WO1996011723A1

WO1996011723A1 - Devices and methods for implementation of pulsed electromagnetic field therapy

Info

Publication number: WO1996011723A1
Application number: PCT/AU1995/000685
Authority: WO
Inventors: Jeffrey D. Edwards; Robert F. Gilmour
Original assignee: Australasian Medical Technology Limited
Priority date: 1994-10-17
Filing date: 1995-10-17
Publication date: 1996-04-25

Abstract

Disclosed are devices and methods for therapy of medical conditions in which therapy occurs through operation of a medical therapy device (21, 25) without manual manipulation of controls on the device (21, 25) by patient or practitioner. Instructions for operation of the device may be imported to a microprocessor and driver for the device from a smart card or like memory module (26). Therapy may be monitored by reading of data stored in the memory module (26) and the therapy delivered by the device (21, 25) may be modified in response to modification of data stored in the smart card (26) in accordance with a given stage of therapy. The devices and methods are particularly applicable to pulsed electromagnetic field therapy, for example, in the treatment of osteoarthritis.

Description

O 96/11723 PCI7AU95/00685

1

DEVICES AND METHODS FOR IMPLEMENTATION OF PULSED ELECTROMAGNETIC FIELD THERAPY. Technical Field.

The present invention relates to the field of electromagnetic field therapy ("EMFT") and pulsed electromagnetic field therapy ("PEMFT") and, in particular, to methods and devices for implementation of therapies based on PEMFT or EMFT.

PacKgrounti Art.

The therapeutic application of pulsed electromagnetic field therapy has been gaining credibility as an effective and beneficial therapy. Over 200,000 people have been involved in clinical trials that have established pulsed electromagnetic field therapy as a highly effective and appropriate therapy for a number of muscular skeletal disorders. Electromagnetic fields are propagated into the tissues requiring treatment by means of application of particular electrical characteristics to an inductive coil. The electromagnetic field is generally produced by applying a predetermined and pre-shaped electrical current form to one or more inductive coil(s) in order to produce a desirable magnetic field with specified field characteristics. The magnetic field and therefore the applied therapy is generally referred to as the "waveform". The characteristics of the waveform are dependent upon the applied electrical current and the magnetic and physical characteristics of the inductor(s) or coil(s).

The parameters and characteristics of the resulting electromagnetic field are the subject of great academic and medical debate. See, for example, US Patent Nos 4757804, 4911686, 4993413, 5131904, 5100373, 5014699 and Australian Patent Application No. 52909/79. Nevertheless, certain electromagnetic field types have been approved by the US Food and Drug Administration for use in human subjects.

In recent times, pulsed electromagnetic field therapy has been proven through clinical trials to have efficacy in many disorders affecting the tendons and other connective and soft tissues of the body in addition to its known osteo active abilities. Of significant interest in soft tissue disorders are the clinical trials conducted by the Queensland Sports Federation Institute, Queensland University, and replicated by the SAB Sports Injury Clinic, University of Cape Town. In both cases, PEMF was found to be effective in a range of chronic, acute and inflammatory disorders. Dr Atlas and Dr McArthur concluded "PEMF effective in reducing pain, swelling and bruising, especially in acute injuries, and the effects were usually evident after the first or second treatments". Also, Dr Harris of the Queensland University reported in a publication titled "A Report on a Clinical Trial of the Effects of PEMF on Tissue Injuries", that PEMF is beneficial in the treatment of tissue disorders. While none of the trials propose an explanation for the means and mechanisms by which PEMF achieves this efficacy, an insight into the complex and varied beneficial cellular effects is provided by the double blind clinical trials of leron et al and Binder et al that revealed that PEMF was pro-active in angiogenesis and chondrogenesis. In addition, Dr Riva (Rome 1980) stated.... "from collagen in all its anatomical variations to the smooth muscular tissues, we draw the information that PEMF influences the activity of cellular elements and/or structures". In a report relating to PEMF and various soft tissue injuries (physiotherapy 60/6) it was reported that PEMF "has a definite biological effect on recently injured soft tissues, especially in the reduction of swelling, the diminution of pain and in the improvement of function".

These reported effects are further supported by "PEMF Modifies Biomedical Processes (Basset, Bioessays 6)," Modulation of Collagen Production in cultured Fibro blasts by PEMF" (Murray/Farndale - 1985), "Treatment of Soft Tissue Injuries by PEMF" (Wilson, 1972), "PEMF Therapy of Persistent Rotator Cuff Tendonitis" (Binder, Parr, Hazelman - 1984). See also "Membrane Phinomena and Cellular Processes under the action of PEMF" (2nd International Congress of Magneto-Medicine 1980).

Of special relevance to bone fractures is "Fundamental and Practical Aspects of Therapeutic Uses of PEMF" by CA. Bassett (Crit Reviews Biomedical Eng V17.5) and "The Development and Application of PEMF for Ununiting Fracture and Arthrodes" (Orth Clinics of NA V15.1) in which clinical, double blind trails and In-vitro studies are cited in support of the use of PEMF in cases of slow and ununiting fractures.

