There are two kinds of bridge ventilator devices being worked on during the Covid-19 pandemic. Both types are for use in a non-ICU setting. Note, an ICU vs. non-ICU use of ventilator for Covid-19 patients has an interesting requirement. It is common that Covid-19 patients are using a ventilator in ICU for 21 days. In contrast, with a non-Covid-19 medical issue, a patient averages 3-4 days in ICU. This is why bridge devices should not be used an in ICU because the devices may not be able run continously for 21 days.
The two types are:
- Ambu bag version which automates compressing/releasing of the bag to generate air flow to the patient.
- Modified CPAP or BiPAP devices.
Please also read this medical article regarding ventilators and Covid-19:
https://www.statnews.com/2020/04/08/doctors-say-ventilators-overused-for-covid-19/
Having read the article, I have moved the modified-CPAP ventilator from UC/Berkeley (Cal) to top of the list.
Also see https://www.ventilatorsos.com/our-solution.html
Uses an external Oxygen tank. Filters exhaled air otherwise the room gets contimated with Covid-19. Also, uses a tube inserted into patient's trachea vs. a mouth piece.
The thought process behind the list is to not include the kitchen sink of ventilators out there. One criteria for exclusion is if an Ambu bag ventilator is too costly (e.g. Umbulizer, $2k) and also has a patent dispute. A kitchen sink for ventilator list is included at this repo: https://github.com/PubInv/covid19-vent-list - however, this repo lists a ventilator with no information, viz., http://www.pakengimed.com/ncov/. The PubInv repo also includes the Umbulizer, but this list has excluded it as explained above. The PubInv repo includes good info for learning ventilator.
So far a spreadsheet like comparison has not been made because many ventilators do not provide any details.
Both MIT and Rice ventilstors use gears. Prototype gears are made out of plastic, acrylic, or aluminium which wear out sooner and won't work in production design. I think the Virgin Orbit ventilator mechanical design does not use any gears which reduces the number of parts and makes volume production easier and faster.
https://www.youtube.com/watch?v=oLQ5bXakWq8&feature=youtu.be
Version 0 does not support sensor. Uses 500 cc of air to patient. Device is complete with software, BOM, CAD designs, etc.
https://github.com/apollobvm/apollobvm
Software is not complete, nor is BOM. CAD files are complete. I suspect MIT is at least few weeks away to complete software, and documentation.
Device has been tested with a porcine animal using spirometer to log air volume.
Mechanical and Electrical BOMs have been released.
The cost of the device is around $1000.
THe Honeywell pressure sensor costs $65 and is out of stock. MIT has also recommended to use an analog sensor for quick monitoring.
Any solution should be utilized only in a healthcare setting with direct monitoring by a clinical professional. While it cannot replace an FDA-approved ICU ventilator, in terms of functionality, flexibility, and clinical efficacy, the MIT E-Vent is anticipated to have utility in helping free up existing supply or in life-or-death situations when there is no other option.
https://git.ist.ac.at/technology-transfer/ist-emergency-ventilator
Based on MIT e-vent but includes source code to the Arduino board. MIT still hasn't released their code.
Has been tested with artificial lung.
https://news.utexas.edu/2020/04/01/solving-the-ventilator-shortage-with-windshield-wiper-parts/
https://www.youtube.com/watch?v=vdLXp7uGFX4&feature=youtu.be
Also see, https://media.wired.com/clips/5e852d038dd572000828b715/master/pass/Transpoo_Ventilatorbroll.mp4
Plans to control three key variables: breaths per minute; tidal volume, which is how much air comes out of the bag; and the inspiratory-expiratory profile, which the time spent breathing in versus breathing out. The first is a function of motor speed, adjusted with a dial. The others can be adjusted by swapping out parts. To change tidal volume, a user can hook up a smaller or larger version of the piece that pushes on the bag. The shape of the rotating cam (think of a lumpy potato versus a round one) defines how much of the time the bag is being compressed, and thus the inspiratory-expiratory rate.
https://github.com/ermtl/Open-Source-Ventilator
The device lists a pressure sensor part, viz., Bosch Sensortech BME280 / BMP280 sensor
Arduino source code is here in the above repo:
https://www.monolithicpower.com/en/mps-open-source-ventilator
https://ventilator.stanford.edu/
Useless since the design is not open.
The device is too long. Hospital beds are likely to be closer together and multiple devices setup will be tricky. The device also needs wall mounts.
https://www.youtube.com/watch?v=X9gFanQHSrE
Also see, https://www.bbc.com/news/world-asia-india-52106565
https://www.aerobiosys.com/jeevan-lite
Looking at the device picture, I don't have a clue what pipe goes to the patient and how the device pumps air, manually or mechanically.