Digital sensor for miniature medical thermometer, and body temperature monitor

A method of manufacturing a thermometer, comprising:

• providing a multivibrator including a capacitor having first and second conductive paths associated therewith, one of said first and second paths being a charge path for the capacitor and the other of said first and second paths being a discharge path for the capacitor, the multivibrator also including at least first and second resistors wherein the first and second resistors are connected in said first path, and the first resistor, but not the second resistor, is connected in said second path, and wherein the first and second resistors have respective resistance values that are substantially independent of temperature,
• measuring charge and discharge times of the capacitor and calculating a reference value of a cell function based on said charge and discharge times, and
• replacing the second resistor with a temperature-dependent resistor.

A method of manufacturing a thermometer, comprising;

• providing a multivibrator including a capacitor having first and second conductive paths associated therewith, one of said first and second paths being a charge path for the capacitor and the other of said first and second paths being a discharge path for the capacitor, the multivibrator also including at least first and second resistors wherein the first and second resistors are connected in said first path and the first resistor, but not the second resistor, is connected in said second path, and wherein the first resistor has a resistance value that is substantially independent of temperature and the second resistor has a resistance value that varies with temperature and is a function of temperature, the resistance value of the second resistor at a reference temperature being substantially equal to the resistance value of the first resistor,
• measuring charge and discharge times of the capacitor at the reference temperature and calculating a value of a cell function, and
• recording the value of the cell function.

A thermometer comprising:

• a multivibrator including a capacitor having first and second conductive paths associated therewith, one of said first and second paths being a charge path for the capacitor and the other of said first and second paths being a discharge path for the capacitor, the multi-vibrator also including at least first and second resistors wherein the first and second resistors are connected in said first path, and the first resistor, but not the second resistor, is connected in said second path, and wherein the first resistor has a resistance value that is substantially independent of temperature and the second resistor has a resistance value that varies with temperature and is a function of temperature,
• a means for measuring duration of the charge time and duration of the discharge time of the capacitor and calculating the ratio of the discharge time to the charge time, and
• a means for transmitting said ratio to a receiver for calculating a corresponding temperature value.

A device for measuring temperature, comprising a pulse generator including a resistor such that the pulse generator generates pulses of duty cycle dependent on the resistance of the resistor, and a duty-cycle measurement circuit for measuring the duty cycle of the pulses and outputting a value dependent on the measured value of the duty cycle, and wherein the resistor has a non-zero temperature coefficient of resistance.

A measurement system, for measuring the value of a parameter, comprising:

• a transmitter unit that includes a sensor device for sensing the parameter, a transmitter device, a photodetector, and a controller, and
• a receiver unit that includes a light emitting device that can be energized to emit an activation signal and a confirmation signal,
• and wherein the photodetector delivers the activation signal and the confirmation signal to the controller, and the controller is responsive to the activation signal to initiate activation of the transmitter unit and is responsive to the confirmation signal within a predetermined interval after the activation signal to complete activation of the transmitter unit.

A measurement system comprising a transmitter for receiving data representing a value of a parameter and transmitting said value, and a receiver for receiving the transmission from the transmitter, wherein the transmitter includes a means for resolving future time into a succession of transmission intervals and for resolving each transmission interval into a plurality of transmission slots, a means for calculating a number based on a predetermined algorithm, a means for selecting one of said transmission slots based on the calculated number, and a means for transmitting said value during the selected transmission slot, and wherein the receiver includes a means for predicting when the transmitter will transmit said value and for enabling the receiver to receive the transmission from the transmitter during said selected transmission slot.

A measurement system, for measuring the value of physiological parameter, comprising:

• a transmitter unit that includes a sensor device for sensing the physiological parameters a transmitter device, and a photodetector the transmitter unit having an active state, in which the sensor device generates a sensor signal having a characteristic that depends on the physiological parameter and the transmitter device emits a transmitter signal that depends on the characteristic of the sensor signal, and the transmitter unit also having an inactive state, and
• a receiver unit that includes a light emitting device,
• and wherein the light emitting device of the receiver unit can be energized when the transmitter unit is in the inactive state to emit an activation signal and a confirmation signal and the photodetector is responsive to the activation signal to initiate activation of the transmitter unit and is responsive to the confirmation signal within a predetermined interval after the activation signal to complete activation of the transmitter unit.