement of the rocking element can be used. Similarly, a variety of mechanical connection structures can be used between articulating point 304 and one end of the linking element to effect the movement of the linking element and its corresponding movement of the moving element attached at the other end.

[79] In order for the rocking element to 'rock' about pivot point 303, the positioning of articulating points 302 and 304 relative to the pivot point 303 is important. The linear alignment between pivot point 303 and articulating point 302 (shown as symbol #) and the linear alignment between the pivot point 303 and articulating point 304 (shown as symbol #) must form an angle at least less than 180° in order to permit a mechanical 'rock' of the rocking element about a fixed pivot point. The angle formed by the alignment of articulating points 302 and 304 relative to pivot point 303 is preferably between about 90° and about 60°, more preferably about 80°.

[80] In an alternative embodiment, certain connections within the actuation assembly, i.e., articulating or pivot points, can be substituted with living hinges provided such possess the structural and material integrity for that purpose. Being of simpler contiguous one-piece structure, living hinges can be a cost-effective option which is advantageous for manufacturing.

[81 ] The tension line 60, which can also be called a 'slider,' can be in the form of a wire, rod, cord, cable, and the like - provided it can withstand and transmit the operative forces exerted upon it in association with the distal portion of the device and its foreseen resistance from the tissue engaged by the device, as well as functionally comply with the flexibility dynamics of the shaft 10. The tension line 60 can be composed of any material that can be formed into a wire-like linear configuration and that possesses adequate material strength for its purpose. Preferably, the tension line is composed of a metallic material. The tension line 60 can, in other embodiments, be a single contiguous construction or multi-portion, jointed and/or segmented construction and include secondary operative components as well. The tension line 60 can interact with the rocking element(s) 7OA and 7OB directly or indirectly through secondary component(s) or contiguous structures. In the embodiment shown in Figures 1 through 3 and 6, the tension line 60 is connected to the actuation assembly 50 via a contiguous stem 114 of a U-bracket 112. The elongated shaft 10 component can comprise a shaft lumen (not shown) running along the longitudinal axis of the shaft which movably accommodates the tension line within. Alternatively, the tension line can reside within a contiguous trough or channel running along the exterior of the shaft.

[82] In a preferred embodiment (and as illustrated in the figures 1, 2A, 2B, 3 A, 3B, 3C, and 5), the actuation assembly comprises a '4-bar' pivotal articulation structure between the components, wherein the articulating connections between 1) the tension line 60 and the rocking element(s) 70; 2) the rocking element(s) 70 and recessed bridge portion 30 of the shaft 10; 3) the rocking element(s) 70 and the linking element(s) 80; and 4) the linking element(s) 80 and movable (trap) element 22 of the device, all include a pivotal hinge structure.

[83] The invention further comprises a system comprising a device as described above together with an elongated sheath 12 having a longitudinal axis, a proximal end and distal end 13, and having a sheath lumen 14 within running along the sheath longitudinal axis and terminating at a distal port 19 (see Figures 1, 4 A and 4B). The lumen 14 within the sheath 12 can accommodate at least a portion of the device. The tension line 60 and distal portion of the device 11 can completely reside within the sheath lumen 14, with the distal portion 11 of the device being extendible beyond the distal port 19 of the lumen 14 for its operation and tissue engagement stage. Wherein the trap elements have been actuated and are 'stacked' in opposition to one another (see Figure 4B) for tissue capture, the combined height of the trap elements 20 and 22 and shaft 10 at the distal portion of the device can increase or 'double.' In this embodiment, the dimensions of the sheath lumen 14 can accommodate both the non-actuated (see Figure 2A and Figure 4A) and actuated 'stacked' stages (see Figure 2B and Figure 4B) of the device.

[84] The cross-sectional diameter or size of the sheath component can vary according to its desired features or the intended procedure. In general, it is preferred that the outer diameter of the sheath exceed the outer dimensions of the device so as to reduce the likelihood of unintentional trauma or obstacles during insertion and positioning of the device within the patient and movement through the body conduits associated with the procedure.

