Respiratory Rate Monitor Trainer (VPL-BIO-RRM)

The respiratory rate monitor consists of the following:

  • Thermistor
  • High-gain cascaded amplifier
  • Pulse-forming circuit
  • Comparator
  • Frequency counter.


A temperature-sensitive diode or thermistor sensor is held under one nostril. The short time constant of the sensor enables the element to accurately track temperature fluctuations. The millivolt signal is amplified and used to fire a comparator. The comparator’s pulse rate is converted into a frequency by the synthesizer. The frequency change feeds the frequency counting circuit, which has been previously described.

Most of the circuits used here have been previously encountered. In the laboratory, an overall system is evaluated. The temperature sensor on one panel is connected to the meter rate section on the second panel.

The study includes theory, laboratory testing, and evaluation.

The student will be able to:
1. Describe the basic functioning of the respiratory system.
2. Describe two methods of measuring respiratory rate.
3. Measure the respiratory rate of individuals in relaxed and excited states.
4. Evaluate a respiratory recording instrument


Note: Specifications can be changed, added or subtracted without notice in our constant efforts for improvement.