Important Questions and Answers: Medical Electronics - Assist Devices and Bio-Telemetry

ASSIST DEVICES AND BIO-TELEMETRY

1. Define circulatory system

It is a type of transport system. It helps in supplying the oxygen and digested food to different parts of our body and removing CO2 from the blood. The heart is the center of the circulatory system.

2.Define heart, lung?

Heart is a pumping organ which eats regularly and continuously for years. It beats seventy times a minute at rest. Contraction is systole and relaxation is diastole.

3.Define circulation?

We can define from the engineering point of view, the circulation is a high resistance circuit with a large pressure

4. Classify the pacemakers

Fixed rate pacemakers.

Ventricular Synchronous pacemakers

Demand pacemakers

Atrial Synchronous pacemakers

5. Different methods of stimulation

External stimulation,

Internal stimulation

6.What is a Defibrillator?

A defibrillator is an electronic device that creates a sustained myocardial depolarization of a patient s heart in order to stop ventricular fibrillation or artial fibrillation.

7.What are the characteristics of a DC amplifier?

It may need balanced differential inputs giving a high common mode ratio (CMRR). It should have an extremely good thermal and long term stability.

8. Enumerate the merits and demerits of a dc amplifier?

It is easy to calibrate at low frequencies.It is able to recover from an overload condition unlike it’s AC counterpart.

9.Give the purpose of bridge circuits. What are the different types?

The bridge circuits are used in instrumentation systems for the measurement of resistance , inductance and capacitance.

Types:

DC type and

AC type.

10.What are the 2 types of wheatstone bridge?

Null type bridge

Deflection type bridge.

11.What are the different types of AC bridges?

AC bridge using push-pull transducers

AC bridge with push-pull inductive transducers

Inductive transducer

Blumlein Bridge Capacitive transducer

12.Define slew rate

Slew rate is defined as the maximum output voltage change per unit time.

13.List the requirements of an instrumentation amplifier

Low drift

High i/p impedance

High linearity

High CMRR

High noise rejection capability

14.Give few applications of instrumentation amplifier.

The instrumentation amplifier finds increasing application in the amplification of the output signalsobtained from thermocouples, strain gauge bridge and biological electrode.

15.What is a filter?

A filter is often a frequency selective circuit that passes a specified band of frequencies and blocks or attenuated signal of frequencies outside this band.

16. Specify the advantages of an active filter

Gain and frequency adjustment flexibility

No loading problem

Low cost

17.What is frequency scaling?

The procedure of converting a cutoff frequency to a new cutoff frequency is called frequency scaling.

18.What is quality factor?

The ratio of resonant frequency to bandwidth is known as the quality factor Q.

19.What is acquisition time of S/H circuit?

Acquisition time is the time required for the capacitor to charge up to the value of the input voltage after the switch is first started.

20.What is aperture time of S/H circuit?

The aperture time is the time required for the switch to change from ON state to OFF state.

Pacemakers - A device capable of generating artificial pacing impulses and delivering them to heart is known as pacemaker system or pacemaker

External stimulation- Used to restart the normal rhythm of the heart in case of cardiac standstill.

Internal stimulation-It prevents normal self triggering of the heart.

Dc Defibrillation - a capacitors charged to a high dc voltage and then rapidly discharged through electrodes across the chest of patient.

Anterior-anterior paddles are applied to the chest. Anterior-posterior paddles are applied to both the patients chest wall and back so that energy is delivered through the heart.

Telemetry - Telemetry is a technology that allows remote measurement and reporting of information.

Motorracing - Motor racing, allowing race engineers to interpret the vast amount of data collected during a test or race, and use that to properly tune the car for optimum performance