Of specific relevance is the Double Blind clinical trial by Sharai et al,

(Bioelectrical Repair and Regrowth 1985, 230) entitled "The Treatment of Non- Uniting Fractures of the Tibia with PEMF". In all, there now exists a vast body of scientific research, as well as approval by the US FDA, for the application of

PEMF in cases of slow and non uniting fractures of the tibia.

Of interest in body joint disorders are the clinical trials by Trock, Bollet et al titled "A Double Blind Trial of the Clinical Effects of PEMF in Osteo arthritis". This trial reported "beneficial effects in the amelioration of symptoms, subjective improvement in functional ability and decrease in objective findings". Such positive effects are further supported by Basset, (Jama 1982), Mooney (Spine 1990), Goodman (Biochem 1989), De Loecker (Electromagnetic Med 1990), Murray (Biochem 1989), Grant (Ann NY Ace Sci 1991). Certain types of waveform are known to stimulate certain kinds of activity.

By way of example, Basset (op cit) has developed a waveform in the form of a package of multiple individual pulses repeated as a block at a frequency of 15 Hz which has been shown to be osteogenic and proliferative in its effect, while a single narrow pulse repeated at 72 Hz has been shown to be Angio and Chondroactive in its effect.

Osteo arthritis, for example, is a complex condition involving many differing cellular structures, variable underlying pathology and differing stages of degeneration and inflammation, the problem arises that single waveform treatment is incapable of delivering optimal treatment in all cases and at all stages of the rehabilitation process.

Some attempts have been made in the past to combine the benefits of known angio active waveforms with known benefits provided by osteo active waveforms in order to affect both the inflammatory factors as well as the osteo degenerative ones. Such previous attempts have resulted in a single fixed ratio and repeating waveform and overlaying these with a basically osteo active waveform. This results in a compromise waveform that embodies a little of each type. For example, Markoff et al, in treatment of osteo arthritis in 1993, created such a compromise waveform by taking Basset's conventional and well known osteo active waveform and modifying the pulse width of each rectangular sub¬ section until they more resembled the angio active type that has been shown to assist in inflammation. The result was a single non-varying PEMF waveform that had some of the properties of each type and therefore had some efficacy at both the inflammatory level and the proliferative level. Efficacy has been shown to exist with such compromise waveforms, although the therapeutic benefit to each particular phase of the rehabilitation process would appear to have been compromised.

In any event, while the approach has some therapeutic benefit, the inflexibility of fixed and non-varying waveforms provide no means through which the physician may modify or optimise the therapy in accordance with particular patient's needs. The present invention is predicated on the discovery that modification of the therapy on a progressive basis may extract optimum efficacy at various stages of the rehabilitation process.

In addition, current treatment devices involve manual manipulation of dials and buttons on the equipment. Further, selection of a particular treatment device introduces a danger of human error or loss of optimal treatment parameters with resulting loss of efficacy. Therapy modification has generally been in response to externally recorded or verbally provided information relating to patient compliance and device usage. Such reported verbal information may be unreliable and result in less than optimal treatment.

It is therefore a first object of the invention to provide a method and device for delivering a range of beneficial PEMF waveforms, especially for the treatment of osteo-arthritis, in a mixed, complex and/or serially progressive manner that reduces the need to compromise central efficacy and to do so on a staged, complex or serially progressive manner in order to provide optimal therapy at all phases of the rehabilitation process. It is a second object of the invention to provide a method and device that reduces or avoids the risks and costs associated with manually executed serial therapy programs while at the same time providing therapy that is simple to use, automated in its application and suitable for outpatients and home care, as well as institutional, application.

It is a third object of the invention to provide a method of monitoring the progression of treatment and regulating the therapy and compliance therewith to achieve a high degree of efficacy. Summary of the Invention.

With at least one such object in view, the present invention provides a method of treatment of a disorder of tissues comprising application to tissues of a patient, preferably in a region of the body afflicted with the disorder, of pulsed electromagnetic fields at extremely low frequency, the waveform of the electromagnetic field being automatically managed in accordance with a stage of therapy.

Preferably, the nature of the waveform is managed, in accordance with the nature and stage of therapy, in a complex, mixed or serially progressive manner. Thus, in the initial stages of therapy, a chondroactive or angioactive waveform might be employed, possibly in a complex combination, and at a stage of therapy, for example, after a number of therapy periods, time, treatments, sessions or cycles, the waveform might be modified to provide a different waveform such as an osteoactive or proliferative waveform. Such a treatment scheme may be especially appropriate for treatment of osteo arthritis though it is not intended to restrict application of the method to the above mode or treatment of such condition. The method may also be applied to treatment of soft tissue, muscular or skeletal disorders or injury or any combination of these.

