WO1990006152A1 - Control of fns variations of response emg - Google Patents

Control of fns variations of response emg Download PDF

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Publication number
WO1990006152A1
WO1990006152A1 PCT/US1989/005385 US8905385W WO9006152A1 WO 1990006152 A1 WO1990006152 A1 WO 1990006152A1 US 8905385 W US8905385 W US 8905385W WO 9006152 A1 WO9006152 A1 WO 9006152A1
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WIPO (PCT)
Prior art keywords
emg
response
time
fns
pattern
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Application number
PCT/US1989/005385
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French (fr)
Inventor
Daniel Graupe
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Sigmedics, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by Sigmedics, Inc. filed Critical Sigmedics, Inc.
Priority to DE68926243T priority Critical patent/DE68926243T2/en
Priority to EP90900525A priority patent/EP0446271B1/en
Publication of WO1990006152A1 publication Critical patent/WO1990006152A1/en

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    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/24Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
    • A61B5/316Modalities, i.e. specific diagnostic methods
    • A61B5/389Electromyography [EMG]
    • A61B5/395Details of stimulation, e.g. nerve stimulation to elicit EMG response
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/24Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
    • A61B5/316Modalities, i.e. specific diagnostic methods
    • A61B5/389Electromyography [EMG]
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61NELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00Electrotherapy; Circuits therefor
    • A61N1/18Applying electric currents by contact electrodes
    • A61N1/32Applying electric currents by contact electrodes alternating or intermittent currents
    • A61N1/36Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
    • A61N1/36003Applying electric currents by contact electrodes alternating or intermittent currents for stimulation of motor muscles, e.g. for walking assistance

Definitions

  • the stimulated muscles produce an EMG (electromyographic) signal at the stimulated site, in response to that stimulation, even in paralyzed parts of the body.
  • This response-EMG undergoes pattern changes with the progression of muscle fatigue.
  • the present invention employs pattern recognition of the response-EMG where pattern parameters are identified whose variation with time is a function of the progression of muscle fatigue. This time variation is employed to automatically adjust FNS pulse width and/or pulse level to compensate for that fatigue in an automatic manner that does not require the patient's attention. Additional embodiments of the present invention provide for diagnostic uses of this pattern recognition, and for muscle contractions other than for standing or walking.
  • FIGS. 2(a) and 2(b) illustrate two patterns of typical response-EMG signals at FNS-stimulated quadricep muscles
  • FIGS. 3(a) and 3(b) illustrate response-EMG waveforms before and after fatigue.
  • the EMG Pattern Recognition Subsystem 60 analyzes the Response EMG signals, as discussed hereinafter, and outputs a first control signal 66, coupled to a FNS Level/Pulse Width Controller 50, which responsive thereto outputs a second control signal 55, coupled to the FNS Stimulator Subsystem 40.
  • the FNS Stimulator 40 automatically adjusts the level and/or pulse width of the FNS signal outputs 41, 42, 43 and 44 responsive to the second control signal 55 as output from the FNS Controller 50.
  • EMG signals are sensed from stimulated muscles as a response-EMG signal.
  • the dynamic pattern of the response-EMG signals are repeatedly monitored over time and analyzed.
  • a finite set of parameters associated with the pattern and capable of indicating a propensity of fatigue are analyzed.
  • the control signal is provided to the FNS stimulator subsystem so as to modify the FNS stimuli coupled to the FNS electrodes so as to prevent fatigue.
  • the finite set of parameters can be determined in accordance with a least squares polynomial fit to the response-EMG signal such as defined in Chapter 5 of Reference [6] set forth in the Background of the Invention herein.
  • an improved system and method overcomes loss of balance with the progress of muscle fatigue, by using response-EMG control of FNS in paraplegics who are standing or walking with a cane or walker or elbow- crutch support.
  • the importance of such control in paraplegics is obvious, since paraplegics have no sensation of muscle fatigue.
  • muscle fatigue has already caused loss of balance, in terms of knee bending, it is too late for the patient to adjust FNS levels or pulse width to strengthen stimulation.
  • the patient cannot take his hands off his walker or crutches to adjust the FNS level or pulse width, nor can he even afford to divert his attention to perform such an adjustment.
  • EMG control of FNS has been proposed using EMG signals from the stimulated muscles (i.e. "response-EMG") where the first or second peak of the EMG signal is employed.
  • response-EMG EMG signals from the stimulated muscles
  • peaks are widely varying in value and the EMG's shape may differ from patient to patient.
  • the dynamic pattern of the response-EMG does change.
  • the present invention utilizes change in pattern recognition parameters, not maximal values or peaks.
  • changes in specified pattern recognition parameters or in area are the factor that determined fatigue.
  • area or pattern recognition parameters need peak (reach maximum) in the non-fatigued response EMG in the present invention.
  • area when area is considered they always happen (but need not) to be maximal at the non-fatigued situation.
  • Other pattern recognition parameters are not always maximal in the non-fatigued situation, but can be utilized in accordance with the present invention.

