ABSTRACT
Objective A practical and highly accurate algorithm for dynamic monitoring of plantar pressure was proposed, the magnitude of vertical ground reaction force (vGRF) during walking was measured by a capacitive insole sensor, and reliability of the prediction accuracy was verified. Methods Four healthy male subjects were require to wear capacitive insole sensors, and their fast walking and slow walking data were collected by Kistler three-dimensional (3D) force platform. The data collected by the capacitive insole sensors were pixelated, and then the processed data were fed into a residual neural network, ResNet18, to obtain high-precision vGRF. Results Compared with analysis of the data collected from Kister force platform, the normalized root mean square error (NRMSE) for fast walking and slow walking were 8.40% and 6.54%, respectively, and the Pearman correlation coefficient was larger than 0.96. Conclusions This study provides a novel algorithm for dynamic measurement of GRF in mobile scenarios, which can be used for estimation of complete GRF outside the laboratory without being constrained by the number and location of force plates. Potential application areas include gait analysis and efficient capture of pathological gaits.
ABSTRACT
Objective To evaluate of the efficacy of transcranial electrical stimulation motor evoked potential (TES-MEP)in combination with cortical somatosensory evoked potential (CSEP) monitoring during the anterior or posterior approach spinal surgery for cervical spondylitie myelopathy (CSM).Methods TES-MEP on the bilateral anterior tibial muscle and flexor hallucal brevis and thenar muscles and CSEP on the bilateral posterior tibial nerve and ulnar nerve were observed simultaneously in 135 patients during spinal surgery.Intravenous anesthesia was employed in all the patients.The results of TES-MEP,CSEP and combined monitoring were analyzed statistically.Pre-oporative and post-operative motor and sensory functions of the spinal cord were compared. Result Success rate of TES-MEP,CSEP and the combined monitoring was 87.4%.97.8%and 100%,respectively.Out of 135 patients,nine patients (6.7%) were detected with the positive evoked potentials due to surgical operation.The sensitivity of TES-MEP and CSEP in assessing the spinal cord motor function was 100%and 83.3%,respectively,while that in assessing the spinal cord sensory function was 77.8%and 100%,respectively.The sensitivity and specificity of the combined monitoring was both 100%. Conclusion The successful detection rate and accuracy of the combined monitoring for spinal cord function are apparently higher than that of simple TES-MEP or CSEP.The causes for operative maneuvers evoking a positive evoked potential include complete anterior decompression of the spinal canal,intervertebral bone graft,laminoplasty for OPLL and hematoma compression caused by a failed drainage in a posterior-anterior approach surgery.
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BACKGROUND: Epidural block(EB) is one of the effective and widely used remedies for lumbar disc herniation(LDH) . Animal experiments have been conducted to study the changes in the local tissue structure in the spinal canel after several treatments with EB.OBJECTIVE: To study the effect of EB for LDH on the local tissue structures in the spinal canel.DESIGN: A non-randomized and controlled clinical observation.PARTICIPANTS: Department of Pathology and Laboratory of Electron Microscope of an Affiliated Hospital of a University.SUBJECTS: Forty patients with LDP, who failed to respond to EB treatment and subsequently received discectomy in the Department of Orthopaedics,First Affiliated Hospital of Sun Yat-sen University from May 1992 to December 1997, were enrolled in this study, with 20 patients receiving discectomy but not EB treatment serving as the control group.METHODS: From the 60 cases, totally 120 specimens of yellow ligament and the disc tissues were obtained during discectomy for optical microscopical examination. A portion of the yellow ligament and the lumbar disc tissues were chosen from EB group(12 cases) and non-EB group(10 cases), respectively, for electron microscope examination(involving altogether 44specimens) . The changes in histology and ultrastructnres in the specimens were compared between the two groups.MAIN OUTCOME MEASURES: ① Main results: the reactive proliferation of the tunica adventitia and inflammatory reaction of the intervertebral disc and yellow ligament; ② Secondary results: changes in the ultrastructure of the anulus fibrosus, nucleus pulposus and yellow ligament.RESULTS: No significant difference was found between the two groups either in light microscopy or electron microscopy in the degree of smoothness and the inflammatory reaction of the cavosurface of the yellow ligament and the disc tissues, nor in the cellular ultrastructures and fibrous arrangement.CONCLUSION: There is no direct relationship between lumbar EB and epidural scar adhesion formation. EB does not affect the ultrastructures of the local tissues in the spinal canal, but care must be taken of the sterilization in the surgical procedure, as chronic inflammatory reaction in the yellow ligament and disc tissues can be present in some patients.
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Objective To investigate the clinical application of transcranial magnetic stimulation motor evoked potentials (TMS-MEP) of rectus abdominis in the diagnosis of thoracic spinal cord injury. Methods The innervation of rectus abdominis and dermatomal distribution were studied in 5 adult cadavers. MEP of bilateral rectus abdominis in different segments was measured and recorded in 25 normal subjects for reference and in 23 patients with T4-T12 spinal cord injury. Results The anatomic study showed that rectus abdominis was innervated by 7 pairs of intercostal nerve from T6 to T12, useful to determine the MEP recording points in the body surface. In all normal subjects, T6-T12 MEP of bilateral rectus abdominis were recorded successfully and the referential range of normal MEP was established. The MEP peak latencies of each level were significantly different each with other. Among 23 patients suffering from thoracic spinal cord injury, 12 cases with complete paralysis had no MEP record below the injured level and no neurological recovery during the follow-up; while in 11 cases with incomplete paralysis, abnormal MEP were recorded in all but one with T4 fracture, the MEP of this patient disappeared below T6. The change of MEP of rectus abdominis was consistent with the level of fracture except in 1 case. During follow-up, 9 cases with incomplete paralysis patients showed recovery to different extent. Conclusion According to neuroanatomy, segmental MEP of rectus abdominis can be evoked and recorded in all normal subjects. The MEP peak latencies are significantly different in each level. MEP of rectus abdominis is proved to have the localizing and characteristic diagnostic value in the evaluation of the thoracic spinal cord injury.