Monitoring glossary lectures 3-5

Question 1

Poiseuilles’s Law

Answer 1

resitance =8xVxL/pi r^4

Question 2

leakage current

Answer 2

current that passes from energized electrical portions of device to metal chassis and the to the earth ground natural occurrence. all electrical equipment has leakage current

Question 3

macroshock

Answer 3

causes ventricular fibrillation high value

Question 4

microshock

Answer 4

low value current that passes directly to heart via in dwelling needle or catheter

Question 5

< 1ma for 1 sec

Answer 5

faint tingling

Question 6

1-8 mA

Answer 6

maximum harmless current

Question 7

10-20 mA

Answer 7

PAINFUL SHOCK WITH LOSS OF MUSCULAR CONTROL LET GO THRESHHOLD

Question 8

20-50MA

Answer 8

EXTREME PAIN FAINTING CANNOT LET GO

Question 9

100-200mA

Answer 9

VENT. FIB. WILL START BUT RESPIRATORY WILL BE OK

NERVE DAMAGE

Question 10

200+mA

Answer 10

CARDIAC ARREST SEVER BURNS DEATH

Question 11

standard safe microshock leakage

Answer 11

5mA OR 60 Hz

Question 12

line isolation monitor

Answer 12

predicts next fault monitors impedance

Question 13

biometrics

Answer 13

science that include measurment off physiological variables and parameters

Question 14

range

Answer 14

all input levels of amplitude and frequency which device is expected to operate

Question 15

sensitivity

Answer 15

how small a variation that can be detected. ratio of output amplitude vs input amplitude

Question 16

linearity

Answer 16

degree that variations in the output follow variation in input 1 to 1

Question 17

hysteresis

Answer 17

“to be behind” variable response

Question 18

frequency response

Answer 18

variation in sensitivity over a frequency range of measurement. system should be able to respond quickly enough to reproduce all frequency components of waveform

Question 19

natural frequency

Answer 19

frequency response id dependent on this. you want high natural frequency system to obtain more accurate pressure meausurements at lower frequencies

Question 20

accuracy

Answer 20

measure of closeness to actual true value (lab pump LPM reading vs actual)

Question 21

precision

Answer 21

degree of reproducibility of a measurement (in lab can you do it again)

Question 22

types of errors

Answer 22

range tolerances,mechanical (errors in meter movement), component errors due to drift or temp. variation, poor frequency responce, improper zeroing or calibration, atmospheric pressure

Question 23

stability

Answer 23

ability of system to resume steady state following disturbance

Question 24

electrode

Answer 24

captures biopotential

Question 25

transducer

Answer 25

converts non electrical physical force (pressure,temp) to an analogous electrical signal that is in proprtion

Question 26

artifacts

Answer 26

false signals superimposed on true signal

Question 27

dynamic response

Answer 27

systems ability to measure physiological pressure changes

Question 28

fidelity

Answer 28

indication of systems capacity to produce physiological event

Question 29

natural frequency

Answer 29

what system vibrates at when stimulated by pulsatile signals

Question 30

overshoot/undershoot

Answer 30

system vibration when patient's pressure wave contains a component frequency equal to systems natural frequency

Question 31

ringing

Answer 31

small spikes on waveform due to inadequate dynamic response characteristics

Question 32

hemodynamic pressure

Answer 32

energy in form of pressure wave imparted by blood from lv

Question 33

kinetic energy

Answer 33

associated w motion

Question 34

hydrostatic pressure

Answer 34

fluid density and gravity conttribute

Question 35

inertia

Answer 35

inabilty to move or act. long tubing will create lag time

Question 36

formula for natural frequency

Answer 36

catheter radius x sqrt (volume elasticity of tranducer membrane/catheter length x fluid density x pi)

Question 37

ideal frequency

Answer 37

40-50 hz 20 hz minimum

Question 38

underdamping causes

Answer 38

compliant pressure tubing dercrease if waveform contains harmonic equal

Question 39

overdamping cause

Answer 39

component frequency exceed frequency response of system portions of those waveforms dependent on those waveforms will be obscured

Question 40

damping formula

Answer 40

4 x viscosity of fluid/ fluid density x cathter rad. ^2

Question 41

optimal damping coefficient

Answer 41

d=.64

Question 42

nature of over damped waveform

Answer 42

underestimates sbp and dbp due to air bubble,overly compliant tubing, catheter kinks,clots,stopcocks,no fluid in flush bags low flush bag pressure

Question 43

nature of underdamped

Answer 43

overestimates sbp and dbp due to long tubing and increased vascular resistance

Question 44

resonance

Answer 44

tendency of a system to oscillate at a greater amplitude st some frequencies