The stark reality of the COVID-19 pandemic has exposed the cracks in health care systems to adequately provide support to the affected patients.
We realize the importance of ventilators as critical for the care of people with lung failure, one of the complications suffered by patients with severe COVID-19 attacks. The scarcity of ventilators is worsened by the fact that hospitals have to reserve ventilators to treat non-COVID-19 cases such as heart attacks, strokes and other emergency cases even at this time of the pandemic.
While we appreciate that the time at hand is not adequate to develop a fully compliant ventilator based on the government specifications, we believe that developing a low-cost portable automatic respirator with minimum features available to Wanjiku would save lives. Among other features, the machine should have invasive and non-invasive feature, and supports 400-700 mL tidal volume, with a continuous working capability for 2-3 days. Furthermore, any innovation must be attentive to the needs of the larger group of the population as opposed to the few.
To tackle this imminent shortage, at DewCIS we envision a simply home-made ventilator, a mechanical breathing device that is able to blow both air and oxygen into the lungs. Rather than reinventing the wheel, our innovation is to reuse locally available parts to assemble a ventilator. Our vision is to empower every homestead to own a ventilator at minimum cost, using a simple one-page instruction DIY manual.
The device is made of an automatic motor pulling a tough string pulley tied to the board, which then squeezes the bag-valve mask, often called ‘Ambu Bag,’ used for resuscitation in emergency situations, to push oxygen and air into the lungs.
Assembling “Wanjiku” Ventilator, I Prototype
The device can be assembled from locally readily reusable parts, and consumer off-the-shelf components
Motor & Motor ControllerA basic direct current (dc) motor with 7 kg torque is preferable. A car wiper motor would do. The motor controller gives the various modes of operating the motor.
Tough string1-meter long tough nylon string, easily available from a used clothe
Bag-valve maskoften called ‘Ambu Bag,’ used for resuscitation in emergency situations, available at local chemists
12V direct current (dc) supplya car battery would do, an old computer power supply module or an adaptor for the 240V alternating current (ac) supply
Arduino MicrocontrollerSupports programmable features of the apparatus.
Other parts including casing can be crafted at home or from local jua kali kiosks.
This Wanjiku ventilator is portable, and therefore adoptable in villages and other low cost residential areas without reliable power supply, and is inexpensive enough to scale up in bulk production. In dire situations, an ingenious 4-way valve splitter can be used to serve upto 4 different patients.
Future models & improvements
Craft a more durable base and casing to offer sturdy mechanism.
Introduce gears and pulleys for a smooth air flow and eliminate jerking.
Program the motor motions to allow supports of a range of tidal volumes.
Include user interface to allows selection of preset inspiratory:expiratory ratios.
