Corona Virus Covid 19


The simplest mechanical device we could devise to assist a person’s breathing would be a hand-driven, syringe-type pump that is fitted to the person’s mouth and nose using a mask. A variation of this is the self-inflating, elastic resuscitation bag. Both of these require one-way valve arrangements to cause air to flow from the device into the lungs when the device is compressed, and out from the lungs to the atmosphere as the device is expanded. These arrangements are not automatic, requiring an operator to supply the energy to push the gas into the lungs through the mouth and nose. Thus, such devices are not considered mechanical ventilators.
Automating the ventilator so that continual operator intervention is not needed for safe, desired operation requires three basic components:
  1. A source of input energy to drive the device;
  2. A means of converting input energy into output energy in the form of pressure and flow to regulate the timing and size of breaths; and
  3. A means of monitoring the output performance of the device and the condition of the patient.
There was a time when you could take a handful of simple tools and do routine maintenance on your car engine. About that time the average clinician could also completely disassemble and reassemble a mechanical ventilator as a training exercise or to perform repairs. In those days (the late 1970s), textbooks1 describing ventilators understandably paid much attention to the individual mechanical components and pneumatic schematics. In fact, this philosophy was reflected to some extent in previous editions of this book. Today, both cars and ventilators are incredibly complex mechanical devices controlled by multiple microprocessors running sophisticated software (Fig. 3-1). Figure 3-2 shows the pneumatic schematic of a current intensive care ventilator. All but the most rudimentary maintenance of ventilators is now the responsibility of specially trained biomedical engineers. Our approach to describing ventilator design has thus changed from a focus on individual components to a more generalized model of a ventilator as a “black box,” that is, a device for which we supply an input and expect a certain output and whose internal operations are largely unknowable, indeed, irrelevant, to most clinical operators. What follows, then, is only a brief overview of the key design features of mechanical ventilators with an emphasis on input power requirements, transfer functions (pneumatic and electronic control systems), and outputs (pressure, volume, and flow waveforms). The rest of the chapter focuses on the interactions between the operator and the ventilator (the operator interface), and between the ventilator and the patient (the patient interface).




Chapter 3. Basic Principles of Ventilator Design | Principles and Practice of Mechanical Ventilation, 3e | AccessMedicine | McGraw-Hill Medical
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MIT-based team works on rapid deployment of open-source, low-cost ventilator
Clinical and design considerations will be published online; goal is to support rapid scale-up of device production to alleviate hospital shortages.Listen
David L. Chandler | MIT News Office
March 26, 2020
Press Inquiries


The new device fits around an Ambu bag (blue), which hospitals already have on hand in abundance. Designed to be squeezed by hand, instead they are squeezed by mechanical paddles (center) driven by a small motor. This directs air through a tube which is placed in the patient's airway.

