?I don’t have my computer with me, but I’m trying to forward you the 29 page document. Scan the document for the phrase ”general standard ”and you will find a list of the standards they are referring
You are welcome to use this language as it refers to the open source development. ?Happy to help someone with submission.
Thanks!!!
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From: Gordon Gibby <docvacuumtubes@...>
Date: April 10, 2020 at 08:59:12 EDT
To: "Johnson,William T" <WJohnson@...>, Caroline W <cewebst2@...>, Sem Lampotang <SLampotang@...>
Subject: Document prelim
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Good Morning/Afternoon Gordon and Happy Easter!!
Thanks for your very nice words, I really appreciate it and very happy to help you out and your team. ?Helping you, your team and mankind means more to me than any credit. ?I get plenty of credits at the moment but that is small compared to what you are doing there. ?If you would like a break from the OSVent project, check out the cover story in the February QST and page 77 of the recent May QST. ?Congratulations on all the successes you and your team have accomplished.
Marc Alan
WA9ZCO
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If anyone here has the IEC standards that the FDA is referring to, and I can get you the list, but right now my wife is driving, please speak up quickly.
if somebody else is ready to file with the FDA and I can help them, likewise speak up. ??
you can get the pressure and flow diagrams fairly easily by simply instrumenting what we already have built. ? All the schematics are open source, all the boards are open source, ?you can cite my hardware, and I will run code for you if you need.
there’s absolutely no reason that they should not be fully submitted to the FDA on Tuesday or Wednesday unless there’s something in those standards that completely eludes me. ?I am flabbergasted that people have not moved quicker on the submission process, especially after I ran through a 29 page preliminary in three hours. ?
this is ?not something to make a career out of, this is a project that needs to get finished.
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Hi Gordon, ? What standards do you need? One or more of us may have access to current copies… ? B ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Gordon Gibby
Sent: Sunday, April 12, 2020 9:16 AM
To: [email protected]
Subject: Re: [VentilatorDevelopers] FDA Approval ? OK folks you’re not gonna believe this: the latest screwup is it we don’t have the standards to read to finish what I wrote in three hours for regulatory submission, because people are waiting for some company to open on Tuesday and get them for free. ?
so what we need is for some other group to submit this, I will be happy to help them, and they need to get access to the IEC standards that the FDA made so plainly obvious in their document. ??
I can give you a 29 page document that can be finished in a matter of a few hours and a day of testing. ? Somebody has to get a fire under their butt. ??
?
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OK folks you’re not gonna believe this: the latest screwup is it we don’t have the standards to read to finish what I wrote in three hours for regulatory submission, because people are waiting for some company to open on Tuesday and get them for free. ?
so what we need is for some other group to submit this, I will be happy to help them, and they need to get access to the IEC standards that the FDA made so plainly obvious in their document. ??
I can give you a 29 page document that can be finished in a matter of a few hours and a day of testing. ? Somebody has to get a fire under their butt. ??
?
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Re: High cycle Rainbird and passive valve testing
Report attached along with some observations and analysis. Relatively high variations in cycle to cycle delta pressure were seen with the plastic spring PEEP valves compared to a steel coil spring valve.
Now at 1,080,000 cycles.
?? Bob Benedict
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Oh my, the code is so crappy. ?there are only a couple of buttons that I can figure out.
There is a button that selects which parameter it will be adjusted and I only have two that work in my code, breaths per minute and I to e ratio
Apparently I put the buttons in, in the wrong order, the select button is between the plus and minus buttons
The other button seems to stop ventilation and restart it.
Beyond that, it has been guesswork, because I really haven’t had a chance to play with it much?
I don’t have the top line working at all. ?only the second line is working
But the darn thing will keep a patient alive!
