Abstract: A heart rate monitor can comprise a heart rate sensor and a strap. The heart rate sensor can contact a tail of an equine and comprise an optical heart rate module (OHR) and a transmitter. The OHR module can output light into skin of the equine, receive reflected light, and convert the reflected light into electrical signals. The transmitter can wirelessly transmit heart rate data based on the electrical signals. The strap can removably receive the heart rate sensor and removably couple to the tail of the equine.

Abstract: A wearable electronic device for detecting diver respiration comprises a transducer element and a processing element. The transducer element is configured to receive sonar waves and communicate a corresponding receiver electronic signal. The processing element is configured or programmed to receive the receiver electronic signal, identify that a breath of the diver has occurred from the receive electronic signal, determine a respiration rate of the diver based on a plurality of breaths, and present an indication of the respiration rate to the diver.

Abstract: A wearable electronic device for detecting diver respiration comprises a transducer element and a processing element. The transducer element is configured to receive sonar waves and communicate a corresponding receiver electronic signal. The processing element is configured or programmed to receive the receiver electronic signal, identify that a breath of the diver has occurred from the receive electronic signal, determine a respiration rate of the diver based on a plurality of breaths, and present an indication of the respiration rate to the diver.