Biomedical Instrumentation Multiple Choice Questions on “QRS Detection Techniques”.
1. ______ is used to determine the physical performance characteristics of a cardiac patient.
a) Data compression techniques
b) Stress test electrocardiography
c) Stress amplitude ECG
d) QRS detection techniques
Answer: b
Clarification: Stress test or exercise electrocardiography is used when the diagnosis of coronary arterial disease is suspected or to determine the physical performance characteristics of a cardiac patient. The test involves the recording of the electrocardiogram during dynamic or occasionally isometric exercise.
2. Which of the following are devices used for testing physical fitness?
a) Treadmill and sphygmomanometer
b) Ergometer and sphygmomanometer
c) Treadmill and Ergometer
d) Sphygmomanometer and Event recorders
Answer: c
Clarification: Both the treadmill and ergometer can be used as stand-alone devices for testing physical fitness. Advanced ergometers and treadmills can store and display activity data, transfer it to a PC and download patient data from PC.
3. Which of the following is the type of exercise protocols used in treadmill tests?
a) The Balke-Bruce Protocol
b) The Bruce-Ware Protocol
c) The Balke-Ware Protocol
d) The Balke Protocol
Answer: c
Clarification: There are two basic kinds of exercise protocols used in treadmill tests: i) The Balke-Ware Protocol and ii) The Bruce Protocol. Both protocols are satisfactory for most clinical purposes. However, they may have to be modified to suit the condition of the individual being subjected to exercise testing.
4. In the Balke-Ware Protocol, how much speed it uses with progressive increments in the load every 2 minutes?
a) 3.3 km/hour
b) 3.3 km to 5.3 km /hour
c) 3.3 miles to 5.3 miles /hour
d) 3.3 miles/hour
Answer: d
Clarification: In the Balke-Ware Protocol, it uses a constant speed of 3.3 miles/hour (5.3 km/hour), with progressive increments in the load every 2 minutes. This is achieved by increasing the grade or incline of the motor-driven treadmill.
5. ______ is a blood pressure measuring instrument.
a) Sphygmomanometer
b) Ergometer
c) Treadmill
d) Holtemanometer
Answer: a
Clarification: Sphygmomanometer, an instrument for measuring blood pressure, typically consisting of an inflatable rubber cuff which is applied to the arm and connected to a column of mercury next to a graduated scale, enabling the determination of systolic and diastolic blood pressure by increasing and gradually releasing the pressure in the cuff.
6. In the ST segment measurement _________ is either between the P and Q waves or in front of the P wave.
a) J point
b) Isoelectric baseline
c) ST measurement point
d) ST value
Answer: b
Clarification: The current standard for determining the ST segment measurement is by measuring the voltage difference between the value at a point 60-80 ms after the J point and the isoelectric baseline. The isoelectric baseline is either between the P and Q waves (the P-R interval) or in front of the P-wave (the T-P interval).
7. _________ is a signal of low amplitude and low frequency content.
a) QRS complex
b) R-R interval
c) ST segment
d) T-P interval
Answer: c
Clarification: The ST segment is a signal of low amplitude and low-frequency content. Therefore, a sampling rate of 250 samples /s is adequate. To ensure that the ST segment can be measured accurately, the incoming ECG signals must have a low-end bandwidth of 0.05 Hz.
8. In the ST segment measurement, what is the bandwidth of the ST filter which is used to remove unwanted baseline noise?
a) 0.05 Hz
b) 0.67 Hz
c) 0.5 Hz
d) 0.067 Hz
Answer: b
Clarification: To ensure that the ST segment can be measured accurately, the incoming ECG signals must have a low-end bandwidth of 0.05 Hz. A special ST filter with a higher low-end bandwidth of 0.67 Hz is used to further remove unwanted baseline noise.
9. ________compare various algorithms employed for processing stress ECG signals.
a) Friesen
b) Jen and Hwang
c) Clynes
d) Alfonso
Answer: d
Clarification: Alfonso compares various algorithms employed for processing stress ECG signals. It may be observed that the exercise test when applied in an appropriate manner and interpreted by an experienced cardiologist is a very useful tool in the functional assessment of normal and abnormal cardiovascular physiology.
10. At an interval of _______ the Bruce Protocol uses simultaneous increments in both speed and treadmill grade.
a) 250 sec
b) 120 sec
c) 160 sec
d) 198 sec
Answer: c
Clarification: At an interval of 3 minutes the Bruce Protocol uses simultaneous increments in both speed and treadmill grade. Typically during a Bruce Protocol, Heart Rate and Rating of Perceived Exertion are taken every minute and Blood Pressure is taken at the end of each stage (every three minutes).