# US 12,181,352 B2 · Insole XYZ force detection system

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- Number: US 12,181,352 B2
- Document ID: US12181352B2
- Status: Granted
- Kind: B2
- Application number: 17/575,594
- Filed: 2022-01-13
- Published: 2022-12-08
- Granted: 2024-12-31
- Earliest claimed: 2021-06-03
- Assignees: Sigmasense, LLC.
- Applicants: Sigmasense, LLC.
- Inventors: Michael Shawn Gray; Kevin Joseph Derichs; Richard Stuart Seger, Jr.; Timothy W. Markison
- Web page: https://patentgrep.com/patent/US12181352B2

## CPC

- A43B 3/40: Batteries
- G01L 1/146: {for measuring force distributions, e.g. using force arrays (G01L1/148 takes precedence)}
- A43B 3/44: with sensors, e.g. for detecting contact or position
- A43B 3/48: with transmitting devices, e.g. GSM or Wi-Fi®
- A43B 13/00: Soles; Sole-and-heel integral units
- A43B 17/00: Insoles for insertion, e.g. footbeds or inlays, for attachment to the shoe after the upper has been joined
- A61B 5/1038: {Measuring plantar pressure during gait}
- A61B 5/6807: {Footwear}
- A61B 5/7225: {Details of analogue processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation (input circuits for detecting, measuring, or recording bioelectric or biomagnetic signals A61B5/30; specific diagnostic methods using bioelectric or biomagnetic signals A61B5/316)}
- A61B 2562/0247: Pressure sensors
- A61B 2562/046: in a matrix array
- A43B: CHARACTERISTIC FEATURES OF FOOTWEAR; PARTS OF FOOTWEAR
- G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G)
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)

## Abstract

A low power force detection system includes variable capacitors, a drive sense module, and a processing module. A drive sense circuit of the drive sense module is operable to provide an analog and frequency domain signal to a variable capacitor. The drive sense circuit is further operable to detect a characteristic of the variable capacitor based on the analog and frequency domain signal and to generate a representative signal of the characteristic. The processing module is operable to generate a digital value based on the representative and to write the digital value to memory.

## Claims

### Claim 1

A low power force detection system comprises:
a plurality of variable capacitors, wherein a variable capacitor of the plurality of variable capacitors includes:
two plates;
one or more conductive layers; and
one or more insulating layers when the variable capacitor includes more than one conductive layer;
a drive sense module operably coupled to the plurality of variable capacitors, wherein a drive sense circuit of the drive sense module is coupled to one or more variable capacitors of the plurality of capacitors, and wherein the drive sense circuit is operable to:
provide an analog and frequency domain signal to the one or more variable capacitors;
detect a characteristic of the one or more variable capacitors based on the analog and frequency domain signal; and
generate a representative signal of the characteristic; and
a processing module operable to the drive sense module, wherein the processing module is operable to:
generate a digital value based on the representative; and
write the digital value to memory.

### Claim 2 (depends on 1)

The low power force detection system of claim 1, wherein the analog and frequency domain signal comprises:
a DC signal component; and
an oscillating signal component that has a frequency and a magnitude.

### Claim 3 (depends on 1)

The low power force detection system of claim 1, wherein the characteristic comprises:
an impedance based on a current and a voltage, wherein one of the current and the voltage is regulated and the other is a reference.

### Claim 4 (depends on 1)

The low power force detection system of claim 1 further comprises:
the drive sense circuit being including:
an operational amplifier operable to generate an analog signal representing impedance of the one or more variable capacitors; and
an analog to digital converter operable to generate the representative signal as an unfiltered digital representation of the representing impedance of the one or more variable capacitors;
the processing module being further operable to:
digitally filter the representative signal to produce a high-resolution digital value of the impedance of the one or more variable capacitors.

### Claim 5 (depends on 1)

The low power force detection system of claim 1 further comprises:
a clock circuit operable to generate a sampling clock and a digital clock, wherein a sampling rate for sampling impedance of the one or more variable capacitors is derived from the sampling clock and wherein the writing the digital value to the memory is done a write rate that is derived from the digital clock.

### Claim 6 (depends on 5)

The low power force detection system of claim 5, wherein the clock circuit is further operable to:
generate a real-time clock, wherein the processing module time stamps the digital value in accordance with the real-time clock as part of writing the digital value to the memory.

### Claim 7 (depends on 1)

The low power force detection system of claim 1 further comprises:
a communication circuit operably coupled to the processing module and to the memory, wherein the communication circuit communicates with a computing entity to download stored digital values to the computing entity.

### Claim 8 (depends on 1)

The low power force detection system of claim 1 further comprises:
a power source circuit operable to provide power to the low power force detection system, wherein the power source circuit includes one or more of:
a battery;
a battery charger;
a linear regulator;
a power supply; and
a power harvesting circuit.

