Signal conditioning device for interfacing intravascular sensors having varying operational characteristics to a physiology monitor

A system for taking a measurement from within a blood vessel to determine a flow characteristic within the blood vessel, the system comprising:

• a flexible elongate member having mounted thereon a sensor device driven by an electrical current;
• a cable electrically connecting the sensor device to a signal conditioning device wherein the signal conditioning device comprises:
• a processing unit;
• a sensor interface circuit supplying a sensor drive signal for energizing a sensor carried by an attachable intravascular measurement device and providing a measurement signal;
• a physiology monitor interface including an input for receiving a sensor excitation signal from the physiology monitor and an output for transmitting a signal generated in accordance with sensed measurements arising from the sensor drive signal;
• a power supply circuit interposed between the physiology monitor interface and the processing unit, the power supply circuit including a signal converter that receives a portion of power supplied by the sensor excitation signal and powers at least the processing unit with power derived from the portion of power supplied by the sensor excitation signal.

A method for assessing blood flow characteristics within a blood vessel by means of an intravascular sensor connected to a signal conditioning device, the method comprising the steps of:

• first connecting the intravascular sensor to the signal conditioning device through a first cable;
• second connecting the conditioning device to a physiology monitory through a second cable, the physiology monitor providing an excitation signal that is used in part to power the intravascular sensor;
• advancing the intravascular sensor to a target site within a patient's vasculature;
• measuring a physiological parameter with the intravascular sensor;
• processing, by the signal conditioning device, the physiological parameter measurement rendered during the measuring step to render a conditioned measurement signal;
• and
• transmitting, by the signal conditioning device, a signal to the physiology monitor that corresponds to the conditioned measurement signal.

A signal conditioning device interposed between an intravascular measurement device and a physiology monitor, the signal conditioning device facilitating establishing signal compatibility between the physiology monitor and intravascular measurement devices having varying operating characteristics, and wherein the measurement devices include a pair of resistive sensing elements, the signal conditioning device comprising:

• a sensor current source providing two separate excitation signals to independently drive the pair of resistive sensing elements of an attached measurement device;
• a data input for receiving a temperature compensation calibration value provided for the attached measurement device;
• and
• a variable current source providing an adjustment current, determined at least in accordance with the temperature compensation calibration value, to at least a compensated one of the pair of resistive sensing elements.