A breathing aid that was designed and built in less than a week to keep Covid-19 patients out of intensive care has been delivered to London hospitals for clinical trials. The device delivers a steady stream of oxygen and air to patients who are struggling to breathe and can be used on standard wards, unlike ventilation, which requires patients to have an invasive procedure and sedation in an intensive care unit. Such continuous positive airway pressure (Cpap) devices, which are being used extensively in hospitals in Italy and China, bridge the gap between an oxygen mask and full ventilation. UK hospitals have the apparatus but it is in short supply. Engineers from UCL and doctors at University College London hospital (UCLH) developed the device, which is claimed to be an improvement on existing Cpap systems, with Mercedes Formula One in less than 100 hours from first meeting to first production model. The device has been approved by the UK’s Medicines and Healthcare products Regulatory Agency. “These devices will help to save lives by ensuring that ventilators, a limited resource, are used only for the most severely ill,” said Prof Mervyn Singer, a UCLH critical care consultant who worked on the design. “While they will be tested at UCLH first, we hope they will make a real difference to hospitals across the UK by reducing demand on intensive care staff and beds, as well as helping patients recover without the need for more invasive ventilation.” Cpap machines are used routinely in UK hospitals to support patients with breathing difficulties on wards or at home, but the equipment is in short supply. The devices use positive pressure to send a blend of air and oxygen into the mouth and hose at a steady rate, thereby boosting the amount of oxygen that enters the lungs. The positive pressure means that when the patient breathes out, structures in the lung that exchange oxygen, the alveoli, stay open which aids oxygenation and makes breathing less effortful. Tim Baker, an engineer on the UCL team, said: “Given the urgent need, we are thankful that we were able to reduce a process that could take years down to a matter of days. “From being given the brief, we worked all hours of the day, disassembling and analysing an off-patent device. Using computer simulations, we improved the device further to create a state of the art version suited to mass production.” Tim Cook, a professor of anaesthesia and intensive care medicine at the Royal United hospital Bath NHS foundation trust, said: “If the patient can stay on a Cpap machine they can stay on a ward looked after by specialised nurses rather than ICU nurses. “A ward can probably look after 10 of these patients with two nurses and one doctor. Ten patients on ICU may need five or 10 nurses and three to four doctors. The cost and manpower needed on ICU is much, much greater, and ICU is a lot more complex and hazardous.” Duncan Young, a professor of intensive care medicine at Oxford University, said the speed at which the device had been developed was “remarkable” but added that the use of Cpap machines in patients with contagious respiratory infections was controversial, as any small leaks around the mask could potentially spray droplets from patients’ airways on to clinical staff. Singer said the risk of transmitting the virus through such droplets should be “very low” if care staff were wearing appropriate personal protective equipment.