And it is sitting there clicking both valves independently, So I split the load to the two solenoids between the two MOSFETs
You would laugh, the first time I tried to solder that wire I shorted both to ground. ?Stapleton’s board has NO solder mask, and very little clearance, and it is hard as heck to make connections without shorting to ground surrounding them
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On Apr 12, 2020, at 11:01, Ashhar Farhan <farhanbox@...> wrote:
? Gordon your code is pretty usable. I am a bit confused about the user interface though. Can you show us a video of the way user interface works on the two line display? The automotive canister valve purge solenoid, the only thing I could get in town, is the hottest part, dissipating under 10 W, using a room thermometer I measure its case temperature at 117°F.? My wife confirms by grasping it solidly that that is near but not quite to the temperature that she prefers her shower water. ? ?
The orbit lawn sprinkler is Warm but significantly cooler.
I wanted to get objective documentation of these temperatures, this is after an entire operating hour at 50% duty cycle, so steady state, at an ambient room temperature of 79°F ? ?(Summer in Florida)
Gordon On Apr 12, 2020, at 10:40, Gordon Gibby via <docvacuumtubes=[email protected]> wrote:
?And any of you guys using my crappy code, I’m sure you can see that I have screwed up the first line displays, which probably were supposed to display the peak pressure or total volume or something, but I’ve certainly felt them up, and it wasn’t important to me so they will need some fixing—-if you’re going to work with anything based on what I’ve sent out!!! ?
Code I did for Marcelo properly reads the BMP 280 sensor. ?don’t know if he has employed the lock out of the I2C bus or not, ?i’m pretty sure he has a watchdog timer. ? ?Apparently he doesn’t yet have the flow measurement code, but all of that is really easy to add. ? It would be fairly simple to take his code and add to it from The stuff others have worked out and make the whole thing run. ?
I can test anything anyone writes on my little bitty system here and fix little bitty things but I’m not bright enough to understand all of his cool displays and various things,..... so you’ll have to fix that yourself. ? One person simply cannot keep track of all of this ?
MA, I heard the UF team was extraordinarily impressed with your valve! ? You provided an incredible benefit to people in more difficult circumstances, because your valve works without any machining whatsoever!!!! ? Five minutes of work and it is done. ? That was an incredible gift. ? You should be very proud of that contribution.? Without creating liability for you, every chance I am going to try to mention it. ? ??
The hundreds and hundreds of thousands of tests run by volunteers here, and you know who you are, will not be unnoticed!!!
Gordon
On Apr 12, 2020, at 10:29, Gordon Gibby via <docvacuumtubes=[email protected]> wrote:
?Marcelo it will be easy to switch the code out by demonstrating that yours accomplishes the same outcome.? But in some parts of the world, lives are at stake.? Every hour that we delay is precious to some family.? We must move forward. Required testing has to be done now, not Wednesday. ?i’m sure you understand.? Folks, we need this finished!!!!? Delay is like cancer; delay builds upon delay, until you have nothing.? That’s why all of us have worked morning noon and night for two weeks now.? Conquering obstacle after obstacle ? Only a steadfast commitment that we will make this work as fast as we possibly can and get it to the FDA will save the most number of lives.....somewhere we may not ever even know. ?
?I can not finish the baseline code (or supposed to be) until I get BMP280 sensor. FedEx is supposed to deliver it tomorrow by 5:00PM ET.
I may get the code up/running tomorrow late night.
I would suggest you to delay one or two days the FDA submission. It will give us more time for testing.
|
Gordon your code is pretty usable. I am a bit confused about the user interface though. Can you show us a video of the way user interface works on the two line display?
The automotive canister valve purge solenoid, the only thing I could get in town, is the hottest part, dissipating under 10 W, using a room thermometer I measure its case temperature at 117°F.? My wife confirms by grasping it solidly that that is near but not quite to the temperature that she prefers her shower water. ? ?
The orbit lawn sprinkler is Warm but significantly cooler.
