AWABS - Blood pressure

Question 1

Why is mercury used for blood pressure

Answer 1

Mercury is heavier than water

If something lighter like water was used then column of comparative fluid would need to be extremely large (eg. 2m long)

Question 2

Sounds listened for when measuring

Answer 2

Korotkoff sounds

Question 3

DINAMAP machine

Answer 3

Device for Indirect Non-invAsive Mean Arterial Pressure

Essentially electronic BP machine

Question 4

Maximum length that an arterial line tubing should be

Answer 4

1.2 m long

Question 5

Electrical circuit used in arterial lines

Answer 5

Quarter-bridge strain gauge circuit

Question 6

How Quarter-bridge strain gauge circuit works out BP

Answer 6

4 resisters in circuit with 1 being a variable resistor which allows changes in pressure to be detected

Question 7

Different arterial line traces expected in different artery sites of line

Answer 7

Question 8

Implication of arterial line trace changing in amplitude (swinging)

Answer 8

Patient is underfilled

Question 9

Resonance

Answer 9

Ability of an object to oscillate in response to a movement

Question 10

Natural frequency

Answer 10

Frequency of …

Question 11

Damping

Answer 11

A decrease in the amplitude of an oscillation as a result of energy loss from system due to eg. friction

Question 12

Damping coefficient

Answer 12

Value between 0 and 1

Question 13

Critical damping

Answer 13

Damping coefficient 1.0

Degree of damping that allows most rapid return to equilibrium

Question 14

Optimal damping

Answer 14

Damping coefficient 0.64

Best combination of rapid response to change in the input value with minimal overshoot