A group of patients who are good candidates for the application of Functional Electrical Stimulat... more A group of patients who are good candidates for the application of Functional Electrical Stimulation (FES) to restore reciprocal walking is described. They have incomplete lesions of the spinal cord. Because of the degree of preserved voluntary control, proprioception and sensation some of these patients can achieve crutch assisted walking by means of multichannel electrical stimulation: In a number of cases the patient has sufficient strength and voluntary control in the upper limbs and at least one leg to provide safe standing for short periods in forearm crutches. For these patients a two channel stimulator controlled by a handswitch was applied to achieve safe and practical crutch assisted walking in a relatively short period of time.
In the restoration of gait for paraplegics using functional electrical stimulation, the method mo... more In the restoration of gait for paraplegics using functional electrical stimulation, the method most commonly used to produce hip flexion for the swing phase of gait has been the elicitation of the flexion withdrawal response. Several problems have been noted with the response: there is a decrease in the magnitude of the hip flexion to repeated stimuli (habituation); long latency; and inhibition of the response when stimulated bilaterally. These have been characterized and methods for overcoming the problems tested. Results show that increasing stimulation frequency reduces latency. Habituation can be reduced in some subjects by multiplexing two sites of stimulation. Habituation can further be reduced by applying single high-intensity pulses and this has been used in a one-step-ahead controller for regulating hip flexion angle. Inhibition due to bilateral stimulation had been significantly reduced by altering the timing of the stimulation to the two legs.
(Editorial note This session was intended to permit panel members to present a summary of their i... more (Editorial note This session was intended to permit panel members to present a summary of their interpretation of current trends in the field of medical applications of computers. Their presentations are reported here in summary form, followed by the discussion which they stimulated.)
The use of television/computer systems for the analysis of human movement is now well established... more The use of television/computer systems for the analysis of human movement is now well established in some bioengineering centres. At Strathclyde, TV systems have been in routine use for clinically related studies for a number of years.
Photogrammetric techniques are widely used for the study of human movement. These techniques allo... more Photogrammetric techniques are widely used for the study of human movement. These techniques allow the 3-D positions of anatomical landmarks to be determined at regular time intervals. The development of computer interfaced optoelectronic measurement systems has significantly reduced the time and manual effort involved in data acquisition, making the use of photogrammetry in locomotion analysis feasible on a routine basis. These perspectives have provided the impetus for the application of time series techniques for determining velocities and accelerations of limb segments.
Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society Volume 13: 1991
... fig.4 Nodal Membrane Potentials at four Moment after start of Stimulation Pulse. Fibre diamet... more ... fig.4 Nodal Membrane Potentials at four Moment after start of Stimulation Pulse. Fibre diameter = 8um nerve fibre diameter ratio of anodal currents um 0.60.2 0.70.3 0.80.2 0.9:Ol 12 X X X A P 10 x X A P A P 8 x APAPAP 6 APAPAPAP 4 APAPAPAP Table 1 Response of Nerve ...
The aim of this study was to investigate the use of functional electrical stimulation (FES) as a ... more The aim of this study was to investigate the use of functional electrical stimulation (FES) as a means of pressure sore prevention in seated spinal cord injured (SCI) subjects. Nine SCI subjects took part in tests in which electrical stimulation was applied to the quadriceps with the lower legs restrained. Ischial pressures were measured during periods of quiet sitting and FES application. A strain gauged lever arm was used to measure the knee moment during quadriceps stimulation. The average pressure drop at the right and left buttocks was 44 mmHg and 27 mmHg respectively. In general the greatest reductions occurred in subjects with larger knee moments; however, there was no direct relationship between the pressure reduction obtained and the quadriceps strength. This form of FES may be useful as a prophylactic aid in the management of pressure sores in SCI subjects.
Journal of Medical Engineering & Technology, 2010
The aim of this paper is to show the feasibility of the use of functional electrical stimulation ... more The aim of this paper is to show the feasibility of the use of functional electrical stimulation (FES) applied to the lower back muscles for pressure sores prevention in paraplegia. The hypothesis under study is that FES induces a change in the pressure distribution on the contact area during sitting. Tests were conducted on a paraplegic subject (T5), sitting on a standard wheelchair and cushion. Trunk extensors (mainly the erector spinae) were stimulated using surface electrodes placed on the skin. A pressure mapping system was used to measure the pressure on the sitting surface in four situations: (a) no stimulation; (b) stimulation on one side of the spine only; (c) stimulation on both sides, at different levels; and (d) stimulation at the same level on both sides, during pressure-relief manoeuvres. A session of prolonged stimulation was also conducted. The experimental results show that the stimulation of the erector spinae on one side of the spine can induce a trunk rotation on the sagittal plane, which causes a change in the pressure distribution. A decrease of pressure on the side opposite to the stimulation was recorded. The phenomenon is intensified when different levels of stimulation are applied to the two sides, and such change can be sustained for a considerable time (around 5 minutes). The stimulation did not induce changes during pressure-relief manoeuvres. Finally, from this research we can conclude that the stimulation of the trunk extensors can be a useful tool for pressure sores prevention, and can potentially be used in a routine for pressure sores prevention based on periodical weight shifts.
BJOG: An International Journal of Obstetrics & Gynaecology, 1988
Summary. A microcomputer was used to analyse uterine activity during spontaneous labour in 30 nul... more Summary. A microcomputer was used to analyse uterine activity during spontaneous labour in 30 nulliparous and 30 parous patients. The intrauterine mean active pressure (MAP) in the nulliparous group was 1·51 kPa (SD 0·45) in the first stage and 2·71 kPa (SD 0·77) in the second stage. For the parous group, the MAP in the first stage was 1·22 kPa (SD 0·37) and in the second stage was 2·92 kPa (SD 0·98). A significant parity difference in MAP and contraction frequency was observed in the first stage but not in the second stage. Epidural analgesia did not appear to influence uterine activity in the first stage but was associated with a lower MAP, contraction frequency and intensity in the second stage. During the first stage, MAP increased by 21% in nulliparas and by 39% in multiparas. The rise in MAP was mainly due to an increase in contraction frequency.
A training intervention study using functional electrical stimulation-rowing (FES-R) in a group o... more A training intervention study using functional electrical stimulation-rowing (FES-R) in a group of eight individuals with tetraplegia. To assess the feasibility of a structured progressive FES-R training programme in people with tetraplegia, and to explore the number and type of FES-training sessions required to enable continuous FES-R for 30 min. A fully integrated sports centre, elite rowing training centre and university sport science department. Eight participants with chronic complete and incomplete tetraplegia (C4 to C7, American Spinal Injury Association Impairment Scale A, B and C) who had not previously used any form of FES-assisted exercise, participated in the study. Participants completed a progressive FES-assisted training programme building to three continuous 30-min FES-R sessions per week at 60-80% of their predetermined peak power output. Thereafter, rowing performance was monitored for 12 months. number and type of FES-training sessions required before achieving 30...
On May 18, 1992 a symposium at Case Western Reserve University in Cleveland, Ohio, USA had the go... more On May 18, 1992 a symposium at Case Western Reserve University in Cleveland, Ohio, USA had the goal of defining the tasks needed to reach clinical utility of investigational neural prosthetic ambulation devices. The characteristics and stage of development of four systems were detailed: the Lousiana State University reciprocating gait orthosis (LSU-RGO) with muscle stimulation; the modular hybrid functional neuromuscular stimulation (FNS) orthosis ; the Cleveland VA-Case Western Reserve University (VA-CWRU) implant system; and the Parastep® system. Multicenter clinical trials are under way for the Parastep® system and are planned to start within the next 2 years for the LSU-RGO with muscle stimulation, the V A-CWRU 8-channel system, and the floor reaction orthosis component of the modular hybrid FNS system. Current investigational systems provide little advantage over the standing wheelchair in some occupations but they do expand social, recreational, and exercise capabilities. Disabled people and some leading rehabilitation physicians are willing to test basic ambulation devices but the regulatory approvals must first be obtained for multicenter clinical trials. Corporate partners are central to the development of devices, their clinical testing, and their subsequent market ing. A key requirement for developing and disseminating motor prostheses is the education of clinicians so that they will participate in trials and be prepared to prescribe the prostheses when they reach the market.
