Capacitive Touch Sensor for Foot Drop Paralysis Stimulator

THAILAND, Mahidol University

iCAN 2011 Beijing China

Apivan Trungtrakul, Jirawat Jitprasutwit, Ratikorn Chaivattanatham

Advisor: Zeng Lertmanorat, Ph.D.

Foot drop

@Faculty of Physical Therapy, Mahidol University

Cause of foot drop

Stroke

20% of survivors

They have foot drop.

Every year

15 million people suffer a stroke

5 million are left permanently disable

1 million Foot Drop per year

In Thailand

At less 400,000 Foot Drop

Treatments

• Tendon transfer (surgery)

• Ankle foot orthotic (joint support)

Tendon transfer Ankle foot orthotic

Electrotherapy: Foot drop stimulator (FDS)

Sensor part

Electrical stimulator part

Control part

Nerve & Muscle

Contraction!!!

FDS in commercial

OdstockEurope

1,700 $

Bioness L300USA

6,500 $

Force sensor

WalkAideUSA

4,495 $

XFT ElectronicChina

1,380 $

Tilt sensor

Our sensor

Capacitive technique

Simple calculation

Sensor benchmark

Power consumption

Durability

Cost

Reliability

Extra electronic circuit

SCORE -1 -1 3

Tilt sensor Force sensor Cap. sensor

FDS system & accessory

Capacitive

sensor

FDS system

Electrode

Controller

&

stimulator

Set parameter via software

Commercial FDS

300 – 400 USD (Thailand only)

1 adjustable knob

2 interface buttons

3 stimulation modes

WalkUp FDS

Clinical Trial

Summary

New Sensing Technique Capacitive touch sensor

Low Power Consumption 2.75 nA

High durabilityPCB-based Sensor