I wanted to get objective documentation of these temperatures, this is after an entire operating hour at 50% duty cycle, so steady state, at an ambient room temperature of 79°F ? ?(Summer in Florida)
Gordon On Apr 12, 2020, at 10:40, Gordon Gibby via <docvacuumtubes=[email protected]> wrote:
?And any of you guys using my crappy code, I’m sure you can see that I have screwed up the first line displays, which probably were supposed to display the peak pressure or total volume or something, but I’ve certainly felt them up, and it wasn’t important to me so they will need some fixing—-if you’re going to work with anything based on what I’ve sent out!!! ?
Code I did for Marcelo properly reads the BMP 280 sensor. ?don’t know if he has employed the lock out of the I2C bus or not, ?i’m pretty sure he has a watchdog timer. ? ?Apparently he doesn’t yet have the flow measurement code, but all of that is really easy to add. ? It would be fairly simple to take his code and add to it from The stuff others have worked out and make the whole thing run. ?
I can test anything anyone writes on my little bitty system here and fix little bitty things but I’m not bright enough to understand all of his cool displays and various things,..... so you’ll have to fix that yourself. ? One person simply cannot keep track of all of this ?
MA, I heard the UF team was extraordinarily impressed with your valve! ? You provided an incredible benefit to people in more difficult circumstances, because your valve works without any machining whatsoever!!!! ? Five minutes of work and it is done. ? That was an incredible gift. ? You should be very proud of that contribution.? Without creating liability for you, every chance I am going to try to mention it. ? ??
The hundreds and hundreds of thousands of tests run by volunteers here, and you know who you are, will not be unnoticed!!!
Gordon
On Apr 12, 2020, at 10:29, Gordon Gibby via <docvacuumtubes=[email protected]> wrote:
?Marcelo it will be easy to switch the code out by demonstrating that yours accomplishes the same outcome.? But in some parts of the world, lives are at stake.? Every hour that we delay is precious to some family.? We must move forward. Required testing has to be done now, not Wednesday. ?i’m sure you understand.? Folks, we need this finished!!!!? Delay is like cancer; delay builds upon delay, until you have nothing.? That’s why all of us have worked morning noon and night for two weeks now.? Conquering obstacle after obstacle ? Only a steadfast commitment that we will make this work as fast as we possibly can and get it to the FDA will save the most number of lives.....somewhere we may not ever even know. ?
?I can not finish the baseline code (or supposed to be) until I get BMP280 sensor. FedEx is supposed to deliver it tomorrow by 5:00PM ET.
I may get the code up/running tomorrow late night.
I would suggest you to delay one or two days the FDA submission. It will give us more time for testing.
|
The automotive canister valve purge solenoid, the only thing I could get in town, is the hottest part, dissipating under 10 W, using a room thermometer I measure its case temperature at 117°F. ?My wife confirms by grasping it solidly that that is near but not quite to the temperature that she prefers her shower water. ? ?
The orbit lawn sprinkler is Warm but significantly cooler.
I wanted to get objective documentation of these temperatures, this is after an entire operating hour at 50% duty cycle, so steady state, at an ambient room temperature of 79°F ? ?(Summer in Florida)
Gordon
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On Apr 12, 2020, at 10:40, Gordon Gibby via groups.io <docvacuumtubes@...> wrote:
? And any of you guys using my crappy code, I’m sure you can see that I have screwed up the first line displays, which probably were supposed to display the peak pressure or total volume or something, but I’ve certainly felt them up, and it wasn’t important to me so they will need some fixing—-if you’re going to work with anything based on what I’ve sent out!!! ?
Code I did for Marcelo properly reads the BMP 280 sensor. ?don’t know if he has employed the lock out of the I2C bus or not, ?i’m pretty sure he has a watchdog timer. ? ?Apparently he doesn’t yet have the flow measurement code, but all of that is really easy to add. ? It would be fairly simple to take his code and add to it from The stuff others have worked out and make the whole thing run. ?
I can test anything anyone writes on my little bitty system here and fix little bitty things but I’m not bright enough to understand all of his cool displays and various things,..... so you’ll have to fix that yourself. ? One person simply cannot keep track of all of this ?
