STTR Phase I: Design of a Handheld Multi-sensor Passive Pulmonary Function Testing Device

The broader impact/commercial impact of this Small Business Technology Transfer (STTR) Phase I project is development of a pulmonary function testing device for detection and diagnosis of pulmonary conditions. Today more than 650 million globally, nearly 10% of the world?s population, suffers from lung conditions like Asthma and Chronic Obstructive Pulmonary Disease (COPD). Currently, the most well-established method for lung function testing is spirometry, which requires the patient to conduct an unnatural breathing maneuver. In addition, spirometry cannot detect lung conditions for certain patient population. The proposed technology can be used without special breathing maneuver, and can differentiate more lung conditions than spirometer. Since the proposed device can be used while the patient is breathing normally, it will also cater to currently under-served patient segments, e.g. young children and senior citizens, for detection and diagnosis of pulmonary conditions. By targeting a portable form-factor, this technology will empower point-of-care pulmonary testing where it is currently infeasible. The proposed project will develop be the first handheld implementation of the well-studied principle of forced oscillation technique (FOT), where an acoustic pressure wave is sent via the mouth to a patient?s lungs and reflections are used to measure lung function. Thus, no special breathing maneuver is required from the patient. To achieve the handheld form-factor, the team proposes two complementary innovations. First, the team will develop a new coherent multi-speaker transmitter, which will reduce the size of the biggest component, i.e., speaker, in current implementations of FOT. To replace the huge speaker capable of generating sufficient magnitude pressure waves at very low frequencies, the team proposes to employ many small speakers with specially designed input signals such that they coherently add at the destination. Second, the team will develop coherent multi-sensor receiver to measure pressures waves from patient?s lungs which are often very small in amplitude, and interlaced with waves due to patient?s breathing. The team proposes to employ multiple sensors to measure flow and pressure of the reflected waves, such that the received signal to noise ratio can be increased by coherently processing the multiple received waveforms.