Currently, physicians cannot assess respiratory function in COVID-19 patients remotely. COVID-19 infection deteriorates patients’ ability to breathe due to discomfort, fluid accumulation, and exhaustion. While most patients can safely recover at home, patients and physicians via telemedicine cannot decide whether hospital treatment is needed without a physical exam. This uncertainty results in countless visits to emergency rooms (ERs) without hospital admission, needlessly exposing uninfected patients.
Our device provides a validated quantitative assessment of respiratory function for home-use, enabling COVID-19 patients to accurately report meaningful changes in their condition to a remote healthcare provider. FDA classifies the medical device as a diagnostic spirometer (21CFR 868.1840). While the underlying principle of spirometry is not new, our inexpensive, simple device for home-use represents a breakthrough for telemedical evaluation of COVID-19 patients.
A handheld facemask provides a hermetic seal to confine measurements to air moving through the patient’s nose and mouth. Our spirometer measures differential pressure across resistance to the gas flow during inspiration and expiration to continuously calculate airflow reciprocating through the lungs. Airflow is mathematically integrated over time to yield the gas volume exchanged by the lungs with each breath. When calculated over one minute, this value is called “minute ventilation”. Minute ventilation is inversely proportional to CO2 partial pressure in arterial blood, the index by which physicians identify respiration adequacy. Our prototype uses a microprocessor, pressure sensor, and LCD display connected with wires, but when manufacturing to scale, we will utilize off-the-shelf components connected in a custom printed circuit board.
The display continuously presents respiration rate, minute ventilation and flow versus time. With this information and data from forced expiration maneuvers, physicians can track respiratory function in COVID-19 patients by telemedicine, thereby avoiding unnecessary hospital visits.
Review of predicate summaries from the FDA database indicates that no clinical testing is required. Instead, we will demonstrate gas flow performance testing, evidence of compliance with electrical safety IEC 606-1 and biocompatibility under ISO 10993 to support our 510(k) application.
A patent search of CPC-classifications A61B and A61H revealed no devices capable of measuring minute ventilation in a home environment. The only devices incorporating respiratory airflow measurement are mechanical ventilation systems designed for use in pulmonary function laboratories. These systems are prohibitively expensive and must be operated by medical professionals, making them unsuitable for home-use. Similarly, commercial searches revealed no examples of spirometers capable of measuring minute ventilation in the home. Instead, the only spirometers available for home-use are designed for the limited application of peak flow measurement, unsuitable for COVID-19 assessment.
This device could be sold to ER and primary care teams, allowing physicians to deploy this device to high-risk patients. Each unit will cost less than $25, far less costly than an unnecessary visit to an ER – in dollars and danger. We estimate approximately $1.8-2.2 billion annualized savings in the U.S. Funding is requested for miniaturization, testing to comply with FDA regulatory review, and freedom-to-operate analysis. Furthermore, this device may allow monitoring of other illnesses including COPD, asthma, and pneumonia.