Abstract

The present invention employs FNS stimulation (40) through electrodes (21, 22, 23, 24). The response-EMG is sensed by electrodes (31, 32, 33, 34) for pattern recognition (60) of the response-EMG where pattern parameters are identified whose variation with time is a function of the progression of muscle fatigue. This time variation is employed to adjust FNS pulse width and/or pulse level (50) to compensate for that fatigue in an automatic manner that does not require the patient's attention. The present invention also provides for diagnostic uses of this pattern recognition, and for muscle contractions other than for standing or walking.

Description

Control of FNS Variations of Response EMG
Technical Field
This invention relates to functional neuromuscular stimulation (FNS) and more particularly to improved control of FNS.
Background Art
Paraplegic patients and certain other paralyzed patients who suffered from an upper motor unit spinal cord injury and undergo FNS (Functional Neuromuscular Stimulation) experience muscle fatigue within a time span that is usually shorter than is normal, but they have no sensation of this fatigue due to their paralysis. Furthermore, when FNS is used functionally, as is its implied purpose, to stand and walk, the patients need the support of a walker or canes or elbow crutches, and are unable to manually adjust FNS levels or pulse widths to compensate for that fatigue, since the time when such adjustment is necessary is exactly when the patients cannot divert attention and hands to anything else. Work on electrical stimulation of paraplegics has been done by this inventor and by others.
References include:
[1.] Kralj, A., Electrical Stimulation of Lower Extremities in Spinal Cord Injury, Proc. Nato Advance Studies Inst. On Spinal Cord Injuries, Stoke Mandeville, England, 1981;
[2.] Kralj, A. et al. Electrical Stimulation Providing Functional Use of Paraplegic Patients' Muscles, Med. Prog. Tech. , Vol. 1 , pp 3-9, 1980; [3.] Liberson, W.T. et al. Functional Electrical Stimulation of the Peroneal Nerve Synchronized With the Swing Phase of the Gait of Hemiplegic Patients, Arch. Phys. Med., Vol. 92, pp 101-105, 1961;
[4.] Graupe D. et al.. Patient Controlled
Electrical Stimulation Via EMG Signature Discrimination for Providing Certain Paraplegics with Primitive Walking Functions, Journal Biomed. Eny. , Vol. 5, pp 220-226, 1983;
[5.] Graupe, D. and Kohn, K.H. A Critical Review of EMG - Controlled Electrical Stimulation in Paraplegics, CRC Crit. Rev. in Biomed. Eng., Vol. 15, pp 187-210, March 1987; and
[6.] Graupe, D. Identification of Systems, 2nd Edition, Krieges Publishing Co., Malabar, FL, 1976.
Additionally, the present inventor has a pending U.S. Patent Application No. 014,389. In Reference [5], this inventor has shown that the surface (transcutaneous) response EMG as taken at the vicinity of the electrical stimulation sites in response to the stimuli applied at these sites, changes with the progression of the fatigue of the stimulated muscles during electrical stimulation. Furthermore, it was explained in Reference [5] that the paraplegic patient has no sensation of his fatigue and of its progression, until his knee collapses from its extended (standing) position and bends, such that he falls down. When the patient's falling starts, the patient has no time nor has he the ability to use his hands nor his fingers to increase stimuli levels or sites of stimuli pulse width to overcome his fatigue. All he can do is at best to hold himself by his arms on the walker and thus achieve a somewhat controlled fall. The need for automatic monitoring of the muscle fatigue and of automatic (not manual) adjustment of stimulation to overcome this fatigue is therefore essential. A proposal for this adjustment is the subject matter of this inventor's U.S. Patent Application No. 014,389. In U.S. Patent Application No. 014,389 this adjustment is based on measuring and storing and comparing successive peaks in the response EMG and storing and comparing the time interval from the start of a given stimuli and the occurrence of the peak in its corresponding response EMG signal. In many cases the peak may be higher after considerable muscle fatigue has set in, than immediately after stimulation level adjustment. In other cases no peak at all is formed prior to onset of fatigue. Hence this invention also covers situations when no peaks are considered or when the highest peak is not necessarily occurring prior to onset of fatigue i.e., when lower peaks do not indicate progression of muscle fatigue.
Disclosure Of Invention Under FNS, the stimulated muscles produce an EMG (electromyographic) signal at the stimulated site, in response to that stimulation, even in paralyzed parts of the body. This response-EMG undergoes pattern changes with the progression of muscle fatigue. The present invention employs pattern recognition of the response-EMG where pattern parameters are identified whose variation with time is a function of the progression of muscle fatigue. This time variation is employed to automatically adjust FNS pulse width and/or pulse level to compensate for that fatigue in an automatic manner that does not require the patient's attention. Additional embodiments of the present invention provide for diagnostic uses of this pattern recognition, and for muscle contractions other than for standing or walking.
The present invention is especially beneficial for upper motor neuron paraplegic patients, certain guadraplegics, stoke patients and cerebral palsy patients.
In accordance with the present invention, an improved system and method of automated control of Functional Neuromuscular Stimulation (FNS) is provided for responsive to pattern variations of the Response-EMG (electromyographic) signal produced by the muscle in response to the FNS.
Brief Description Of Drawings
The present invention can be more clearly understood by reference to the detailed description in conjunction with the drawings, wherein:
FIG. 1 illustrates a response-EMG controlled FNS system coupled to a patient,
FIGS. 2(a) and 2(b) illustrate two patterns of typical response-EMG signals at FNS-stimulated quadricep muscles, and
FIGS. 3(a) and 3(b) illustrate response-EMG waveforms before and after fatigue.
Modes For Carrying Out the Invention
Referring to FIG. 1, a paraplegic patient 10 has electrodes 21, 22, 23 and 24 and sensors 31, 32, 33 and 34, attached to his (or her) legs 12, such as by an electrode gel. Electrodes 21, 22, 23 and 24 are coupled by electrical leads 41, 42, 42 and 44, respectively, to an FNS stimulator 40. Sensors 31/ 32, 33 and 34 are also attached to the patients leg 12, such as by an electrode gel, and are coupled via electrical leads 61, 62, 63 and 64 respectively, to an EMG Pattern Recognition Subsystem 60. The sensors 31 to 34 provide Response-EMG signals for coupling to the EMG Pattern Recognition Subsystem 60. The EMG Pattern Recognition Subsystem 60 analyzes the Response EMG signals, as discussed hereinafter, and outputs a first control signal 66, coupled to a FNS Level/Pulse Width Controller 50, which responsive thereto outputs a second control signal 55, coupled to the FNS Stimulator Subsystem 40. The FNS Stimulator 40 automatically adjusts the level and/or pulse width of the FNS signal outputs 41, 42, 43 and 44 responsive to the second control signal 55 as output from the FNS Controller 50.
Thus, FIG. 1 illustrates a functional neuromuscular stimulation system. The FNS electrodes 21-24 are coupled to the skin at the vicinity of a muscle to be stimulated. The FNS stimulation subsystem selectively outputs FNS stimulus signals 41 to 44 coupled via leads 41 to 44 to the FNS electrodes 21 to 24. The EMG electrodes 31 to 34 are coupled in the vicinity of the muscle to be stimulated, for sensing response-EMG signals responsive to the FNS stimulation subsystem. An EMG pattern recognition subsystem selectively analyzes multiple Response-EMG signals over time, and selectively provides FNS control signals 61 to 64 via electrical leads 61 to 64 responsive to recognized deviations beyond a predefined threshold level of change in patterns of the response-EMG signals, where the changes of the pattern over time are changes relative to the EMG pattern within a specified small time interval after initial application of the FNS stimuli, and after each successive readjustment of FNS stimuli.
An FNS adjustment subsystem adjusts the FNS stimulus signals responsive to changes over time in the EMG pattern as recognized by said EMG pattern recognition means, so as to prevent fatigue. The FNS and EMG electrodes are preferably attached to the surface of the skin, such as by use of an electrode gel. However, the FNS and EMG electrodes can alternatively be implanted beneath the surface of the skin. Pattern recognition can be accomplished in terms of measuring the point-wise difference over a given fixed number of points in the response-EMG voltage vs. time signals as obtained at the response- EMG electrodes between their voltage values at discrete time points immediately after any adjustment of stimulus level vs. the corresponding value at any time later when fatigue may have started to take effect. The time scales are all with respect to the time instant tQ of the initiation of each stimulus in a train of FNS stimuli, where each point considered in the two patterns that are compared is the same distance from the time instant of initiation point for each pattern. As one alternative to the above, the area differences rather than point-wise differences are considered as the selected parameter to be analyzed as between EMG patterns.
Numerous alternate systems can be constructed in accordance with the teachings of the present invention. The methodology is as follows.
FNS electrodes are attached to the patient's legs, and coupled to a FNS stimulator subsystem, which periodically outputs electrical stimuli. EMG electrodes are attached to the patient's legs, coupled to an EMG pattern recognition subsystem which analyzes the response-EMG signals and responsive thereto selectively outputs a FNS adapted control signal. The FNS stimulator subsystem outputs stimulus signals to the FNS electrodes which are modified responsive to the control signal, so as to prevent fatigue in the patient.
EMG signals are sensed from stimulated muscles as a response-EMG signal. The dynamic pattern of the response-EMG signals are repeatedly monitored over time and analyzed. A finite set of parameters associated with the pattern and capable of indicating a propensity of fatigue are analyzed. When at least one of said parameters has a significant change beyond a predetermined minimum value, indicative of fatigue, the control signal is provided to the FNS stimulator subsystem so as to modify the FNS stimuli coupled to the FNS electrodes so as to prevent fatigue. The finite set of parameters can be determined in accordance with a least squares polynomial fit to the response-EMG signal such as defined in Chapter 5 of Reference [6] set forth in the Background of the Invention herein. The finite set of parameters can be determined in terms of a transfer function fit to the response-EMG, where the response-EMG is considered as an impulse response, such that the transfer function becomes the inverse Laplace transform calculated for that impulse response which is the response-EMG pattern of EMG voltage vs. time, starting at the time instant at which the stimulus impulse is being applied by the stimulator.
Alternatively, the finite set of parameters can be determined by analysis of deviation of the response-EMG pattern from its mean over time. Alternatively, the finite set of parameters can be determined by means of analysis of said response-EMG signals by analysis of differences between successive extremes of said pattern over time.
