device and method for measuring physiological parameters of a biological being comprising : at least two spaced apart electrodes at least one of which is in contact with - the being for providing a bio - potential measurement including a low frequency ac voltage and / or a dc voltage wherein one of the electrodes is a reference electrode providing a reference for the dc voltage , the low frequency ac voltage and / or dc voltage measurement used to determine the physiological parameters . the device can be built in many forms ; can measure physiological parameters including those related to diabetes , cardiovascular , organ , tissue , brain and neural function , local and limb metabolic condition , pharmacokinetic , pharmaco - dynamics and psychological conditions , temperature , or combination thereof and their trends . the device can include an automatic alarm system for warning a patient of an out of tolerance condition .