Development, and evaluation of a handheld digital inspiratory airflow resistance monitor, to aid remote respiratory consultations in primary care, post the COVID19 pandemic

ABSTRACT

Respiratory medicinal therapies are most frequently delivered using inhalers. There are two types (MDI and DPI) which each have different characteristics and requirements. Even between brands of the same type, variations exist. This study developed a prototype handheld, digital device that can measure the inhalation airflow rate against resistance, alongside a value for the peak inspiratory airflow and breath-hold time. Allowing the assessment of inspiratory capacity, in a remote, post-COVID-19 environment. Currently, the Clement-Clarke InCheckTM device measures inspiratory effort. This device has an analogue scale and measures only peak inspiratory airflow. Therefore, MPXV7007 differential pressure sensor was used, as it can create a pressure differential that can then be related to airflow. The device was linked via blue tooth to a smartphone. Proof of concept was evaluated using a sample of healthy male volunteers (n=4). Ethics approval was obtained (ERGO/FEPS/68640). Repetitive comparative testing was carried out, on the prototype device, against each resistance level, and repeated on the InCheckTM device (usual care). The mean of these readings was compared to illustrate the performance of the prototype device against the InCheck TM device. The performance of the prototype is in agreement with the InCheckTM device, albeit with a relatively consistent bias of around -31 L/min. The table in (Figure1) shows on average an overall -31 L/min difference in the means. The measurements are comparable, however, a larger population is required including people with lung disease, to apply in clinical practice.