A new negative pressure ventilator that requires less personnel resources developed in the fight against COVID-19

A new negative pressure ventilator that provides additional treatment options for patients with respiratory failure, including patients with COVID-19, and whose design can be easily adapted to developing countries, provides anesthesiologists, nurses and engineers. Created by the including team. The details of the new Exovent system are similar in design, but much smaller and easier to use than the devices used to treat polio patients in the 1950s. anesthesia..

The authors have shown that this system requires clinical trials to be fully tested, but makes it more comfortable for patients who do not need to sleep or have an artificial airway installed. I will. After closely monitoring the patient initially, this system means less care and can be used anywhere in the hospital and in some cases at home. The staffing requirements for new systems are usually much lower than those of typical intensive care unit ventilators today and lower than those of other non-intensive care unit systems for illnesses of comparable severity.

Negative pressure devices reduce extracorporeal pressure to dilate lung tissue, allowing it to function like normal breathing.On the other hand, conventional ventilators Continuous positive airway pressure The currently used (CPAP) system pushes air into the lungs under positive pressure. Research on positive pressure devices has been largely abandoned since the 1950s because positive pressure devices have become much smaller, cheaper, and more convenient.

The Exovent Task Force, formed in March 2020 in response to the COVID-19 crisis, was inspired by a request from the UK Government for rapid innovation to combat the challenges presented by SARS-CoV-2. I did. The team consists of anesthesiologists, critical care consultants, nurses, clinicians, engineers, scholars, scientists and manufacturers. This initiative was not part of the UK’s Ventilator Challenge. The project promoted innovation in positive pressure devices only.

“The Exovent team focused on exploring the benefits of negative pressure ventilation, based on lessons learned from nearly 100 years of use of negative pressure ventilation during the 1950s polio epidemic.” Co-author Dr. Malcolm Coultard of Translational explains. Clinical Research Institute, Newcastle University, UK.

The use of negative pressure is far less disturbing and much more like normal breathing than positive pressure ventilation through a tube inserted into the trachea or delivery of CPAP via a tight-fitting face mask. I will. The exovent system is non-invasive. This means that the patient does not need to intubate the trachea, so oxygen can be delivered in the form of a regular oxygen mask or nasal prong without the need for anesthesia. A high flow oxygen device that puts pressure on the oxygen supply in the hospital. Patients can stay conscious, take food and medicine by mouth, and talk to their loved ones over the phone.

The exovent chamber consists of a standard hospital bed-mounted base that includes its own section of mattress and a removable top that fits the torso with neck and hip seals (to the photo below). See link). The self-supporting pump unit is connected to the base with a flexible hose, and the control unit can adjust the pressure around the fuselage. The subject’s torso can be observed through the window and accessed through a porthole that seals around the caregiver’s arm. The thin neoprene neck and hip seal should be loosely attached to a person before adjusting the chamber.

The test was conducted with 6 healthy adult volunteer members of the development team in the presence of 3 senior anesthesiologists. All subjects were tested slightly upwards in the supine position (upward) and 3 were tested in the prone position (downward). Various negative pressure settings were tested and measurements of vital capacity measurements (lung performance) were recorded. These showed that Exovent can provide both increased lung dilation to spontaneously breathing people and strong ventilation that completely takes over people’s breathing, using only moderate negative pressure.

The nurse reported that the exovent chamber could be quickly placed and removed by two people. They said windows and portholes allowed patients to be safely monitored and cared for, even though direct access to the torso was inevitably reduced. In the supine position, the subject’s head can be easily positioned so that the larynx is visible for tracheal intubation, if necessary, without removing or adjusting the neck seal. For patients who have progressed to the need for intubation, it is probably not necessary to hold the patient in the exovent (although it is easy and safe to do so)-and in the case of emergency intubation, there is no need to delay in the meantime the exovent is removed I did.

All volunteers felt the chamber was comfortable, especially the neck and hip seals were soft, easy to adjust, and spontaneously broke and stretched their arms without significantly affecting the pressure stability of the chamber. I reported that I could touch my face.

All that matters subject I felt “in control”, knowing that I could quickly release the vacuum by opening a wide gap under one of the seals if needed. Explained that when the ventilation mode was used, all subjects allowed the exovent to take over breathing and relaxed the sensation without feeling the desire to “fight it” or feeling unnatural or uncomfortable. Did. One participant fell asleep within minutes.

“We are very pleased to announce this life-saving system, a state-of-the-art reinvention of existing technology,” said Ian Joesbury, CEO of exovent and co-author of the article. “Because patients do not need to be sedated, alternative treatment options that may treat more COVID-19 patients other than intensive care are opened up.”

The UK version of Exovent is estimated to cost around £ 8,000 (US $ 10,496, € 8856). This is considerably cheaper than existing positive pressure devices that cost around £ 15,000 for CPAP and over £ 30,000 for intensive care units. Care ventilator. It is also estimated that a low-cost global version of Exovent can be manufactured for less than £ 500 (US $ 652, € 550).

The author adds: “The expected benefits of exovent over positive pressure ventilators may be particularly relevant to low- and middle-income countries, with less resources needed to ventilate conscious patients, and oxygen being oxygen. As a result, oxygen savings may be improved. Instead of the continuous oxygen supply required for positives, it only needs to be supplied directly to the patient via a face mask or nasal prongs as needed. pressure system. “

They are much less invasive than PPV and very easy to implement, so the threshold for using Exovent when available is much lower and more patients are targeted for treatment. It explains that it will be. Even if traditional intensive care ventilator hardware is available in hospitals in low- and middle-income countries, (a) to intubate, paralyze, and sedate as needed, and (b) to manage unconsciously. The resources needed mean intensive care. Intensive care ventilation is not available except for a few individuals due to the great lack of intravenous or tube nutrition, skin care, etc. The author explains: “It’s more staffing than equipment, and Exovent is much easier and cheaper to use.”

Thanks to over £ 1 million of volunteer time investment from the exovent team, rapid development and prototyping by Marshall ADG, and a partnership with Warwick Manufacturing Group (WMG) High Value Manufacturing Catapult, the system has been formally evaluated and approved. I’m ready. The author plans to submit the design to the Medicines and Healthcare Products Regulatory Agency (MHRA), which regulates medical devices in the United Kingdom, and hopes to receive approval by mid-2021.

Provided by AAGBI