Sensor Based Portable Tremor Suppression Device for Stroke Patients

Abstract

Objective: Tremor is a clinically depicted commonly encountered neurological disorder which results after a stroke or brain injury like Parkinson's disease which causes rhythmic and reflex oscillatory movement of a body, particularly upper arm, which is difficult to diagnose and manage. Tremor is influenced by Physiological and Psychological factors which can affect any age group specifically in middle age and older persons. The modern treatment facilities and features available are very expensive and unreachable for rural people. Hence there arises a necessity to develop a portable device to overcome such situations. Methods: This paper introduces a portable and wearable device using accelerometer sensor assisted with pneumatic mechanism for tremor suppression in the upper arm. This portable device may help to suppress tremor and improve muscle control and coordination in the upper arm. Once the device is connected with the patients arm, the pneumatic circuit supplies required air through the hand cuff to keep the arm on control with reference to the signal obtained from the accelerometer sensor. The results: The performances of the device are measured in three different stages say before inflation, during partial inflation and full inflation. The results depicts 30% of improvement in tremor suppression at three different levels of tremor occurrence which is measured in terms of voltage between 1.6 and 2V at high, medium and low levels at different time intervals with frequency <10Hz. Conclusion: This device is a cost effective and portable closed loop system which is exclusively designed to reduce the tremor without affecting the upper limb voluntary movements.

Need for mechanically and ergonomically enhanced tremor-suppression orthoses for the upper limb: a systematic review

“…( probably none) 3 healthy subjects (simulating tremor) [71]1/1 (EFE) [71]0.942 / 0.150 [71]11Pneumatic Hand CuffPSG College of Tech. [72]semi-activePneumatic cuff [72]?30 (AA) [72]Yes [72]1 tremor subject (ET) [72]2/2 (WFE, WD) [72]? /?12DVB OrthosisLoureiro/Pons [73]semi-activeViscous shear resistance [73]6.5 -25,000 N/(m/s) [73]98 (PSD) [72]14.13% (magnitude change) [73]1 tremor subject (ET) [73]2/2 (WFE, WD) [73]?…”

“…[72]semi-activePneumatic cuff [72]?30 (AA) [72]Yes [72]1 tremor subject (ET) [72]2/2 (WFE, WD) [72]? /?12DVB OrthosisLoureiro/Pons [73]semi-activeViscous shear resistance [73]6.5 -25,000 N/(m/s) [73]98 (PSD) [72]14.13% (magnitude change) [73]1 tremor subject (ET) [73]2/2 (WFE, WD) [73]? / 0.200 [73]13The Viscous BeamKotovsky/Rosen [74]passiveViscous shear resistance [74]0.002 Nm/(deg/s) [74]?Yes [74]5 tremor subjects [74]1/2 (WFE, no WD) [74]0.265 /?…”

Design of a lightweight passive orthosis for tremor suppression

“…In comparison to the hand cuff by Kalaiarasi et al, which uses a semi-active pneumatic system to suppress tremor and achieves a tremor reduction of 31% of the acceleration amplitude [27], our system achieves a tremor peak reduction from 74 to 82%, analysed with PSD for the three significant tasks of Drinking, Pouring and Drawing-Spiral. Taking the average efficacy of all six tasks (considering 0% as being non-significant), we reduce tremor by 39%.…”

“…Kalaiarasi et al developed a variable-stiffness air cuff system relying on inflatable air handcuffs using an accelerometer-threshold based control [27]. They can achieve 31% tremor acceleration amplitude reduction, whilst maintaining that voluntary movements in the arm are unaffected without providing any validation of the voluntary movements [27]. However, the used handcuff is not delineated, nor is the material used, its weight, geometry, positioning or appearance.…”

Medical Devices for Tremor Suppression: Current Status and Future Directions

“…Apart from magnetically driven semi-active orthoses, Kalaiarasi and Kumar designed a pneumatically controlled hand cuff [ 114 ]. Similarly, this device is built along with an accelerometer that sends tremor frequency data to a controller.…”