Biomedical Eng in Physiotherapy

7/31/2019 Biomedical Eng in Physiotherapy

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APPLICATIONS OF

IOMEDICAL ENGINEERING IN

ORTHOPAEDIC

PHYSICALTHERAPY


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Anyone who stops learning is old,

whether at twenty or eighty. Anyone

who keeps learning stays young.

The greatest thing in life is to keep

your mind young. Henry Ford


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Orthopaedic physical therapy

Orthopaedic physical therapy is a branch ofphysical therapy which mainly deals with boneand joint related problems

The main aims of treatment are to relieve pain,enhance healing, strengthen muscles andimprove mobility


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Modalities

A method of therapy that involves physical orelectrical therapeutic treatment

Physical therapists use a variety of modalitiesto help treat their patients.

There are a variety of treatment modalities that

can help strengthen, relax, heal muscles andreduce pain.


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Classification of modalities

Electromagnetic

Electrical

Sonic Radiation

Mechanical


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How are Modalities Related?

Electromagnetic energy modalities Shortwave and microwave diathermy

Electrotherapy

Faradic and galvanic currents

TENS

IFT

Iontophoresis

Acoustic energy modalities

Ultrasound


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Radiation modalities Infrared therapy

ultraviolet therapy

Laser hterapy

Conduction modalitiesparaffin wax

contract bath

Mechanical modalitiesTraction

CPM


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Shortwave Diathermy

Heats tissue by introducing high frequencyelectrical current

Performs through electrostatic field heating orelectromagnetic/induction field heating

Pulsed diathermy is relatively new Not continuousreduces likelihood of significant

tissue temperature increase

Utilizes drum electrode

Produces both thermal and non-thermal effects


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Equipment

High frequency generator with an oscillatoralong with amplifier for converting ACcurrent to DC

Also has circuit that tunes to patientTreatment applicator is either condenser or

inductive type

With condenser, patient is part of circuitand requires use of flexible electrodes

Inductiveutilizes drum or cable

electrodes


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Electrotherapy

Low frequency

Electrical stimulation

Iontophoresis

Medium frequency

IFT

High frequency SWD

MWD


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Electrotherapy

Physical Principles

Electricity displays magnetic, chemical, mechanical, andthermal effects on tissueVolume of current (ampere)

Rate of flowResistance

Force that current moves along = voltage

Electricity is applied to nerve tissue at certain intensities

and duration to reach tissue excitability thresholdsresulting in membrane depolarizationTarget sensory, motor, and pain nerve fibers in an effort to

produce specific physiological effects


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Electrical Stimulating Units

Three types of unitsTENS - transcutaneous electrical nerve stimulators

NMES/EMS - neuromuscular electrical stimulators orelectrical muscle stimulators

MENS/LIS - microcurrent electrical nerve stimulatorsor low-intensity stimulators

Generate 3 types of current Monophasic

Direct current or galvanic current - flow in one directiononly from (+) to (-) or vice versa

Used to produce muscle contraction, pain modulation, ionmovement (determined by specific parameters)

Biphasic Alternating current where direction of flow reverses during

each cycle

Useful in pain modulation and muscle contractions


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Ionotophoresis Chemical ions are transported through intact skin

using electrical current -- used to treat skininfections or to produce a counterirritant effect Requires use of low voltage direct current on continuous

mode w/ a long pulse duration (allows for migration ofions)

Polarity of pads is set relative to the medication/solutionbeing used


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Low Intensity Stimulators Microcurrent electrical nerve stimulator Operates at low frequencies and intensities (sub-

sensory) Used to stimulate healing of soft tissue and bone


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INTERFERENTIAL THERAPY

The name Interferential therapy stems

from the concept of two currents

interfering with each otherThis becomes readily apparent when one

views the four electrodes (quadripolar) that

are necessary to produce the standardinterferential effect in a patient


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Makes use of 2 separate generators, emitting current

at slightly different frequencies Quad polar pad placement is used creating

interference pattern

Creates a broader area of stimulation


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Transmission of Thermal Energy

Conduction

Heat is transferred from a warmer object to a coolerone

Dependent on temperature and exposure time

Temperatures of 116.6o F will cause tissue damageand temperatures of 113o F should not be in contact

w/ the skin longer than 30 minutes Examples include moist hot packs, paraffin, ice

packs and cold packs


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ConvectionTransfer of heat through movement of fluids or

gases

Temperature, speed of movement, andconductivity of part impact heating

Whirlpools

Radiation Heating is transferred from one object through

space to another object

Shortwave diathermy, infrared heating and

ultraviolet therapy

Conversion Generation of heat from another object (sound,

electricity or chemical agents)

P ffi B h


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Paraffin Bath

Equipment

A paraffin wax and mineral oil combination, heated to

126-130o F

Indications

Useful in treating chronic injuries

Effective for angular areas of body such as hands,wrists, elbows, ankles and feet


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Contrast Bath

Equipment

Requires use of hot and cold tubs


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Ultrasound

Modality which stimulates repair of soft tissueand pain relief

Form of acoustic energy used for deep tissueheating

Operates at inaudible frequency

Sound scatters and is absorbed as it penetrates

tissues -- losing energy = attenuation

Impedance and penetration are determined byproperties of media (densities)


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Equipment

High frequency generator which provides

electrical current through a coaxial cable to atransducer applicatorThrough piezoelectric effect electrical current is

transformed into acoustic energy through contraction

and expansion of piezoelectric crystals Frequency ranges between .75 and 3.0 MHz

1 MHz ultrasound allows for deeper penetration while3 MHz is absorbed more superficially


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Traction

Drawing tension applied to a body segment


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Low Level Laser Therapy

Light Amplification by Stimulated Emission of Radiation

Used for collagen synthesis, control of microorganisms,increased vascularization, and pain/inflammation reduction

Helium-neon and gallium-arsenide lasers are currently beingexplored by the FDA


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Continuous Passive Motion(CPM)


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Purposes

Produce passive joint motion

Moves the limb through ROM by grasping itproximal and distal to the joint

Effects: Enhance nutrition

Increase metabolic activity

Stimulate tissue remodeling and re growth of healing

tissues:Articular cartilage

Tendons

Ligaments


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Safety in Using Therapeutic

Modalities

Equipment must be used and maintained inappropriate manner

Following manufacturer recommendations

Regarding use and maintenance

Failure to follow recommendations = negligence

Documents

Biomedical Eng in Physiotherapy