Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- VentilatorDevelopers
- Messages
Search
Re: FINISHING: Capturing Baselines, and Adjusting Alarms
There are lots of reasons.
1.? I personally don't yet understand exacty how to work well with Github 2.? Your code did not have bMP280 for several days due to the simple fact you were doing your best to even FIND the device.? ? 3.? During that time we pursued other code. 4.? You're a professional programmer and use things that dumb people like me have more trouble understanding. 5.? Dumb people like me sometimes better understand simpler code that has more descriptive comments. 6.? We're all doing the best we can.? ?I spent three hours the other night helping get the BMP280 working in YOUR CODE -- so, PlEASE RUN WITH IT!!! We need something that does what the FDA is going to want.? As we go along, we udnerstand better and better what that might be.? ?Therefore mistakes will be made along the way.? ?I just got my TRANSDUCER/POWER SUPPLY board working -- but still don't have the right part for one of it.? ?? MAKE IT WORK FOLKS!!! Thanks for all of the efforts everyone is making.? We are very close to the finish line, folks.? Please keep going. gordon |
Re: Transducer board // power supply
For the first time, i have a working "transducer board" / power supply that can handle both AC and battery inputs.
It isn't perfect, it is just all I have at the moment and a lot of blood sweat and tears went into getting even that. the photo is attached (you can see that I had some "issues" such as limited parts availability, unwillingness to risk parts, goofs, etc) The Schematic is attached -- and yes, you will have to pick the values off the photo of the board (will do better later) In the built board, I have only so far put in ONE of the two trickle charging parallel current sources.? ?No matter.?? TWO ISSUES: 1.? The Adafruit board works? (0x77) but I could not get the KeeYee BMP280 board to work.? Why?? I dunno.? ?Wrong bus voltage?? Dunnno.? SEND 3.3 VOLTS TO THE I2C BUS please -- the Ashar 0.1schematic/Stapleton 1.0 Board use 3.3 volt bus.? ? 2.? Dumb me, the AC Power green led stays dimly lit even when the battery is having to run the thing.? ?May have to put a resistor in parallel with the Green LED to get it to quit.? ?Will work on that later.?? This is of course optional.? ?I was instructed to add battery backup (I'm a volunteer, remember?) by the UF Team -- so I did.? ?Now it turns out tht the FDA will accept merely having a commercial UPS running the thing.? Duh!? ?We didn't know that until a day ago. No warrntees; no guarantees; use any of this information at your own risk. |
Re: FINISHING: Capturing Baselines, and Adjusting Alarms
Mike.? ?
You're a maufacturer. UF is a design team. I'm a volunteer. UF will do whatever it takes to get this to the FDA as soon and as likelly to succeed as possible. That's THEIR contribution.? ? They don't provide liability insurance,? and they have ONE GOAL:? get it to the FDA. YOU have different capabilities and different issues --- please do the best that you can.? ?I'm tryng to accommodate whatever Marcelo / etc need.? ? Gordon |
Re: #ExhalationValve
#ExhalationValve
Thanks!!? ?I was surprised to see that indeed there is a difference in the way Rainbird does it.? ?The Team at UF has measured the expiratory resistance across the ORBIT valve that I modified and found it apparently EXCELLENT -? and this requres NO 3 D prnting and NO machine work --- but you ahve to have a valve that can be modified.? ?So will work for some and will not work for others.
the UF team (I'm *NOT* the head) will pick whatever they think best for their shot at an EUA.? ?I don't have a dog in that race;? I'm here to help as much as possible. Gordon |
Re: #ExhalationValve
#ExhalationValve
Hi Mark W.
AJ and another on our team have done that immediately after they saw this issue and started it up again.? Just heard from them that its at 325K cycles and still going fine.? Thanks for the suggestion. To David and Gordon: We were going to test the sprinkler valve too in the exhalation valve as suggested by MA.? We don't have the right parts for that since the rain bird can't be modified as suggested from what we've read here.? Jim |
Re: FINISHING: Capturing Baselines, and Adjusting Alarms
Please stick with the 2 x 16 as the primary supported display as this is what I have laid out for my board and the device I had been attempting to secure for volume commitments.? I believe this was the display that was the final consensus a week ago.
