When patients need oxygen therapy, they sometimes also need physical help to breathe. The OVSI Ventilator enables assisted breathing, pumping oxygen to the patients’ lungs to keep them alive.

All the components fit within a compact and robust instrument the size of a briefcase. The different deliver oxygen therapy adapted to the patients’ needs – supporting them patients whether they require assisted breathing or just a constant flow of oxygen.

The OVSI ventilator is a pressure based system, it has the capability to use external oxygen supply to mix with the ambient air to increase the oxygen concentration to the patient.

Technical specifications


Respiratory Rate
5 - 60 breaths/minute

O2 Supply
0.3 - 8 bar


Inspiratory Pressure
15 - 50 cm H20

Inspiratory/Expiratory ratio
5:1 - 1:5

air self-supply

24V DC + 30 minute backup battery

0 - 20 cm H20

21% - 95%

500 x 400 x 200mm

Target Cost
$500 - $1000

Assisted or automatic

The OVSI ventilator can support a patient from assisted to fully automatic respiration.

Patient triggered: The patient breathes independently. The OVSI ventilator uses a pressure sensor to detect the patient's attempt, and triggers the inspiration.

Mechanically triggered: The breaths are triggered without input from the patient. The OVSI ventilator recognises if the patient is not receiving enough oxygenation, and provides timed respiration. The patient has no influence on the time of inspiration.

Modes of operation

The OVSI ventilator is designed to be versatile and can operate in three modes.

Non-Invasive Ventilation: The OVSI ventilator can be used to assist patients who have difficulty breathing. Mandatory breaths are synchronized with the breathing attempts of the patient, both in and out. If the mandatory breath is shortened on account of the synchronization with expiration, the next mandatory breath is extended. If the patient stops breathing all together, the OVSI ventilator will trigger mandatory breaths. The patient can breathe spontaneously during the complete breathing cycle.

Synchronized Intermittent Mandatory Ventilation (Pressure Control + Pressure Support): The OVSI ventilator can be used to assist patients who have some, but insufficient, breathing and can be used for weaning patients off ventilation. The ventilator provides mandatory breaths which are synchronized with the patient’s spontaneous efforts at a pre-set rate. The OVSI ventilator will adapt the respiration cycles to prevent a change in the number of mandatory breaths. During spontaneous breathing, the patient can be supported using pressure support mode.

Pressure Control - Mandatory Ventilation: The OVSI ventilator can be used to assist patients who have difficulties in breathing, by setting a mandatory number of breaths which are machine-triggered. The machine permits spontaneous breathing during the whole breathing cycle.

A versatile ventilator

The OVSI Ventilator incorporates a series of sensors that detect the pressure of air the patient breathes, and adjusts the oxygen outputs accordingly. This makes the most of every oxygen molecule, ensuring a mindful use of resources.

The OVSI Ventilator is adaptable to many oxygen supply systems, like piped oxygen or canisters, when such high-pressure oxygen resources are available. Furthermore, our modular approach enables connectivity between the OVSI Ventilator and the OVSI Concentrator – which work seamlessly together, to provide an integrated solution for oxygen therapy.


The OVSI ventilator is a low-cost, high-quality instrument designed for a range of end-uses required in Intensive Care Units, from non-invasive C-PAP to full mechanical ventilation.

The prototypes developed in the Whittle Lab (University of Cambridge) and Prodrive is now under production development by Defy in South Africa, where it has already been submitted for emergency regulatory approval.

Open-source licence

The design of the OVSI Ventilator will be available under open-source licence at GitLab (CERN-OHL-S), which will enable other partners to further develop the design to full manufacture. A team of students from the Sensor CDT of the University of Cambridge will work throughout the summer 2021 with our partners to release iterations of the design on Git-Lab.

Manufacturing this technology will require suitable infrastructure to comply with local regulatory requirements, but OVSI designs will be available fairly, to facilitate potential in-country manufacture and enable the creation of local ecosystems that outlast our project.

The OVSI ventilator does not have regulatory approval in any jurisdiction. It is the responsibility of licensees to comply with all applicable laws in relation to their use of the designs including without limitation obtaining applicable regulatory approval for medical devices manufactured to the designs in all relevant jurisdictions.