MA, I heard the UF team was extraordinarily impressed with your valve! ? You provided an incredible benefit to people in more difficult circumstances, because your valve works without any machining whatsoever!!!! ? Five minutes of work and it is done. ? That was an incredible gift. ? You should be very proud of that contribution. ?Without creating liability for you, every chance I am going to try to mention it. ? ??
The hundreds and hundreds of thousands of tests run by volunteers here, and you know who you are, will not be unnoticed!!!
Gordon
On Apr 12, 2020, at 10:29, Gordon Gibby via groups.io <docvacuumtubes@...> wrote:
? Marcelo it will be easy to switch the code out by demonstrating that yours accomplishes the same outcome. ?But in some parts of the world, lives are at stake. ?Every hour that we delay is precious to some family. ?We must move forward. Required testing has to be done now, not Wednesday. ?i’m sure you understand. ?Folks, we need this finished!!!! ?Delay is like cancer; delay builds upon delay, until you have nothing. ?That’s why all of us have worked morning noon and night for two weeks now. ?Conquering obstacle after obstacle ? Only a steadfast commitment that we will make this work as fast as we possibly can and get it to the FDA will save the most number of lives.....somewhere we may not ever even know. ?
On Apr 12, 2020, at 10:14, Marcelo Varanda via groups.io <mv_email@...> wrote:
?I can not finish the baseline code (or supposed to be) until I get BMP280 sensor. FedEx is supposed to deliver it tomorrow by 5:00PM ET.
I may get the code up/running tomorrow late night.
I would suggest you to delay one or two days the FDA submission. It will give us more time for testing.
|
Voltage Notes:
The medical grade IEC certified power supply is producing 14.95 V under load. ??
I’m feeding that into the highest voltage input of my transducer/power supply board, and under load the output of that board is 12.28 V
The output from the MOSFETs going to the two separate solenoids is approximately 11.12 bolts, both identical, measured at the front panel connector.?
That is exactly what I was hoping for, and this is about as good as I could wish! ? The medical grade power supply is only barely above room temperature. ?It is clearly loafing. ?
So the voltages and currents are absolutely perfect in my estimation
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On Apr 12, 2020, at 10:40, Gordon Gibby via groups.io <docvacuumtubes@...> wrote:
? And any of you guys using my crappy code, I’m sure you can see that I have screwed up the first line displays, which probably were supposed to display the peak pressure or total volume or something, but I’ve certainly felt them up, and it wasn’t important to me so they will need some fixing—-if you’re going to work with anything based on what I’ve sent out!!! ?
Code I did for Marcelo properly reads the BMP 280 sensor. ?don’t know if he has employed the lock out of the I2C bus or not, ?i’m pretty sure he has a watchdog timer. ? ?Apparently he doesn’t yet have the flow measurement code, but all of that is really easy to add. ? It would be fairly simple to take his code and add to it from The stuff others have worked out and make the whole thing run. ?
I can test anything anyone writes on my little bitty system here and fix little bitty things but I’m not bright enough to understand all of his cool displays and various things,..... so you’ll have to fix that yourself. ? One person simply cannot keep track of all of this ?
MA, I heard the UF team was extraordinarily impressed with your valve! ? You provided an incredible benefit to people in more difficult circumstances, because your valve works without any machining whatsoever!!!! ? Five minutes of work and it is done. ? That was an incredible gift. ? You should be very proud of that contribution. ?Without creating liability for you, every chance I am going to try to mention it. ? ??
The hundreds and hundreds of thousands of tests run by volunteers here, and you know who you are, will not be unnoticed!!!
