Heart rate monitors measure the heart rate during exercise or vigorous activity and gauge how hard the patient is working. Newer heart rate monitors consist of two main components: a signal acquisition sensor/transmitter and a receiver (wrist watch or smart phone). In some cases, the signal acquisition is integrated into fabric worn by the user or patient. MCUs analyze the ECG signal and determine the heat rate, while an 8-bit MCU can suffice for a simple heart rate monitor. For more complex analysis, such as heart rate variability, activity level and breathing rate, a high-end 32-bit MCU may be used. Furthermore, low power wireless technologies are used to allow the sensor to communicate to the receiver.
Freescale offers 8-bit and 32-bit MCUs that are applicable across the entire spectrum of heart rate monitors. In addition, the Freescale portfolio includes inertial sensors or accelerometers for activity monitoring and ZigBee® and proprietary wireless solutions to enable communication between the sensors and the receiver.