This study investigated the effect of functional electrical stimulation (FES), applied during wal... more This study investigated the effect of functional electrical stimulation (FES), applied during walking, on the gait of children with spastic cerebral palsy (CP). Eight children (five males, three females; mean age 13y 2mo, SD 2y 2m; range 8y 11mo to 17y 6mo) diagnosed with diplegic (n=6) or hemiplegic (n=2) spastic CP completed the study. All participants were ambulant. Core FES strategies based on common CP gait deviations were developed and tailored for each child. FES strategies for each child were evaluated in two separate test sessions. Effects of FES on gait were monitored with three-dimensional motion analysis. Within each test session each child's gait was assessed when walking without FES (phase A) and with FES (phase B). An A-B-A-B test sequence was employed allowing the effects of the withdrawal and reinstatement of FES to be assessed. All children performed 10 consecutive walks in each phase. Replication of this sequence on a separate day allowed the repeatability of the intervention to be evaluated. Outcome measures, including summary variables of kinematic data, temporal-spatial variables, and mode of initial contact, were predefined for each child and targets for clinical significance were set for these outcome measures. Comparisons were performed between these targets and the actual outcomes. Consistent clinically significant improvements were recorded for three children: one child showed some improvement that was statistically significant but not clinically significant. Results for one child were mixed. There was no change in the remaining three children. Gait analysis proved to be a useful tool in both developing and determining the effectiveness of FES strategies.
A wearable Arduino system (ESP32s) is described that uses optical time of flight (VL6180X) and in... more A wearable Arduino system (ESP32s) is described that uses optical time of flight (VL6180X) and inertial measurement unit (SENtral EM7180) sensors to estimate the Minimum Foot Clearance (MFC) of participants during gait. It is envisaged that an affordable wearable device that can acquire kinematic data outside the laboratory over periods of several weeks may find application in falls risk assessment in those with ambulatory disorders including the elderly. A geometric model is presented, and a preliminary trial was conducted with able-bodied subjects to test the correlation and agreement of the device with a Vicon 3D motion capture system, consisting of 12 infrared cameras located at the University of Warwick. The correlation between the device and the gait laboratory data yielded a correlation coefficient of r = 0.88. Agreement was tested using the Bland-Altman plot where the line of equality was within the 95% confidence interval of the mean difference suggesting that the device ca...
0~ CI/' the problems which occurs in the development of a control system for functional electrica... more 0~ CI/' the problems which occurs in the development of a control system for functional electrical stimulation of the lower limbs is to detect accurately speciJic events within the gait cycle. We present a method for the classification of phases of the gait cycle using the artificial intelligence technique of inductive learning. Both the terminology of inductive learning and the algorithm used for the analyses are fully explained. Given a set of examples of sensor data from the gait events that are to be detected, the inductive learning algorithm is able to produce a decision tree (or set of rules) which classify the data using a minimum number of .ren.rors. The nature of the redundancy of the .sensor set is examined by progressively removing combinations of' sensors and noting the effect on both the size of the decision trees produced and their clas$icatian accuracy on 'unseen' testing data. Since the algorithm is able to calculate which sensors are more important (informative), comparisons with the intuitive appreciation of sensor importance of ,five researchers in the fields were made, revealing that those sensors which appear intuitively most mformative may, in,fact, provide the least information. Comparison results with the standard statistical rlass$cation technique of linear discriminant analysis are also presented, showing the relative simplicity of the inductively derived rules together with their good class$cation accuracy. In addition to the control of F&S, such techniques are also applicable to automatic gait analysis and the construction of expert system.r,for diagnosis of gait pathologies.
FES rowing is a new form of high-intensity, whole body, physical exercise for individuals with sp... more FES rowing is a new form of high-intensity, whole body, physical exercise for individuals with spinal cord injury. Preliminary results are presented for RG, co-author and trained paraplegic FES rower. RG has regularly used FES rowing since 2003 and has competed successfully in major international indoor rowing championships. The kinematic analysis reveals a faster stroke rate and shorter stroke length than normal. This is associated with the absence of sagittal trunk motion due to the method of trunk stabilization used in this simple configuration. The temporal pattern of the handle control switch indicates a well-honed motor skill in which the rower is continuously predicting the system dynamics and muscle responses. The control switching points occur with surprisingly high synchronization with the rowing cycle, typically within +/- 30ms. This suggests that the control of FES rowing, once learned, can be performed with minimal cortical load. Switching for drive begins during recovery, thus the quadriceps are eccentrically active and highly loaded during the early drive phase. Handle forces exceeded 350N and may result in significant joint loading. For example, RG has had a 14.7% increase in BMD associated with FES rowing.