Gordon
On Apr 12, 2020, at 10:29, Gordon Gibby via groups.io <docvacuumtubes@...> wrote:
? Marcelo it will be easy to switch the code out by demonstrating that yours accomplishes the same outcome. ?But in some parts of the world, lives are at stake. ?Every hour that we delay is precious to some family. ?We must move forward. Required testing has to be done now, not Wednesday. ?i’m sure you understand. ?Folks, we need this finished!!!! ?Delay is like cancer; delay builds upon delay, until you have nothing. ?That’s why all of us have worked morning noon and night for two weeks now. ?Conquering obstacle after obstacle ? Only a steadfast commitment that we will make this work as fast as we possibly can and get it to the FDA will save the most number of lives.....somewhere we may not ever even know. ?
On Apr 12, 2020, at 10:14, Marcelo Varanda via groups.io <mv_email@...> wrote:
?I can not finish the baseline code (or supposed to be) until I get BMP280 sensor. FedEx is supposed to deliver it tomorrow by 5:00PM ET.
I may get the code up/running tomorrow late night.
I would suggest you to delay one or two days the FDA submission. It will give us more time for testing.
|
And any of you guys using my crappy code, I’m sure you can see that I have screwed up the first line displays, which probably were supposed to display the peak pressure or total volume or something, but I’ve certainly felt them up, and it wasn’t important to me so they will need some fixing—-if you’re going to work with anything based on what I’ve sent out!!! ?
Code I did for Marcelo properly reads the BMP 280 sensor. ?don’t know if he has employed the lock out of the I2C bus or not, ?i’m pretty sure he has a watchdog timer. ? ?Apparently he doesn’t yet have the flow measurement code, but all of that is really easy to add. ? It would be fairly simple to take his code and add to it from The stuff others have worked out and make the whole thing run. ?
I can test anything anyone writes on my little bitty system here and fix little bitty things but I’m not bright enough to understand all of his cool displays and various things,..... so you’ll have to fix that yourself. ? One person simply cannot keep track of all of this ?
MA, I heard the UF team was extraordinarily impressed with your valve! ? You provided an incredible benefit to people in more difficult circumstances, because your valve works without any machining whatsoever!!!! ? Five minutes of work and it is done. ? That was an incredible gift. ? You should be very proud of that contribution. ?Without creating liability for you, every chance I am going to try to mention it. ? ??
The hundreds and hundreds of thousands of tests run by volunteers here, and you know who you are, will not be unnoticed!!!
Gordon
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Show quoted text
On Apr 12, 2020, at 10:29, Gordon Gibby via groups.io <docvacuumtubes@...> wrote:
? Marcelo it will be easy to switch the code out by demonstrating that yours accomplishes the same outcome. ?But in some parts of the world, lives are at stake. ?Every hour that we delay is precious to some family. ?We must move forward. Required testing has to be done now, not Wednesday. ?i’m sure you understand. ?Folks, we need this finished!!!! ?Delay is like cancer; delay builds upon delay, until you have nothing. ?That’s why all of us have worked morning noon and night for two weeks now. ?Conquering obstacle after obstacle ? Only a steadfast commitment that we will make this work as fast as we possibly can and get it to the FDA will save the most number of lives.....somewhere we may not ever even know. ?
On Apr 12, 2020, at 10:14, Marcelo Varanda via groups.io <mv_email@...> wrote:
?I can not finish the baseline code (or supposed to be) until I get BMP280 sensor. FedEx is supposed to deliver it tomorrow by 5:00PM ET.
I may get the code up/running tomorrow late night.
I would suggest you to delay one or two days the FDA submission. It will give us more time for testing.
|
Marcelo it will be easy to switch the code out by demonstrating that yours accomplishes the same outcome. ?But in some parts of the world, lives are at stake. ?Every hour that we delay is precious to some family. ?We must move forward. Required testing has to be done now, not Wednesday. ?i’m sure you understand. ?Folks, we need this finished!!!! ?Delay is like cancer; delay builds upon delay, until you have nothing. ?That’s why all of us have worked morning noon and night for two weeks now. ?Conquering obstacle after obstacle ? Only a steadfast commitment that we will make this work as fast as we possibly can and get it to the FDA will save the most number of lives.....somewhere we may not ever even know. ?