Preferably, progression of therapy is automatically monitored, and if necessary modified, such that the therapy is optimised in its application. Therapy may be adapted in accordance with the disorder and/or injury suffered by the patient and any other relevant factors. Actual patient usage may be collected in an automated manner informing the practitioner as to the stage of treatment and patient compliance therewith. This may be of special importance where complex or mixed mode therapies are undertaken, for example, as described above. O 96/11723 PCI7AU95/00685

The waveform may be generated in response to parameters such as timing sequence(s) or other data which may be employed to generate a particular waveform. Such parameters may be tested and verified through an appropriate cyclic redundancy check in order to provide additional safety. The parameters may be modified in response to actual patient usage or other factors, for example, onset of other conditions requiring therapy.

Modification of therapeutic strategy may occur, in a controlled manner, during a treatment session or at commencement of a treatment session, or otherwise as appropriate. In a second aspect the present invention provides an electromagnetic therapy device producing pulsed electromagnetic fields comprising an extremely low frequency pulsed electromagnetic field inductor to generate and administer extremely low frequency electromagnetic field therapy to a region of the body for therapy, a power supply and a waveform generator electrically connected to the inductor for energising the same and a data storage means wherein an extremely low frequency pulsed electromagnetic field therapy is controlled in response to data stored in the data storage means.

The data storage means may take the form of a memory module, optionally a smart card, integrated circuit, chip or memory card or like or other memory module. Although it may be preferred that the memory module is portable to increase the flexibility of the treatment device, this is not essential. When brought into communication with the remainder of the device, data transfer may occur therefrom. As the smart card or other data storage means may be programmed with data such as patient identity, session attendance, actual device usage, duration of therapy and waveform generating parameters, such as pulse width, duration, frequency, amplitude and/or duty cycle, such that the appropriate waveform-chondroactive, angioactive or osteoactive or any combination of these as required for treatment of a disorder - is generated for a particular treatment stage. The card may be such that the therapy device is matched with a card or patient or only operates to provide the desired waveform for a given patient and disorder thus ensuring patient compliance. Otherwise, the card may be programmed with information regarding the treatment employed, and undergone, by the patient so that compliance may be monitored. The smart card or other data storage means may be programmed by a therapy designer in the absence of the patient or the treatment device. This may permit numerous treatment schedules to be time and cost effectively programmed without inconvenience to the user or compromising the availability of the treatment device. Equally, data may be transferred and stored in the smart card allowing the stage and nature of therapy to be monitored and compared with efficacy. The device and/or memory module may be provided with data transfer means to enable transfer of data between the module and a driver circuit for the device. In the case of a PEMF therapy device, the driver circuit may drive the waveform generator.

The treatment device may be implemented with the inductor disclosed in the applicant's copending PCT Application No. IB9400216 or the orthotic devices disclosed in the applicant's copending PCT Application No.

AU9500208.

The invention provides in a further aspect a memory module programmed with instructions for the operation of a medical therapy device without manipulation of device controls during a therapy session. The therapy may be pulsed electromagnetic field therapy.

Preferably, the memory module is portable and may take the form of a smart card, memory card, integrated circuit card or chip card.

Brief Description of the Drawings. The present invention may be better understood from the following description of preferred embodiments thereof made with reference to the accompanying drawings in which:

Figure 1 is a schematic diagram of the treatment device in accordance with one embodiment of the present invention; Figure 2 is a schematic diagram of a number of waveforms that may be generated by the present invention; Figure 3 is one example of a treatment scheme in accordance with the present invention;

Figure 4 demonstrates an example of a waveform data structure;

Figure 5 is a diagram of an embodiment of the device to be employed for bone growth stimulation.

Detailed Description of the Invention.

Referring now to Figure 1 , there is provided a pulsed electromagnetic therapy device comprising a driver unit 21 and a therapy applicator 25 as available from the applicant under the trade mark CELLERATOR. The driver unit 21 incorporates electronic current shaping and waveform generating circuitry of known design and may be powered by internal or external sources in conventional manner. DC power may, for example, be obtained from power mains via a step down transformer, or from a battery pack, or from an internal or external rechargeable or disposable portable battery. The waveform generating circuitry comprises an electronic driver suitably including timing means and a transistor based current driver means for appropriately shaping the current delivered to the inductor provided in applicator 25 which will be described in detail below. The current input to the inductor is shaped by the circuitry to provide for the frequency (timing), amplitude (current value) and duty cycle prescribed for the waveform(s) appropriate for the PEMFT treatment to be administered. However, the specific circuitry utilised is not critical to the practice of the present invention.

Driver unit 21 also incorporates a card insertion slot 22 whereby a smart card, integrated circuit card or like memory module 26 may be inserted and read or written to through the means of a card reader/writer device for example as known in the electronic arts.