If the software must be submitted then I will send my IO used to simplify routing and make a compact designed for manufacture board in a few minutes. I suggest that you have two files in the hardware abstraction layer where port definitions are made. You can then conditionally assemble either image for either board or easily add support for other / future boards. 73 Mike N8WFF |
Re: FINISHING: Capturing Baselines, and Adjusting Alarms
What is the reason that Software Developers collaborating with this project are not working on the baseline in CSSALT GitHub? Please be free to openly criticize if there is something wrong there the same way I did so about the other Software. If we had all collaborated with that baseline, for example, had integrated the BMP280 sensor, we would have all these requirements being easily implemented. Thanks, MV |
Re: FINISHING: Capturing Baselines, and Adjusting Alarms
Forgot to attach photo? (oops!)?
Note you're looking at the BACK of the cover.? ?? Will cut a hole big enough for the 20x4 to fit into.? ?Can bezel in the 16x2 without problems.? I'll try the 20x4 and if I can get the ONE that I have to work, I'll tentative insert that one on the cover.? If I can't....then the 16x2 goes in.? ?Let's get this finished! Gordon |
Re: FINISHING: Capturing Baselines, and Adjusting Alarms
Just For Your Information.? ? Attached is a photo of the BACKSIDE of the cover, and the box that i got from Home Dpot.? There wern't many choices.
The battery was glued in place (for better or worse)? ?2 days ago for stability. I've picked a location and will cut a rectangular hole for a 20x4 display --- With a bezel a 16x2 can be accomodated.? ?We can caulk or RTV for waterproofing.? ? I finally have ONE? ?20x4 display.... There is enough room above the battery to allow me to install 4 buttons.? ? I tried to accomodate the physical layout of the Ashhar v1.0 board, while also allowing what I'm calllng the Stapletonv1.0 board (which Dr. Stapleton kindly layed out, had made, and BUILT 5 copies of, to the Ashar 0.1 schemtic -- and it WORKS) -- the displays may be on wires to make these work, doesn't matter for getting through the FDA.? (Matters if youre building 5,000!) The only purpose here is to let the software FINISHERS? (not developers, FINISHERS!)? know roughly where I' going.? ?Somehow we have to FINISH this project.? ?The little transducer board/power switcher will fit on a side or somewhere.? ?i will likely mount the main board to the cover of the case, on standoffs ( I got in an assortment)? First I have to go build the transducer/power supply board....so that's what I'll be doing for the next hour or so....) Time to FINISH this project. Gordon |
FINISHING: Capturing Baselines, and Adjusting Alarms
Folks, it is time to FINISH the software.??
