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
ABSTRACT
Objectives: New or increased cough is an important sign of pulmonary exacerbation. There is unmet need to objectively quantify and analyse cough trends in early life. Advances in flexible electronics and materials allow development of soft, skin-like, accelerometer-based wearable devices that seamlessly interface with the human body in unique locations, enabling the simultaneous capture of low-frequency body, chest, and throat motion along with high-frequency vocal, throat, and lung sound signals associated with various body processes including coughs and vital signs. Methods: A small, flexible, fully wireless, accelerometer-based mechano-acoustic sensor (MAS) was applied using gentle adhesives to the suprasternal notch of 10 paediatric CF subjects during regular clinic visits. A 15-minute protocol consisting of eliciting cough, throat clearing, speech, and laughs in various head/body orientations, ambient environments, and physical activity intensities. The MAS recorded at a high bandwidth 1.6kHz rate and automatically uploaded to a cloud server upon replacement on a wireless charging platform. Results: The captured sensor data was analysed using an existing machine learning algorithm developed for COVID-19 symptom tracking. Preliminary results show the device differentiates cough from other vocal, respiratory noises and motion artifacts, both at rest and during activity. A majority of children found the device to be acceptable, though device size and adhesive removal caused minor discomfort for some. Conclusion: The extraction of well-classified cough events is feasible, facilitating further analysis of cough episode duration, force, and clinically relevant features associated with early decompensation, response to treatment, and daily symptom tracking. Objective measurement of cough may be useful as a clinical study outcome measure and for clinical monitoring. Future work will include evaluation for longer time periods during stability and pulmonary exacerbations.