Body-focused repetitive behaviors (BFRBs), symptoms of Obsessive Compulsive Disorder (OCD) and other conditions involving compulsions (e.g., Autism Spectrum Disorder) involve compulsively causing physical injury and/or damaging one’s physical appearance. These are among the most poorly understood symptoms; they are often misdiagnosed and undertreated. BFRBs include hitting oneself, biting, pulling out hair, skin picking and cutting, as well less severe but damaging behaviors such as nail biting, thumb sucking, and nose picking (Families & Health). These symptoms affect at least 5% of the population (Families & Health); hair pulling alone affects 1%, or about 3 million people in the US (Diefenbach, Reitman & Williamson 2002). BRFBs are highly comorbid. Studies have shown that as many as 70% of those with one BRFB will have another co-occurring BRFB (Conelea, Frank & Walther, 2017). While often impairing, affecting medical health and/or disfiguring, these symptoms are frequently reported but often not observed in clinical settings. This makes diagnosis, as well as treatment planning and monitoring, exceedingly difficult. To avoid pain and disfigurement, it is imperative to identify a reliable means to automatically identify and monitor BFRBs, especially outside the clinic setting. Clinicians need data on BFRB frequency and timing for the purposes of diagnosis, treatment planning and monitoring while patients need immediate, real-time feedback to make behavioral therapies more effective.
To address this previously unmet clinical need, we have created a prototype for a wrist-worn device called the “Tingle” that can monitor and record BFRBs while also providing real-time (haptic) feedback (on the wrist) to the individual with BFRBs when they occur. The Tingle is the subject of U.S. Patent Application #15/816,706 filed January 26, 2018.
Wrist-worn inertial measurement unit (IMU) sensors and proximity sensors are routinely used to track changes in hand position, but are inadequate for identifying specific locations. In a pilot study, we tested whether the addition of thermal sensors increases the accuracy of position tracking for better detection of BFRBs. Healthy adult participants simulated BFRBs while wearing the Tingle, which incorporates thermal sensors to monitor BFRBs. The addition of thermal sensor data significantly increased a neural network’s detection accuracy when compared against IMU and proximity sensor data alone. This study presents preliminary evidence of the advantage of including thermal sensors and the Tingle wearable device’s potential use in BFRB diagnosis and management.
This proof of concept leads to the critical next step of applying the Tingle to the clinical setting in which we will confirm the Tingle’s effectiveness in preparation for an FDA New Device Application and plan for commercialization. This will open the way for broad distribution in clinical practice as a diagnostic tool and to support the evaluation and implementation of pharmacological and behavior therapies for BFRBs.
The above 3D model represents the top half of the Tingle device enclosure. By 3D printing the enclosure, we are able to precisely orient the sensors mounted inside. The holes in the model correspond to individual sensors, a button and an indicator LED.