[85] In one embodiment, the sheath lumen 14 can be dimensioned with at least twice the height of the non-actuated device distal portion so as to permit retraction of the actuated device and trapped tissue sample back into the lumen. In this embodiment, it may be possible to effect repetitive tissue sampling and subsequent complete withdrawal of the device from the sheath and reinsertion of the device to obtain additional samples from the tissue site.

[86] The system of the invention, i.e., the combination of the device and the sheath, can be used per se as a surgical instrument. In this embodiment, typically an access portal would be used as part of the procedure through which the system would be introduced into the patient. Alternatively, the system of the invention can be used in conjunction with other surgical or medical equipment. For example, the system can be used in combination with a ureteroscope or other similar instrument, thereby 'sharing' the lumen or cannula of the ureteroscope.

[87] One significant advantage associated with the invention is that it permits the use of a relatively large cavity size to be used for tissue engagement or collection, while simultaneously affording a reduced or minimal cross-sectional diameter of a sheath accommodating the device. In a preferred embodiment (see Figure 10), the sheath lumen 14 can be dimensioned only to accommodate the non-actuated shaft and open traps in linear alignment, but would also necessitate withdrawal of both the sheath and device once tissue has been captured within the traps in closed position. Thus in this embodiment, the lumen 14 only accommodate the minimal height of the non-actuated state of the device. In a further preferred embodiment, the sheath 12 can comprise two or more lumens so as to permit simultaneous usage of additional instruments or visualization/optic equipment within.

[88] In Figure 10, there is depicted one embodiment of a system contemplated by the invention in which the sheath 12 component comprises a dual lumen structure - one sheath lumen 14 accommodating the device (within which is shown the distal end 21 of the fixed trap element 20) and an additional lumen 99. In this embodiment, the sheath 12 simultaneously accommodates the device of the invention alongside an additional tool or instrument (not shown). Lumen 99 can be used to insert and accommodate visualizing equipment, such as a fiberoptic viewing and/or illumination device. The dimensions of lumen 14 can vary, but in a one embodiment the lumen 14 can be sized to accommodate the device in half-height non-actuated resting state, such that the outer dimensions, e.g., diameter, of the sheath 12 can be reduced or minimized. In this embodiment, the device can be extended beyond the end 13 of the sheath 12 to obtain the sample or otherwise operate, and the device can be collectively withdrawn with the sheath from the target site.

[89] The component parts of the device, e.g., the shaft, tension line, trap elements, actuation assembly components, can be composed of any sterilizable material having sufficient rigidity to maintain its configuration throughout the procedure with which it is intended for use. Suitable materials include plastics and polymeric materials, and metals and metallic alloys. The shaft component can be composed of medical grade stainless steel, titanium, nickel-titanium alloys (e.g., Nitinol), and the like, for example. In one embodiment, the shaft and sheath can be flexible or semi-rigid to permit maneuver of the device in use.

[90] The shaft and trap element shape, size and configuration can vary as well. For instance, the shaft can have an overall rounded, ovule, square or rectangular cross- sectional shape. In a preferred embodiment, the cross-sectional dimensions of the individual fixed trap element, movable trap element and thick portion of the shaft component should be substantially similar so as to permit their alignment and movement within the interior dimensions or diameter of the lumen of the sheath.

[91] The sheath portion of the system of the invention can be constructed to be rigid, semi-rigid or flexible, and can be composed of various materials suitable for medical context of use. Suitable materials include metals, metallic alloys, e.g., structured as a hollow tube, or soft durometer plastics and polymeric materials, e.g., silicone or polyurethane.

[92] The shaft, tension line and sheath components of the system of the invention can be constructed to cooperate in terms of rigidity or flexibility. The structural attributes of rigidity and flexibility of the components of the invention can be dictated by the requirements of the particular procedure contemplated for the device and system. In other words, when procedures involving serpentine or convoluted passage are involved, enhanced collective flexibility of the shaft, sheath and tension line will be desirable. On the contrary, these components can be of more rigid or semi-rigid construction in procedures wherein use of the device requires mechanical precision without maneuverability.