Images: courtesy of the researchers

One of the most pressing shortages facing hospitals during the Covid-19 emergency is a lack of ventilators. These machines can keep patients breathing when they no longer can on their own, and they can cost around $30,000 each. Now, a rapidly assembled volunteer team of engineers, physicians, computer scientists, and others, centered at MIT, is working to implement a safe, inexpensive alternative for emergency use, which could be built quickly around the world.
The team, called MIT E-Vent (for emergency ventilator), was formed on March 12 in response to the rapid spread of the Covid-19 pandemic. Its members were brought together by the exhortations of doctors, friends, and a sudden flood of mail referencing a project done a decade ago in the MIT class 2.75 (Medical Device Design). Students and faculty working in consultation with local physicians designed a simple ventilator device that could be built with about $100 worth of parts, although in the years since prices have gone up and the device would now cost $400 to $500 in materials. They published a paper detailing their design and testing, but the work ended at that point. Now, with a significant global need looming, a new team, linked to that course, has resumed the project at a highly accelerated pace.
The key to the simple, inexpensive ventilator alternative is a hand-operated plastic pouch called a bag-valve resuscitator, or Ambu bag, which hospitals already have on hand in large quantities. These are designed to be operated by hand, by a medical professional or emergency technician, to provide breaths to a patient in situations like cardiac arrest, until an intervention such as a ventilator becomes available. A tube is inserted into the patient’s airway, as with a hospital ventilator, but then the pumping of air into the lungs is done by squeezing and releasing the flexible pouch. This is a task for skilled personnel, trained in how to evaluate the patient and adjust the timing and pressure of the pumping accordingly.
The innovation begun by the earlier MIT class, and now being rapidly refined and tested by the new team, was to devise a mechanical system to do the squeezing and releasing of the Ambu bag, since this is not something that a person could be expected to do for any extended period. But it is crucial for such a system to not damage the bag and to be controllable, so that the amount of air and pressures being delivered can be tailored to the particular patient. The device must be very reliable, since an unexpected failure of the device could be fatal, but as designed by the MIT team, the bag can be immediately operated manually.
The team is particularly concerned about the potential for well-meaning but inexperienced do-it-yourselfers to try to reproduce such a system without the necessary clinical knowledge or expertise with hardware that can operate for days; around 1 million cycles would be required to support a ventilated patient over a two-week period. Furthermore, it requires code that is fault-tolerant, since ventilators are precision devices that perform a life-critical function. To help curtail the spread of misinformation or poorly-thought-out advice, the team has added to their website verified information resources on the clinical use of ventilators and the requirements for training and monitoring in using such systems. All of this information is freely available at
“We are releasing design guidance (clinical, mechanical, electrical/controls, testing) on a rolling basis as it is developed and documented,” one team member says. “We encourage capable clinical-engineering teams to work with their local resources, while following the main specs and safety information, and we welcome any input other teams may have.”
The researchers emphasize that this is not a project for typical do-it-yourselfers to undertake, since it requires specialized understanding of the clinical-technical interface, and the ability to work in consideration of strict U.S. Food and Drug Administration specifications and guidelines.
Such devices “have to be manufactured according to FDA requirements, and should only be utilized under the supervision of a clinician,” a team member said. “The Department of Health and Human Services released a notice stating that all medical interventions related to Covid-19 are no longer subject to liability, but that does not change our burden of care.” he said. “At present, we are awaiting FDA feedback” about the project. “Ultimately, our intent is to seek FDA approval. That process takes time, however.”
The all-volunteer team is working without funding and operating anonymously for now because many of them have already been swamped by inquiries from people wanting more information, and are concerned about being overwhelmed by calls that would interfere with their work on the project. “We would really, really like to just stay focused,” says one team member. “And that’s one of the reasons why the website is so essential, so that we can communicate with anyone who wants to read about what we are doing, and also so that others across the world can communicate with us.”
“The primary consideration is patient safety. So we had to establish what we’re calling minimum clinical functional requirements,” that is, the minimum set of functions that the device would need to perform to be both safe and useful, says one of the team members, who is both an engineer and an MD. He says one of his jobs is to translate between the specialized languages used by the engineers and the medical professionals on the team.
That determination of minimum requirements was made by a team of physicians with broad clinical backgrounds, including anesthesia and critical care, he says. In parallel, the group set to work on designing, building, and testing an updated prototype. Initial tests revealed the high loads that actual use incurs, and some weaknesses that have already been addressed so that, in the words of team co-leads, “Even the professor can kick it across the room.” In other words, early attempts focused on super “makability” were too optimistic.
New versions have already been fabricated and are being prepared for additional functional tests. Already, the team says there is enough detailed information on their website to allow other teams to work in parallel with them, and they have also included links to other teams that are working on similar design efforts.
In under a week the team has gone from empty benches to their first realistic tests of a prototype. One team member says that in the less than a week full they have been working, motivated by reports of doctors already having to ration ventilators, and the intense focus the diverse group has brought to this project, they have already generated “multiple theses worth” of research.
The cross-disciplinary nature of the group has been crucial, one team member says. “The most exciting times and when the team is really moving fast are when we have an a design engineer, sitting next to a controls engineer, sitting next to the fabrication expert, with an anesthesiologist on WebEx, all solid modeling, coding, and spreadsheeting in parallel. We are discussing the details of everything from ways to track patients’ vital signs data to the best sources for small electric motors.”
The intensity of the work, with people putting in very long hours every day, has been tiring but hasn’t dulled their enthusiasm. “We all work together, and ultimately the goal is to help people, because people’s lives understandably hang in the balance,” he said.
The team can be contacted via their website.

Note: An earlier headline on this story suggested the device could be built for $100, but that estimate was for an earlier version. Today, the device would cost at least $400 to $500 in parts

MIT-based team works on rapid deployment of open-source, low-cost ventilator
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Engineering staff, students work to deliver automated bag valve mask to address COVID-19 crisis
•Mar 27, 2020


Rice University
19.7K subscribers

A team at Rice University has developed an automated bag valve mask ventilation unit that can be built for less than $300 in parts and help patients in treatment for COVID-19. The university expects to make plans to build the unit freely available online. Up-to-date details about the project, dubbed the ApolloBVM, and its progress are available here: #corona #ventilator #engineering


Home appliances firm makes ventilator for coronavirus patients | AFP
•Mar 24, 2020


AFP News Agency
612K subscribers

British home appliances firm Gtech, which specialises in making vacuum cleaners, has made a prototype of a medical ventilator which founder Nick Grey says can be scaled to mass production within weeks. Made largely from off-the-shelf parts, the ventilator runs on compressed air and can be assembled with a simple production line.