The characteristics of memory module 26 may be described as follows. The memory module takes the form of a conventional smart card which includes a printed circuit board on which is mounted an integrated circuit chip to allow data storage and control of the operation of the card. The smart card may be of contact or non-contact type. The components are preferably encapsulated in a protective body made from a dielectric material. If a non-contact type smart card is employed, there is no electrical connection made between the card and the card reader/writer device. The integrated circuit chip is provided with power from an electromagnetic coil which may itself be powered by an external source, for example, for source powering the device. A further electromagnetic coil may be included to allow data to be transferred from the card to the card reader/writer device and vice versa.

The card reader/writer device incorporates coils corresponding with the coils provided in the smart card. When the coils of the card reader/writer device are energised, current is also induced in the coils of the smart card allowing transfer of data. Transfer of data in either direction may proceed for as long as there is an electromagnetic couple between card and card reader/writer device.

In the illustrated embodiment, it is the insertion of the smart card 26 that enables a therapy session to commence. There are no manual controls provided on the driver unit 21 other than a user operable button 24 to energise the unit. The user might also be able to stop a treatment session by operating the button to de-energise the device to stop or "pause" therapy. In this case, therapy proceeds in accordance with a program reliant on data stored or transferred to the smart card 26. Equally, the progression of therapy may be monitored by writing of data concerning the treatment to the smart card and, optionally later, reading of data stored in the integrated circuit of the card by the practitioner in a card reader or similar device. Nevertheless, some visual indicators of correct operation of the driver unit may be desirable so two LED indicators 23 are provided for this purpose. Otherwise the therapy device may operate automatically and without supervision by patient or practitioner to generate therapy while recording details of therapy type, duration, session number and any other relevant information onto the smart card for later retrieval or for use internally as a means of modifying therapy in accordance with device usage.

The smart card or memory module may take the form of a free access EEPROM or other suitable smart, IC or chip card. The card may be provided with identification information for the patient, card and medical therapy device designated for the patient. The patient identification may be of a secure encrypted type and require the entry of a personal identification number (PIN) prior to device programming. Disorder type information may be desirable for both operational and auditing procedures. There may be incorporated cyclic redundancy check (CRC) and checksum verification routines to check data integrity. Such routines are known in the electronic arts.

Therapy information, may be serialised by advantageously numeric code, contain sequential therapeutic device instructions such that the device generates the required therapeutic waveforms at a given stage of therapy. Information relating to the programmer and the date and time that therapy may be applied may also be incorporated in the memory module. Any desired range of information may be recorded and held non-volatile by the memory card and, as long as such information has meaning to a microprocessor or similar means in the therapy device, any desired form of therapy control may be applied. Empty or currently unused memory locations may be used for storage of information regarding the operations, e.g generation of waveforms, executed by the device, the type of therapy administered and actual usage dose rate and time.

Such information may be read by the therapy designer or practitioner later to extract accurate information regarding device usage, medications delivered, therapies applied and any desired aspect of operation of the device. Efficacy may be compared with this functional log to provide an accurate means of refining and further improving therapy outcomes without the need for constant supervision, documented note and other patient management systems. Referring now to applicator 25, this provides the actual magnetic fields employed during therapy and could include, or take the form of, an orthotic device, as disclosed in the Applicant's copending PCT Application No. AU9500208, the contents of which are hereby incorporated by reference.

In any event, applicator 25 incorporates inductor(s) designed specifically for the propagation of harmonic free, therapeutic, extremely low frequency

("ELF") electromagnetic fields for application at distances of less than λ/6 ( β wavelengths), i.e in the "Near Field" as it is commonly known. Together with the waveform generator and driver circuitry provided in applicator 25 and driver unit 21 , waveforms of any desired form may be generated. The actual waveform or inductor employed is not essential to the present invention. Indeed, the nature and characteristics of the electromagnetic fields are recommended and approved by statutory bodies, e.g US FDA, in various parts of the world and may change as knowledge increases.

Nevertheless, the inductor may take the form of a planar focal inductor comprising a single continuous filament of conductive material, wound spirally into a flexible coil and having a central void of diameter that is from about 15% to about 40% of the diameter of the coil as defined by an outer perimeter thereof. Such an inductor is the subject of the Applicant's copending PCT Application No. IB9400216, filed 7th June, 1994, the contents of which are hereby incorporated by reference.

The inductor is located within the protective housing of applicator 25. The therapeutic device and smart card or other memory module may be employed in the following manner. A suitably qualified person may use their skill and expertise to design and construct a particular therapy program for a particular patient and wish to monitor efficacy against actual device usage in order to better refine that, and future, applications of PEMF therapy. In such cases, a unique identification code may be recorded on the memory module for purposes of patient and therapy identification and therapy auditing.