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On Apr 12, 2020, at 10:14, Marcelo Varanda via groups.io <mv_email@...> wrote:
?I can not finish the baseline code (or supposed to be) until I get BMP280 sensor. FedEx is supposed to deliver it tomorrow by 5:00PM ET.
I may get the code up/running tomorrow late night.
I would suggest you to delay one or two days the FDA submission. It will give us more time for testing.
|
I can not finish the baseline code (or supposed to be) until I get BMP280 sensor. FedEx is supposed to deliver it tomorrow by 5:00PM ET.
I may get the code up/running tomorrow late night.
I would suggest you to delay one or two days the FDA submission. It will give us more time for testing.
|
Thanks jack! ?I’ll review. ? Worked perfectly when I pulled a wire. ?Disabled calls from then on!! ?Forced me to add a way to turn it back on! ?Ouch.?
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On Apr 12, 2020, at 10:01, jjpurdum via groups.io <jjpurdum@...> wrote:
?
Gordon:
See below:
- SOFTWARE NEEDED: 1) A way to reset the I2C protections
-- see my line 678 and 688 -- need to do that if, for example, all four
buttons are held down, perhaps??? I don't follow this section of code. I don't see how I2CBusAllowed is set during setup(). It would seem to me that the test on the I2C bus should come after an attempt to instantiate the BME280 object. I did hook up my newly-arrived pressure sensor to some test code, but have not been able to successfully simulate an I2C bus failure other than unplugging it, which is pretty obvious.
2) A way to ADJUST the high pressure limits (can be adjusted in steps of 5 cm or as fine as 1 cm if you prefer:) 3) A way to ADJUST the low pressure limit? (can be adjusted in steps of 5cm or as fine as 1 cm if you prefer) 4)? A way to ADJUST the low tidal volume alarm (can be adjusted in 100 mL increments is fine) 5)? A way to ADJUST the high tidal volume alarm? (can be adjusted in 100 mL increments is fine) I would add another encoder and let it handle these adjustments, although there seems to be a bias against using encoders. Marcelo could add two new menu options to the UI: "Pressure Limits" and "Tidal Volume" and use the up/down switches to set them.
6)?
A way for the user to halt ventilation briefly (e.g. 3 seconds) and
REZERO the pressure and flow measurements -- airway pressure will drop
to PEEP within 2-3 seconds and flow will decline to zero if the patient
is not spontanteously breathing.? Ventilation AUTOMATICALLY starts back
up after three seconds.? ?Makes it impossible for the user to screw t
up. I need to think more about this one...
Jack, W8TEE
<GLG0410.zip> <Apr12Finished.jpeg>
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Gordon:
See below:
- SOFTWARE NEEDED: 1) A way to reset the I2C protections
-- see my line 678 and 688 -- need to do that if, for example, all four
buttons are held down, perhaps??? I don't follow this section of code. I don't see how I2CBusAllowed is set during setup(). It would seem to me that the test on the I2C bus should come after an attempt to instantiate the BME280 object. I did hook up my newly-arrived pressure sensor to some test code, but have not been able to successfully simulate an I2C bus failure other than unplugging it, which is pretty obvious.
2) A way to ADJUST the high pressure limits (can be adjusted in steps of 5 cm or as fine as 1 cm if you prefer:) 3) A way to ADJUST the low pressure limit? (can be adjusted in steps of 5cm or as fine as 1 cm if you prefer) 4)? A way to ADJUST the low tidal volume alarm (can be adjusted in 100 mL increments is fine) 5)? A way to ADJUST the high tidal volume alarm? (can be adjusted in 100 mL increments is fine) I would add another encoder and let it handle these adjustments, although there seems to be a bias against using encoders. Marcelo could add two new menu options to the UI: "Pressure Limits" and "Tidal Volume" and use the up/down switches to set them.
6)?
