# US 2016/0349291 A1 · Methods, Devices And Systems Which Determine A Parameter Value Of An Object Or An Environment From A Voltage Reading Associated With A Common Mode Signal Of A Balanced Circuit

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2016/0349291 A1
- Document ID: US20160349291A1
- Status: Published application
- Kind: A1
- Application number: 15/233,426
- Filed: 2016-08-10
- Published: 2016-12-01
- Earliest claimed: 2012-07-18
- Assignees: Millar Inc.
- Applicants: Millar Inc.
- Inventors: Huntly D. Millar; Richard T. Thornton; Robert L. Pauly
- Web page: https://patentgrep.com/patent/US20160349291A1

## CPC

- G01R 17/10: AC or DC measuring bridges
- A61B 5/1073: {Measuring volume, e.g. of limbs}
- A61B 5/11: Measuring movement of the entire body or parts thereof, e.g. head or hand tremor or mobility of a limb {(A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721)}
- A61B 5/14539: {for measuring pH}
- A61B 5/14542: {for measuring blood gases (A61B5/14551 takes precedence)}
- G01K 7/20: in a specially-adapted circuit, e.g. bridge circuit
- G01K 13/20: Clinical contact thermometers for use with humans or animals
- G01L 1/2262: {involving simple electrical bridges}
- G01L 1/2281: {for temperature variations}
- G01L 9/045: {with electric temperature compensating means (non electric temperature compensating means G01L19/04)}
- G01L 9/065: {with temperature compensating means (non electric temperature compensating means G01L19/04)}
- A61B 2562/0247: Pressure sensors
- A61B 2562/0271: Thermal or temperature sensors
- A61B 2562/029: Humidity sensors
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- G01K: MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR (radiation pyrometry G01J5/00)
- G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G)

## Abstract

A method for determining a value of a parameter of an object or an environment includes positioning a device having a balanced circuit in or on an object or within a particular environment, wherein the balanced circuit comprises elements which are operationally sensitive to changes in a parameter of the object or the environment. The method further includes measuring a common mode signal of the balanced circuit and determining, from the common mode signal, a value of the parameter. An exemplary implementation of the method includes determining temperature using a resistive sensor having a Wheatstone bridge circuit with two variable resistors and two fixed resistors. Embodiments of systems and devices configured to employ such methods are provided, particularly medical probes, electronic signal monitoring devices, and systems employing such devices.

## Claims

### Claim 1

A method for determining values of parameters of an object or an environment, wherein the method comprises:
positioning a device in or on an object or within a particular environment, wherein the device comprises a balanced circuit, and wherein the balanced circuit comprises elements which are operationally sensitive to changes in a first parameter of the object or the environment;
measuring a common mode voltage derived from the balanced circuit which correlates to a common mode signal of the balanced circuit;
determining, from the measured common mode voltage, a value of the first parameter;
measuring a differential voltage between signal output nodes of the balanced circuit; and
determining, from the differential voltage, a value of a second parameter of the object or environment which is different from the first parameter, wherein at least one of the steps of measuring the differential voltage and determining the value of the second parameter is performed substantially simultaneously with at least one of the step of measuring the common mode voltage and determining the value of the first parameter.

### Claim 2 (depends on 1)

The method of claim 1, wherein the first and second parameters are selected from a group consisting of temperature, pressure, volume, velocity, pH, oxygen concentration and humidity.

### Claim 3 (depends on 1)

The method of claim 1, wherein the balanced circuit is a half-bridge Wheatstone bridge circuit.

### Claim 4 (depends on 3)

The method of claim 3, wherein half-bridge Wheatstone bridge circuit comprises two variable resistors respectively comprising opposing sides of the Wheatstone bridge circuit.

### Claim 5 (depends on 1)

The method of claim 1, wherein the device is a medical probe.

### Claim 6

A system, comprising:
a device having a balanced circuit;
an electronic signal monitoring unit configured for electrical communication with the device to measure electrical parameters of the balanced circuit;
circuitry for coupling to the balanced circuit, wherein the circuitry, when coupled to the balanced circuit, is configured to:
generate a common mode voltage which correlates to a common mode signal of the balanced circuit; and
generate a differential voltage of the balanced circuit, wherein the electronic signal monitoring unit comprises means for measuring the differential voltage and the common mode voltage; and
a storage medium comprising program instructions which are executable by a processor for respectively determining, from the common mode voltage and the differential voltage, different parameters of an environment in which the device is arranged.

### Claim 7 (depends on 6)

The system of claim 6, wherein the different parameters are selected from a group consisting of temperature, pressure, volume, velocity, pH, oxygen concentration and humidity.

### Claim 8 (depends on 6)

The system of claim 6, wherein one of the different parameters is temperature, and wherein the device is absent a temperature sensor distinct from the balanced circuit.

### Claim 9 (depends on 6)

The system of claim 6, wherein the circuitry is disposed between the device and the electronic signal monitoring unit.

### Claim 10 (depends on 6)

The system of claim 6, wherein the circuitry is disposed within the device.

### Claim 11 (depends on 6)

The system of claim 6, wherein the circuitry is disposed within the electronic signal monitoring unit.

### Claim 12 (depends on 6)

The system of claim 6, wherein the device is a medical probe.

### Claim 13 (depends on 6)

The system of claim 6, wherein the balanced circuit is a half-bridge Wheatstone bridge circuit.

### Claim 14

A device, comprising:
a Wheatstone bridge circuit having two fixed resistors and two variable resistors;
compensation circuitry coupled to the Wheatstone bridge circuit which is configured to compensate for variations of a resistive coefficient of a conductive material comprising the Wheatstone bridge circuit due to ambient temperature changes of the conductive material; and
common mode signal circuitry coupled to the Wheatstone bridge circuit which generates a voltage correlating to a common mode signal of the Wheatstone bridge circuit.

### Claim 15 (depends on 14)

The device of claim 14, wherein the compensation circuitry comprises one or more fixed resistors in parallel with at least one of the two variable resistors of the Wheatstone bridge circuit.

### Claim 16 (depends on 14)

The device of claim 14, wherein the device is a medical probe.

### Claim 17 (depends on 16)

The device of claim 16, wherein the common mode signal circuitry is disposed within an electrical connector of the medical probe.

### Claim 18 (depends on 16)

The device of claim 16, wherein the common mode signal circuitry is disposed within a tip of the medical probe.

### Claim 19 (depends on 16)

The device of claim 16, wherein the medical probe is a catheter.

### Claim 20 (depends on 14)

The device of claim 14, further comprising reference voltage circuitry for generating a biased reference voltage relative to an excitation voltage applied to the Wheatstone bridge circuit.