Additionally, parameters relating to initial therapy output, number of permissible therapies and duration for each therapy session may be recorded along with a serially progressive modification table for purposes of modifying therapy in accordance with therapy progression and/or actual therapy device usage. All such data, and any other relevant data, may be recorded and maintained non-volatile on the memory module which may, but not essentially, be given to the patient for home-care application with expected reduction in institutional administration and management costs. Referring now to Figure 2, the conduct of a therapy session may be understood in which three possible waveforms are required at some stage of the therapy. The three waveforms are not intended to be limiting of the present invention and many other possible waveforms exist.

In Figure 2(a), there is shown a mixed sequence of waveforms including a single block of Chondroactive type waveforms 55 interspersed with a group of Osteoactive waveforms 56. Such a sequence of waveforms may be appropriate to provide therapy to differing cellular components known to be involved in a particular disorder, disease or injury; for example, osteoarthritis.

The waveform parameters such as pulse width, duration, duty cycles and frequency, execution order, change table and various counters, such as session and progression counters, are held non-volatile in memory module 26. When the memory module, smart card 26, is inserted into the card reader/writer of driver unit 21 data stored in the integrated circuit of smart card 26 may be transferred to a microprocessor or equivalent hardware within the driver unit 21 in a manner known in the electronic arts. The microprocessor, being installed with a commercially available software/firmware operating system to enable communication with the memory module, reads the parameters or other instructions stored on the card and executes the instructions in accordance with rules established either internally or via a down load facility from the memory module to generate desired current pulses for supply to the inductor. Initially, the microprocessor may verify the identification codes on the card 26 in a matching process to ensure that the correct card is being used with the correct device and for the correct purpose.

The microprocessor imports operational parameters from the card and then produces a serial stream of digital information representing the various mark, space and repeat patterns desired in a therapeutic waveform for a particular patient. The resulting serial data stream is presented to driver circuitry for the waveform generator of conventional design that translates digital data into pulses of electrical current of desired waveform which are transferred to the inductor without other human intervention. Data integrity may be verified by cyclic redundancy check (CRC) checksum or other similar verification method, the method being known in the electronic arts. The current is supplied to the inductor to produce the desired electromagnetic field for propagation into tissues requiring therapy, for example, for treatment of osteoarthritis.

Additionally, but not essentially, the microprocessor of driver unit 21 may write data back to the memory module 26 for storage or updating of certain information which, in turn, may be used as a log of device usage or, equally beneficially, be used to modify the therapeutic waveform in accordance with a stage of therapy as reflected, for example, by device usage or other predefined rules.

In this manner, the therapy device may automatically and, without any necessary intervention, verify, load and monitor progression of a secure prescription of PEMF therapy without the need for the therapy designer to have access to the therapy device or the need to manipulate manual controls. The method of treatment is therefore potentially fully automated.

Referring to Figure 2(b) there is shown a schematic of a progressive therapy program in which a proven waveform such as a Chondroactive waveform is generated by the waveform generator in response for a period prior to execution of a secondary waveform, in the case illustrated, an Osteoactive waveform used in therapy of osteoarthritis. A session counter may be employed to determine the modification or change over point and such counter may be preset, automatically generated or modified in response to actual device usage. A progression counter may, but not essentially, be employed to enable a number of total repeated phased therapies to be executed. In such case the progression counter may be preset, automatically generated or modified in response to actual device usage or other data reflecting the stage of therapy. Referring to Figure 2(c), there is shown a complex serially progressively variable waveform which may, but not essentially, commence with predefined waveform parameters and, in response to actual device usage, modify parameters - for example pulse width and frequency - in the case illustrated pulse width is increased, (but any desired modification in accordance with any desired rules, advantageously incorporated in the smart card, may occur) in response to actual usage in order to create a progressive therapy waveform with parameters established in direct response to actual device usage. These complex, mixed or serially progressive waveforms may be tailored by the practitioner to other factors such as observed efficacy and this may be done in a controlled manner avoiding manual manipulation of controls on the therapy device. The interrelationship of the smart card and microprocessor of the therapy hardware system may now be described with reference to Figures 3 and 4 as follows.

The smart card may be provided with a non-volatile memory table, shown schematically in Figure 3, in which therapy parameters such as the waveform parameters described above are maintained. Alternatively, the memory module may be internal to the hardware. In the case illustrated, three sets of waveform data, waveform data 1 , waveform data 2 and waveform data 3 corresponding to angioactive, chondroactive and osteoactive waveforms to be generated by the waveform generator when instructed to execute these by the microprocessor in the therapy hardware system. It will be recalled that the microprocessor is instructed by data or program material incorporated within the smart card.

Accordingly, an angioactive waveform may be generated for a certain number of sessions as counted by a session counter. At the conclusion of the required number of sessions as predetermined for the counter, a chondroactive waveform (waveform data 2) may be generated and the cycle described above repeats as shown conveniently in Figure 2(b).

