Hand Tremor Sensing Module

Group #4

Ander SahoneroAndrew Mendoza

Anisley ValenciagaTatiana Bejarano

Ricardo Siu

Purpose and Goals

Investigate the types of tremors present in humans

Examine the causes and treatments Determine the frequency at which

they appear All of this will be done in order to

construct a medical device which can be used as a tremor sensor

Then use device to observe subject at rest , standing up, and after exercising

What is a tremor?

Unintentional, sometimes rhythmic movement of muscles of the body

Commonly occur within the hands, also occur in head, neck, arms, legs, torso, or other body parts

Can propagate from one region of the body to another

Occur between frequencies of 5 to 15 Hz

Two main types: physiological and pathological

Causes of Tremors

Natural Causes Caffeine Stress, Anxiety, and

Fatigue Prescription, Medication,

Age Low Blood Sugar Alcohol Drug Abuse

Causes of Tremors

Neurological Disorders Caused by problems arising in parts of the

brain whose purpose is to control muscles in specific areas of the body• Parkinson’s• Multiple Sclerosis• Strokes

Types of Tremors

Resting Tremor These tremors are

present when your muscles are resting

The tremor may go away or become less noticeable when you move muscles that are involved

Action Tremors Occur at the end of a

intended movement ( writing, pressing a button, or reaching for an object)

The tremor will usually disappear while the affected body part is at rest

Three main types of tremors:

Kinetic Tremors Holding arm or leg in one

position for a period of time against gravity (writing, holding a cup, holding your arms out, or when you stand up straight)

Types of Tremors

Physiologic tremor - every normal individual and has no clinical significance

Essential tremor-is the most common of the more than 20 types of tremor

Parkinsonian tremor - damage to structures within the brain that control movement

Dystonic tremor -all ages who are affected by dystonia

Psychogenic tremor - can occur at rest or during postural or kinetic movement

Orthostatic tremor -fast (>12Hz) rhythmic muscle contractions that occur in the legs and trunk immediately after standing

Rubral tremor is characterized by coarse slow tremor which is present at rest, at posture and with intention

Cerebellar tremor - slow, broad tremor -extremities that occurs at the end of a purposeful movement

Tremor Video

Are there cures for Tremors?

There are no cures for most tremors

There are some medications that can be taken to reduce effects

Psychogenic tremors

can be treated

Treatment for Tremors

Drug treatment for parkinsonian tremor Levodopa and/or dopamine-like drugs Lowering effects include amantadine

hydrochloride an anticholine drugs Propranolol or beta blockers

are used when treating essential tremors

Elimination of trigger such as caffeine and altering diet

Physical therapy

Mechanical interface design

A piezo-film transducer was utilized which a circuit was able to convert changes in displacement to electrical signals

After going through the filters, the transducer is capable of obtaining readings for frequencies that fall within the range of normal hand tremor frequencies

Our device picks up frequencies between 1 Hz and 10Hz

Fabricating Interface

One objective of our tremor sensing equipment was to make it fully portable and,

when functioning as an activity measuring device,

wearable

Hand positioning Testing procedure

must follow this plan of action: The equipment is to

be set on a stable base

Hand is to be unsupported and the finger positioned lightly above the transducer

Hand (right or left) must be placed in a rested position

Measurement to be taken at the index finger or middle finger

Positioning of belt When the equipment is

to be used as an activity measuring device: The device is simply worn

across the waist in a belt-like fashion

Detach the Velcro straps Place the belt around your

waist Fasten belt to your girth,

making sure it is securely fastened so device is not shaking while your exercising

 

Components

Piezoelectric transducer: to change mechanical energy into electrical energy

10-segment LED bar graph: displays intensity of tremor

Components

LM 3914 IC: driver of the LED bar

LM 741: operational amplifier to modify input

Components

Potentiometer: used as a variable resistor

Diode: to allow current to pass in one direction

Components

Breadboard: is a construction base for a electronic circuit

Jumper wires: used to transfer electrical signals from on part of the breadboard to the central microcontroller

Resistors: two-terminal passive electronic component which implements electrical resistance as a circuit element

Capacitors: device for storing electric charge.

Apparatus

Transducer

Low Pass

LED and Driver

Potentiometer

Envelop Detector Input Amplifier

Design of Circuit

Apparatus

Transducer

Low PassLED and Driver

Potentiometer

Envelop Detector

Input Amplifier

Final Circuit Design

Schematics

Input Amplifier

Schematics

Low Pass Filter

Schematics

Amplifiers Combined

Schematics

Envelope Detector

Schematics

Electronic Module Design

Compromises Required

In order to make it portable, we used a smaller graph display

To make design meet the power supply specifications a bulky battery pack was used

Final Product

Video Demonstration

Long Term Data/ Results

Output of the assembly when

the person is resting

Output of the assembly when

the person is standing

Output of the assembly after

running for 5 minutes

Future Directions General

A smaller transducer Integration of a recording module

Tremor Sensor Better patient interface LED displays warning when a certain threshold

is reached Actigraph

Improve the design by encasing it• More durable and rugged design

Live Demonstration

We will now perform a live demonstration of our hand

tremor detector with the help of a live subject (patient)

from the audience, where a signal tremor will be

displayed