This is Saturday, and I plan to build a physical hardware today,? The team at UF needs a freeze on the hardware and needs to have something that WORKS.? ?The FDA requires FAR LESS testing than we get done very single day now. We have now conquered the I2C issue, whether optimally or not. Now in my view we only need two more things: (1)? SOME WAY for the user to be able to notify the software "Now is the time to gather our baseline pressure, or zero this or that"? -- as needed for sensors.? ?Because we can't just assume that on a restart that the patient is disconnected, and the clinician may require a change in a pressure, or a timing, or add positive-end-expiratory-pressure (PEEP) that CHANGES the baseline pressure that our system sees in the BMP280.? ?So we need a way to allow the user to indicate? "now is the chance to grab your baelines for this or that" (2) SOME WAY for the user to modify the Alarms.? ?I don't really care how fancy, and I don't think the FDA cares either.? ?And we don't have infinite memory available.? -- The LOW PRESS alarm needs to fire if the inspiratory pressure never increases above 3 cm above baseline during inspiration.? ?(The baseline will CHANGE if the clinician adds more PEEP mechanically.)? -- The HI PRESS alarm needs to be in some way adjustable.? ?Find a way.? Default is 35 cm H2o above "baseline" and range is probably 20-60 cmH2O -- The TIDAL VOLUME needs low and high alarms and they need to be adjustable? in SOME WAY-- either in reference to what is happening, or even more simply (and QUITE WORKABLE) just set to absolute numbers.? ?For example, a reasonable set of tidal volume alarms might be:? ?(THIS IS A SUGGESTION NOT A REQUIREMENT)? Tidal Alarms? LOW? ? ? ? HIGH ? ? ? ? ?1? ? ? ? ? ?100? ? ? ? ? 300 ? ? ? ? ? 2? ? ? ? ? ?200? ? ? ? ?400 ? ? ? ? ? 3? ? ? ? ? ?300? ? ? ? ?600 ? ? ? ? ? 4? ? ? ? ? ?400? ? ? ? ?700 ? ? ? ? ? 5? ? ? ? ? ?500? ? ? ? ?800 ? ? ? ? ? 6? ? ? ? ? ?600? ? ? ? ?900 ? ? ? ? ? 7? ? ? ? ? ?700? ? ? ? ?1000 ? ? ? ? ? 8? ? ? ? ? ?800? ? ? ? ?1100 (all values are cc? (equivalent to milliliters) If you can individually just set low and high tidal volumes, --- that probably even BETTER.? Being able to set high and low to specific values is how most aneshtesthisa equipment that I used in my career normally worked.? ?But this is not "normal" anymore.? ? ?We just need a way to make some setting..... I don't particularly care at this moment exactly HOW and I don't think the FDA cares either. But we need it FINISHED THANKS!!! Gordon Gibby My current crappy code enclosed.? NO WARANTEE FOR ANY PURPOSE WHATSOEVER.? ?But it now survives removing an I2C line. |
Re: #ExhalationValve
#ExhalationValve
it occurred to me that shortening the length of rubber tubing would reduce shear stress due to longitudinal expansion and would also increase life Erich Schulz,?mbbs, mba, fanzca 0410 277 408 On Sat, 11 Apr 2020 at 15:01, <sydneygold888@...> wrote: AJ , if the damage to the butyl tube is occurring where it pushes over the PVC tube , have you shaved off the sharp corner and radiused the edge of the PVC tube to take away the notch effect? ? |
Re: Anyone working on solutions that work on 12VDC and facilities without compressed air?
On Fri, Apr 10, 2020 at 09:55 PM, Erich Schulz wrote:
Let me know if have any drawings TomI have some small RC servos on order, from a USA shipper. Will likely be hand cutting and layering plexiglas sheets to try something out. I have a tiny CNC router, but have not become proficient with the mechanical CAD tools yet. For now I'm better with hand tools and paper.? Tom, wb6b |
Re: Anyone working on solutions that work on 12VDC and facilities without compressed air?
On Fri, Apr 10, 2020 at 09:40 PM, Jerry Gaffke wrote:
It will take a lot of refillsTrue. Scuba tanks may only be viable as a backup when power is out or transport. Fire stations may be able to fill the tanks, especially if some of the firefighters are scuba divers and have a fill adaptor. I wonder what the logistics of that would be. I suppose if the compressed air in the hospital was a weak link in a power outage (along with all the other equipment that must be kept running), then a battery backup on the ventilator would be moot.? Tom, wb6b |
Re: #ExhalationValve
#ExhalationValve
AJ , if the damage to the butyl tube is occurring where it pushes over the PVC tube , have you shaved off the sharp corner and radiused the edge of the PVC tube to take away the notch effect? ?
That might double or triple the lifespan. |
Re: Anyone working on solutions that work on 12VDC and facilities without compressed air?
