Acceptability and usability of a soft, flexible, wearable device for cough detection in children with cystic fibrosis

ABSTRACT

Background: Cough is a common symptom in cystic fibrosis (CF), and an increase in cough is an important sign of worsening lung disease and pulmonary exacerbation, the most common cause of hospitalization in people with CF. Objective monitoring of cough could be an important outcome measure for clinical trials, especially in children too young to perform pulmonary function tests. There are no accurate, objective methods of quantifying the frequency, severity, and duration of cough. Devices that have been tested to measure cough are neither highly reliable nor user friendly. We developed a mechano-acoustic sensor (MAS) a 4.8- cm- x 2.8-cm- (1 inch) long, thin, lightweight, stretchable, wireless device that adheres easily and securely to the skin surface and is worn at the base of the neck. The devicewas validated in adults being monitored for COVID- 19. This study evaluated usability and acceptability to children and their parents. Method(s) In Cohort 1, a small, flexible, fully wireless accelerometer-based MASwas applied to the suprasternal notch of children with CF using gentle adhesives. Participants were asked to perform activities that included forced coughs while sitting, lying down, and performing activities such as jumping or jogging and other pharyngolaryngeal activities such as swallowing, speaking, and throat clearing. The sessions were an average of about 30 minutes long. In Cohort 2, participants were asked to test the device for a longer period of wearable time (4-6 hours) in various settings, including outpatient clinics, inpatient rooms, and outside clinic and athome environments. Upon completion, all participants from both cohorts were asked to fill out the Acceptability and Usability Questionnaire, which consisted of six questions ranked on a 4-point Likert scale. Result(s) Cohort 1 included 21 children aged 3 to 18 (mean age 9.25 +/- 4.85), and Cohort 2 included 12 children aged 7 to 18 (mean age 12.15 +/- 4.42). On 31 (94%) questionnaires returned, 35.5% of participants strongly agreed and 61.3% agreed with the statement "I [or my child] like(s) wearing the cough sensor." Similarly, most participants found the cough sensor easy to use (74.2% strongly agreed, 25.8% agreed) and comfortable to wear (64.5% strongly agreed, 29.0% agreed), although they found the adhesive sticker difficult to take off and the device too obvious or large. Conclusion(s) Although qualitative and quantitative acceptability and usability data were overall positive, we have redesigned the cough sensor for comfort and are continuing enrollment. The new sensor, 3.5 x 1.6 x 0.8 cm, is smaller and sits lower on the neck so participants can better conceal it underneath clothing (Figure 1). We are providing universal adhesive remover wipes to all participants. Future work includes long-term monitoring (1-2 weeks) of pulmonary exacerbations using the new devices and further assessing usability and acceptability from participants.(Figure Presented) Figure 1. New cough sensor design with a longer neck and a smaller body, allowing it to be better concealed underneath a shirtCopyright © 2022, European Cystic Fibrosis Society. All rights reserved