The technology

FreeO2 automatic oxygen titration (OxyNov) uses the measure of oxygen saturation of arterial blood (SpO2) to automatically adjust the flow of oxygen to a person through a nasal cannula or non‑occlusive mask. The technology operates on a closed loop and continuously adjusts the flow rate administered based on SpO2, to achieve and maintain a target SpO2. The device includes a safety feature that informs the user by an alarm if there is a breakdown or failure of oxygen supply.

The device is intended to be used in a hospital setting for treating chronic obstructive pulmonary disease (COPD) or acute respiratory distress syndrome (ARDS), which may be caused by COVID‑19. The FreeO2 aims to reduce the time a person spends in hypoxia or hyperoxia, improving clinical outcomes and reducing hospital stays.

The FreeO2 system has an inbuilt pulse oximeter to measure SpO2 levels. It automatically adjusts the oxygen flow rates (between 0 and 20 litres per minute, with or without humidification) based on this. This is measured using an oximeter worn continuously by the patient, which connects to the system by either Bluetooth or a standard 9‑pin connector. The SpO2 monitor continuously feeds the algorithm at a rate of 1 value per second. A proportional integral controller adjusts the oxygen flow delivered by a mass-flow controller from 0 litres per minute to 20 litres per minute, to maintain SpO2 at a predefined target. The FreeO2 system also provides continuous monitoring of respiratory parameters in people who are spontaneously breathing. This can be displayed in graph format for up to 72 hours after collection to support management. The device uses mains supply with a battery back up in the case of power supply interruption.

The system was developed in collaboration with the Department of Electronic and Informatics Engineering, Laval University, Quebec and University Occidental Britany Brest, France and the 2 associated University Hospitals.


The company claims the device is a new innovative technology offering automatic oxygen titration and weaning to regulate SpO2 levels, that is not available with standard manual measurements.

Current care pathway

NICE's guideline on chronic obstructive pulmonary disease (COPD) recommends oxygen therapy as a treatment option for exacerbations of COPD. ARDs caused by COVID‑19 may also need passive oxygen therapy before further treatment considerations such as continuous positive airway pressure (CPAP) intubation and mechanical ventilation. The British Thoracic Society's guideline for oxygen use in healthcare and emergency settings – summary of recommendations states that pulse oximetry must be available in all locations where emergency oxygen is used, and oxygen saturation should be checked by pulse oximetry in all patients who are breathless and acutely ill.

Oxygen therapy as an appropriate intervention should be prescribed according to a target saturation range and be monitored to remain in this range. Standard care involves using a manual oxygen flow regulator and a SpO2 monitor. This needs healthcare professionals to manually measure both inspired oxygen concentration and SpO2, which may be used to inform and monitor according to the National Early Warning Score (more information available in NICE's medtech innovation briefing on National Early Warning Score systems that alert to deteriorating adult patients in hospital). If oxygen levels are below the target range for the patient or if the saturation falls by 3% or more then oxygen therapy should be prescribed to achieve a target saturation (94% to 98% for most people who are acutely ill). Oxygen is given through a nasal cannula or a face mask. The measurements should be repeated regularly, and appropriate oxygen flow adjustments made to bring SpO2 into the individual target range. NICE guidance highlights that inappropriate oxygen therapy in people with COPD may cause respiratory distress.

The following publications have been identified as relevant to this care pathway:

Population, setting and intended user

FreeO2 is suitable for people who need oxygen therapy, from babies over 1 month old to adults. It is intended to be used after admission to A&E and after triage until SpO2 levels are considered to be managed, or for the length of stay in hospital.

Various healthcare professionals may give oxygen therapy once appropriate training has been done. Staff giving oxygen should be trained across a range of devices to ensure oxygen is given safely, using appropriate devices and flow rates to achieve the target saturation.


Technology costs

The FreeO2 system is available for purchase at £9,600 per unit (excluding VAT). There are no additional consumable costs related specifically to the use of this system. The expected lifespan of FreeO2 is 5 years, with a yearly preventative maintenance and calibration cost of £450.

Costs of standard care

Various SpO2 monitors are available ranging in price from £144 to £450, with separate sensors varying in price from £42 to £225.

Resource consequences

The FreeO2 device is not currently used in the NHS.

Using FreeO2 in the NHS would incur an additional cost compared with standard manual delivery of oxygen. Assuming reliable SpO2 measurements and adjustments are produced, this may be offset if the claimed benefits of reduced morbidities and length of hospital stay are seen. There is limited published evidence to support these claimed benefits.

One economic evaluation was located relating to the cost of FreeO2 technology (Poder et al. 2018). This examined the cost effectiveness of FreeO2 in 47 people hospitalised with acute exacerbation of COPD in Quebec. The study reported generated savings of 20.7% of the per-patient costs at 180 days (£1,695.31). This decrease is not significant at the 95% threshold (p=0.13), but the time spent at target oxygen saturation, time spent in hyperoxia, and level of severe hypoxaemia all improved (p<0.001). The incremental cost-effectiveness ratios reported indicate that FreeO2 is more cost effective than manual oxygen titration.

The company provides free onsite user training on instillation and implementation. Ongoing staff training can be delivered on request. No changes in facilities and infrastructure were identified for the adoption of FreeO2.