This project investigates a wearable approach to analyze thoracic motion and breathing abnormalities associated with seronegative spondyloarthropathies, a group of autoimmune diseases in which the body attacks its own musculoskeletal system. These conditions commonly affect the spine and rib cage, leading to reduced thoracic flexibility and altered breathing patterns across different regions of the chest.

The proposed prototype consists of a chest mounted wearable belt embedded with five IMU sensors positioned around the rib cage. These IMUs capture multi axis acceleration and orientation data, allowing detailed measurement of chest motion in different thoracic regions during breathing. All sensor data is collected by an onboard microcontroller and transmitted wirelessly to a phone or laptop for further processing and analysis.

Chest velocity and expansion are derived from IMU acceleration data using numerical integration techniques. Because the data is discrete, successive Riemann sum approximations are applied to estimate velocity and displacement. This enables accurate reconstruction of chest expansion patterns, providing quantitative insight into respiratory mechanics affected by spinal pathology and supporting objective assessment of disease related breathing limitations