Novel acoustic evaluation system for scratching behavior in itching dermatitis: Rapid and accurate analysis for nocturnal scratching of atopic dermatitis patients

Abstract

Quantitative analysis of itching in patients with itching dermatitis including atopic dermatitis (AD) is indispensable for the evaluation of disease activity and response to therapy. However, the objective evaluation system for itching is limited. We have developed a new objective and quantitative scratching behavior detection system using a wristwatch-type sound detector. The scratch sound detected on the wrist is recorded on a personal computer through a filtering, squaring and smoothing process by specific hardware. Subsequently, the data is automatically processed and judged for the scratching movement using specific software based on the periodicity and energy of the signal. Twenty-four measurements for healthy volunteers and those with AD by this system were evaluated by comparison with a simultaneously recorded video analysis system. The ratio of scratching time in sleeping time evaluated by these two systems was almost identical. The healthy subjects scratched their skin approximately 2 min during 6 h of sleeping time, while the mean scratching time of AD subjects was 24 min in their sleeping time. In contrast to the time-consuming video analysis system, this system takes only several minutes for evaluation of an overnight record. This scratch sound detection system is expected to serve as a new objective evaluation tool for itching dermatitis, namely, AD, and development of anti-itch therapies for dermatitis.

Automated acoustic detection of mouse scratching

“…Nevertheless, automated detection of itch remains an important goal. In this regard, it is noteworthy that acoustic method to quantify nocturnal scratching of atomic dermatitis patients using a wristwatch-type sound detector has recently been developed [14], and it is hoped that automated detection will provide an objective measure of itch that will be a useful endpoint in future clinical trials for pruritus.…”

“…In this paper we propose a new method for automation through acoustic detection of scratches which is related to the template matching method of [13], applied to rodents, and [14], applied to humans. Acoustic detection is non-invasive and can be performed in the dark, which is important because mice are nocturnal and lighting conditions that enable the visual assessment of scratching are known to be stressful for mice.…”

Mobile System Design for Scratch Recognition

“…An infrared camera was also introduced objectively to identify the severity of itching in patients with atopic dermatitis [3]. However, a long time is necessary to go through one night of recording, and blind positioned hands (i.e., hands covered with a blanket) are difficult to identify [3,9].…”

“…In addition, these devices are mainly used for the purpose of research and cannot practically be used for patient care purposes. Recently, a watch-type scratch sound detector [9] was introduced to detect body-conducted sound from scratch movements. Although the method shows impressive performance with regard to accuracy, it often fails to identify the location of the scratching site.…”

Assessment of Pruritus in Patients With Psoriasis and Atopic Dermatitis

“…97 This novel device has the ability to specifically detect bone-conducted scratching sounds, which are transmitted to a piezoelectric sensor on the wrist. 97 This novel device has the ability to specifically detect bone-conducted scratching sounds, which are transmitted to a piezoelectric sensor on the wrist.…”