The design of an embedded spinal cord stimulator

Abstract

Spinal cord stimulation is a physical therapy methodology utilizing electrical impulses, pulses, or a combination of various standard electrical waveforms to block pain. However, standard forms are not functioning effectively for each illness due to the unique conditions of the patient. Therefore, patient-specific waveforms (or user-defined waveforms) integrated with nondestructive, complete, or partially noninvasive and effective medical instruments to help relieve pain are required. In the literature, 2 different designs have been discussed: the bedside/portable and the implantable/surgical types. This work is introducing a new hybrid type: a portable touch-screen multichannel embedded spinal cord stimulator. This work is made of 3 parts: the hardware and the software designs, and an embedded interface introducing the system to external medical systems or patients. The hardware and software designs are explained in detail. The S3C2440 microprocessor-based embedded spinal cord stimulator generates not only 6 standards types of signals, but also user defined waveform(s). This requires medical experts' close relation, consultation, and cooperation with biomedical engineers who are able to design and develop new instruments with new requirements. In this paper, a microprocessor-based spinal cord stimulator is developed in the Samsung S3C2440 environment and PIC18F452-based channel boards. The S3C2440 environment is the main controller unit and the therapy signal is produced by the channel boards as a signal generator. The software is prepared by MS Visual Studio 2008 and Hi-Tech C. The frequency, duty-cycle, and amplitudes of the pulses can be altered by software control. The architecture of the stimulators is designed to be modular; therefore, its different blocks can be reused as standard building blocks. The designed and developed embedded spinal cord stimulator enables both home and bedside health care. The system is battery-operated, portable, user-friendly, and cost-effective.