A monitoring device for obtaining data from a patient during a respiratory and/or cardiac cycle of the patient. The monitoring device includes a compliant variable capacitor securely attached to the patient. The capacitance of the compliant variable capacitor changes during movement of the patient caused by the respiratory cycle and/or a cardiac cycle. The changing capacitance is used to generate a monitoring signal that includes the frequency, timing and amplitude of either the respiratory or cardiac cycle. The signal from the monitoring device is provided to a medical imaging system such that the medical imaging system can compensate for the motion of the patient during the reparatory/cardiac cycle.