Finally, an osteoactive waveform is generated for a certain number of sessions until therapy is concluded. It will be apparent, however, that any number of waveform parameters may be programmed within the smart card. Further, any number of waveforms may be executed within a single treatment session and a clock rather than a session counter may be employed as a measure of the stage of therapy. In addition, the waveform may be modified - though still in essence angioactive, chondroactive or osteoactive - by recalculation of pulse width, duration, frequency, amplitude at any time as reflected by a session counter, clock or other means. This may occur in a serially progressive manner as shown in Figure 2(c) in which modification occurs in response to data in change table and the waveforms may be mixed or combined in any desired manner.

If the device is accidentally powered down or deliberately paused, for example at completion of individual therapy sessions, the session counter or clock data remains non-volatile and is read back on power up allowing the system to progress serially.

In addition, the session counter or clock may be read by external means so actual usage can be calculated without the necessity to rely on patient reports. Referring now to Figure 4, there is shown a data block structure provided in the smart card comprising approximately, but not essentially, of 19 bytes.

The first three bytes in the illustrated example provides serial number information in order to provide each treatment module or smart card with a unique and traceable serial number. The series of data blocks, in the case illustrated being 5 bytes, serve the purpose of storing, in a non-volatile manner, the treatment parameters required by the driver circuit for the waveform generator in order to generate the desired therapeutic waveform. In the case illustrated, the first byte is used to establish the mark period, the second byte accommodates the space period, the third byte is the number of repetitions of mark 1 and space 1 required for the waveform block. The fourth byte may be used to establish the number of rest or non active cycles prior to repetition of the entire block, if needed. The number of repeats of the therapy required is established by byte 5.

The second group of 5 bytes is a repetitive structure that enables a differing second waveform parameter to be used in cases where a swept or mixed therapy output is desirable as described above. Byte 14, being Cycles before Report back, is used to establish the time of therapy or sub-units thereof and is executed prior to write back to the Session Counter. Byte 15 is used to establish the number of permissible session counter writes in each therapy session. Byte 16, is the current therapy Sessions Write back counter and is used to hold non-volatile the number of write backs executed during each therapy session. In usage, this byte is duplicated in an alternative byte register and held non-volatile as the duration timer for each executed session. The byte held in location 16 may be set at 256 to enable extended periods operation, or may be set to a lesser value in order to limit the total session duration. Byte 17, Treatment Pointer is the total number of therapy sessions used by the patient. Bytes 18 and 19 are used as CRC checksums and serve to validate the data storage to assure that therapy data has not been corrupted.

^• Patient compliance can be readily checked simply by reading the Treatment Pointer data byte, between 0 and 256 to establish the number of sessions undertaken by the patient. The Session Write Back Counter, used during actual therapy to establish session period, is duplicated serially in another register. Examination of each sessions write back counter provides information on the period of each therapy. In this manner, multi-therapies may be generated simply and easily, the number of treatment sessions and the duration of each session can be used to provide accurate and readily usable information on actual patient usage. Alternatively, empty or currently unused memory locations within the memory module may be used for storage of information regarding the operations executed by the device, the type of therapy administered and actual usage time. In either event, efficacy may be compared with such functional log and an accurate means may be provided over refining and further improving therapy outcomes without the need for supervision, documented note and other patient management systems.

The therapy device and method is not limited in its application to therapy for osteoarthritis. Figure 5 shows an embodiment in which the therapy device is a tibial fracture bone growth stimulation device. The driver circuitry and other modules may be enclosed in an encloser 31 which may include an LCD display 32, LED indicators 33, and a manually operated start/stop button 34. Smart card or chip card receptacle 35 may provide a finger grip for ease of insertion and withdrawal of smart card or chip card 36, which may - but need not necessarily be - inserted into enclosure 31. The embodiment includes a wearable neoprene orthotic 37 incorporating a PEMF inductor coil or coil(s) which may encircle the region requiring therapy and hold the entire device stable. Power jack 38 may be provided for supply of external power for operation of the device or recharge of the battery. The device may be powered by an internal battery.

Operation of the device proceeds in accordance with instructions incorporated within the therapy card 36. Although the invention has been described with respect to methods and devices for PEMF therapy, there is no reason to restrict the invention to such applications.

Therefore, in a further aspect, the present invention provides a method of operation of a medical device wherein operation of the device is automatically managed in accordance with a stage of therapy of the patient.

In a still further aspect, the present invention provides a medical device comprising a driver circuit, a power supply and a data storage means wherein operation of the device is controlled in response to data stored in the data storage means. Preferred features of the method and device of the preceding aspects of the invention may be the same, the necessary modifications being made to allow for therapy other than PEMF therapy, as those described above in relation to PEMF therapy. That is, for example, the data storage means may be a smart card or the like. Operation of the device may occur in accordance with data stored on the data storage means without patient or practitioner intervention.

Compliance and progress of therapy may be monitored in a manner substantially in accordance with that described above.

