Answer:
The doctor could perform the thermistor technique, which is more used and meets clinical needs, but still have other techniques that could be perform.
Step-by-step explanation:
Breath rate gives details about oxygen consumption and carbon dioxide exhalation. Muscle action controls respiratory action, resulting in increased lung volume. The main function of the respiratory system is to provide oxygen and remove carbon dioxide from blood tissues. Some of the techniques used for measurement are:
- This is an indirect method for measuring respiration rate. External electrodes are applied to the chest. The impedance pneumograph measures respiration rate with a relationship between respiratory depth and thoracic impedance change. High frequency current is passed through chest electrodes and detects the modulated signal.
- The air is warmed during its travel through the lungs and respiratory tract. Therefore, there is a temperature difference between inhaled and exhaled air. A thermistor is placed in front of the nostrils using a retention device. It detects the temperature difference. When the temperature difference between outside air and exhaled air is small, the thermistor is heated to a temperature. Its resistance varies relatively with respiratory rate. This helps to detect the cooling effect of airflow. Thermistors are placed in a bridge circuit whose unbalanced signal is amplified to obtain the respiratory signal. This method is used frequently and meets clinical needs. However, when the patient does not respond to spontaneous breathing movements, thermistors cannot be used.
- The transducer is attached to a rubber band and wrapped around the chest. When a person breathes, breathing movement results in resistance change in the strain gage.
- When CO2 contained within the subject's alveolar air is continuously monitored, the respiration rate is measured. The measurement depends on the absorption property of infrared rays within the gases. When infrared rays pass through the exhaled air that has CO2, it absorbs some of the radiation. Therefore, there is loss of thermal energy. Detector converts the loss in the heating effect of the rays into an electrical signal. This signal is used to calculate respiration rate.