Rising number of medical staff infected with coronavirus in Italy

Elisa Oddone

Almost 400 cases of Covid-19 have been traced to a Tablighi Jamaat event in Delhi

a group of people standing in a room: Medical workers in protective suits transfer a patient from the intensive care unit of the Gemelli Hospital to the Columbus Covid Hospital, which has been assigned as one of the new coronavirus treatment hospitals in Rome [Gemelli Policlinico/Handout via Reuters]

© [Gemelli Policlinico/Handout
via Reuters] Medical workers in protective suits transfer a patient from the intensive care unit of the Gemelli Hospital to the Columbus Covid Hospital, which has been assigned as one of the new coronavirus treatment hospitals in Rome [Gemelli Policlinico/Handout via Reuters]

As coronavirus cases jump and deaths surge in Italy, new figures show an "enormous" level of contagion among the country's medical personnel.
At least 2,629 health workers have been infected by coronavirus since the onset of the outbreak in February, representing more than eight percent of total cases, according to a report published on Wednesday by Gruppo Italiano per la Medicina Basata sulle Evidenze or GIMBE - Italy's Group for Evidence-based Medicine.

The data has sent shock waves through the country's already strained healthcare system.

Pictures: Coronavirus (COVID-19) outbreak around the world
  • Slide 1 of 119: City workers fumigate a street to help contain the spread of the new coronavirus in La Paz, Bolivia, Thursday, April 2, 2020. (AP Photo/Juan Karita)
  • Slide 2 of 119: NHS workers applaud on the streets outside Royal Liverpool University Hospital during the Clap for our Carers campaign in support of the NHS as the spread of the coronavirus disease (COVID-19) continues, Liverpool, Britain, April 2, 2020. REUTERS/Phil Noble     TPX IMAGES OF THE DAY
  • Slide 3 of 119: A volunteer from the Blue Sky Rescue team  disinfects at the Qintai Grand Theatre in Wuhan, Hubei province, the epicentre of China's coronavirus disease (COVID-19) outbreak, April 2, 2020. Picture taken April 2, 2020. REUTERS/Aly Song
  • Slide 4 of 119: A New England Patriots Boeing 767-300 jet with a shipment of over one million N95 masks from China, which will be used in Boston and New York to help fight the spread of the coronavirus disease (COVID-19), arrives at Logan Airport, Boston, Massachusetts, U.S., April 2, 2020.  Jim Davis/Pool via REUTERS

  • Slide 119 of 119: A health worker sprays disinfectant amid concerns of the spread of the COVID-19 coronavirus at the Temple of Literature in Hanoi on March 10, 2020. (Photo by Nhac NGUYEN / AFP) (Photo by NHAC NGUYEN/AFP via Getty Images)
City workers fumigate a street to help contain the spread of the new coronavirus in La Paz, Bolivia, Thursday, April 2, 2020. (AP Photo/Juan Karita)
ull Screen
© Juan Karita/AP Photo
City workers fumigate a street to help contain the spread of coronavirus in La Paz, Bolivia, on April 2.

"We extracted this number from data provided by the National Health Institute," GIMBE director Nino Cartabellotta, a public health expert, told Al Jazeera.
"Figures regarding the contagion among doctors, nurses and general health professionals have started being disclosed only on March 11. Hundreds of new cases have been daily recorded since then. But medical personnel on the front line should be the first one to be protected."
Cartabellotta said that the actual number was likely to be higher because healthcare workers are not always tested and protection measures at hospitals were inadequate.
Many who tend to coronavirus patients are still only using surgical face masks with no proper protective filters to shield them from contagion.
The percentage of health workers infected in Italy is almost double the number registered throughout the epidemic in China, where more than 3,200 have died.
According to figures published in JAMA Network Open, an online medical site from the Journal of the American Medical Association, infected medical staff in China made up 3.8 percent of the total cases, with only five deaths.
Over 60 percent of the medical staff who were infected were registered in the epicentre's outbreak, Wuhan.
Italy is the worst-hit country after China.
On Wednesday, Italy announced that over the past 24 hours, the number of deaths had risen by 475 to 2,978, an increase of 19 percent, as cases jumped to a total 35,713.
There are no official figures on the number of medical personnel who have died of coronavirus in Italy.
According to Italian daily Corriere della Sera, a general practitioner from the province of Lodi died on Wednesday. This raised the death toll of family doctors in the area to four. Other regions have also registered losses among medical staff.
A lack of equipment, resources and personnel has piled pressure on Italy's health system.
Italy does not produce masks. With the pandemic spreading, some of its closest neighbours have been reluctant to export supplies they may need soon.
"The problem right now is the supply of the protective gear," Cartabellotta said. "The government should have thought of this some time ago. It is logical that following the global explosion of the pandemic, countries producing masks and other protective devices are now keeping them to themselves and stopped their exports.
"We already have a limited number of doctors and nurses. Under extreme circumstances, we could even ask them to keep working even if [they] tested positive for coronavirus. Still, they should be equipped with protective devices to avoid spreading the virus further."
An emergency decree presented by the government on Monday allocated 3.5 billion euros ($3.8bn) towards the ailing health system.
"We are importing medical personnel from abroad and throwing new young healthcare professionals without licenses into the fray," Cartabellotta said. "If we don't provide them with adequate protection, it will end up like in a war where soldiers don't die while fighting on the battlefield, but because of lack of equipment. The more medical personnel is infected, the weaker the responsiveness of the healthcare system."

