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Electronics of Hemod
Electronics of Hemodynamics Quiz prep for 1-16-16
Question | Answer |
---|---|
Cap. = | Capacitor Stores energy in farads ex: defibrillator |
Bat. = | Battery (DC storage device) |
Gnd. = | Ground (zero voltage, ABSORBS charge) |
Diode = | Directs current flow in one direction only (changes AC to DC), looks like arrow |
Res. = | Resistor (inhibits flow of electrons) medical devices and appliances are resistors, force electricity to do work ; represents workload |
Induct. = | Inductance coil; Transformer; Inductor- stores or converts magnetic flux, think of a coil; boosts current to power x-ray equipment, MRI |
DC Power does what: | defibrillates- direct current |
AC power does what: | fibrillates - 120 V; 60sec/cyc |
What kind of power is found in pacemakers | DC power and parallel circuit |
The strain gauge converts fluid pressure to an electrical signal using: | variable resistors |
Two pressure channels are required to record | Simultaneous pressures |
Calibration assures: | Proper baseline and top pf scale for all channels |
Adjusting the band pass filter to reduce "noise", you change | Hz (frequency filter) |
A 40mm scale is commonly used for: | Right heart pressures |
When using standard disposable transducers with fluid filled catheters, where is the "Wheatstone Bridge" located? In the: | Transducer |
The electrical signal is converted into a waveform on the screen by a process called: | Modulation-demodulization |
What is the modem responsible for | Modulation-demodulization |
The calibration factor for hand calculating pressures sampled on a 100 scale using paper with a grid 50mm high is: | 2 ( 100 divided by 50 = 2) |
If the transducer is zeroed while lying below the level of the catheter inside the patient's chest, the subsequent pressure reading will be: | mistakenly high |
The phlebostatic axis refers to the: | Mid-axillary line |
Phlebostatic axis? | central venous collection of blood - midaxillary, right armpit |
When monitoring BP by radial arterial line on pt that is in a sitting position where should the zeroing port of the pressure monitoring system be positioned? | at the level of the radial artery catheter |
Temperature drift of a pressure transducer should be corrected periodically by: | opening to air, and pressing the zero button |
Your patient has a heart rate of 84. What frequency filter would you select to assure an optimal damping coefficient for a frequency response to the tenth harmonic of his fundamental frequency? | 84 divided by 60 = 1.4; 1.4x 10= 14Hz |
How do you calculate a patients fundamental frequency? | bpm divided by 60= beats per second |
How do you find the tenth harmonic of a patients fundamental frequency? | multiply fundamental frequency by 10 |
Hand calculate patients edp for a 200mmHg pressure scale, LV edp 6 small boxes on a 50 mm paper recording 9 each box is 4mm) | 6x4 = 24mmHg |
Performing the fast flush "Square Wave Test" is for the purpose of: | Testing for optimal damping |
What is a synonym for zeroing? | balancing |
How do you confirm the zero baseline? | by opening to air |
Which of the following would likely be reasons for sampling pressures on a 100 mmHg scale?: normal right heart pressures; normal left heart pressures; AO pressure in a hypotensive patient; PA pressure in a patient with pulmonary hypertension | AO pressure in a hypotensive patient and PA pressure ina patient with pulmonary hypertension |
Air in the system will cause | damping of the waveform |
if you select a scale that's too small: | the waveform will get chopped off/ go off the chart |
If you tell the computer you are recording PC wedge : | it will look for an A wave, V wave and mean |
What is the most accurate form of hemodynamic waveform measurement? | paper recording with simultaneous ECG and waveform |
Tue or False: Dead ender caps should be left on during Zeroing | False, it would result in overshoot, no air equals increased pressure |
It is possible to obtain both CVP and PA/PCW pressures using one transducer without breaking the system by using a: | male to male adapter (blue port and yellow port on Swan) |
Respiratory variation is a significant factor monitoring which waveform? | PCW |
The formula for determining the calibration factor for hand calculating pressure waveforms is: | mm of pressure scale / mm of paper |
The zeroing port of the stopcock should be at the level of the | tip of the monitoring catheter |
A scale commonly used in monitoring femoral arterial pressure is: | 200 mmHg |
A scale commonly used in monitoring right heart pressures is: | 40 mmHg |
Phasic pressure is | instantaneous changes |
It is possible to eliminate catheter whip artifact in a hemodynamic waveform by using a: | band pass filter (measured in Hz) |
What kind of tube connecting a fluid filled catheter to the pressure transducer would have the poorest frequency response? | long, soft, small in diameter |
What kind of tube connecting a fluid filled catheter to the pressure transducer would have the highest frequency response? | long, stiff, large in diameter |