In accordance with the present invention, an improved system and method overcomes loss of balance with the progress of muscle fatigue, by using response-EMG control of FNS in paraplegics who are standing or walking with a cane or walker or elbow- crutch support. The importance of such control in paraplegics is obvious, since paraplegics have no sensation of muscle fatigue. When muscle fatigue has already caused loss of balance, in terms of knee bending, it is too late for the patient to adjust FNS levels or pulse width to strengthen stimulation. Furthermore, when balance is lost, the patient cannot take his hands off his walker or crutches to adjust the FNS level or pulse width, nor can he even afford to divert his attention to perform such an adjustment.
Use of EMG control of FNS has been proposed using EMG signals from the stimulated muscles (i.e. "response-EMG") where the first or second peak of the EMG signal is employed. However, such peaks are widely varying in value and the EMG's shape may differ from patient to patient. But, as taught by the present invention, in all situations, the dynamic pattern of the response-EMG does change. Hence, in accordance with the present invention, pattern identification of this EMG is performed in terms of a finite set of parameters, pj^.-.p , and progression of fatigue is determined by repeatedly monitoring these parameters over time, such that when at least one significant parameter changes beyond a predetermined minimal percentage value, fatigue is considered to exist to a degree that requires automatic increase in FNS level and/or pulse width.
For example, pattern recognition can be in terms of parameters of a least squared polynomial fit to the EMG pattern or in terms of a transfer function fit. Since recognition is of differences between patterns (i.e., between patterns before and during muscle fatigue), recognition of differences can be directly implemented by measuring the point-wise difference either between the before and during curves of the response-EMG as in either of FIGS. 2(a) or 2(b) as obtained before and during muscle fatigue for successive points starting at the time of applying each stimulus to provide a time reference for comparison. In one embodiment, this can also be with respect to deviation of the pattern from its mean.
In the simplest case differences between areas under the patterns of the response-EMG before and during the progression of fatigue can be so considered.
In accordance with the present invention specific parameters of response EMG area are employed rather than peaks.
With the use of response EMG area, its integral over time clearly changes (it always decreases so the change is uni-directional) with the progression in all situations. These results have been empirically measured over several years, with examples as shown in FIG. 2.
Hence while there are many situations where peaks in the EMG signal will lead to a totally erroneous conclusion regarding fatigue, the area (integral over time) of the response-EMG always yields the correct conclusion.
Note that both the area and the peak of the response-EMG are measured from time tQ, not from time t=0, since between t-0 and t=t0, we only have the artifact of the stimulus and not the response-EMG. Note that in FIG. 3(a) the highest value of the response-EMG after t=t« is not a peak at all, whereas the local maximum (local peak) in FIG. 3(a) is below the peak of FIG. 3(b) .
The present invention utilizes change in pattern recognition parameters, not maximal values or peaks. In the case of the present invention, changes in specified pattern recognition parameters or in area are the factor that determined fatigue. Neither area or pattern recognition parameters need peak (reach maximum) in the non-fatigued response EMG in the present invention. However, when area is considered they always happen (but need not) to be maximal at the non-fatigued situation. Other pattern recognition parameters are not always maximal in the non-fatigued situation, but can be utilized in accordance with the present invention.
In all cases the controller considers the pattern before fatigue to be that response-EMG pattern (solid line in FIGS. 2(a)-2(b) obtained immediately following the first switching on of the stimulation or immediately following any increase in stimulation levels whereas the EMG pattern (dashed lines in FIGS. 2(a)-2(b)) during the progression of fatigue is considered to be any response-EMG pattern at the same electrode location at any time later. All patterns are compared as patterns of EMG voltage vs. time, where time is measured starting from the time tg at which any stimulation pulse is initiated or re-initiated by the stimulator, noting that these stimuli are applied and re-initiated at successive time intervals varying from between 20 and 50 milliseconds.
Referring to FIGS. 2(a) and 2(b), two typical Response-EMG signal waveforms, as sensed by sensors 31-34, at FNS stimulated quadricep muscles, are illustrated. Numerous other waveform patterns may also occur. The first peak in each waveform represents the FNS Stimulation Artifact. The solid line waveforms represent the response-EMG pattern under no fatigue conditions. The dashed line waveforms represent progression of muscle fatigue conditions, measured at later times, which are sensed and utilized in accordance with the present invention, as described hereinabove.
While there have been described herein various embodiments and illustrations of the present invention, it will be understood by those skilled in the art that various other embodiments and adaptations are possible. Therefore, the scope of this invention is not limited to the disclosed embodiments, but is to be construed by the broadest reading of the appended claims.

