Chapter 2

Question 0

Polarity

Answer 0

Refers to the positive or negative nature of a measured signal

Question 1

Voltage

Answer 1

Refers to electromotive force expressed in a measurement of volts

Question 2

Current

Answer 2

Refers to the flow of electricity in a circuit

Question 3

Resistance

Answer 3

Refers to anything that restricts or deters the flow of a current

Question 4

Differential amplification

Answer 4

Differential amplifiers are required because the signal frequencies generated by the head are also being generated by othere sources

Question 5

Using the head as a signal source

Answer 5

Virtually all bio electric activity is based on the concentration and flow of ions across the cellular membrane.

This transmembrane potential is based on the concentration of ions (charges) inside the cell to those outside of the cell

Question 6

CMRR

Answer 6

The ability of the differential amplifier to perform the function of eliminating unwanted signals is called common mode rejection ratio or CMRR

Question 7

What is the modern EEG amplifier generally have the common mode ratio set at

Answer 7

5000 to 10,000 or more

Question 8

DC (direct current) voltage

Answer 8

Is defined as the potential that exists as a value between two terminals, as in a battery. Direct-current always flows in one direction from naked terminal to the positive terminal. DC potentials me either be positive or negative.

Question 9

AC (alternating current)

Answer 9

A voltage is referred to as an AC voltage if it’s potentially between the two connecting terminals alternating charges polarity. AC waveforms may take many complex shapes. the brainwave recording is a good example of how complex AC waveforms

Question 10

Frequency

Answer 10

Frequency refers to how often or how frequent a wave repeats itself

Question 11

Hertz or Hz

Answer 11

The number of times there is a polarity change with a return to original condition in one second

Question 12

Time and frequency are

Answer 12

Reciprocal to each other or as one increases the other decreases

Question 13

EEG frequency bands

Answer 13

The rhythmicity of EEG signals gives a means of Quantitatively describing EEG records, because the frequency of a rhythm can be measured

Question 14

Delta waves

Answer 14

Delta waves

Question 15

Theta waves

Answer 15

4-8Hz

Question 16

Alpha waves

Answer 16

8-13Hz

Question 17

Beta waves

Answer 17

> 13Hz

Question 18

Equations in electronics

Answer 18

If E = voltage, I = current and R = resistant then:

E= IR
I=E/R
R=E/R

Question 19

Electrical safety in the diagnostic environment is a high priority for several reasons

Answer 19

1. Technicians and other medical personnel assume medical responsibility for the welfare of patients seen in the testing environment and during diagnostic procedures
2. Patients are usually connected to multiple pieces of electrode diagnostic equipment simultaneously
3. Fluids are typically in abundance in the testing environment
4. Patient seen in the testing center are often sick or weakened condition and cannot ambulate as they normally would
5. Patients with heart conditions are often susceptible to lower levels Electrical activity

Question 20

To ensure proper safety from excessive leakage current, loss of instrument current ground, and other hazardous electrical possibilities, the following procedure should be taken:

Answer 20

1. Ensure that all diagnostic equipment is equipped with a 3-pronged grounded
2. Maintain periodic maintenance on diagnostic equipment
3. Do not use extension cords with diagnostic equipment
4. Do not use a direct patient ground leads when executing portable procedures
5. Check all equipment for Frayed, loose, or torn wires
6. Report abnormal interference patterns as this may indicate poor ground of the instrument
7. Ensure that the testing area is dry free, from spills ,and that the patient has a low resistance ground To earth
8. Always power on the equipment before the patient is hooked to the equipment. Likewise, always remove all interfaces between the patient and electrodiagnostic equipment before turning off the equipment.

Question 21

AC frequencies range from

Answer 21

Essentially DC through infinity

Question 22

Limitation is defined by

Answer 22

Numbers for lowest and highest frequencies

Question 23

The range of frequency included by

Answer 23

The lower where in the higher figure it’s called the band width of the system

Question 24

In EEG the frequency of interests are

Answer 24

DC (0Hz) to 100Hz

Question 25

AC coupled by calibrators

Answer 25

Have a cutoff frequency above DC

Question 26

The frequencies at the upper and lower it ends at the bandwidth referred to

Answer 26

70% values

Question 27

There are three controls on a narrow diagnostic instrument

Answer 27

Low-frequency filters, high-frequency filters, and 60Hz filters

Question 28

Low frequency filters

Answer 28

The primary of the LFF is attenuation of frequencies below a certain point, while allowing frequencies above this point to pass relatively unobtrusive

Question 29

LFF

Answer 29

Low-frequency filters

Question 30

HFF

Answer 30

High frequency filters

Question 31

Time constant

Answer 31

It’s the time required for a capacitor to charge to 63% of its full charge

Question 32

The decay time constant, or Falltime constant is:

Answer 32

It’s the time required for a capacitor to discharge to 37% of the full charge

Question 33

60Hz Rejection filter

Answer 33

60Hz Rejection filter

Question 34

The cutoff frequency is

Answer 34

The frequency above which the significant attenuation

Question 35

Alternating current power wiring

Answer 35

When the AC power comes into the building it passes through a substation and is transformed from very high voltage to a low potential to be used inside the building

Question 36

Thermistors

Answer 36

Nasal and oral thermistors are used in polysomnography to record airflow from the nose and mouth

Thermistors are sensitive to changes in temperature