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At-home respiratory health check




Delhi, DL, India


Shwaas was an internal product development effort, commercially available from 2017 to 2018.

We developed an Android app that connect to an OEM-made spirometer via Bluetooth. The spirometer was palm-sized device with a built-in LCD display for immediate access to test results.

Flow and volume parameters were transmitted to the Shwaas app. The app allowed data download in PDF and CSV (excel-readable) formats.

How it works

The app is designed for offline use, but also enables users to create an account and save their spirometry data. All the parameters captured by the device are transmitted to the app.

The device measures exhaled (expiratory) air flow using a rotary turbine. The number of rotations of the turbine is proportional to the volume of air, and the frequency of rotation is proportional to the flow rate. Based on these principles, infrared (IR) sensors are used to translate movement of the turbines to flow rate and air volume. The device assesses all major flow and volume related respiratory parameters, as described below.

FVC: Forced Vital Capacity

The volume of air that can forcibly be blown out after full inspiration.

FEV1: Forced Expiratory Volume

The volume of air that can forcibly be blown out in one second after full inspiration.


The ratio of FEV1 to FVC, expressed in percentage.

PEF: Peak Expiratory Flow

The maxima on flow-volume curve, i.e. the highest flow rate.

FEF25: Forced Expiratory Flow

Flow rate at 25% of vital capacity (FEV).

FEF75: Forced Expiratory Flow

Flow rate at 75% of vital capacity (FEV).


The average flow rate between 25% and 75% of the vital capacity.

Launch date
Jan 2017
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