A stand-alone continuous cardiac Doppler pulse monitoring patch provides visual and auditory signals that a pulse is detected or not detected in a human subject. The invention is a small patch with a peel-away adhesive surface that is applied to the skin of the subject, preferably near a large artery. The adhesive surface of the patch includes a conductive medium to enhance transmission and reception of ultrasonic waves. The patch includes an integral power source, transmitters and receivers to send and detect reflected ultrasonic waves, a transducer to convert the reflected waves into an electrical signal, a processor to analyze the signal, a light to indicate the presence and strength of a pulse, and a speaker also to indicate the presence and strength of a pulse. The Doppler effect of waves reflecting from blood pumped from a heart is used to detect a pulse in the subject. The presence of a pulse is analyzed by the processor to determine the frequency and strength of blood flow. The processor causes the light to blink at a rate to indicate the frequency of rhythmic blood flow. In a further embodiment, the processor analyzes the strength of the blood flow and causes the light to increase or decrease in intensity to reflect the strength or weakness of the flow. The processor may also drive a speaker to emit sounds, such as beeps, that indicate the frequency and strength of blood flow. The absence of blood flow may be indicated by the absence of light or sound, or by separate light or auditory signals.