A way for the user to halt ventilation briefly (e.g. 3 seconds) and
REZERO the pressure and flow measurements -- airway pressure will drop
to PEEP within 2-3 seconds and flow will decline to zero if the patient
is not spontanteously breathing.? Ventilation AUTOMATICALLY starts back
up after three seconds.? ?Makes it impossible for the user to screw t
up. I need to think more about this one...
Jack, W8TEE
|
COMPLETELY WORKING SELF-CONTAINED VERSION OF VENTILATOR CONTROLLER
-- Working code (crappy code) attached.
-- Note lines 678 and 688 of .ino file:? protections against I2C bus failure are intentionally jammed so that you can test easier.? (Ohterwise, one failure and you simply cannot get anything mmore from the BMP.
-- I'm using both MOTOR_A and MOTOR-B output:
Motor_A is driving the (normally closed) inspiratory valve? ?300mA @ 12VDC
Motor_B is driving the (normally open) expiratory valve control automotive solenoid? -- approx 750 mA @ 12VDC? (that valve will operate with much lower voltage and I may create a little diode network to cut its voltage down somewhat. Not sure yet.? ?No issue for programmers)
- SOFTWARE NEEDED:
1) A way to reset the I2C protections -- see my line 678 and 688 -- need to do that if, for example, all four buttons are held down, perhaps???
2) A way to ADJUST the high pressure limits (can be adjusted in steps of 5 cm or as fine as 1 cm if you prefer:)
3) A way to ADJUST the low pressure limit? (can be adjusted in steps of 5cm or as fine as 1 cm if you prefer)
4)? A way to ADJUST the low tidal volume alarm (can be adjusted in 100 mL increments is fine)
5)? A way to ADJUST the high tidal volume alarm? (can be adjusted in 100 mL increments is fine)
6)? A way for the user to halt ventilation briefly (e.g. 3 seconds) and REZERO the pressure and flow measurements -- airway pressure will drop to PEEP within 2-3 seconds and flow will decline to zero if the patient is not spontanteously breathing.? Ventilation AUTOMATICALLY starts back up after three seconds.? ?Makes it impossible for the user to screw t up.
By the way. ... at the moment we have no way to turn this thing completely off.? ?You have to remove ALL power.? That's fine for the moment.??
The Battery backup will go for probably 2 hours.? ?Tested to 1 hour, worked perfectly.? 3.3 AHr sealed lead acid built in.
We may be ready for an FDA submission 24-hour testing and waveforms measurement, folks.? ?It is time to WRAP THIS UP
Code below works on?
a)? Ashar schematics 0.1, implemented in Stapleton boards 1.0
b)? should work fine iwth Ashhar schematic v1..0 -- and the boards we have in hand, not yet built.
ATTENtiION SOFTWARE DEVELOPERS:??
GO PROGRAMMERS!!!!? I? "want"? (translate:? I have no control over you; I'm begging, & pleading folks! )? ?finished code by 8PM Eastern Daylight TODAY that does all the above.? ?I'm sure I've screwed up something and we won't know WHAT until we give it a whirl.? ?If you don't know the constant for the pressure/obstruction/orifice just make it up.? ?See my code where I *GUESSED* a coefficient.? ?We'll fix that later.? ?The physics is pretty simple and we don't have time (or processor or memory) for "fancy".? ?We just need WORKING.? Fancy can come later, folks.? ?You'll have MONTHS to make it perfect? ?We have DAYS to get this submitted!? **WORKING** is what we need.? ?I'm sure there will be some tweak needed that we haven't thought of....but we won't until we are doing real testing with real users.??
THANKS!!!??
Gordon
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Re: High cycle Rainbird and passive valve testing
Bob, thank you very much, please send it as a word type document so that Carolyn gets it also, and throw in a photo or two if you can. ?She needs that kind of documentation.
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On Apr 11, 2020, at 23:22, KD8CGH <rkayakr@...> wrote:
?Gordon
?? I can update the 4/11 doc (post 1432).