Claims

1. A functional neuromuscular stimulation system, characterized by:
FNS electrodes (21, 22, 23, 24) for coupling to the skin at the vicinity of a muscle to be stimulated;
FNS stimulation means (40) for selectively outputting FNS stimulus signals coupled to said FNS electrodes;
Stimulus-Response-EMG electrodes (31, 32, 33, 34) for coupling in the vicinity of said muscle to be stimulated, for sensing Response-EMG signals responsive to said FNS -stimulation means;
EMG pattern recognition means (60) for recognition of fatigue patterns for selectively analyzing multiple Response-EMG signals and for selectively providing FNS control signals responsive to recognized deviations beyond a predefined threshold level of change in patterns of said Response-EMG signals wherein said changes of said pattern over time are changes relative to the EMG reference pattern which is the EMG pattern within a specified small time interval after initial application of the FNS stimuli, and after each successive readjustment of FNS stimuli; and
FNS adjustment means (50) for automatically adjusting the FNS stimulus signals responsive to the pattern recognition means responsive to changes over time in the EMG pattern as recognized by said EMG pattern recognition means, so as to prevent fatigue.
2. The system according to claim 1 further characterized by said FNS electrodes are for coupling to the surface of the skin.
3. The system according to claim 1 further characterized by said FNS and EMG electrodes are for implantation beneath the surface of the skin.
4. The system according to claim 1 further characterized by said EMG electrodes are for coupling to the surface of the skin.
5. The system according to claim 1 further characterized by said EMG electrodes are for implantation beneath the surface of the skin.
6. The system according to claim 1 further characterized by said adjustment means provides for adjustment of FNS signals by adjusting FNS stimuli pulse width.
7. The system according to claim 1 further characterized by said adjustment means provides for adjustment of FNS signals by adjusting FNS stimuli amplitudes.
8. The system according to claim 1 further characterized by pattern recognition is in terms of measuring the point wise difference over a given fixed number of points in the Response-EMG voltage vs. time signals as obtained at the Response-EMG electrodes between their voltage values at discrete time points immediately after any adjustment of stimulus level vs. the corresponding value at any time later when fatigue may have started to take an effect, wherein the.time scales are all with respect to the time instant of the initiation of each stimulus in a train of FNS stimuli, and wherein each point considered in the two patterns that are compared is the same distance from the time instant of initiation point for each pattern.
9. The system according to claim 1 further characterized by pattern recognition is in terms of measuring the area differences over a given fixed number of points in the Response-EMG voltage vs. time signals as obtained at the Response-EMG electrodes between their voltage values at discrete time points immediately after any adjustment of stimulus level vs. the corresponding value at any time later when fatigue may have started to take an effect, wherein the time scales are all with respect to the time instant of the initiation of each stimulus in a train of FNS stimuli, and wherein each point considered in the two patterns that are compared is the same distance from the time instant of initiation point for each pattern.
10. A method of functional neuromuscular stimulation, characterized by:
Electrically stimulating selected muscles;
Sensing Response-EMG signals from said stimulated muscles;
Repeatedly monitoring over time and analyzing the dynamic pattern of the Response-EMG signals;
Identifying a finite set of parameters associated with said pattern;
Detecting when at least one of said parameters has a significant change behond a predetermined minimum value; and
Adjusting said electrical stimulation responsive to said detecting.
11. The method according to claim 10 further characterized by said finite set of parameters are determined in accordance with a least squares polynomial fit to the Response-EMG signal.
12. The method according to claim 10 further characterized by said finite set of parameters is determined in terms of a transfer function fit to the Response-EMG, where the Response-EMG is considered as an impulse response, such that the transfer function becomes the inverse Laplace transform calculated for that impulse response which is the Response-EMG pattern of EMG voltage vs. time, starting at the time instant at which the stimulus impulse is being applied by the stimulator.
13. The method according to claim 10 further characterized by said finite set of parameters is determined by analysis of deviation of the Response- EMG pattern from its mean over time.
14. A functional neuromuscular stimulation system, characterized by: means for selectively and adjustably electrically stimulating selected muscles; means for sensing Response-EMG signals from said stimulated muscles; means for repeatedly monitoring over time and analyzing the dynamic pattern of the Response-EMG signals; means for identifying a finite set of parameters associated with said pattern; means for detecting when at least one of said parameters has a significant change beyond a predetermined minimum value; and means for automatically modifying said electrical stimulation so as to prevent fatigue in said stimulated muscle, responsive to said means for detecting.
15. The system according to claim 14 further characterized by said finite set of parameters are determined in accordance with a least squares polynomial fit to the Response-EMG signal.
16. The system according to claim 14 further characterized by said finite set of parameters is determined in terms of a transfer function fit to the Response-EMG, where the Response-EMG is considered as an impulse response, such that the transfer function becomes the inverse Laplace transform calculated for that impulse response which is the Response-EMG pattern of EMG voltage vs. time, starting at the time instant at which the stimulus impulse is being applied by the stimulator.
17. The system according to claim 14 further characterized by said electrical stimulation is comprised of a plurality of pulses having definable electrical characteristics of voltage level, duration and time spacing, wherein said means for modifying is further comprised of: means for varying at least one of said electrical characteristics responsive to said means for detecting.
18. The system according to claim 14 further characterized by said means for identifying is further comprised of: means for selecting a voltage versus time varying signal characteristic as a selected parameter of said Response-EMG signal, which characteristic, changes in a detectable manner indicating the propensity for muscle fatigue conditions in said stimulated muscle, said system further characterized wherein said means for detecting is responsive to said selected parameter.
19. A diagnostic neuromuscular system, characterized by:
EMG electrodes for coupling in the vicinity of a muscle, for sensing Response-EMG signals from said muscle; and
EMG pattern recognition means for selectively analyzing multiple Response-EMG signals and for selectively providing control signals responsive to recognized deviations beyond a predefined threshold level of change in patterns of said Response-EMG signals wherein said changes of said pattern over time are changes relative to the Response-EMG pattern within a specified small time interval after an initial time.
20. The system according to claim 19 further characterized by pattern recognition is in terms of measuring the point wise difference over a given fixed number of points in the Response-EMG voltage vs. time signals as obtained at the Response-EMG electrodes between their voltage values at discrete time points immediately after any said initial time reference vs. the corresponding value at any time later when fatigue may have started to take an effect, wherein the time scales are all with respect to the time instant of the initiation, and wherein each point considered in the two patterns that are compared is the same distance from the time instant of initiation point for each pattern.
21. The system according to claim 19 further characterized by pattern recognition is in terms of measuring the area difference over a given fixed number of points in the Response-EMG voltage vs. time signals as obtained at the Response-EMG electrodes between their voltage values at discrete time points immediately after any said initial time reference vs. the corresponding value at any time later when fatigue may have started to take an effect, wherein the time scales are all with respect to the time instant of the initiation, and wherein each point considered in the two patterns that are compared is the same distance from the time instant of initiation point for each pattern.
PCT/US1989/005385 1988-11-29 1989-11-28 Control of fns variations of response emg WO1990006152A1 (en)

