Hand Tremor Sensing Module Group #4 Ander Sahonero Andrew Mendoza Anisley Valenciaga Tatiana 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

Neurological Disorders 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 Parkinson’s Damage to brain structures that control movement Patients have trouble initiating movement Generally after age 60 Multiple Sclerosis Caused by damage to the myelin sheath, nerve impulses are slowed down or stopped. Commonly diagnosed between ages 20 and 40 Strokes Occurs when blood flow to a part of the brain is interrupted because a blood vessel in the brain is blocked or bursts open May cause brain damage because oxygen to brain is deprived

Three main 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 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 Steps Taken to produce product: Circuit parts soldered unto a small soldering board. A small 3’x3’ Plexiglas sheet was used as a base for the equipment. Using small ½’ wooden stands, the battery pack was attached on top of base Two 2’ slots were cut into the base to allow for a Velcro strap to go through. The soldering board was then screwed unto the clear Plexiglas base using 1¾’ screws and secured using 4mm nuts. In order to create a wearable device, a Velcro strap was inserted through the 2’ slots on the Plexiglas. The Velcro strap then served as a wearable belt that would go tightly around the waist and function as an activity measuring device.

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 Design of Circuit Low Pass Envelop Detector Input Amplifier LED and Driver Transducer Design of Circuit Low Pass Envelop Detector Input Amplifier Potentiometer

Apparatus Final Circuit Design Input Amplifier Low Pass Potentiometer Transducer LED and Driver Low Pass Final Circuit Design Potentiometer Envelop Detector

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 Figure 6- Output of the assembly when the person is standing. (Data Tables, Table 4)

Future Directions General Tremor Sensor Actigraph 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