SBIR-STTR Award

A computer controlled switching stimulator/amplifier is proposed which is capable of delivering electrical stimuli between pairs of intracranial electrodes, while simultaneously monitoring the EEG potentials on all implanted electrodes immediately before and after stimulus application In phase 1, a key feasibility issue will be to study the electro-chemical effects that that leave residual potentials on the electrodes immediately after stimulation which can block viewing the EEG. The knowledge gained will be used to build a breadboard EEG amplifier-stimulus generator combination which will permit recording and observation of the EEG in the stimulated channel as soon as possible after termination of the stimulus waveform train. Phase 2 will have the specific aim of embodying the design into a marketable product capable of expansion to at least 128 channels. Two 128 channel systems will be built. The developed hardware and software will be beta tested using human subjects who would normally be scheduled for clinical functional mapping prior to resective brain surgery for epilepsy. The technology developed will also be useful for brain functional mapping preceding other resective surgery such as for tumors.

Thesaurus Terms:
biomedical equipment development, brain mapping, electroencephalography, electrostimulus computer assisted diagnosis, electrochemistry, image guided surgery /therapy, image processing bioimaging /biomedical imaging

We will develop a modern, computer-controlled electrical stimulator for performing functional mapping by cortical stimulation. The primary application is for use with patients who are candidates for surgery to control or eliminate occurrence of epileptic seizures. Other applications will include functional mapping to plan surgery for other brain diseases such as tumors and research on brain electrical stimulation to control seizures. The need and specifications for the system come from recommendations of an expert panel of clinical users who have been consulted throughout the conception and Phase I research and will continue to be consulted in Phase II. In Phase I, we solved key technical issues associated with the design of the electrical stimulator and EEG amplifiers to minimize the interference to the exquisitely sensitive EEG amplifiers caused by the relatively huge electrical stimulation pulses. In Phase II, we will utilize the knowledge gained in Phase I to build two prototype systems. These will be tested on epilepsy patients in the normal course of their hospitalization for pre-surgical evaluation