Context and objectives :
 
The objectification of pain measurement is an important issue for monitoring patients with chronic pain. But it is complex because chronic pain is the pain of illness that uses first-rate systems that depend on the CNS and that integrates personal components related to the individual in himself. It is something more complex that goes beyond the mere sensory processing of the nociceptive message from a biological and biochemical point of view.

Facial recognition has promising results in identifying and measuring the intensity of acute pain induced outside physiological and psychological adaptations that exist in the process of chronicizing pain (bilateral asymmetry, key-time intervals, frequency of micro-expressions…).

This study analyzes non-invasive markers specific to chronic pain. The challenge is to see the differences in the expression of pain and the variations according to the biological variability (sex, age…). Understanding these differences allows a more objective approach to measuring pain.

Methodology : The protocol is based on behavioral and biometrics data (morpho-geometry of maxillofacial structure and body posture) to obtain subconscious responses. These data will be mixed with anthropological interviews on the pain experience (sensory evaluation) to obtain self-reported conscious responses.

The study is realized in conjunction with clinical tests on endometriosis and neuropathy which include 100-130 patients for each pathology. Cohorts of healthy patients (pain induced by electrode / cold bath) will serve as a reference to understand the phenomena of adaptation and expression related to the chronicization of pain. 

Results and conclusions: Study in progress

PAIN MEASUREMENT AND ANALYSIS : A BIOMETRIC APPROACH TO THE CHRONICIZATION OF PAIN