As an example of the manner in which the above aspects of the invention may be employed, the medical device may be an infusion pump. It may be desirable to provide a patient with a means of administering certain infusion medication on an unsupervised home care basis. The data storage means being a smart card or the like may be programmed with information, for example, pertaining to the dose rate and permitted frequency of application, the timing of each application in addition to security features as described above. In such a case, the memory card may be programmed with a medication prescription along with an encrypted algorithm for purposes of verifying the patient prior to medication delivery. In such case, the memory card and the infusion pump device, pre-loaded with medication, may be presented to the patient for self administration at home. Upon insertion of the card into the infusion pump device, and the passing of initial security and verification tests as mentioned previously, the device, under the instructions programmed on the card may request the input of a secret or unique patient ID or pin number. In such case, software installed within the infusion pump, for example in the form of a microprocessor, would decrypt the input pin and compare this with the recorded pin held secure and non-volatile on the card. In this manner, unauthorised use of the device may be avoided and security even further enhanced.

After successfully passing any number of security systems that may be desirable to be deployed, the card would transfer data to the microprocessor. The microprocessor software provides signals, e.g electrical current, to the driver circuit, say a servo for the motor of the pump, in a manner above described its initial operational instructions which may, but not essentially, include information of dosage, duration and repetition rate. If deemed desirable, the device may read from the card information relating to time of day for administration and in this manner the device may sound an alarm to notify the user that administration of medication is required. The infusion pump may then write back to the card any medication information for later retrieval and, in this manner, therapy programs may later be modified to further improve efficacy. At the completion of a predetermined number of medication applications, the card or the device may inform patients that they should return the device and card to the prescribing physician for further consultation. In this manner, the present invention provides means by which medical therapy may be administered securely and without need for manual manipulation of controls on an infusion pump.

The above embodiments of the present invention are provided for the purposes of illustration only and are not intended to be restrictive of the scope of the invention. Modification and variation may be apparent to those skilled in the art and form part of the present invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A method of treatment of a disorder of tissues comprising application to tissues of a patient of pulsed electromagnetic fields at extremely low frequency, the waveform of the electromagnetic field being automatically managed in accordance with a stage of therapy.

2. The method of claim 1 wherein said pulsed electromagnetic field is applied to a region of a body afflicted with the disorder.

3. The method of claim 1 or 2 wherein said waveform takes the form of a complex, mixed or serially progressive waveform.

4. The method of any one of claims 1 to 3 wherein said waveform is automatically modified at a given stage of therapy.

5. The method of claim 4 wherein said given stage of therapy is defined by a predetermined parameter selected from the group consisting of therapy periods, sessions, treatments, cycles, treatment time and any combination of at least two of said parameters.

6. The method of any one of claims 1 to 5 wherein a chondroactive waveform is employed in an initial stage of therapy.

7. The method of any one of claims 1 to 5 wherein an angioactive waveform is employed in an initial stage of therapy.

8. The method of claims 1 to 5 wherein an angioactive waveform is employed in combination with a chondroactive waveform in an initial stage of therapy.

9. The method of any one of claims 6 to 8 wherein the waveform is modified to an osteoactive waveform in a later stage of therapy.

10. The method of any one of claims 1 to 5 wherein a combination of at least two waveforms selected from the group selected from angioactive, chondroactive and osteoactive waveforms is employed during a therapy stage.

11. The method of claim 11 wherein modification of said waveform from one form to another occurs without patient or practitioner intervention.

12. The method of any one of claims 1 to 11 wherein a waveform is generated in response to a parameter selected from desired pulse width, duration, frequency, amplitude and duty cycle, at least one of said parameters being automatically modified in accordance with a stage of therapy.

13. The method of claim 12 wherein modification occurs during a session of therapy.

14. The method of claim 13 wherein modification occurs in a serially progressive manner.

15. The method of any one of claims 1 to 14 applied to the treatment of osteoarthritis.

16. The method of any one of claims 1 to 14 applied to the treatment of a soft tissue condition.

17. The method of any one of claims 1 to 14 applied to the treatment of a muscular disorder or injury.

18. The method of any one of claims 1 to 14 applied to the treatment of skeletal disorder or injury.

19. The method of claim 18 wherein said disorder or injury is a tibial fracture.

20. The method of any one of claims 1 to 19 wherein treatment undergone by the patient is automatically monitored.

21. An electromagnetic therapy device producing pulsed electromagnetic fields comprising an extremely low frequency pulsed electromagnetic field inductor to generate and administer extremely low frequency electromagnetic field therapy to a region of the body for therapy, a power supply and a waveform generator electrically connected to the inductor for energising the same and a data storage means wherein an extremely low frequency pulsed electromagnetic field therapy is generated in response to data stored in the data storage means.

22. The device of claim 21 wherein said data storage means is memory module.

23. The device of claim 21 or 22 wherein said data storage means is portable.

24. The device of claim 23 wherein said data storage means is selected from the group consisting of smart cards, memory cards, integrated circuit cards and chip cards.

