Monitoring respiration of a vehicle operator

A method comprising:

• generating an alternating current signal to one of a first sensor electrode or a second sensor electrode, wherein the first sensor electrode is associated with a seatbelt and located adjacent to a torso of a vehicle operator of a vehicle, and the second sensor electrode is positioned to be proximate to at least one of an arm, hand, leg, or foot, of the vehicle operator;
• receiving from the other one of the first sensor electrode or the second sensor electrode, a signal indicative of a capacitance;
• and
• determining, by a processor, a respiration rate based at least partially on the signal indicative of the capacitance,
• wherein there are multiple second sensor electrodes, the method further comprising:
• determining that the vehicle operator is contacting a certain one of the second sensor electrodes;
• determining that the vehicle operator has contacted the certain second sensor electrode for a threshold time;
• and
• receiving the signal indicative of the capacitance from the certain second sensor electrode.

An apparatus comprising:

• a first sensor electrode associated with a seatbelt for restraining a vehicle operator of a vehicle;
• a second sensor electrode positioned within the vehicle to be proximate to a body part of the vehicle operator;
• a signal generator that generates a signal to one of the first sensor electrode or the second sensor electrode;
• a capacitance-to-voltage converter that converts a capacitance signal received from the other one of the first sensor electrode or the second sensor electrode to a voltage signal;
• and
• a voltage measurement circuit that determines, at least in part, a respiration rate based on an amplitude and period of the voltage signal received from the capacitance-to-voltage converter.