SENSORY SYSTEMS INSTRUMENTATION

BY

MARYAM IDRIS MUSA (20142926)

MSc BIOENGINEERING

IntroductionSensory system instrumentation refers to the

application of engineering techniques and analyses

using sensory system which is part of the peripheral

nervous system to design devices that can be used

for detection, measurement and monitoring of

physiological signals.

Examples of Sensory DevicesThe Hearing Aid:This is an electroacoustic device which is designed to amplify sound for the wearer. It receives sound through a microphone, which converts the sound waves to electrical signals and sends them to an amplifier. The amplifier increases the power of the signals and then sends them to the ear through a speaker.

Thermometer:

This measures temperature or temperature gradient using a variety of different principles. These include thermal expansion of solids or liquids with temperature or the change in pressure of gas on heating or cooling. The digital contains diode as temperature-sensing element. The radiation-type thermometers measure the infra red energy emitted by an object

Balloon Catheter This is a type of "soft" catheter with an inflatable "balloon" at its tip which is used during a catheterization procedure to enlarge a narrow opening or passage within the body. The deflated balloon catheter is positioned, then inflated to perform the necessary procedure, and deflated again in order to be removed. It is used for the treatment of chronic epiphora and nasolacrimal obstruction in children and adults.

Contact lenses:A contact lens is a thin, clear disks of plastic

that floats on the surface of the eye. They are designed to correct refractive errors and maintain ocular health. Contact lenses are used to correct the same conditions that eyeglasses correct:myopia (near sightedness);hyperopia (farsightedness);astigmatism (blurred vision due to the shape of the cornea);presbyopia (inability to see close up).A soft contact-lens biosensor (SCL-biosensor) for novel non-invasive bio monitoring of tear fluids has recently been fabricated. The biosensor has an enzyme immobilized electrode on the surface of a polydimethyl siloxane (PDMS) contact lens.

continued

Smart contact lens

These are contact lenses with embedded sensors

and other miniaturized electronics to measure

glucose levels in the tear fluid of the eyes.

The measurements would be transmitted wirelessly

to a mobile device, for viewing by diabetic

patients and their doctors.

Another possible use of the technology would be

to provide near-focusing capability for intraocular

lenses that are implanted during cataract surgery.

This would benefit people with presbyopia who

would otherwise need reading glasses.

Narrow-band UVB PHOTOTHERAPYfor Skin Diseases

MECHANISM OF ACTION

In the skin, NB-UVB radiation is absorbed by DNA

and urocanic acid.

Inhibits DNA synthesis.

Inhibits epidermal keratinocyte

hyperproliferation.

Induces T-cell apoptosis.

Induces immunosuppression.

Induces anti-inflammatory cytokines.

Alters antigen presenting cell activity.

Thus, the ability of NB-UVB radiation tosystemically suppress the major components ofcell mediated immune function is linked to itsbeneficial effect in several inflammatory skindiseases.

LED Light Therapy Device

This is use to treat skin disease psoriasis vulgaris.A light-emitting diode (LED) is a two-lead semiconductor light source. It is a basic pn-junction diode, which emits light when activated.

When a suitable voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect called electroluminescence, and the colour of the light (corresponding to the energy of the photon) is determined by the energy band gap of the semiconductor.

FUNCTIONS OF A BIOMEDICAL ENGINEER

A biomedical engineer designs medical instruments that help healthcare personnel

Detection

Monitoring and

Treatment of diseases associated with the sensory systems

Conclusion

The nervous system is the body’s principal regulatory system, and pathological processes in it often lead to serious functional disturbances. With the help of instruments such as EEG, ECG.EMG etc. these processes can be measured and its activities monitored which can help in diagnosis and treatment diseases.

References International Journal of Advanced Research in Electrical, Electronics and Instrumentation Engineering(An ISO 3297:

2007 Certified Organization)Vol. 3, Issue 3, March 2014Copyright to IJAREEIE www.ijareeie.com 7707. Review on Biomedical Instrumentation

Basic concepts of medical instrumentation. Medical instrumentation: application and design. Fourth edition. John G. Webster

Handbook of Biomedical instrumentation by Khandpur

www.wikipedia.org

www.meditech.com

www.Princeton.edu

www.ncbi.nlm.nih.gov/pubmed

Introduction to Biomedical Instrumentation. 2010.Mandeep Singh