Rising number of medical staff infected with coronavirus in Italy
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Senior Billi
Nothing is clear that how is this virus is acting and from where it is attacking us ?
Even Medical Staff on duty is getting affected.
It means, something is still needed to understand about it's working in environment.
MIT Scientists are saying it is Air Borne also.
While others claiming nothing about such thing.
More research and affected people's experience can tell with time about it's impact and more prevention measures to be taken.
When HIV Aids came they had different ideas then after 5-10 years, most of the perception changed much.

It is mostly quite clear.
Of course more research. But part of the problem - *with part of the research* - is that there is not yet enough data. Data regarding the spread...per country, per has to be per country. Initial symptoms and outcomes also vary. (Like refer to differences in people's immune systems and so on.)

> Even Medical Staff on duty is getting affected.

Of course they are! They get the most exposure - to the aerosol and to surfaces contaminated by it. ...And how much, the extent to which they are exposed, depends on the protocols and procedures implemented by their management, etc. (And of course the level of exposure depends on where, how many patients, etc., etc.)

> MIT Scientists are saying it is Air Borne also. While others claiming nothing about such thing.

It is. That - the basics of it - is very clear, has been from the start. It is spread by airborne particles, spray of fine droplets created when infected people cough or sneeze - or when they laugh or speak loudly. (That last part is not included in basic information from WHO.)

It is airborne from the time it is expelled from an infected person until it lands on the ground. (The ground, the floor, the surface as in a table or a wall or a railing or something.)

How far - how long it is airborne - will vary; it may be airborne longer when there is more air movement - people moving, displacing air, or drafts or breeze that keeps it airborne longer. (Seconds, milliseconds. Unlikely to be as much as one minute. But, not certain, not so clear.) :) ....................... There is information, based on research on colds and influenza viruses (which are basically similar to this,) on how long it survives on various surfaces...all i remember of what i read is that it lasts longer [than?] on metal surfaces, and much longer on polypropylene...polyethylene? - in other words, what is used in consumer goods packaging.

The medical term - the term that doctors and so on use - is aerosol. So when you read an article or you hear medical experts talking about it, saying aerosol, it means the aerosol as in the spray from people's mouths and nostrils.

I noticed it last night, cabinet ministers media briefing, minister of Health at a medical school hospital, with the medical expert who is heading the team...he referred to the aerosol...and I thought how even if the home language is English, more than 90% do not know the meaning of the word, the root of it, they only know it as the spray cans of consumer products.

Then, the contaminated surfaces... surfaces become contaminated by that spray and by being touched by infected persons.
The concern there / what is not so clear, is how long the virus survives on surfaces.

That leads to the next point that is not clear (which is why you mentioned it)...that is, why are Chinese [and others] spraying bleach or some other disinfectant on surfaces in public spaces?
Although the official/etc. information has said that it does not survive long on the ground / the floor surfaces...we saw those photos.

What I am wondering is whether the particles of spray that land on the ground are then stirred up by people moving, by their feet, and then upwards with air moving as people move, and breeze.
... And particles land, and dry out, but...there you see how it matters how many people in a space, moving in a space. In other words, more spread of particles even in the seconds before it lands on the floor.

It is clear that it does transmit more when there are more people in a space...more particles, more concentrated, therefore more exposure of persons to it.

The spread in South Korea was most seriously influenced by infections that happened at a very big church gathering.
Now the most serious incident / source of transmission in South Africa is a large church gathering about 2 weeks ago - which included guest/s from Germany.
Yesterday news was that a nurse at a clinic in another province tested positive, and she was at that church event. Already, some days before, the leader of the ACDP (African Christian Democratic Party) was tested positive, he had attended the event and he had associated with the foreign guest/s. So they were tracing all persons that had attended it...and now all who the nurse had been in contact with since she returned home and back to work at a clinic. ...Note that her home and workplace is maybe 800 km. or so from the church place. That is why lockdown.

Big Daddy

Super User
I knew this virus was around in 2019. Trump administration was aware of it and was worried about the pandemic. This whole blaming China was carefully drafted plan to make it look like US does not have this problem. Throughout 2019 people were getting sick enough for administration to worry about the pandemic. I think the democratic investigation will now make it a big deal during election time.

Top administration officials said last year threat of pandemic kept them up at night