[93] The component parts of the device and system of the invention can be manufactured in accordance with equipment and techniques readily available to those skilled in the medical device manufacturing field. For instance, the sheath can be prepared using molding techniques for plastics and soft durometer materials. Rigid components can be prepared using various tools and equipment designed to configure and shape metallic materials, for instance.

[94] The proximal end of the device can comprise an actuation mechanism to operate the device. A wide variety of mechanisms can be used, provided they are structured to directly or indirectly move the shaft component and tension line relative to one another. Furthermore, the mechanism can be hand-held, manually operated or effected by an automated apparatus. Examples of suitable hand-held manually operated mechanisms that can be used include, but are not limited to, structured in the form of scissors, clamps, trigger-and-handle assemblies, plunger assemblies, sliding tab mechanisms, and the like. A variety of well-known suitable manually-operated and automated mechanisms can be used for the proximal actuation mechanism for use in conjunction with the device of the invention, and such mechanisms and structures are readily available to those skilled in the medical device manufacturing arts.

[95] Preferably, all of the assembled componentry of the device and system of the invention are collectively sterilizable, disposable, or both. In addition to the importance of sterility associated with the invention, disposability is another desirable attribute for surgical instruments in general. If, on the other hand, the device is constructed to be reusable, it is important that the collective components and materials be able to withstand temperature and/or chemical sterilization techniques.

[96] EXAMPLE 1 Ureteroscopic Procedure using the Device of the Invention

[97] In use, the device and system of the invention can be applied in a variety of surgical procedures wherein access to the tissue site is restricted by the size of the entry portal or natural orifice or passageway. One procedure in which the device of the invention can be used is in the sampling of urothelial tissue wherein the tissue site is accessed through the urethra, bladder and ureter using a ureteroscope. [98] In one example, a semi-rigid ureteroscope or flexible urteroscope can be utilized to cannulate the ureteral orifice after passage through the urethra into the bladder. Access to the ureteral orifice can be gained by direct vision, over a guidewire, or through a ureteral access sheath. The ureter, renal pelvis and renal calyces (upper urinary tract) can be inspected and the target tissue site (e.g., pathology site) can be identified for tissue engagement (e.g., biopsy). The ureteroscope can be maneuvered and positioned in proximity to the target site under optic visualization, and the device can be introduced into a working lumen of the ureteroscope at its proximal end. The device can be maneuvered independently (e.g., adjusted, withdrawn and/or re-inserted) through the ureteroscope working channel or lumen as needed. Manipulation of the ureteroscope can be accomplished using, for example, via an internal steering guide wire system, to better position the device directly over the proposed sampling site, and the device within the ureteroscope can conform to the flexible maneuvering of the ureteroscope.

[99] Once the distal portion of the device is exposed to the extent needed for its operation, the device can be manually actuated by a proximal hand-held mechanism (e.g., a plunger assembly, slide mechanism, and the like). The distal portion of the device (e.g., the trap elements) in open position can be advanced into contact with the tissue under endoscopic guidance, for example. The device (e.g., actuation assembly and trap elements) can be fully actuated and closed to sever and capture the tissue sample. The device can then subsequently be gently withdrawn along with the ureteroscope, and the tissue sample discharged or removed from the trap containment outside the patient's body.

[100] In procedures similar to that described herein above, the device of the invention can also be used with other endoscope, laparoscopic and/or automated (robotic) procedures wherein tissue engagement and/or manipulation is desired. Examples of such procedures include, but are not limited to, colonoscopies, gastroscopies, biliary procedures, bronchoscopic procedures, and the like. Tissue engagement activities can include biopsies, grasping, retraction, and the like. Aside from tissue engagement, it will be understood by one skilled in the surgical field that the device of the invention can be used to remove objects at a target site aside from tissue.

[101] Industrial Applicability:

[102] The invention is useful in the medical field, particularly the endoscopic surgical field wherein minimally invasive techniques, equipment and instrumentation are desired or contemplated. The device and system of the invention are particularly useful in procedures wherein relatively larger tissue sample sizes are desired without substantial compromise to minimally invasive operational parameters.

