Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physics RCOA > Invasive monitoring > Flashcards

Invasive monitoring Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

What is dynamic response?

A

The speed at which it is able to settle on a new value following a stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What 3 factors interact to affect dynamic response?

A
  • Damping
  • Input frequency
  • Natural (resonant) frequency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is natural frequency?

A

Frequency at which system oscillates when set in motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is input frequency?

A

The frequency of energy input into the system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is resonance?

A

When there is an energy input at the same frequency as the natural frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is damping?

A

Loss of energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is critical damping?

A
  • Damping coefficient of 1
  • No overshoot & long time for amplitude to settle at 0
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does a higher damping coefficient mean?

A

Smaller amplitude response to resonance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When does maximum resonance occur?

A

When input frequency is equal to natural frequency (1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is resonance avoided in an arterial line?

A

Natural frequency should be at least 8 times greater than the max anticipated input frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is natural frequency calculated?

A

Natural freq = speed / wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the optimum damping coefficient for a system?

A

0.64

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the role of an arterial transducer?

A

Convert pressure energy into electrical energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the 3 types of arterial transducers?

A
  • Wire strain gauge
  • Bonded strain gauge
  • Capacitive transducer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is resistivity?

A

The degree to which a material opposes the flow of electrical current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do wire strain & bonded arterial transducers work?

A
  • Contain wires that vary their resistance as arterial pressure is altered
  • Fluctuating in accordance with geometry & resistivity
  • WIRE: Inc art pressure decreases tension of resistance wire = inc CSA & reduced length
  • BONDED: Coil of resistance wire, as art pressure wires stretched - tension & resistance inc
17
Q

What is the equation for resistance of a wire?

A

R = p x l/CSA

p = resistivity
l = length
CSA = Cross-sectional area

18
Q

How does temperature affect resistivity?

A

Inc temp: semiconductors = decrease, metal = increase

19
Q

How does a capacitive transducer work?

A
  • 2 capacitor plates, 1 attached to diaphragm
  • Inc in art pressure reduces distance between 2 plates
  • Inc in capacitance of the capacitor so reduces resistance
  • Change in resistance produces waveform
20
Q

What is a Wheatstone bridge circuit?

A
  • 4 resistors with different properties arranged in a quarter/full-bridge circuit
  • R1/R2 = R3/R4. (R4 = unknown resistance of strain gauge)
  • R4 is calculated by altering R3 resistor until voltmeter = 0
  • R4 can be plotted against time and converted into arterial pressure
21
Q

How does adding a 3rd Sin wave into Fourier analysis affect an arterial trace?

A

Wave more likely to equal resonant frequency of the system
Resonance more likely to occur - amplitude increases x10

22
Q

How is pulse contour analysis calculated?

A

Area under sin wave of arterial trace
Calculates SV & CO

23
Q

What does the dicrotic notch on an arterial trace represent?

A

End of systole & AV valve closure

24
Q

How does hypovolaemia effect the dicrotic notch?

A

Shifts to the right due to delayed AV closure

25
Q

How does early inspiration effect swing on an arterial line?

A
  • Inc intrathroacic pressure compresses pulmonary vessels
  • Inc LV preload
  • Inc SV
26
Q

How does late inspiration effect swing on an arterial line?

A
  • Prolonged inc in intrathoracic pressure compresses now empty pulmonary vessels
  • Reduces LV preload
  • Reduces SV
27
Q

What 2 parameters quantify degree of swing on art line?

A
  • SV Variation: Variation in SV over resp cyle (30secs)
  • Pulse pressure variation: Variation in PP over resp cycle (30secs)
28
Q

How can an arterial line be amplified?

A
  • Simple: Increases amplitude of signal by adjusting gain
  • Differential: Reduces electrical interference by bandwidth frequency/common-mode rejection
29
Q

What are the calibration issues with an art line?

A
  • Zero: Actual reading at 0 displays inaccurately (high)
  • Gain: Actual reading displays as lower - needs amplifier

Physics RCOA (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions