Patent ID: 7689270

Claim:
A physiological sensor system for recording an electrical measurement signal of a patient in a magnetic resonance device, comprising: a first measuring electrode that measures a first electrical measurement signal of the patient; a first signal amplifier unit connected to the first measuring electrode by a first cable connection and placed in a close proximity to the patient, wherein the first cable connection comprises: a low-impedance conductor, a first electrical resistor connected with the first measuring electrode and arranged at a first end of the low-impedance conductor, and a second electrical resistor connected with the first signal amplifier unit and arranged at a second end of the low-impedance conductor, wherein the first and the second electrical resistor has a resistance value in an order of magnitude of an electrical resistance between a skin of the patient and the first measuring electrode; a second measuring electrode that measures a second electrical measurement signal of the patient; a second signal amplifier unit connected to the second measuring electrode by a second cable connection and placed in a close proximity to the patient, wherein the second cable connection comprises: a low-impedance conductor, a first electrical resistor connected with the second measuring electrode and arranged at a first end of the low-impedance conductor, and a second electrical resistor connected with the second signal amplifier unit and arranged at a second end of the low-impedance conductor, wherein the first and the second electrical resistor has a resistance value in an order of magnitude of an electrical resistance between a skin of the patient and the second measuring electrode; a shielded housing in which the first and the second signal amplifier units are arranged, wherein the respective second end of the low-impedance conductor of the first and second cable connections is capacitively coupled to the shielded housing through a respective feedthrough capacitor, wherein the first and the second cable connections due to being capacitively coupled to the shielded housing form a shielded connection arrangement with respect to high-frequency signals resulting from operation of the magnetic resonance device; a differential amplifier coupled to the first and second signal amplifier units to receive a respective output signal from the first and second signal amplifier units and supply a difference measurement signal; and a signal processing unit connected to the differential amplifier to process the difference measurement signal.