?????? Bob Benedict
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UQ Ventilator Design Hackathon
Hi Folk,
FYI my alma mater is running a? to "Design an ‘open source’, low-cost, simple ventilator that can serve COVID-19 patients, in an emergency timeframe."?
The Prof running the hackathon emailed me tonight to tell me he had over 200 students (mostly 2nd and 3rd year engineers of different flavours) enrolled. Sadly the event web-page?features yet-another-baq-squeezer?(henceforth to be referred to as YABS). I will do my utmost to derail any desires to pursue this strategy! You may wish to consider if there are any opportunities for them to address particular pain points you are having.
Commencing Tuesday 14 April at 9am and ending Friday 17 April at 3pm. The event will be closed by out by presentations of designs by teams from 3pm to 5pm. (all times UTC-10).
This event was part of my motivation?for writing the .? e Erich Schulz,?mbbs, mba, fanzca 0410 277 408
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Thanks Tom!
I lovethe approach of layered (presumably laser cut) plexiglass for some components - being able to visually inspect the workings of a valve is very convenient to exclude faults, and check for wear and
debris.?
For reasons I can't put my finger on I feel uncomfortable with direct mechanical linkage of the expiratory and inspiratory valves?like this. This part would need to cycle at 12-20 cycles/minute for weeks so wear and release of plexiglass dust could be problematic. Figuring out how to put actuators on standard valves is definitely a challenge. Erich Schulz,?mbbs, mba, fanzca 0410 277 408
On Sun, 12 Apr 2020 at 21:18, Tom, wb6b < wb6b@...> wrote: On Fri, Apr 10, 2020 at 09:55 PM, Erich Schulz wrote:
Let me know if have any drawings Tom
Hi Erich, I found some cheat sheets and was able to figure out OpenSCAD well enough to produce this exploded view drawing. Basically the valve consists of five layers of plexiglass sheet sandwiched together. Likely 2.38mm thick. The top manifold layer is twice or more thicker. This is just a first rough concept drawing, with no premature optimizations included. An overpressure poppet valve and a negative pressure one way valve should be added to the valve body. A strip on enclosed foam elastomer of some sort could replace the small gap barrier across the bottom of the valve disk in the "air chamber" layer of the valve assembly.? It could be a safety feature in that it is possible to allow some play of the valve disk against the top valve plate (the layer below the manifold). The air pressure will hold the valve disk against the top plate. If supply pressure is lost and a positive pressure be exerted by the patient, or negative pressure from the patient the valve disk could lift away from the top valve plate and provide an air path. However, it will be reverse to the normal flow. Inline filters should be included in the supply and exhaust lines if enabling this "safety" breathing path is desired. I'm waiting on the RC servos I ordered to arrive to see how well this design works. Tom, wb6b -----  ----- ?
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On Fri, Apr 10, 2020 at 09:55 PM, Erich Schulz wrote:
Let me know if have any drawings Tom
Hi Erich, I found some cheat sheets and was able to figure out OpenSCAD well enough to produce this exploded view drawing. Basically the valve consists of five layers of plexiglass sheet sandwiched together. Likely 2.38mm thick. The top manifold layer is twice or more thicker. This is just a first rough concept drawing, with no premature optimizations included. An overpressure poppet valve and a negative pressure one way valve should be added to the valve body. A strip on enclosed foam elastomer of some sort could replace the small gap barrier across the bottom of the valve disk in the "air chamber" layer of the valve assembly.? It could be a safety feature in that it is possible to allow some play of the valve disk against the top valve plate (the layer below the manifold). The air pressure will hold the valve disk against the top plate. If supply pressure is lost and a positive pressure be exerted by the patient, or negative pressure from the patient the valve disk could lift away from the top valve plate and provide an air path. However, it will be reverse to the normal flow. Inline filters should be included in the supply and exhaust lines if enabling this "safety" breathing path is desired. I'm waiting on the RC servos I ordered to arrive to see how well this design works. Tom, wb6b -----  ----- ?
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Bob Benedict, KD8CGH
Marcelo Varanda
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