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DE68926243T DE68926243T2 (en) 1988-11-29 1989-11-28 CONTROL OF A FUNCTIONAL NERVOUS STIMULATOR DEPENDING ON CHANGES IN EMG REACTION SIGNALS
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US07/277,323 US5016635A (en) 1988-11-29 1988-11-29 Control of FNS via pattern variations of response EMG

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0512018A1 (en) * 1989-04-07 1992-11-11 Sigmedics, Inc. Stimulator for surface stimulation in paralyzed patients
US11864898B2 (en) 2020-11-06 2024-01-09 Myocene Muscle fatigue determination method and system

Families Citing this family (72)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5300096A (en) * 1992-06-03 1994-04-05 Hall H Eugene Electromyographic treatment device
EP0700658B1 (en) * 1994-09-10 1999-11-03 Hewlett-Packard GmbH A device and a method for equalizing a patient's potential with respect to medical equipment
WO1997004705A1 (en) * 1995-07-31 1997-02-13 Motorola Inc. Hybrid fes and active orthosis method and system for controlling the movement of a limb
US5748845A (en) * 1995-07-31 1998-05-05 Motorola, Inc. FES method and system for controlling the movement of a limb
JP2000507111A (en) * 1995-08-04 2000-06-13 オリヴェ,ホセ ハビエル ロディエラ Method and apparatus for monitoring and / or regulating neuromuscular blockade, particularly blockade caused by muscle relaxants used during anesthesia
US5674262A (en) * 1996-01-26 1997-10-07 Kinetic Concepts, Inc. Pneumatic compression and functional electric stimulation device and method using the same
US7324851B1 (en) 1998-08-05 2008-01-29 Neurovista Corporation Closed-loop feedback-driven neuromodulation
US9375573B2 (en) 1998-08-05 2016-06-28 Cyberonics, Inc. Systems and methods for monitoring a patient's neurological disease state
US6366813B1 (en) 1998-08-05 2002-04-02 Dilorenzo Daniel J. Apparatus and method for closed-loop intracranical stimulation for optimal control of neurological disease
US9320900B2 (en) 1998-08-05 2016-04-26 Cyberonics, Inc. Methods and systems for determining subject-specific parameters for a neuromodulation therapy
US9042988B2 (en) 1998-08-05 2015-05-26 Cyberonics, Inc. Closed-loop vagus nerve stimulation
US7231254B2 (en) 1998-08-05 2007-06-12 Bioneuronics Corporation Closed-loop feedback-driven neuromodulation
US7403820B2 (en) * 1998-08-05 2008-07-22 Neurovista Corporation Closed-loop feedback-driven neuromodulation
US7747325B2 (en) 1998-08-05 2010-06-29 Neurovista Corporation Systems and methods for monitoring a patient's neurological disease state
US9415222B2 (en) 1998-08-05 2016-08-16 Cyberonics, Inc. Monitoring an epilepsy disease state with a supervisory module
US8762065B2 (en) 1998-08-05 2014-06-24 Cyberonics, Inc. Closed-loop feedback-driven neuromodulation
US7209787B2 (en) 1998-08-05 2007-04-24 Bioneuronics Corporation Apparatus and method for closed-loop intracranial stimulation for optimal control of neurological disease
US7242984B2 (en) 1998-08-05 2007-07-10 Neurovista Corporation Apparatus and method for closed-loop intracranial stimulation for optimal control of neurological disease
US7277758B2 (en) 1998-08-05 2007-10-02 Neurovista Corporation Methods and systems for predicting future symptomatology in a patient suffering from a neurological or psychiatric disorder
JP2002524124A (en) * 1998-09-04 2002-08-06 ウルフ リサーチ プロプライエタリー リミテッド Medical implantation system
US6411843B1 (en) 1999-05-28 2002-06-25 Respironics, Inc. Method and apparatus for producing a model EMG signal from a measured EMG signal
GB9922153D0 (en) * 1999-09-21 1999-11-17 Hutton Harry T A telemetry system for monitoring nerve patterns and dynamically inducing physiological responses based on the intelligent adaptive mapping of nerve pattern r
EP1307137A1 (en) * 2000-08-14 2003-05-07 Neopraxis Pty Ltd An exercise apparatus for a person with muscular deficiency
EP1309275A4 (en) * 2000-08-14 2005-02-02 Neopraxis Pty Ltd Muscle fatigue meter
US6644976B2 (en) 2001-09-10 2003-11-11 Epoch Innovations Ltd Apparatus, method and computer program product to produce or direct movements in synergic timed correlation with physiological activity
US6829510B2 (en) * 2001-12-18 2004-12-07 Ness Neuromuscular Electrical Stimulation Systems Ltd. Surface neuroprosthetic device having an internal cushion interface system
AU2002323810A1 (en) * 2002-08-05 2004-02-23 Japan As Represented By President Of National Cardiovascular Center Medical treatment system using biological regulation function alternate, cardiac pacing system based on the medical treatment system, blood pressure regulating system, and cardiac disease treating system
US8868172B2 (en) 2005-12-28 2014-10-21 Cyberonics, Inc. Methods and systems for recommending an appropriate action to a patient for managing epilepsy and other neurological disorders
US8725243B2 (en) 2005-12-28 2014-05-13 Cyberonics, Inc. Methods and systems for recommending an appropriate pharmacological treatment to a patient for managing epilepsy and other neurological disorders
US20070213796A1 (en) * 2006-03-10 2007-09-13 Mcginnis William J Ring electrode
EP2586489B1 (en) 2006-05-01 2014-12-24 Bioness Neuromodulation Ltd Improved functional electrical stimulation systems