This paper describes restoration of motor function in patients with paralyzed extremities due to ... more This paper describes restoration of motor function in patients with paralyzed extremities due to upper motor neuron disorders by functional electrical stimulation (FES). Percutaneously indwelling intramuscular electrodes were implanted into the muscles of the paralyzed upper and lower extremities to be controlled by FES. Stimulation patterns for extremity FES were created from electromyography (EMG) during motion in healthy subjects. By using a percutaneous FES system, all of the joint movement in the extremities could be controlled as long as severe lower motor neuron damage did not exist. In the paralyzed upper extremity, motor function of not only the hand but also the wrist, elbow, and shoulder could be restored with well-coordinated manner by EMG-based stimulation data and utilized for vocational tasks in the hemiplegic and quadriplegic patients. Continuous bias stimulation to the paralyzed muscle in combination with volitional contraction of its antagonistic muscles provided the patient with more volitional and natural control of the upper extremity. Restoration of locomotive movement in the paraplegics at around T-8 level was also achieved by FES under the usage of a walker.
A novel crutch, the harness crutch, is &scribed which reduces loading on the arms during the swin... more A novel crutch, the harness crutch, is &scribed which reduces loading on the arms during the swing phase of swingthrough gait. l?te &ice wa.s fabricated by attaching a modified mountainem'ng harness by two side straps, to mo@ed axiL2zry crutches. 7'7~ harness crutch was compared with the saddle crutch, dtxribed by Taylor in 1883. 17re sadaYe crutch produced pressures in excess of 500 m&g in ti perirwal area; no fiessures were produced in thtk area with the harnwc cmtch Ischial pressures produced by 'both systems were similar. In sk out of eight non-impaired subjects, sign$cantiy morefice ~4s transmit&d to the harness crutch (an average 47% of body weight) than to the saddle crutch (an average 40% of btiy weigh). A comparison of the oxygnr cost of swing-through gait was ma& between the harness crutch and unmod$ed axillq crutches; with the hamess crutch oxygen cost was sign@antly lower (p < 0.01) and there were no signijcant difknces in speed and stria2 length.
A group of patients who are good candidates for the application of Functional Electrical Stimulat... more A group of patients who are good candidates for the application of Functional Electrical Stimulation (FES) to restore reciprocal walking is described. They have incomplete lesions of the spinal cord. Because of the degree of preserved voluntary control, proprioception and sensation some of these patients can achieve crutch assisted walking by means of multichannel electrical stimulation: In a number of cases the patient has sufficient strength and voluntary control in the upper limbs and at least one leg to provide safe standing for short periods in forearm crutches. For these patients a two channel stimulator controlled by a handswitch was applied to achieve safe and practical crutch assisted walking in a relatively short period of time.
In the restoration of gait for paraplegics using functional electrical stimulation, the method mo... more In the restoration of gait for paraplegics using functional electrical stimulation, the method most commonly used to produce hip flexion for the swing phase of gait has been the elicitation of the flexion withdrawal response. Several problems have been noted with the response: there is a decrease in the magnitude of the hip flexion to repeated stimuli (habituation); long latency; and inhibition of the response when stimulated bilaterally. These have been characterized and methods for overcoming the problems tested. Results show that increasing stimulation frequency reduces latency. Habituation can be reduced in some subjects by multiplexing two sites of stimulation. Habituation can further be reduced by applying single high-intensity pulses and this has been used in a one-step-ahead controller for regulating hip flexion angle. Inhibition due to bilateral stimulation had been significantly reduced by altering the timing of the stimulation to the two legs.
(Editorial note This session was intended to permit panel members to present a summary of their i... more (Editorial note This session was intended to permit panel members to present a summary of their interpretation of current trends in the field of medical applications of computers. Their presentations are reported here in summary form, followed by the discussion which they stimulated.)
The use of television/computer systems for the analysis of human movement is now well established... more The use of television/computer systems for the analysis of human movement is now well established in some bioengineering centres. At Strathclyde, TV systems have been in routine use for clinically related studies for a number of years.
Photogrammetric techniques are widely used for the study of human movement. These techniques allo... more Photogrammetric techniques are widely used for the study of human movement. These techniques allow the 3-D positions of anatomical landmarks to be determined at regular time intervals. The development of computer interfaced optoelectronic measurement systems has significantly reduced the time and manual effort involved in data acquisition, making the use of photogrammetry in locomotion analysis feasible on a routine basis. These perspectives have provided the impetus for the application of time series techniques for determining velocities and accelerations of limb segments.
Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society Volume 13: 1991
... fig.4 Nodal Membrane Potentials at four Moment after start of Stimulation Pulse. Fibre diamet... more ... fig.4 Nodal Membrane Potentials at four Moment after start of Stimulation Pulse. Fibre diameter = 8um nerve fibre diameter ratio of anodal currents um 0.60.2 0.70.3 0.80.2 0.9:Ol 12 X X X A P 10 x X A P A P 8 x APAPAP 6 APAPAPAP 4 APAPAPAP Table 1 Response of Nerve ...
The aim of this study was to investigate the use of functional electrical stimulation (FES) as a ... more The aim of this study was to investigate the use of functional electrical stimulation (FES) as a means of pressure sore prevention in seated spinal cord injured (SCI) subjects. Nine SCI subjects took part in tests in which electrical stimulation was applied to the quadriceps with the lower legs restrained. Ischial pressures were measured during periods of quiet sitting and FES application. A strain gauged lever arm was used to measure the knee moment during quadriceps stimulation. The average pressure drop at the right and left buttocks was 44 mmHg and 27 mmHg respectively. In general the greatest reductions occurred in subjects with larger knee moments; however, there was no direct relationship between the pressure reduction obtained and the quadriceps strength. This form of FES may be useful as a prophylactic aid in the management of pressure sores in SCI subjects.
Journal of Medical Engineering & Technology, 2010
The aim of this paper is to show the feasibility of the use of functional electrical stimulation ... more The aim of this paper is to show the feasibility of the use of functional electrical stimulation (FES) applied to the lower back muscles for pressure sores prevention in paraplegia. The hypothesis under study is that FES induces a change in the pressure distribution on the contact area during sitting. Tests were conducted on a paraplegic subject (T5), sitting on a standard wheelchair and cushion. Trunk extensors (mainly the erector spinae) were stimulated using surface electrodes placed on the skin. A pressure mapping system was used to measure the pressure on the sitting surface in four situations: (a) no stimulation; (b) stimulation on one side of the spine only; (c) stimulation on both sides, at different levels; and (d) stimulation at the same level on both sides, during pressure-relief manoeuvres. A session of prolonged stimulation was also conducted. The experimental results show that the stimulation of the erector spinae on one side of the spine can induce a trunk rotation on the sagittal plane, which causes a change in the pressure distribution. A decrease of pressure on the side opposite to the stimulation was recorded. The phenomenon is intensified when different levels of stimulation are applied to the two sides, and such change can be sustained for a considerable time (around 5 minutes). The stimulation did not induce changes during pressure-relief manoeuvres. Finally, from this research we can conclude that the stimulation of the trunk extensors can be a useful tool for pressure sores prevention, and can potentially be used in a routine for pressure sores prevention based on periodical weight shifts.
BJOG: An International Journal of Obstetrics & Gynaecology, 1988
Summary. A microcomputer was used to analyse uterine activity during spontaneous labour in 30 nul... more Summary. A microcomputer was used to analyse uterine activity during spontaneous labour in 30 nulliparous and 30 parous patients. The intrauterine mean active pressure (MAP) in the nulliparous group was 1·51 kPa (SD 0·45) in the first stage and 2·71 kPa (SD 0·77) in the second stage. For the parous group, the MAP in the first stage was 1·22 kPa (SD 0·37) and in the second stage was 2·92 kPa (SD 0·98). A significant parity difference in MAP and contraction frequency was observed in the first stage but not in the second stage. Epidural analgesia did not appear to influence uterine activity in the first stage but was associated with a lower MAP, contraction frequency and intensity in the second stage. During the first stage, MAP increased by 21% in nulliparas and by 39% in multiparas. The rise in MAP was mainly due to an increase in contraction frequency.
