Can Open Source Hardware Mechanical Ventilator (OSH-MVs) initiatives help cope with the COVID-19 health crisis? Taxonomy and state of the art

The impact of the coronavirus pandemic on sedation in critical care: volatile anesthetics in the ICU

PURPOSE OF REVIEW

To reflect on the impact of the coronavirus pandemic on sedation for mechanically ventilated patients.

RECENT FINDINGS

Shortages of intravenous sedatives during coronavirus pandemic renewed interest in using widely available inhaled anaesthetics for sedation of critically ill patients. Universally used for surgical anaesthesia, inhaled anaesthetics may offer therapeutic advantages in patients with acute lung injury with good sedation profiles, rapid clearance and lower lung inflammation in pilot trials. However, enabling ICU sedation with inhaled anaesthetics required technological and human resource innovation during the chaos of the global pandemic. The disruption of standard sedation practices is challenging during normal operations, yet pandemic facilitated innovation in this field by fostering cross-discipline collaboration supported by healthcare professionals, hospitals, research institutes and regulators.

SUMMARY

Although further research is needed to establish the role of inhaled anaesthetics in critical care sedation toolkit, maintaining the spirit of innovation ignited during the recent coronavirus pandemic would require ongoing collaboration and streamlining of processes among healthcare, research and regulatory institutions.

Low-cost, rapidly deployable emergency mechanical ventilators during the COVID-19 pandemic in a developing country: Comparing development feasibility between bag-valve and positive airway pressure designs

The COVID-19 pandemic disrupted the world by interrupting most supply chains, including that of the medical supply industry. The threat imposed by export restriction measures and the limitation in the availability of mechanical ventilators posed a higher risk for smaller, developing countries, used to importing most of their technologies. To actively respond to the possible device shortage, the initiative "Ventilators for Panama" was established and was able to develop two different, non-competing, open-source hardware mechanical ventilator models for emergency use in case of shortages: one based on a bag-valve design and another based on positive airway pressure. The aim of this article is to compare both devices in terms of feasibility and functionality. Results from the functional testing show that both devices perform within specification, as the error percentage is lower than 5% for the desired pressure values and a standard deviation of less than 0.5 for all cases.Clinical Relevance- This study shows the feasibility of quickly deploying two different mechanical ventilator designs for emergency use and their effectiveness.

Design and analysis of a mechanical ventilation system based on cams

Low-cost mechanical ventilators have been developed in order to deal with the shortage of traditional ventilators whose quantity is not sufficient in an emergency context in Perú. Protofy, a company from Spain, designed one of the first low-cost mechanical ventilation systems OxyGEN which was approved by a medicine agency in its country in special context of COVID 19. Therefore, as main of this article, a redesign of this system named OxygenIP.PE was carried out according to local requirements and available technology, but maintaining its working concept based on compression mechanism by cams. Sensors were added and a control algorithm of the respiratory rate was developed. Ventilation curves monitoring over time was implemented; in this sense, a mathematical model of the whole system was developed. OxygenIP.PE was redesigned, fabricated, and tested measuring its ventilation curves over time. Results indicate that this redesign provides a sturdy equipment able to work during a longer lifetime than the original. The replicability of the ventilation curves behavior is ensured, while the mechanism dimensions are adapted for a particular airbag resuscitator. The mathematical model of the whole system can satisfactorily determine the ventilation curves over time and is used to show the air pressure, volume, and flow as a function of the compression arm's angular position and differential pressure through the breathing circuit measurement, furthermore the algorithms designed as a consequence of the mathematical model were implemented for Raspberry and ARDUINO microcontrollers. There were obtained parameters of pressure 10–65 cmH2O, airflow 50–65 l/m, volume 0–0.5 l, at two values of beat per minute (BPM) 15 and 25.

Analysis of Single Board Architectures Integrating Sensors Technologies

Development boards, Single-Board Computers (SBCs) and Single-Board Microcontrollers (SBMs) integrating sensors and communication technologies have become a very popular and interesting solution in the last decade. They are of interest for their simplicity, versatility, adaptability, ease of use and prototyping, which allow them to serve as a starting point for projects and as reference for all kinds of designs. In this sense, there are innumerable applications integrating sensors and communication technologies where they are increasingly used, including robotics, domotics, testing and measurement, Do-It-Yourself (DIY) projects, Internet of Things (IoT) devices in the home or workplace and science, technology, engineering, educational and also academic world for STEAM (Science, Technology, Engineering and Mathematics) skills. The interest in single-board architectures and their applications have caused that all electronics manufacturers currently develop low-cost single board platform solutions. In this paper we realized an analysis of the most important topics related with single-board architectures integrating sensors. We analyze the most popular platforms based on characteristics as: cost, processing capacity, integrated processing technology and open-source license, as well as power consumption (mA@V), reliability (%), programming flexibility, support availability and electronics utilities. For evaluation, an experimental framework has been designed and implemented with six sensors (temperature, humidity, CO₂/TVOC, pressure, ambient light and CO) and different data storage and monitoring options: locally on a μSD (Micro Secure Digital), on a Cloud Server, on a Web Server or on a Mobile Application.

Masi: A mechanical ventilator based on a manual resuscitator with telemedicine capabilities for patients with ARDS during the COVID-19 crisis

In this article, we introduce a portable and low-cost ventilator that could be rapidly manufactured, to meet the increasing demand of ventilators worldwide produced by COVID-19 pandemic. These ventilators should be rapidly deployable and with functional capabilities to manage COVID-19 patients with severe acute respiratory distress syndrome (ARDS). Our implementation offers robustness, safety and functionality absent in existing solutions to the ventilator shortage (i.e., telemonitoring, easy-to-disinfect, modularity) by maintaining simplicity. The design makes use of a manual resuscitator as the core respiration component activated by a compression mechanism which consist of two electronically controlled paddles. The quality measurements obtained after testing on a calibrated artificial lung demonstrate repeatability and accuracy exceeding human capabilities of manual ventilation. The complete design files are provided in the supplementary materials to facilitate ventilator production even in resource-limited settings. The implementation of this mechanical ventilator could eliminate device rationing or splitting to serve multiple patients on ICUs.

COVENT-Tester: A low-cost, open source ventilator tester

COVENT-Tester (COVID-19 VENTilator Tester) is a low-cost and open source ventilator tester developed to calibrate the output of medical ventilators, including tidal volume, inspiratory pressure, and oxygen concentration. Currently, there are several open-source ventilator testers, however, existing open-source ventilator testers are unable to measure oxygen concentration. Conversely, commercial ventilator testers with the capacity to measure tidal volume, inspiratory pressure, and oxygen concentration, are very costly. The COVENT-Tester was therefore designed to be low-cost, by using Commercial Off-The-Shelf (COTS) components, to assist the open source community for rapidly manufactured pandemic ventilators. In addition, the COVENT-Tester measurement's validation results show the tester has good accuracy.