EP2034885A4 (en) 2006-06-23 2010-12-01 Neurovista Corp Minimally invasive monitoring systems and methods
US8295934B2 (en) 2006-11-14 2012-10-23 Neurovista Corporation Systems and methods of reducing artifact in neurological stimulation systems
WO2008092119A2 (en) 2007-01-25 2008-07-31 Neurovista Corporation Systems and methods for identifying a contra-ictal condition in a subject
EP2124734A2 (en) * 2007-01-25 2009-12-02 NeuroVista Corporation Methods and systems for measuring a subject's susceptibility to a seizure
US8036736B2 (en) 2007-03-21 2011-10-11 Neuro Vista Corporation Implantable systems and methods for identifying a contra-ictal condition in a subject
CA2685251A1 (en) * 2007-05-04 2008-11-13 Arizona Board Of Regents For And On Behalf Of Arizona State University Systems and methods for wireless transmission of biopotentials
US9788744B2 (en) 2007-07-27 2017-10-17 Cyberonics, Inc. Systems for monitoring brain activity and patient advisory device
US8439845B2 (en) 2007-09-25 2013-05-14 Uroval, Inc. Obtaining measurements of muscle reflexes for diagnosis of patient symptoms
US8444571B2 (en) 2007-09-25 2013-05-21 Uroval, Inc. Obtaining measurements of muscle reflexes for diagnosis of patient symptoms
US9730605B2 (en) 2007-09-25 2017-08-15 Uroval, Inc. Diagnosis of brain and spinal cord injury by bulbocavernosus reflex measurement
US20090171168A1 (en) 2007-12-28 2009-07-02 Leyde Kent W Systems and Method for Recording Clinical Manifestations of a Seizure
US9259591B2 (en) 2007-12-28 2016-02-16 Cyberonics, Inc. Housing for an implantable medical device
US8892210B2 (en) 2008-07-02 2014-11-18 Niveus Medical, Inc. Devices, systems, and methods for automated optimization of energy delivery
US8285381B2 (en) * 2008-07-02 2012-10-09 Niveus Medical, Inc. Systems and methods for automated muscle stimulation
US8265763B2 (en) * 2008-08-26 2012-09-11 Niveus Medical, Inc. Device, system, and method to improve powered muscle stimulation performance in the presence of tissue edema
US9149386B2 (en) 2008-08-19 2015-10-06 Niveus Medical, Inc. Devices and systems for stimulation of tissues
US8849390B2 (en) 2008-12-29 2014-09-30 Cyberonics, Inc. Processing for multi-channel signals
US8588933B2 (en) 2009-01-09 2013-11-19 Cyberonics, Inc. Medical lead termination sleeve for implantable medical devices
ES2683997T3 (en) 2009-02-10 2018-10-01 Nevro Corporation System for administering neural therapy correlated with the patient's condition
AU2010215784B2 (en) * 2009-02-20 2015-04-30 Sage Products, Llc Systems and methods of powered muscle stimulation using an energy guidance field
US8786624B2 (en) 2009-06-02 2014-07-22 Cyberonics, Inc. Processing for multi-channel signals
US8498710B2 (en) 2009-07-28 2013-07-30 Nevro Corporation Linked area parameter adjustment for spinal cord stimulation and associated systems and methods
WO2011060056A2 (en) 2009-11-11 2011-05-19 Niveus Mediacl, Inc. Synergistic muscle activation device
US9643019B2 (en) 2010-02-12 2017-05-09 Cyberonics, Inc. Neurological monitoring and alerts
US20120245482A1 (en) * 2010-09-16 2012-09-27 Bolser Jeffrey W Anesthesia Monitoring Device and Method
US9380978B2 (en) * 2011-06-29 2016-07-05 Bruce Reiner Method and apparatus for real-time measurement and analysis of occupational stress and fatigue and performance outcome predictions
US20140074187A1 (en) * 2012-04-23 2014-03-13 Medtronic, Inc. Electrode selection based on current source density analysis
US9731133B1 (en) 2013-01-22 2017-08-15 Nevro Corp. Systems and methods for systematically testing a plurality of therapy programs in patient therapy devices
US9295840B1 (en) 2013-01-22 2016-03-29 Nevro Corporation Systems and methods for automatically programming patient therapy devices
US9895538B1 (en) 2013-01-22 2018-02-20 Nevro Corp. Systems and methods for deploying patient therapy devices
CA2866025A1 (en) 2013-10-03 2015-04-03 Quiang Song Sensor unit for a functional electrical stimulation (fes) orthotic system
CA2866028A1 (en) 2013-10-03 2015-04-03 Farsad Kiani Electrical stimulation for a functional electrical stimulation system
US9375569B2 (en) 2013-10-03 2016-06-28 Ensilver Canada Controller unit for a functional electrical stimulation (FES) orthotic system
US9867985B2 (en) 2014-03-24 2018-01-16 Bioness Inc. Systems and apparatus for gait modulation and methods of use
DK3173124T3 (en) * 2014-07-23 2020-04-14 System Instruments Co Ltd ELECTRIC STIMULATION EQUIPMENT AND EXERCISE
US9364657B2 (en) 2014-10-31 2016-06-14 Ensilver Canada Cuff unit for a functional electrical stimulation system
US10300277B1 (en) 2015-12-14 2019-05-28 Nevro Corp. Variable amplitude signals for neurological therapy, and associated systems and methods
JP6771154B2 (en) * 2016-01-07 2020-10-21 パナソニックIpマネジメント株式会社 Fall risk judgment device, how to operate the fall risk judgment device, and computer program
WO2017123608A1 (en) 2016-01-11 2017-07-20 Bioness Inc. Systems and apparatus for gait modulation and methods of use
US10722745B2 (en) 2018-06-05 2020-07-28 The Chinese University Of Hong Kong Interactive cycling system and method of using muscle signals to control cycling pattern stimulation intensity
CN112773380B (en) * 2019-11-07 2023-09-22 深圳市理邦精密仪器股份有限公司 Myoelectric signal processing method, processing equipment and storage medium