### Claim 9 (depends on 1)

The low power force detection system of claim 1, wherein the processing module is further operable to generate the digital value by:
converting the representative signal of the characteristic into an impedance value as the digital value.

### Claim 10 (depends on 1)

The low power force detection system of claim 1, wherein the processing module is further operable to generate the digital value by:
converting the representative signal of the characteristic into an impedance value; and
converting the impedance value into a capacitance value as the digital value.

### Claim 11 (depends on 1)

The low power force detection system of claim 1, wherein the processing module is further operable to generate the digital value by:
converting the representative signal of the characteristic into an impedance value;
converting the impedance value into a capacitance value; and
converting the capacitance value into a pressure value as the digital value.

### Claim 12

A low power force detection system comprises:
a plurality of pressure sensor cells arranged in a pattern within a sole of a shoe, wherein a pressure sensor cell of the plurality of pressure sensor cells includes a set of variable capacitors, wherein a variable capacitor of the set of variable capacitors includes:
two plates;
one or more conductive layers; and
one or more insulating layers when the variable capacitor includes more than one conductive layer;
a plurality of drive sense modules operably coupled to the plurality of pressure sensor cells, wherein a drive sense module of the plurality of drive sense modules includes a set of drive sense circuits, wherein a drive sense circuit of the set of drive sense circuits is coupled to a variable capacitor of the set of variable capacitors, and wherein the drive sense circuit is operable to:
provide an analog and frequency domain signal to the variable capacitor;
detect a characteristic of the variable capacitor based on the analog and frequency domain signal; and
generate a representative signal of the characteristic; and
a processing module operable to the drive sense module, wherein the processing module is operable to:
generate a digital value based on the representative; and
write the digital value to memory.

### Claim 13 (depends on 12)

The low power force detection system of claim 12, wherein the pattern comprises:
the plurality of pressure sensor cells distributed substantially evenly throughout the sole from a top view perspective, wherein the plurality of pressure sensor cells is of approximately equal size.

### Claim 14 (depends on 12)

The low power force detection system of claim 12, wherein the pattern comprises:
the plurality of pressure sensor cells arranged in a toe zone, a ball of foot zone, a later midfoot zone, and a heal zone, wherein, within one of the zones, the pressure sensor cells are of approximately equal size.

### Claim 15 (depends on 12)

The low power force detection system of claim 12, wherein the pattern comprises:
a first set of a first size pressure sensor cells in a toe area of the shoe;
a second set of a second size pressure sensor cells in a ball of foot area of the shoe; and
a third set of a third size pressure sensor cells in a heal area of the shoe, wherein the second size is greater than the third size, which is greater than the first size.

### Claim 16 (depends on 12)

The low power force detection system of claim 12 further comprises:
the drive sense circuit being including:
an operational amplifier operable to generate an analog signal representing impedance of the variable capacitor; and
an analog to digital converter operable to generate the representative signal as an unfiltered digital representation of the representing impedance of the variable capacitor;
the processing module being further operable to:
digitally filter the representative signal to produce a high-resolution digital value of the impedance of the variable capacitor.

### Claim 17 (depends on 12)

The low power force detection system of claim 12 further comprises:
a clock circuit operable to generate a sampling clock and a digital clock, wherein a sampling rate for sampling impedance of the variable capacitor is derived from the sampling clock and wherein the writing the digital value to the memory is done a write rate that is derived from the digital clock.

### Claim 18 (depends on 17)

The low power force detection system of claim 17, wherein the clock circuit is further operable to:
generate a real-time clock, wherein the processing module time stamps the digital value in accordance with the real-time clock as part of writing the digital value to the memory.

### Claim 19 (depends on 12)

The low power force detection system of claim 12 further comprises:
a communication circuit operably coupled to the processing module and to the memory, wherein the communication circuit communicates with a computing entity to download stored digital values to the computing entity.

### Claim 20 (depends on 12)

The low power force detection system of claim 12 further comprises:
a power source circuit operable to provide power to the low power force detection system, wherein the power source circuit includes one or more of:
a battery;
a battery charger;
a linear regulator;
a power supply; and
a power harvesting circuit.

### Claim 21 (depends on 12)

The low power force detection system of claim 12, wherein the processing module is further operable to generate the digital value by:
converting the representative signal of the characteristic into an impedance value as the digital value.

### Claim 22 (depends on 12)

The low power force detection system of claim 12, wherein the processing module is further operable to generate the digital value by:
converting the representative signal of the characteristic into an impedance value; and
converting the impedance value into a capacitance value as the digital value.

### Claim 23 (depends on 12)

The low power force detection system of claim 12, wherein the processing module is further operable to generate the digital value by:
converting the representative signal of the characteristic into an impedance value;
converting the impedance value into a capacitance value; and
converting the capacitance value into a pressure value as the digital value.