The sensor fitted to the mask can map the patient’s respiratory profile in a fraction of a second, helping detect hidden lung infections. Credit: Titash Mondal
A printable sensor made by scientists at Indian Institute of Technology Kharagpur can detect normal and rapid breathing patterns1. When attached to a face mask it can map a patient’s respiratory profile in a fraction of a second, revealing any hidden lung infection.
The sensor functions at room and sub-zero temperatures, making it suitable for use at home or by military personnel in freezing high-altitude camps.
Most respiratory sensors work at room temperature, but very few are efficient in sub-zero conditions. Scientists led by Titash Mondal mixed liquid polyisoprene rubber with a few layers of graphene and a cross-linking organic compound. They used the resulting ink to print the sensor on a polymer substrate.
The sensor’s electrical resistance changed in response to increasing strains induced by inhalation and exhalation. A sensor-attached N95 mask detected normal breathing patterns. It also detected conditions like eupnea and tachypnoea.
In a separate experiment, the team, which included Simran Sharma and Ankur Thapa, dipped the sensor in liquid nitrogen and found that the cooled sensor retained its ability to sense breathing patterns.
Fluctuating humidity and temperature around face masks generate signals that can affect how efficiently the sensor detects exact breathing rates. The researchers showed that a silicone-based coating and an embedded electrical device negated these effects. The sensor could wirelessly transmit data on normal and disease-induced rapid breathing rates to a smartphone via Bluetooth, says Mondal.
