Project
| # | Title | Team Members | TA | Documents | Sponsor |
|---|---|---|---|---|---|
| 68 | Insole Pressure Sensing System for Running |
Aarush Sivanesan Joseph Casino Matthew Weng |
Xiaodong Ye | design_document1.pdf proposal1.pdf |
|
| Members: Joseph Casino (jcasino2) Aarush Sivanesan (aarush2) Matthew Weng (mw87) # Problem Runners often develop injuries or inefficient running form due to high impact forces, poor foot-strike mechanics (heel vs midfoot), asymmetrical loading, or inconsistent cadence. Most runners do not have an easy way to measure how their foot actually loads the ground over time, since gait labs and force-sensing soles are expensive and geared towards physical therapy, research, or professional athletics. Existing consumer wearables estimate cadence using wrist/hip motion, but do not directly measure foot-ground pressure/impact. There is a need for a low-profile, shoe-integrated system that can quantify foot impact and pressure distribution during real runs while remaining comfortable, lightweight, and accessible to everyday runners. # Solution We propose a thin-film pressure sensor insole system for running shoes that measures the force applied by the foot to the ground throughout each stride. A flexible sensor array embedded on top of the shoe foam (or placed under the insole) will capture pressure through the foot’s main contact points (forefoot, heel, and midfoot). A small electronics module will attach to the shoe heel or tongue and contain MCU, battery, and Bluetooth modules. The MCU will sample the pressure sensors, detect foot-strike events, and compute basic metrics such as step count, cadence, contact time, and estimated distance (using cadence/stride-length calibration and optional IMU/GPS data). Data will be streamed over Bluetooth Low Energy (BLE) to a phone for visualization, logging, and further analysis. # Solution Components **Subsystem 1: Thin-Film Pressure Sensor Insole Array** This subsystem senses foot pressure at key regions of the shoe to capture impact patterns and pressure distribution during stance. The sensor insole would fit either on top or bottom of the foam insole of the shoe. Components: - Thin-film force sensors (multiple locations): Interlink Electronics FSR 402 - Flexible interconnect/cabling: FFC/FPC cable (0.5 mm pitch) (generic) - Connector (board-side): Molex 503480-0490 (4-pos FFC/FPC connector) (size can be adjusted based on channel count) **Subsystem 2: Analog Front-End + ADC Data Acquisition** This subsystem converts each sensor data to data that can be read to the MCU. To sample all the sensors on the foot, we sample between all the sensors with a MUX. We then properly filter and amplify the data from the sensor through the op-amp. This data then gets digitized through an ADC. Components: - 16-bit ADC: MCP3425A0T-E/CH - Analog multiplexer: CD74HC4067SM96 - Op-amp: TLV9062IDR **Subsystem 3: Microcontroller + BLE Wireless Telemetry** This subsystem houses our MCU which will control sampling,collect data, timestamp data, and transmit results via BLE. Components: - MCU module: ESP32-C3-WROOM-02 - Programming/debug interface: Tag-Connect TC2030-IDC **Subsystem 4: Optional Motion Sensing (IMU)** This extra subsystem provides accelerometer/gyro data to gather speed data, estimate and improve stride data and length, and improve cadence robustness when the pressure signals are noisy. Components: - 6-axis IMU: ST LSM6DSOXTR or equivalent **Subsystem 5: Power Management + Charging** This subsystem powers the in-shoe electronics safely and supports rechargeable operation if applicable. The design regulates battery voltage to stable rails for the MCU and sensors. We have a wide range of batteries that we would like to work with initially to weigh out the pros and cons of each. Components: Battery options: - 3.7V Li-Po (300–500 mAh) - 3V Coin Battery - AAA Alkaline Battery - BMS IC for Li-Po : MCP73831T-2ACI/OT - 3.3V regulator : MCP1700T-3302E/TT **Subsystem 6: Phone Interface / Data Visualization** This subsystem provides the wireless interface between the device and a smartphone or website which displays metrics to the runner and logs sessions. Initial versions can use a simple BLE GATT service viewed in a standard BLE app; a custom website or phone UI can be added if time permits. Components: - BLE GATT profile (firmware-defined) - Prototype viewer: nRF Connect app or alternative # Criterion For Success Efficiency: The system shall sample plantar pressure sensor data at a minimum rate of 100 Hz and transmit the data over Bluetooth Low Energy with no more than 5% packet loss during continuous operation. Accuracy: The system shall detect foot-strike events and report running cadence with an accuracy of ±3 BPM compared to a stopwatch or smartwatch reference over a controlled running trial. Continuity/Longevity: The device shall operate continuously for at least 1 hour on battery power while performing active sensing and BLE data streaming. |
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