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Shwaas Spirometer


Shwaas is a Bluetooth-enabled spirometer that brings together the ease of use of a handheld spirometer with the data logging capabilities of an Android smartphone.

Shwaas is palm-sized device with a built-in LCD display for immediate access to test data.

Flow and volume related parameters are measured and transmitted to any Android smartphone via a built-in Bluetooth module. The Shwaas app allows data download in PDF and CSV (excel-readable) formats.

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.

Shwaas 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.

Shwaas - Bluetooth Enabled Spirometer

Shwaas - Bluetooth Enabled Spirometer

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