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4213467A (en) * 1978-08-11 1980-07-22 Harvard College, President And Fellows Monitoring myoelectric signals
US4291705A (en) * 1979-09-10 1981-09-29 The Regents Of The University Of California Neuromuscular block monitor
US4361559A (en) * 1981-08-20 1982-11-30 E. R. Squibb & Sons, Inc. Antiinflammatory 17,17-bis (substituted thio) androstenes
US4622973A (en) * 1984-06-15 1986-11-18 Empi, Inc. Programmable functional electrical stimulation system
US4669477A (en) * 1985-05-20 1987-06-02 Empi, Inc. Apparatus and method for preventing bruxism
US4805636A (en) * 1986-02-24 1989-02-21 The University Of Michigan System for controlling muscle response
US4753246A (en) * 1986-03-28 1988-06-28 The Regents Of The University Of California EEG spatial filter and method
US4750499A (en) * 1986-08-20 1988-06-14 Hoffer Joaquin A Closed-loop, implanted-sensor, functional electrical stimulation system for partial restoration of motor functions
US4838272A (en) * 1987-08-19 1989-06-13 The Regents Of The University Of California Method and apparatus for adaptive closed loop electrical stimulation of muscles

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
"Electromyographic Control of Functional Electrical Stinulation in Selected Patients" by D. GRAUPE et al, published in Orthopedics, Vol. 7, July 1984, pgs 1134-1138. See entire document. *
"EMG Response to Electrical Stimulation of Quadriceps in Upper-Moter-Neuron Paraplegics and its Employment to control levels of Stimulation at onset of Fatigue", GRAUPE et al, The Journal of Orthopedic Surgical Techniques, Vol. 2, No. 1, 1986, pg 61. *
See also references of EP0446271A4 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0512018A1 (en) * 1989-04-07 1992-11-11 Sigmedics, Inc. Stimulator for surface stimulation in paralyzed patients
EP0512018A4 (en) * 1989-04-07 1992-12-30 Sigmedics, Inc. Stimulator for surface stimulation in paralyzed patients
US11864898B2 (en) 2020-11-06 2024-01-09 Myocene Muscle fatigue determination method and system

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DE68926243D1 (en) 1996-05-15
EP0446271A4 (en) 1993-01-07
DE68926243T2 (en) 1996-11-07
AU4750490A (en) 1990-06-26
AU639898B2 (en) 1993-08-12
EP0446271A1 (en) 1991-09-18
EP0446271B1 (en) 1996-04-10
CA2004110A1 (en) 1990-05-29
US5016635A (en) 1991-05-21

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