RECENT TRENDS IN MEDICAL INSTRUMENTATION
1.What is LED?
The LED is basically a semiconductor PN junction diode capable of emitting electromagnetic radiation under forward conductions.
2.Compare common anode and common cathode displays.
Common anode type display require an active low (or current linking) configuration for code converter circuitry, whereas an active high output circuit is necessary for common cathode LED type display.
3.List the characteristics of LCD.
Light scattering Can operate in reflective or Transmissive configuration.
Do not actively generate light and depend for their operation on ambient or back light.
4 .On what does the operation of LCD depend?
The utilization of a class of organic materials which remain a regular crystal like structure even when they have melted.
5.Name the 2 commonly available types of LCDs.
Dynamic scattering and
Field effect type.
6.What is the purpose of dot matrix displays?
Excellent alphanumeric characters can be displayed by using dot matrix LEDs with an LED at each dot location.
7.What are the commonly used dot matrices for the display of characters?
The commonly used dot matrices for the display of prominent characters are 5 x 7, 5 x 8 and 7 x 9.
8.What are the 2 writing patterns of dot matrix displays?
Common anode or common cathode connection (uneconomical)
X-Y array connection (economical and can be extended vertically or horizontally using a minimum number of wires)
9. Define transducers.
Transducers are defined as a device which when actuated, transforms energy from one form to another. Generally, any physical parameters is converted into electrical form.
10.What are the 2 types of transducers?
11.Name the parameters that dictate the transducer capability
Sensitivity is defines as the electrical output per unit change in the physical parameter. High sensitivity is generally desirable for a transducer.
13.Classify electrical transducers.
14.Name the 2 parts of a transducer
15.Mention the factors considered while selecting a transducer.
Operating range Sensitivity
Frequency response & resonant frequency Environmental compatibility
Minimum sensitivity Accuracy
Usage and ruggedness Electrical parameters
16.What is meant by POT?
POT is a resistive potentiometer used for the purpose of voltage division. It consists for a resistive element provided with a sliding contact called as wiper.
17. Explain the working principle of a strain gauge.
Strain gauge works on the principal that the resistance of a conductor or a semiconductor changes when strained. This property can be used for
measurement of displacement, force and pressure.
18. What is meant by rosette?
It is a combination of strain gauges to a single element strain gauge.
Thermograph - Thermograph, thermal imaging, or thermal video, is a type of infrared imaging
Infrared thermography - is the science of acquisition and analysis of thermal information by using non contact thermal imaging devices
Liquid Crystal Thermography - Liquid crystals are a class of compounds which exhibit colour temperature sensitivity in the cholestric phase
Endoscopy - An endoscopy is a test that looks inside the body. The endoscope is a long flexible tube that can be swallowed. It has a camera and light inside it. Some doctors call it a telescope
Upper Endoscopy - Upper endoscopy enables the physician to look inside the esophagus, stomach, and duodenum (first part of the small intestine)
Arthroscopy: Examination of joints for diagnosis and treatment (arthroscopic surgery)
Bronchoscopy: Examination of the trachea and lung's bronchial trees to reveal abscesses, bronchitis, carcinoma, tumors, tuberculosis, alveolitis, infection, inflammation
Colonoscopy: Examination of the inside of the colon and large intestine to detect polyps, tumors, ulceration, inflammation, colitis diverticula, Chrohn's disease, and discovery and removal of foreign bodies.
Colposcopy: Direct visualization of the vagina and cervix to detect cancer, inflammation, and other conditions.
Cystoscopy: Examination of the bladder, urethra, urinary tract, uteral orifices, and prostate (men) with insertion of the endoscope through the urethra
EGD (Esophogealgastroduodensoscopy): visual examination of the upper gastro-intestinal (GI) tract. (also referred to as gastroscopy) to reveal hemorrhage, hiatal hernia, inflammation of the esophagus, gastric ulcers.
Laparoscopy: visualization of the stomach, liver and other abdominal organs including the female reproductive organs, for example, the fallopian tubes.
Laryngoscopy: examination of the larynx (voice box).
Diagnostic: Goal is to learn something about the tissue
Therapeutic: Goal is to modify the tissue, e.g. kill malignant cells.
Diathermy - is the treatment process by which cutting, coagulation of tissues are obtained.
Induction Electrodes- Creates a stronger magnetic field than electrical field. A cable or coil is wrapped circumferentially around an extremity or coiled within an electrode