EBME Forums Forums Free discussion Free discussion Ventilators for covid-19

I agree Murdoch - stick with 'proven solutions that will have been used over the past 50+years'
China may have availability of ventilators, pressure on their health system is reducing and they have huge manufacturing capability.
I agree with the points raised 1 to 9.

There are a couple of interesting videos on YouTube presented by Dr.Charlene Babcock in Detroit.

In one she demonstrates ("suggests", really) how - in dire need - to connect four patients to a single ventilator; in the other she shows how to set up a Respironics V60 BiPAP (NIPPV, really) machine for use as an invasive ventilator.

Note the terminology she uses:- "Off Label".

Peter asked me to share this revised information from the mhra on ventilators: https://www.gov.uk/government/publi...during-the-coronavirus-covid-19-outbreak
I think designing and building new vents is unnecessary. We could revert to using older and more simple designs that already exist (with the original manufacturers blessing of course)

Yes; I have read the RMVS document; it is an interesting "spec", but I agree with John that there is no need (neither is there any time) to "re-invent the wheel".

For instance, it implies that monitoring (a display) is to be included. This introduces yet another layer of complication for prospective manufacturers, and I would have thought that stand-alone monitors should suffice. If necessary these could be obtained from other sources.

They (we) need to pick on an established design - I have suggested the Siemens Servo 900 C - then crank up production.

Meanwhile, ventilator nomenclature keeps changing ... this .pdf may help.

Just dusting down some servo c's working well and fairly simple, don't have any of the Siemens mixers but have lots other mixers which can feed the low pressure port.

Hi Billy,
Also, they are highly reliable, simple to maintain, and meet the clinical need for Covid-19. There are lots of engineers trained to maintain these, lots of ITU nurses and ITU consultants familiar with this ventilator.

The Siemens 900C can be used for adults, paediatric, and infant use, and has built-in electronic PEEP, and comes with eight different ventilation modes and can be used in intensive care situations, anaesthesia, and transport.

Maybe the answer is to get these manufactured under license. Would be faster than starting from scratch.

Dear all, just had a quick read through this thread and found it extremely interesting. Unfortunately there are two points that I feel need making with regard to reverting back to old ventilator types.

1. The components required to make the earlier generation ventilators are no longer available and the tooling needed to make these components will have long since been scrapped. I.e. analog gauges certain valves and pressure transducers etc.

2. Compared with today’s current turbine ventilators the older ventilators are somewhat difficult to operate and require a great deal of experience when dealing with long-term respiratory patients.

Today’s ventilators are in the main driven by high speed turbines which can be controlled in a rapid and infinitely variable mode. The pneumatics within such ventilators are extremely simple to construct and would enable new manufacturers to produce the hardware side with limited experience. The single most important component of today’s ventilators is software and this would need toSupplied from the current manufacturers to subcontractors under license.

As we know there are two types of ventilation in medicine. The first is for maintenance, as found in time cycled constant flow pressure limited small box ventilators. Most of the older generation theatre ventilators where of this type of construction.
The ventilator is required when dealing with respiratory infections and disease for patients who will need long-term ventilation are infinitely more sophisticated and expensive. In a maintenance ventilator generally the patient is on it for maybe a few hours and once removed on the ventilator will spontaneously begin to Breathe again. The therapeutic ventilator as is used in ICU have modes that take the patient from being completely paralysed such as CMV, to A/C, to SIMV, CPAP all with pressure support. You can’t simply take a patient who has become over days ventilator dependent and switch it off and see them breathe spontaneously. “Weaning” is a critical part of the process.

Those are good points, David ... especially about turbines, and software.

If you were asked to propose a modern machine as the "prototype" for mass production within the constraints of the present crisis (if indeed that was a viable proposition), which one would that be?

And ... do you think there is any mileage at all in using an NIPPV machine of the Respironics V60 type as an invasive ventilator (may be good for "weaning off")? See post #75051 above.

Let’s think about this logically, each hospital ICU has a preferred supplier of make and model of ventilator. The installation, training and support are less problematic if they keep to the current model used within the ICU. If the major manufacturers such as Siemens,Medtronic were to “Buddy” electronic manufacturers from other fields then in may be possible to share expertise and engineering manufacturing information quickly and effectively. If the hospitals were to provide an estimate of its ventilator needs to the manufacturer Then targeted effective production of ICU standard ventilators would hopefully follow.

Our role in this Crisis
There is however a major possible short fall in the support from the Biomed community to the ICU. Not as many engineers as we would wish are conversant with the physiology and ventilation principles as are going to be needed in the coming months. I feel it’s a bit like building cars without training the mechanical engineers in the highway code and the operation of clutch and breaks. We could end up with the blind leading the blind when these machines are installed. A major training program needs to be urgently implemented to enable engineers to understand ventilation principals. From this it would then be possible for manufacturers to train further on the service and repairs of these vents

Please forgive me if the texting grammar above are less than perfect, I’m currently awaiting repatriation from Florida back to the UK and this is all being undertaken on an old iPhone

Dave M