# Development and validation of a multi-modal contactless sensing system for surgical risk analysis in a real-world environment

## TL;DR

GroundCode is a contactless sensing system that measures gait to assess surgical risk in real-world settings, offering accurate and easy-to-deploy health monitoring.

## Contribution

A rapidly deployable, contactless sensing system called GroundCode is developed for surgical risk analysis in real-world environments.

## Key findings

- GroundCode provides highly precise gait measurements with over 90% accuracy.
- The system identifies surgical risk factors such as age, sex, and frailty.
- Preoperative gait metrics are associated with postoperative recovery outcomes.

## Abstract

Gait measurements are a central component of functional assessments and risk stratification before surgery. Various sensors can measure gait metrics, but none are routinely integrated into surgical workflows because they are too challenging to implement at scale in clinical situations. In this manuscript, we report the development and validation of a rapidly-deployable, low footprint, entirely contactless sensing system, called GroundCode, that is explicitly integrated within a surgical workflow. GroundCode combines the Microsoft Kinect with seven floor-mounted single-axis accelerometers, overcoming the weaknesses of each individual sensor technology and providing both robust spatiotemporal resolution (Kinect) and high-fidelity footstep detection and quantification (floor accelerometers). We show that GroundCode-derived gait speed and cadence are highly precise measurements (>90%), and we validate them against two standard clinical gait measurements relevant to pre-surgical evaluations – stopwatch time and six-minute walk test distance. We show that GroundCode-derived gait metrics identify various surgical risk factors, like age, sex, and frailty. In addition, we show that preoperative gait is associated with postoperative quality of recovery. Importantly, we designed this system to be deployed by non-technical personnel and performed this study in a non-laboratory setting, providing proof-of-principle that GroundCode can be used in various real-world environments. We conclude that GroundCode provides highly robust gait measurements in real-world settings with possible applications spanning clinical diagnosis, risk stratification, and digital biomarker development.

Wearables and other sensors offer great promise for monitoring patients both inside and outside of the hospital. But these technologies are often difficult to integrate into clinical workflows because they need technical support, patient compliance, and standardized implementation protocols. To address these limitations, we created a contactless sensor system, called GroundCode, that transforms a room into a continuous health sensor. This facilitates its integration into a surgical workflow for preoperative risk assessment. Our sensing system can be set up in under 10 minutes in any environment and makes highly accurate measurements of how someone walks and moves. This technology has applications for disease diagnosis, clinical risk prediction, and at-home health monitoring, and has the potential to facilitate aging-in-place and other healthcare delivery models that prioritize patient well-being and recovery outside of the hospital.