[103] The invention herein above has been described with reference to various and specific embodiments and techniques. It will be understood by one of ordinary skill in the art, however, that reasonable variations and modifications may be made with respect to such embodiments and techniques without substantial departure from either the spirit or scope of the invention defined by the following claims.

Claims

Claims[1] What is claimed is:

1. A device structured for tissue and object retrieval comprising: comprising: an elongated shaft having a longitudinal axis, proximal region and distal region, said distal region terminating at a contiguous fixed trap located at the distal end of said shaft; said elongated shaft having a recessed bridge portion located proximal to said fixed trap; a movable trap element having a substantially elongated body and open cavity on one side and hingedly coupled to a proximal end of said fixed trap element; said movable trap residing adjacent to said recessed bridge portion when in the open position; both of said fixed trap element and said movable trap element having respective open cavities on one side; said movable trap element and said fixed trap pivotally coupled to one another so as to alternate between a) a first retracted non-actuated state, wherein the first trap element and second trap element are positioned along a shared longitudinal axis in linear sequence and in alignment with said longitudinal axis of said shaft, and b) a second final actuated state, wherein said open cavity of said first trap element and said open cavity of said second trap element are in opposing orientation to one another such that the first and second trap elements together form an encased chamber in a second final closed, actuated state; and wherein relative to the hinged coupling between the movable trap element and the fixed trap element, the unhinged end of the movable trap element travels over about a 180 degree angle about a transverse axis and in alignment with the longitudinal axis of the shaft until the unhinged end of the movable trap element contacts the distal-most end of the fixed trap element.

2. The device according to claim 1, wherein said device comprises an actuation assembly which operates the movement of said movable trap element relative to said fixed trap element, the actuation assembly comprising three points of pivotal movement between a tension line and the hinged portion of the trap elements, and wherein the three pivotal points are in addition to the hinged coupling between the trap elements.

3. The device according to claim 2, further comprising a tension line connected to said actuation assembly.

4. The device according to claim 3, wherein the actuation assembly comprises a 4-bar pivotal articulation structure between the components, wherein the articulating connections between 1) the tension line and the rocking element(s); 2) the rocking element(s) and recessed bridge portion of the shaft; 3) the rocking element(s) and the linking element(s); and 4) the linking element(s) and movable (trap) element of the device, comprise a pivotal hinge structure.

5. A system comprising the device according to claim 1, in combination with a an elongated sheath having a longitudinal axis, a proximal end and distal end, and having a lumen within running along said sheath longitudinal axis and terminating at a distal port; wherein said lumen accommodates at least a portion of the device.

6. The system according to claim 5, further comprising an additional lumen running longitudinally within said sheath.

7. A device comprising an actuation assembly structured to move a movable element relative to a fixed element in alignment with a longitudinal axis in response to linear movement of a tension line mechanically coupled to the actuation assembly, wherein said movable element is hingedly coupled to said fixed element, the actuation assembly comprising: a rocking element having two points of articulation in relation to a pivot point about which said rocking element moves, and one articulating point of which is connected to a tension line; and a linking element, wherein the linking element is simultaneously connected at one end to said movable element adjacent the hinged coupling, and connected to one articulating point of said rocking element at the other end; wherein force exerted by linear movement of said tension line moves said movable element relative to said fixed element, said movement effected through said rocking element and linking element.

8. The device according to claim 7, wherein the actuation assembly comprises a 4-bar pivotal articulation structure between the components, wherein the articulating connections between 1) the tension line and the rocking element(s); 2) the rocking element(s) and recessed bridge portion of the shaft; 3) the rocking element(s) and the linking element(s); and 4) the linking element(s) and movable (trap) element of the device, all comprise a pivotal hinge structure.

9. A device comprising: a tension line, a shaft, a fixed element on said shaft and a movable element hingedly coupled to said fixed element structured for an approximate 180 degree movement pathway aligned with a longitudinal axis of said shaft; an actuation assembly operatively connecting said tension line and said movable element and said fixed elements; said actuation assembly comprising a 4-bar mechanical connection.