Implantable FES system for upright mobility and bladder and bowel function for individuals with spinal cord injury

Abstract

Study design: Postintervention. Objectives: To determine the effectiveness of the Praxis multifunctional implantable functional electrical stimulation (FES) system (Neopraxis Pty. Ltd, Lane Cove, NSW, Australia) to provide standing and stepping ability and bladder and bowel management for individuals with motor complete thoracic level spinal cord injuries (SCI). Setting: Pediatric orthopedic hospital specializing in SCI. Subjects: Three males, ages 17 and 21 years, with motor-complete thoracic level SCI and intact lower motor neurons to the muscles targeted for stimulation. Methods: Each subject was successfully implanted with the Praxis FES system. All three subjects received electrodes for upright mobility and the first two subjects received additional electrodes for stimulated bladder and bowel management. Following training, subjects were evaluated in their ability to use FES for nine mobility activities. Acute and chronic experiments of the effect of stimulation on bowel and bladder function were also performed. Results: All three subjects could independently stand up from the wheelchair and could walk at least 6 m using a swing through gait pattern. Two subjects were able to independently perform swing through gait for 6 min and one subject was able to independently ascend and descend stairs. Suppression of reflex bladder contractions by neuromodulation (subject 1) and stimulated contractions of the rectum (subject 2) were observed in acute experiments. When stimulation was applied over the course of several weeks, a positive effect on bowel function was measured. Stimulated bladder contractions were not achieved. Conclusion: The feasibility of using the Praxis FES system for upright mobility and aiding aspects of bladder and bowel function was demonstrated with three subjects with thoracic level SCI.

Neurogenic bowel management after spinal cord injury: a systematic review of the evidence

“…Nine studies (aggregate N ¼ 137) evaluated the effects of surgical implantation of electrical stimulation systems (Table 10). [51][52][53][54][55][56][57][58][59] There is Level 2 evidence (from one prospective, non-randomizedcontrolled trial) 51 that supports the use of sacral anterior root stimulation to reduce severe constipation in complete injuries. Binnie et al 51 had found that an implanted Brindley stimulator did not reduce oro-cecal time for individuals with Figure 2 Schematic diagram of the enema continence catheter.…”

“…56 Colostomy. A colostomy is the surgical formation of an artificial anus by connecting the colon to an opening in the abdominal wall.…”

An Integrated Stimulator With DC-Isolation and Fine Current Control for Implanted Nerve Tripoles

“…Although physically smaller, the centered unity transistor topology suffers from poor linearity for low-significance bits due to the transistor channel length and threshold voltage variations with . The drain current of a DAC transistor in the saturation region is given by (2) where is the mobility, is the gate oxide capacitance per unit area, is the threshold voltage, is the gate-source voltage, is the drain-source voltage, and is the channel [23]. Increasing while maintaining a constant transistor aspect ratio ( ) results in a smaller which decreases .…”

Functional Electrical Stimulation in Spinal Cord Injury: From Theory to Practice

“…25,33,34 The most well-studied aspect of FES training may be the muscle and bone response. Muscles improve in size, strength, [35][36][37] and composition. Conversion from type IIB to type IIA and type I muscle fibers has been demonstrated, 38 indicating improved fatigue resistance and oxidative capacities.…”