Renesas offers open-source ventilator design to combat COVID-19

Renesas Electronics Corporation has introduced a new open-source ventilator system reference design with ready-to-assemble electronic boards to help the world community wage a war on COVID-19 pandemic.

The design, which will greatly contribute to the global cause, uses two microcontrollers that can monitor and reset each other. The system is equipped with Bluetooth connectivity for IoT endpoint devices, system control, and wireless communication that lets medical professionals monitor several patients simultaneously via a tablet or other mobile device.

It can control the tidal volume and mixture of gas delivered to the patient air into the system.

Features of the reference design:

The ventilator is portable and can be used with or without gas tanks.
It can provide high-pressure oxygen to patients to assist control and pressure control modes.
The assist control mode provides a certain tidal volume of gas to a patient with each inhale.
The system is equipped with a flow sensor board (FS1023) to monitor the gas flow rate at the inhale tube and the tidal volume.
Both gas volume and flow rate are monitored by the FS1023, which is further calculated by the MCU using the rate integrated with time.

How the MCUs work
The oxygen valve is controlled by the MCU to manage the oxygen ratio. The pressure control mode provides a certain pressure to the patient with each inhale. There is one proximal air-pressure sensor connected to the mask to monitor the inhale pressure and send that information to the RX23W MCU.

The blower is driven by a motor control board that is controlled by the RX23T MCU. It uses I2C communication with the RX23W. Apart from it, a humidifier soothes the patient’s breathing, making it more comfortable to be connected for long durations.

Among the product’s other features, the oxygen ratio is controlled by the valve, which is controlled by the MCU and monitored by the flow sensor. The exhale pressure is controlled by MCU through the exhale valve, and the oxygen sensor is used to test FiO2 (fraction of inspired oxygen). While the blower is controlled via pressure/flow sensor feedback, the LCD brightness is controlled by the light sensor monitoring ambient light.

Significantly, this easy-to-assemble three board ventilator design features a battery balance monitor to extend battery lifetime.

“Leveraging our broad product portfolio and system design expertise, we are enabling customers to accelerate their development of medical ventilator systems capable of operating in a home or hospital environment,” said Chris Allexandre, senior VP, IoT and Infrastructure Business Unit at Renesas.

Renesas’s latest product is in sync with its wide portfolio of microcontrollers, analog, power, and SoC products that provide comprehensive solutions to a broad range of automotive, industrial, home electronics, and information communication technology applications.