ETSense: Adaptive Portable Essential Tremor Monitor

Period of Performance: 09/01/2009 - 02/28/2011


Phase 1 SBIR

Recipient Firm

Cleveland Medical Devices, Inc.
Principal Investigator


DESCRIPTION (provided by applicant): The objective is to design, implement, and clinically assess ETSense", an adaptive, compact, portable essential tremor (ET) monitor for optimizing therapeutic interventions. ET affects approximately 4% of the population over age 40 in the United States and is characterized primarily by postural and kinetic (action) tremors of the limbs, which are rated by various subjective tremor rating scales (TRS). These scales all provide a discrete, subjective symptom rating at a discrete point in time, require a clinician to visually assess the patient, and cannot capture complex fluctuations that occur throughout the day in response to interventions. Objectively capturing ET symptoms continuously during daily activities and using adaptive algorithms to both classify tremor types and severity will help clinicians better titrate therapy to minimize symptom fluctuations and expand care to rural and underserved populations. CleveMed has previously developed a compact wireless system to quantify Parkinson's disease (PD) symptoms called ParkinSense". In a clinical study, this system successfully demonstrated objective quantification of PD motor symptoms. The promising results for PD suggest the system may be adapted for quantifying tremor in ET patients by developing specific ET algorithms and more continuous portable monitoring to capture the tremor fluctuations that can occur throughout the day. The primary innovation of the proposed system will be compact, portable user worn hardware for continuous monitoring during activities of daily living and intelligent, adaptive algorithms to continuously classify tremor type and rate severity. Including a combination of accelerometers and gyroscopes will provide a system with much greater sensitivity for tremor type discrimination and severity rating than currently existing uniaxial systems. The final system will be contained in a lightweight, finger-worn housing that does not require a PC and can be worn continuously at home or in public. The device will detect motion (tremor or voluntary) to begin data collection. A button on the device will allow the patient to indicate when medication is taken. All data will be stored in memory for subsequent analysis and report generation detailing symptom fluctuations in response to therapeutic interventions. ETSense will provide a standardized platform for continuous evaluation of ET symptoms. The portable design will allow patients to perform everyday tasks at home, at work, or in public while tremor type and severity is stored. Clinical reports will detail symptom fluctuations for optimizing therapeutic interventions and the development of novel treatment protocols. PUBLIC HEALTH RELEVANCE: Essential tremor, characterized primarily by tremor during movement, affects approximately 4% of the population over age 40 in the United States. Various tremor rating scales exist for subjectively rating tremor severity during a clinical exam. The proposed ETSense adaptive, portable essential tremor monitor will classify tremor type and rate tremor severity continuously throughout the day while a patient performs typical activities, which should help clinicians to better prescribe treatment and aid in the development of novel therapeutic interventions.