Medical sensor patches: Medical sensor patches measure vital signs and send data across to a remote location through wireless technology (
Bluetooth®, BLE,
Wi-Fi®, or NFC). These monitors are typically battery-powered and have low operating currents, to work for longer battery life. The solutions are notably compact, unlike bedside multi-parameter patient monitors.
Wearable Fitness and Activity Monitor: Fitness monitors measure both the amount and rate of exercise of a person (for example, miles and pace run), as well as effort expended (for example, through monitoring heart rate). Typically, a wristwatch or wrist-worn display is used for control and providing feedback. Stored data can be downloaded to a computer through a USB or wireless USB dongle. All parts of the system require ultra-low-power, embedded controllers and low-power RF for communication. Heart-rate monitoring and exercise-output monitoring (for example, a running pace sensor or power sensor) require additional signal conditioning.
ECG: Basic functions of an ECG machine include ECG waveform display, either through an LCD screen or printed paper media, and heart rhythm indication, as well as a simple user interface through buttons. Additional features are required in more and more ECG products, such as patient-record storage using convenient media, wireless or wired transfer, and 2D/3D display on a large LCD screen with touchscreen capabilities. Multiple levels of diagnostic capabilities also assist doctors and people without specific ECG training to understand ECG patterns and their indication of a certain heart condition. After the ECG signal is captured and digitized, it is sent for display and analysis, which involves further signal processing.
Pulse Oximeter: The pulse oximeter measures blood oxygenation by sensing the IR and red-light absorption properties of deoxygenated and oxygenated hemoglobin. The oximeter is comprised of a sensing probe that attaches to the ear lobe, toe, or finger of a patient, and is connected to a data acquisition system for calculation and display of the oxygen saturation level, heart rate, and blood flow. Light sources, typically LEDs, shine visible red and IR light. Deoxygenated hemoglobin allows more infrared light to pass through and absorbs more red light. Highly oxygenated hemoglobin allows more red light to pass through and absorbs more IR light. The oximeter senses and calculates the amount of light at those wavelengths, proportional to the oxygen saturation (or desaturation) of the hemoglobin. The use of light in the absorbency measurement requires the designer to have a true light-to-voltage conversion using current as the input signal.