biophysics

Physiotherapy

Physiotherapy is a form of treatment carried out through the medium of physical forces

Methods of physiotherapy

1.infrared Rays

2.short-wave & microwave diathermy

3.electrical stimulation therapy

4.ultrasound therapy

Name this device and the types

Infrared :electronmagnetic radiation with longer wavelength than visible light

Types : A, B and C

benefits of IR

IR promote local bloods circulation and reduce muscle tension

Risk of IR light

1.burn

2. Low risk of eye damage

UV

UV is a kind of therapy that involves exposing the skin to UV for a prescribed duration of time

Types of UV and penetrance ability

UV A & B

UVB has a short wavelength that reaches the epidermis

UVA has a longer wavelength

That reaches the dermis

Benefits and risk of UV

Benefits

1.improve blood circulation

2.stimulates production of collagen

Risk

Can cause eye conjunctivitis

Short-wave & microwave diathermy

Is the application of high frequency electromagnetic energy that is used to generate heat in tissue

First method to transfer electromagnetic energy

Short-wave is the first method

The body part is placed between two metal plates

Short-wave uses a frequency of

27.12 MHz that corresponds to approximately 11 meters

Microwave diathermy

Is easier to use than short-wave

They are emitted from applicator antenna

They use a frequency of 900MHz

Creates heat around bonny regions

Name this method of physiotherapy

Ultrasonic

It is rather mechanical energy or sound energy duo to the vibration

The frequencies that are used for medical purposes are 1MHz and 3MHz

Ultrasonic working principle

using an ultrasound transducer to transmit continuous sound wave energy into human tissue.

The sound waves cause particles within the tissue to oscillate and vibrate.

This increases in molecular vibration generates heat, creating thermal changes in the targeted area.

What is the basic mechanism of Electrical Stimulation Therapy?

Uses an electrical current via skin electrodes to cause a single muscle or group of muscles to contract.

What are the three types of electrical stimulation therapy, and what is the primary focus of the first two?

1. General electric therapy: Used for alleviating pain and healing wounds.

2. Muscular electric stimulation: Aims to strengthen muscles by reducing muscle spasms.

3. Transcutaneous Electrical Nerve Stimulation (TENS): Used to treat chronic pain.

What is the physical setup and basic mechanism of a TENS Machine?And for which condition we use TENS?

It has multiple leads based on several channels and electrodes to make it ready for functional use.

It involves a high-frequency signal applied to the painful area, which stimulates the nerve and cuts off the pain message to the spinal cord or brain.

It is used for

• Osteoarthritis

• Joint and muscle pain

• Back pain

• Migraines

• Neuralgic pai

Piezoelectric Effect of Ultrasound

1. Electrical signal is converted to sound

2. The sound is reflected duo to contact with tissue

3. Sound is converted back to electronic signal and later to image

Reflection

The amount of reflection is depended on the difference in acoustic impedance

Scattering

Redirection of sound in several directions

Happens when sound waves are interacted by small reflector or rough surface

Transmission

The waves go deeper into body and the reflection shows structure in deeper tissue

Attenuation

The waves go deeper into body so as a consequence the amplitude of the wave decreases

Electrocautery and. Electrosurgery

Electrocautery: direct current

Electrosurgery: alternating current

Frequency used in electrosurgury

We need more than 100kHz since this rate can stimulate muscle

A generated that uses 60 cycle current increase the frequency to 200000 cycle

Bipolar electrosurgery and. Monopolar electrosurgery

Bipolar:In bipolar electrosurgery, both the active electrode and return electrode functions are performed at the site of surgery and patient return electrode is not needed

Monopolar: duo to versatility and clinical effectiveness it is more used only the active electrode is at surgery site and a patient return electrode is placed to finish the circuit

Electrical wave forms

It depends on duty cycle we have 5 waveforms

100% on (pure cut)

50% on (blend 1)

40% on (blend 2)

25% on (blend 3)

6% on (coag)

On refers to duty cycle

Pure cut produces more heat that is why it vaporize tissue

Electrosurgical tissue effects

cutting:hold the electrode away from tissue,used to vaporize

Fulguration: hold the electrode away from tissue,used to coagulate

Desiccation:direct contact between tissue and electrode

Electrosurgical systems

Grounded:uses alternate path to ground to avoid alternate site burn

Isolated:circuit is completed not by the ground but by the generator, Isolated electrosurgical energy recognizes the patient return electrode as the preferred pathway back to the generator.

X-rays and gamma rays

X-rays:originate in the electronic shell

Gamma rays:originate in the nucleus

Diagnostic X-rays

Radiotherapy: a picture sent directly to computer screen

Fluoroscopic: a real time moving inspection

Key points to keep exposure to radiation at minimum

1. Time

2. Distance

3. Shielding

Non-contact tonometer

Measures the pressure in eyes

High pressure indicates glaucoma

Autorefractor

Measures your eyes ability to facus

Retinoscope

Used for testing the eyes of small children and it is very accurate

Opthalmoscope

Examine the retina at the back and also examines blood vessels and the front of optic nerve

The slit lamp

Examining cornea ,iris and lens

Visual evoked potentials

A test that shows how the visual system records light

Electro-oculography

Measures the resting potential of the retina

Ohm’s law

Shows the relation between voltage, current and resistance

What each wave indicate and what is their duration

P wave: atrial depolarization 0.1 sec

QRS wave: ventricular depolarization. 0.08-0.1sec

T wave: ventricular repolarization 0.16 sec

A: sinoatrial node

B: atrioventricular node

Bundle of his

Purkinje fibers