Let me know if have any drawings Tom Erich Schulz,?mbbs, mba, fanzca 0410 277 408 On Sat, 11 Apr 2020 at 14:53, Tom, wb6b <wb6b@...> wrote: On Fri, Apr 10, 2020 at 08:54 PM, <sydneygold888@...> wrote: |
Re: Anyone working on solutions that work on 12VDC and facilities without compressed air?
On Fri, Apr 10, 2020 at 08:54 PM, <sydneygold888@...> wrote:
If using a bellows style with DC servo drive motor we could get infinite output curves with the right software.Good point. From my layman's (but hopefully improving) view that is a good way to go. There is an interesting "museum" of photos of old ventilators. Bellows were ?one of the main designs. Seems like the Bird ventilator was an early departure from that, using a nozzle blowing compressed oxygen into a venturi to suck in air to mix with the compressed O2 gas flow. Timing and control done by air circuits. In many ways that design is more amazing the current designs that can rely on a microprocessor to do the heavy lifting. In my case I'm leaning towards a design that optionally could use one "low pressure" air source (bellows, turbine, bellows or blower air mattress inflators, industrial strength turbine pumps) to power multiple ventilators. So I'm looking at an easy to build, possibility disposable, valve(s) controlled by an RC servo. Also it seems the two port designs are universal, have many accessories designed to work within that system, and have evolved to handle the real world of sick patients driving messy substances into the system.? Many creative designs have been proposed to help in they crisis. Even if many don't make it out of the gate immediately, maybe we will see many of these designs developing into innovative, smaller, simpler to use, more cost effective machines that will make it into the mainstream in the future. ? Tom, wb6b |
Re: Anyone working on solutions that work on 12VDC and facilities without compressed air?
It will take a lot of refills if continuously breathing from scuba tanks for weeks on end.
toggle quoted message
Show quoted text
I'd guess a couple hours per tank for each patient. Not cheap energy-wise to compress air to 2000 psi for no good reason. The regulators are interesting, simple and reliable enough, mostly. Jerry, KE7ER On Fri, Apr 10, 2020 at 03:32 PM, Tom, wb6b wrote:
On Fri, Apr 10, 2020 at 03:09 PM, Arv Evans wrote: |
Re: Anyone working on solutions that work on 12VDC and facilities without compressed air?
ARDS ventilators should really be capable of delivering tidal volumes against 30cmH2O (and arguably 40 for brief periods, such as "recruiting"). It's my impression that power won't be and issue with this (UF) design, but will be with other designs (especially turbine designs). I'm feeling in my bones (having looked at numerous projects now) that control and regulation and sensing are likely to be greater pain points overall. Erich Schulz,?mbbs, mba, fanzca 0410 277 408 On Sat, 11 Apr 2020 at 13:54, <sydneygold888@...> wrote: Tom , the Medtronics uses a Blower from AirFan ( France ) , they put out 86 millibar ( 87 cm / H2o ) aka 34 in/H2o at 100 Litres / minute. |
Re: Anyone working on solutions that work on 12VDC and facilities without compressed air?
Tom , the Medtronics uses a Blower from AirFan ( France ) , they put out 86 millibar ( 87 cm / H2o ) aka 34 in/H2o at 100 Litres / minute.
Ventilators need only 4 - 20 cm H2o? but the AirFans and other brands of high pressure pumps are expensive? and as i mentioned above , their lead time is over 10 months. If using a bellows style with DC servo drive motor we could get infinite output curves with the right software. |
Re: Volume Assembly
¿ªÔÆÌåÓýWe are in the homestretch here folks, we need a few things added to the software, then we have to test it and see what we screwed up, get the stuff that the FDA wants, and get this done with. ?I took 29 pages of their many questions and put out a Pleliminary draft after three hours. ? It really wasn¡¯t that hard. ?They are bending over backwards to try to help these things get done.? Let¡¯s get this project finished! Gordon On Apr 10, 2020, at 21:30, Gordon Gibby via groups.io <docvacuumtubes@...> wrote:
|
to navigate to use esc to dismiss