A training intervention study using functional electrical stimulation-rowing (FES-R) in a group o... more A training intervention study using functional electrical stimulation-rowing (FES-R) in a group of eight individuals with tetraplegia. To assess the feasibility of a structured progressive FES-R training programme in people with tetraplegia, and to explore the number and type of FES-training sessions required to enable continuous FES-R for 30 min. A fully integrated sports centre, elite rowing training centre and university sport science department. Eight participants with chronic complete and incomplete tetraplegia (C4 to C7, American Spinal Injury Association Impairment Scale A, B and C) who had not previously used any form of FES-assisted exercise, participated in the study. Participants completed a progressive FES-assisted training programme building to three continuous 30-min FES-R sessions per week at 60-80% of their predetermined peak power output. Thereafter, rowing performance was monitored for 12 months. number and type of FES-training sessions required before achieving 30...
On May 18, 1992 a symposium at Case Western Reserve University in Cleveland, Ohio, USA had the go... more On May 18, 1992 a symposium at Case Western Reserve University in Cleveland, Ohio, USA had the goal of defining the tasks needed to reach clinical utility of investigational neural prosthetic ambulation devices. The characteristics and stage of development of four systems were detailed: the Lousiana State University reciprocating gait orthosis (LSU-RGO) with muscle stimulation; the modular hybrid functional neuromuscular stimulation (FNS) orthosis ; the Cleveland VA-Case Western Reserve University (VA-CWRU) implant system; and the Parastep® system. Multicenter clinical trials are under way for the Parastep® system and are planned to start within the next 2 years for the LSU-RGO with muscle stimulation, the V A-CWRU 8-channel system, and the floor reaction orthosis component of the modular hybrid FNS system. Current investigational systems provide little advantage over the standing wheelchair in some occupations but they do expand social, recreational, and exercise capabilities. Disabled people and some leading rehabilitation physicians are willing to test basic ambulation devices but the regulatory approvals must first be obtained for multicenter clinical trials. Corporate partners are central to the development of devices, their clinical testing, and their subsequent market ing. A key requirement for developing and disseminating motor prostheses is the education of clinicians so that they will participate in trials and be prepared to prescribe the prostheses when they reach the market.
This study investigated the effect of functional electrical stimulation (FES), applied during wal... more This study investigated the effect of functional electrical stimulation (FES), applied during walking, on the gait of children with spastic cerebral palsy (CP). Eight children (five males, three females; mean age 13y 2mo, SD 2y 2m; range 8y 11mo to 17y 6mo) diagnosed with diplegic (n=6) or hemiplegic (n=2) spastic CP completed the study. All participants were ambulant. Core FES strategies based on common CP gait deviations were developed and tailored for each child. FES strategies for each child were evaluated in two separate test sessions. Effects of FES on gait were monitored with three-dimensional motion analysis. Within each test session each child&amp;amp;amp;amp;amp;amp;#39;s gait was assessed when walking without FES (phase A) and with FES (phase B). An A-B-A-B test sequence was employed allowing the effects of the withdrawal and reinstatement of FES to be assessed. All children performed 10 consecutive walks in each phase. Replication of this sequence on a separate day allowed the repeatability of the intervention to be evaluated. Outcome measures, including summary variables of kinematic data, temporal-spatial variables, and mode of initial contact, were predefined for each child and targets for clinical significance were set for these outcome measures. Comparisons were performed between these targets and the actual outcomes. Consistent clinically significant improvements were recorded for three children: one child showed some improvement that was statistically significant but not clinically significant. Results for one child were mixed. There was no change in the remaining three children. Gait analysis proved to be a useful tool in both developing and determining the effectiveness of FES strategies.
A wearable Arduino system (ESP32s) is described that uses optical time of flight (VL6180X) and in... more A wearable Arduino system (ESP32s) is described that uses optical time of flight (VL6180X) and inertial measurement unit (SENtral EM7180) sensors to estimate the Minimum Foot Clearance (MFC) of participants during gait. It is envisaged that an affordable wearable device that can acquire kinematic data outside the laboratory over periods of several weeks may find application in falls risk assessment in those with ambulatory disorders including the elderly. A geometric model is presented, and a preliminary trial was conducted with able-bodied subjects to test the correlation and agreement of the device with a Vicon 3D motion capture system, consisting of 12 infrared cameras located at the University of Warwick. The correlation between the device and the gait laboratory data yielded a correlation coefficient of r = 0.88. Agreement was tested using the Bland-Altman plot where the line of equality was within the 95% confidence interval of the mean difference suggesting that the device ca...
