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Technology Transfer Office
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Hanover, NH 03755-1404
Phone: (603) 646-3027
Fax: (603) 646-3670

Self-Adaptive Analog-to-Digital Converter for Electroencephalography Monitoring Devices

Long-term monitoring of patients' EEG has several clinically-relevant applications. For patients with medically refractory epilepsy, the effectiveness of a given medication can be measured by the amount of epileptiform activity that is observed in the long-term EEG signal. Also, to distinguish between epilepsy and non-epileptic attack disorder, neurologists can analyze EEG activity that is recorded immediately before, during and after a seizure-like event to determine whether or not the patient is epileptic. Further, for studies on the effect of epilepsy on memory, a long-term count of interictal spikes is compared to memory testing results to discover any relationships between the two.

There is currently a lack of effective long-term outpatient EEG monitoring systems. Available systems are limited by cumbersome and bulky size, limited power availability, and limited data storage. Wireless communication would make the EEG device more portable. The difficulty with conventional wireless schemes is that they run down battery power very quickly, which frustrates the goal of doing long-term monitoring.

Engineers at Dartmouth have invented an analog-to-digital converter (ADC) that manages power consumption by selectively digitizing and transmitting EEG data, allowing the device to run on a timescale that is several orders larger than what has been previously possible. The ADC monitors the EEG signal and varies its conversion resolution, depending on whether or not it has detected an event of clinical significance, such as an ictal episode. During clinically-significant events, the resolution of the ADC will be high, to facilitate analysis by an expert clinician. For the majority of the time, the resolution of the ADC will remain low, as it monitors the EEG signals for the onset of an important event. This way, high quality, but power consumptive, EEG recording will be reserved for only critical events.

This technology is claimed in a pending patent application. We are seeking an industrial partner interested in its commercialization. (Ref: J502)

Last Updated: 7/24/12