25. The device of any one of claims 22 to 24 comprising means to transfer data between said memory module and a driver circuit for said waveform generator.

26. The device of claim 25 wherein said waveform generator generates waveforms in response to instructions in said memory module.

27. The device of claim 26 wherein said waveform generator generates a modified waveform in response to instructions in said memory module.

28. The device of any one of claims 21 to 27 wherein said memory module is programmed with data selected from the group consisting of patient identity, session attendance, actual device usage, duration of therapy and waveform generating parameters.

29. The device of any one of claims 21 to 28 wherein said memory module is programmed with data for matching a patient with said device.

30. The device of any one of claims 1 to 29 wherein said memory module is programmed with data concerning therapy undergone by a patient for monitoring purposes.

31. The device of any one of claims 28 to 30 wherein data programmed in the memory module is modified in accordance with a given stage of therapy.

32. The device of claim 31 wherein said given stage of therapy is defined by a predetermined parameter selected from the group consisting of therapy periods, sessions, treatments, cycles, treatment time and any combination of at least two of said parameters.

33. The device of claim 32 wherein said memory module is provided with a counter to determine said stage of therapy.

34. The device of claim 33 wherein a waveform is modified in response to a predetermined counter value.

35. The device of any one of claims 21 to 34 wherein a waveform is modified during a therapy session in response to modification of data stored in said data storage means without intervention.

36. The device of any one of claims 21 to 35 wherein waveform generator generates a waveform in response to a parameter stored in said memory module, said parameter being selected from the group of desired pulse width, duration, frequency, amplitude and duty cycle and combinations thereof.

37. The device of claims 36 wherein at least one of the waveform parameters are modified in accordance with a stage of therapy.

38. The device of any one of claims 21 to 37 wherein the waveform generates waveforms selected from the group consisting of chondroactive, angioactive and osteoactive waveforms and combinations thereof without patient or practitioner intervention.

39. The device as claimed in claim 28 or 29 wherein said data is verified by data verification means in a therapy session.

40. The device as claimed in any one of claims 21 to 39 wherein said memory module is programmed with data in the absence of a patient.

41. The device as claimed in claim 24 wherein said card is of non-contact type.

42. A memory module programmed with instructions for the operation of a medical therapy device without manual manipulation of device controls during a therapy session.

43. The memory module of claim 42 wherein said medical therapy device is an extremely low frequency pulsed electromagnetic field therapy device.

44. The memory module of claim 42 wherein said medical therapy device is an infusion pump.

45. The memory module of claims 42 to 44 being selected from the group consisting of a smart card, memory card, integrated circuit card and chip card.

46. A method of operation of a medical device wherein operation of the device is automatically managed in accordance with a stage of therapy.

47. The method of claim 46 wherein therapy is delivered in accordance with predetermined parameters.

48. The method of claim 47 wherein said predetermined parameters are modified in accordance with a stage of therapy.

49. A medical device comprising a driver circuit to operate the device, a power supply and a data storage means wherein operation of the device is controlled in response to data stored in the data storage means.

50. The medical device of claim 49 being an infusion pump.

51. The device of claim 49 or 50 wherein said data storage means is a memory module.

52. The device of any one of claims 49 to 51 wherein said data storage means is portable.

53. The device of claim 52 wherein said data storage means is selected from the group consisting of smart cards, memory cards, integrated circuit cards and chip cards.

54. The device of any one of claims 49 to 53 comprising means to transfer data between said memory module and said driver circuit.

55. The device of claim 54 wherein said data transfer means provides signals to said driver circuit to operate the device in response to data stored in said memory module.

56. The device of claim 55 wherein said memory module is programmed with data to operate the device selected from the group consisting of patient identity, session attendance, actual device usage, dose rate and duration of therapy.

57. The device of any one of claims 49 to 56 wherein said memory module is programmed with data for matching a patient with said device.

58. The device of any one of claims 49 to 57 wherein said memory module is programmed with data concerning therapy undergone by a patient for monitoring purposes.

59. The device of any one of claims 56 to 58 wherein data programmed in the memory module is modified in accordance with a given stage of therapy.

60. The device of claim 59 wherein said given stage of therapy is defined by a predetermined parameter selected from the group consisting of therapy periods, sessions, treatments, cycles, treatment time and any combination of at least two of said parameters.

61. The device of claim 60 wherein said memory module is provided with a counter to determine said given stage of therapy.

62. The device of claim 60 or 61 wherein signals provided to said driver circuit are modified in accordance with said given stage of therapy.

63. The device of any one of claims 49 to 62 wherein operation of the device is modified in response to modification of data stored in said data storage means without patient or practitioner intervention.

64. The device of any one of claims 49 to 63 incorporating an orthotic device.

65. The device of claim 64 wherein said orthotic device incorporates an inductor.