Design and construction of a simplified, gas-driven, pressure-controlled emergency ventilator

Developing of an open-source low-cost ventilator based on turbine technology

The COVID-19 pandemic has revealed numerous global health system deficits, even in developed countries. The high cost and shortage of treatment, health care, and medical devices are the reasons. Aside from new mutations, the availability of respirators is an urgent concern, especially in developing countries. Even after the pandemic, respiratory diseases are among the most prevalent diseases. Researchers can help reduce treatment costs by offering scalable, open-source solutions that are manufacturable. Since March 2020, serious efforts have been made to reduce the problems caused by the lack of respirators at the lowest possible cost. In this research paper, a unique and integrated solution for a fully automatic ventilator is presented and described. The design considers the cost, speed of assembly, safety, ease of use, robustness, portability issues, and scalability to fit all requirements for emergency ventilation. Furthermore, the device was developed using turbine technology to generate air pressure. The work describes a low-cost alternative ventilator that uses a novel proportional-valve approach to control oxygen mixing process, control circuit, and control algorithm. The current software supports pressure mode controllers, and it can be upgraded to volume-mode or dual mode without any modifications in the hardware. In addition, the hardware, particularly the electronic circuit, has idle input/output ports for further development. Based on the evaluations of the developed ventilator using an artificial lung, the system exhibited acceptable accuracy regarding to the pressure, leak compensation, and oxygen concentration levels. The designated safety conditions have been met, and the safety alarms tripped according to any violations. Moreover, all design files are provided with clear instructions to rebuild the device, despite the complexity of electronics assembly. The system can be described as a development kit, which can shorten the time for researchers/manufacturers to develop a device equivalent to the expensive devices available in the market.

CRISIS Ventilator: Pilot Study of a Three-Dimensional-Printed Gas-Powered Resuscitator in a Porcine Model

The coronavirus disease of 2019 (COVID-19) has altered medical practice around the globe and revealed critical deficiencies in hospital supply chains ranging from adequate personal protective equipment to life-sustaining ventilators for critically ill hospitalized patients. We developed the CRISIS ventilator, a gas-powered resuscitator that functions without electricity, and which can be manufactured using hobby-level three-dimensional (3D) printers and standard off-the-shelf equipment available at the local hardware store. CRISIS ventilators were printed and used to ventilate sedated female Yorkshire pigs over 24-h. Pulmonary and hemodynamic values were recorded throughout the 24-h run, and serial arterial blood samples were obtained to assess ventilation and oxygenation. Lung tissue was obtained from each pig to evaluate for signs of inflammatory stress. All five female Yorkshire pigs survived the 24-h study period without suffering from hypoxemia, hypercarbia, or severe hypotension requiring intervention. One animal required rescue at the beginning of the experiment with a traditional ventilator due to leakage around a defective tracheostomy balloon. The wet/dry ratio was 6.74 ± 0.19 compared to historical controls of 7.1 ± 4.2 (not significantly different). This proof-of-concept study demonstrates that our 3D-printed CRISIS ventilator can ventilate and oxygenate a porcine model over the course of 24-h with stable pulmonary and hemodynamic function with similar levels of ventilation-related inflammation when compared with a previous control porcine model. Our work suggests that virtual stockpiling with just-in-time 3D-printed equipment, like the CRISIS ventilator, can temporize shortages of critical infrastructure needed to sustain life for hospitalized patients.

The HEV Ventilator: at the interface between particle physics and biomedical engineering

A high-quality, low-cost ventilator, dubbed HEV, has been developed by the particle physics community working together with biomedical engineers and physicians around the world. The HEV design is suitable for use both in and out of hospital intensive care units, provides a variety of modes and is capable of supporting spontaneous breathing and supplying oxygen-enriched air. An external air supply can be combined with the unit for use in situations where compressed air is not readily available. HEV supports remote training and post market surveillance via a Web interface and data logging to complement standard touch screen operation, making it suitable for a wide range of geographical deployment. The HEV design places emphasis on the ventilation performance, especially the quality and accuracy of the pressure curves, reactivity of the trigger, measurement of delivered volume and control of oxygen mixing, delivering a global performance which will be applicable to ventilator needs beyond the COVID-19 pandemic. This article describes the conceptual design and presents the prototype units together with a performance evaluation.

The Multi Split Ventilator System: Performance Testing of Respiratory Support Shared by Multiple Patients

Ventilator sharing has been proposed as a method of increasing ventilator capacity during instances of critical shortage. We sought to assess the ability of a regulated, shared ventilator system (Multi Split Ventilator System, MSVS) to individualize support to multiple simulated patients using one ventilator. We employed simulated patients of varying size, compliance, minute ventilation requirement, and PEEP requirement. Performance tests were performed to assess the ability of the QSVS, versus control, to achieve individualized respiratory goals to clinically disparate patients sharing a single ventilator following ARDSNet guidelines. Resilience tests measured the effects of simulated adverse events occurring to one patient on another patient sharing a single ventilator. The QSVS met individual oxygenation and ventilation requirements for multiple simulated patients with a tolerance similar to a single ventilator. Abrupt endotracheal tube occlusion or extubation occurring to one patient resulted in modest, clinically tolerable changes in ventilation parameters for the remaining patients. The QSVS is a regulated, shared ventilator system capable of individualizing ventilatory support to clinically dissimilar simulated patients. It is also resilient to common adverse events. The QSVS represents a feasible option to ventilate multiple patients during a severe ventilator shortage.