The stimulus router system: A novel neural prosthesis

• Author / Creator

  Gan, Liu Shi

• Neural prostheses (NPs) are electronic stimulators that activate nerves to restore sensory or motor functions. Surface NPs are non-invasive and inexpensive, but are often poorly selective, activating non-targeted muscles and cutaneous sensory nerves that can cause pain or discomfort. Implanted NPs are highly selective, but invasive and costly. The stimulus router system (SRS) is a novel NP consisting of fully implanted leads that “capture” and route some of the current flowing between a pair of surface electrodes to the vicinity of a target nerve. One end of an SRS lead has a “pick-up” terminal that is implanted subcutaneously under the location of a surface electrode and the other end has a “delivery” terminal that is secured on or near the target nerve.
  The studies presented in this thesis address the development of the SRS from animal testing to its implementation as an upper extremity NP in a tetraplegic subject. Chapters 2 and 3 describe the SRS’s basic properties, provide proof-of-principle of the system in animal studies and identify aspects that maximize its performance as a motor NP. The studies showed that selective and graded activation of deep-lying nerves can be achieved with the SRS over the full physiological range. Long term reliability of the system was demonstrated in chronic animal studies. The surface current needed to activate nerves with a SRS was found to depend on the proximity of the delivery terminal(s) to the target nerve, contact areas of the surface electrodes and implanted terminals, electrode configuration and the distances from the surface anode to the surface cathode and delivery terminal. Chapter 4 describes the first human proof-of-principle of the SRS during an intra-operative test. Finally, Chapter 5 describes the implementation of the SRS for restoration of hand function in a tetraplegic subject. Stimulation parameters and force elicited through the SRS, along with usage of the device were monitored up to 10 months after implantation. The system was found to be useful, reliable and robust. It is argued that the results of these studies indicate that the SRS provides the basis for a new family of NPs.

• Subjects / Keywords

  • Neural prosthesis
  • Functional electrical stimulation
  • Spinal cord injury

• Graduation date

  Spring 2010

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3C98D

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.