0~ CI/' the problems which occurs in the development of a control system for functional electrica... more 0~ CI/' the problems which occurs in the development of a control system for functional electrical stimulation of the lower limbs is to detect accurately speciJic events within the gait cycle. We present a method for the classification of phases of the gait cycle using the artificial intelligence technique of inductive learning. Both the terminology of inductive learning and the algorithm used for the analyses are fully explained. Given a set of examples of sensor data from the gait events that are to be detected, the inductive learning algorithm is able to produce a decision tree (or set of rules) which classify the data using a minimum number of .ren.rors. The nature of the redundancy of the .sensor set is examined by progressively removing combinations of' sensors and noting the effect on both the size of the decision trees produced and their clas$icatian accuracy on 'unseen' testing data. Since the algorithm is able to calculate which sensors are more important (informative), comparisons with the intuitive appreciation of sensor importance of ,five researchers in the fields were made, revealing that those sensors which appear intuitively most mformative may, in,fact, provide the least information. Comparison results with the standard statistical rlass$cation technique of linear discriminant analysis are also presented, showing the relative simplicity of the inductively derived rules together with their good class$cation accuracy. In addition to the control of F&S, such techniques are also applicable to automatic gait analysis and the construction of expert system.r,for diagnosis of gait pathologies.
FES rowing is a new form of high-intensity, whole body, physical exercise for individuals with sp... more FES rowing is a new form of high-intensity, whole body, physical exercise for individuals with spinal cord injury. Preliminary results are presented for RG, co-author and trained paraplegic FES rower. RG has regularly used FES rowing since 2003 and has competed successfully in major international indoor rowing championships. The kinematic analysis reveals a faster stroke rate and shorter stroke length than normal. This is associated with the absence of sagittal trunk motion due to the method of trunk stabilization used in this simple configuration. The temporal pattern of the handle control switch indicates a well-honed motor skill in which the rower is continuously predicting the system dynamics and muscle responses. The control switching points occur with surprisingly high synchronization with the rowing cycle, typically within +/- 30ms. This suggests that the control of FES rowing, once learned, can be performed with minimal cortical load. Switching for drive begins during recovery, thus the quadriceps are eccentrically active and highly loaded during the early drive phase. Handle forces exceeded 350N and may result in significant joint loading. For example, RG has had a 14.7% increase in BMD associated with FES rowing.
This paper describes restoration of motor function in patients with paralyzed extremities due to ... more This paper describes restoration of motor function in patients with paralyzed extremities due to upper motor neuron disorders by functional electrical stimulation (FES). Percutaneously indwelling intramuscular electrodes were implanted into the muscles of the paralyzed upper and lower extremities to be controlled by FES. Stimulation patterns for extremity FES were created from electromyography (EMG) during motion in healthy subjects. By using a percutaneous FES system, all of the joint movement in the extremities could be controlled as long as severe lower motor neuron damage did not exist. In the paralyzed upper extremity, motor function of not only the hand but also the wrist, elbow, and shoulder could be restored with well-coordinated manner by EMG-based stimulation data and utilized for vocational tasks in the hemiplegic and quadriplegic patients. Continuous bias stimulation to the paralyzed muscle in combination with volitional contraction of its antagonistic muscles provided the patient with more volitional and natural control of the upper extremity. Restoration of locomotive movement in the paraplegics at around T-8 level was also achieved by FES under the usage of a walker.
A novel crutch, the harness crutch, is &scribed which reduces loading on the arms during the swin... more A novel crutch, the harness crutch, is &scribed which reduces loading on the arms during the swing phase of swingthrough gait. l?te &ice wa.s fabricated by attaching a modified mountainem'ng harness by two side straps, to mo@ed axiL2zry crutches. 7'7~ harness crutch was compared with the saddle crutch, dtxribed by Taylor in 1883. 17re sadaYe crutch produced pressures in excess of 500 m&g in ti perirwal area; no fiessures were produced in thtk area with the harnwc cmtch Ischial pressures produced by 'both systems were similar. In sk out of eight non-impaired subjects, sign$cantiy morefice ~4s transmit&d to the harness crutch (an average 47% of body weight) than to the saddle crutch (an average 40% of btiy weigh). A comparison of the oxygnr cost of swing-through gait was ma& between the harness crutch and unmod$ed axillq crutches; with the hamess crutch oxygen cost was sign@antly lower (p < 0.01) and there were no signijcant difknces in speed and stria2 length.
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Papers by Brian Andrews