Heart rate monitors work by measuring which of the following physiological signals: Pulse pressure Electrical conduction Korotkoff sounds Contraction force

To address the question regarding which physiological signals heart rate monitors measure, let's examine each option provided:

1. Pulse pressure: This refers to the difference between systolic and diastolic blood pressure. Heart rate monitors do not directly measure this; instead, they monitor heart rate based on other signals.

2. Electrical conduction: Heart rate monitors, particularly electrocardiogram (ECG) monitors, specifically measure the electrical activity of the heart. This option is directly related to how heart rate is determined.

3. Korotkoff sounds: These sounds are related to the measurement of blood pressure using a sphygmomanometer, not heart rate monitors directly.

4. Contraction force: While the strength of heart contractions can be an indicator of heart performance, standard heart rate monitors do not measure this directly.

Conclusion

Based on the analysis, the best answer is Electrical conduction. Heart rate monitors measure the electrical signals generated by the heart to determine the heart rate.