Physical function and mobility endpoints are relevant to most, if not all, all clinical indications. Traditional in-clinic performance tests, such as the 6-Minute Walk Test and the Timed 25-Foot Walk, often comprise primary and secondary endpoints in neurodegenerative, cardiorespiratory, and rare disease. Wearable kinematic sensors now provide an opportunity to capture real-world evidence about not only the types of behaviors a patient chooses to participate in but how a patient performs those behaviors in their environment.
For a more advanced biomechanical analysis of physical function and mobility (e.g., detailed gait parameters), sensor fusion techniques can be used to integrate data from multiple sensors simultaneously worn at various anatomical sites.
The accuracy and relevancy of physical function and mobility outcomes depend primarily on sensor wear location, data collection and analysis procedures, and patient population.
Tri-axial Accelerometer - Accelerometer sensors capture static and dynamic linear acceleration, which, when combined with accurate analytics, can be used to identify the types, intensities, and biomechanical properties of physical behaviors. When worn on relevant anatomical sites, they can identify body posture.
Gyroscope- Gyroscopes measure angular velocity about three axes, pitch (x), roll (y), and yaw (z). Angular velocity measured at the ankle is particularly relevant for accurately estimating stride length and velocity.
Magnetometer - By measuring magnetic flux, magnetometers identify the direction of the earth's magnetic north. Combining absolute heading information with accelerometer and gyroscope data can provide valuable information about a change in direction or turning behavior - an outcome relevant for neurodegenerative diseases, such as Parkinson's disease.