Patent ID: 7460899

Claim:
A wrist or arm worn heart rate variability monitor, comprising: at least one sensor embedded in a membrane for detecting heart rate signals generated within a body when placed in contact with the body's wrist, wherein the sensor is capable of monitoring signals selected from the group consisting of optical, infra-red, pressure, ultrasonic and electrical signals; a circuit that conditions the electrical signals and converts the analog signals to digital signal data; a heart rate variability signal processor that monitors and analyzes the digital signal data, calculates parameters comprising the mean digital signal value and at least one standard deviation of the digital signal data monitored and establishes a threshold level based on the calculated parameters evaluated when the user is in an awake state and just prior to real-time heart rate variability data monitoring, wherein the calculated threshold level is neither predetermined nor preset and does reflect the user's actual heart rate and heart rate variability over the defined time interval, and wherein the processor monitors the digital signal data and recognizes the crossing of the established threshold level by the digital signal data and may be programmed to establish a new threshold level into a subsequent sleep state that reflects the body's actual heart rate and heart rate variability within the subsequent sleep state and then performs at least one HRV test using the new threshold level while the body is within the subsequent sleep state and then continues to monitor the body's HRV for additional threshold crossings; an alarm that may be activated to alert the user of abnormal conditions or events or the crossing of a specified threshold level by the heart rate variability; and a memory capable of storing the established threshold levels and real time digital signal data.