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Folks, I tried out the RS-232 9 pin connector. It is leaky as hell. Try this (at home). Take a 9 pin connector and suck at it. If you can feel the air? rush into your mouth, you know it leaky. Get to work with hotglue gun. That's what I am doing now. But we can't use the connector across the pressurised barrier. It might be easier to just stuff the four wires through a small hole and hot glue the hole. - farhan
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From my experiences in building cave radios most connectors leak like this. The idea to pass the wiring through a hole ( with grommet) and seal sounds like the most effective low cost option.
Regards
Ron Taylor G4GXO
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Dear friends? Yes most commercial connectors will leak.? I have designed several medical /products for defence. I could help?
Please let me know how many pin connector do you need?? Also trying to seal it with hot glue is not good.? Please use a good RTV paste.? Dow Corning is an approved? product.? There are others too.?
73? Kumar
On Tue, 24 Mar 2020, 20:39 Ron Taylor via Groups.Io, <cumbriadesigns= [email protected]> wrote: From my experiences in building cave radios most connectors leak like this. The idea to pass the wiring through a hole ( with grommet) and seal sounds like the most effective low cost option.
Regards
Ron Taylor G4GXO
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Ashar -- what about gluing a connector to the top of the sensor chip?? ?Then we coud just use a thin tube to go to the airway circuit, which is the NORM in anesthesia and intensitve unit care.? ?All the differential pressure sensors already have the nipple -- this device was made to sense ambient pressure so it didnt have it.
Gordon
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How about going wireless ? RS 232 to Bluetooth modules are cheap and plenty
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Apparently these do I2C as well as UART -
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That was an option since the beginning. I got a BLE module already but my priority option is LCD + keys. But both will be available, read the concept at:
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On Mar 26, 2020, at 3:45 AM, quad@... wrote:
Apparently these do I2C as well as UART -
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I don't understand the bluetooth issues so not certain about them?but remember you could have 12 patients within a 500 sq foot ICU bay.? ?Will they pick up the wrong patient's ventilator???
On Thu, Mar 26, 2020 at 7:30 AM Marcelo Varanda via Groups.Io <mv_email= [email protected]> wrote: That was an option since the beginning. I got a BLE module already but my priority option is LCD + keys. But both will be available, read the concept at:
MV On Mar 26, 2020, at 3:45 AM, quad@... wrote:
Apparently these do I2C as well as UART -
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In my office when I scan for BT it finds 50+ devices. Each device has a MAC address (similar to Ethernet address). Also, Arduino works standalone. BT is just to set parameters. Even if the connection drops the unit keeps working. It should have no problem.?
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I don't understand the bluetooth issues so not certain about them?but remember you could have 12 patients within a 500 sq foot ICU bay.? ?Will they pick up the wrong patient's ventilator???
On Thu, Mar 26, 2020 at 7:30 AM Marcelo Varanda via Groups.Io <mv_email= [email protected]> wrote: That was an option since the beginning. I got a BLE module already but my priority option is LCD + keys. But both will be available, read the concept at:
MV On Mar 26, 2020, at 3:45 AM, quad@... wrote:
Apparently these do I2C as well as UART -
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I had the same concern as Gordon about the hospital ward configuration.? BT is an option, but my gut says MAC addresses are great for EEs and ITs, but not so great for nurses.
Need to KISS for the initial device. Minimize scope creep.
James
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Fun to think about bluetooth, but Gordon's investigation of the valves seems?
the primary issue for now.??That will make or break this project.
Being able to monitor and log several dozen ventilators?
from one central computer would be a significant feature.
Maybe have a 9600 baud UART TX link out to
an optional module of some sort, could be bluetooth or
Si4432 (on some vacant ISM band) or RS232 or smoke signals.
Controlling the ventilator remotely (such as shutting it off)?
is a fair bit more problematic, I'd think hard before allowing that.
I would not make any of this a priority for version 1.0,
Jerry, KE7ER
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On Thu, Mar 26, 2020 at 04:30 AM, Marcelo Varanda wrote:
That was an option since the beginning.
I got a BLE module already but my priority option is LCD + keys. But both will be available, read the concept at:
?
?
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Where in the system is this connector needed?
??? Bob?? KD8CGH
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Even I get very confused by bluetooth.? ?When I turn on my computer and try to connect to my pactor modem by bluetooth I see multiple pactor modems (bdcause I have used it with different setups) and I have trouble finding which one.? ?I can only imagine what a nurse might do and not recognize that the monitor is connected to patient across the room....instead of the patient right in front of her/him1!!!!!!!
We have to make absolutely certain that what we build is pretty idiot proof becuse the peole are under a lot of stress and mistakes happen.? ?We have had huge concern over that in operating rooms as well.... more than once my display has been showing me vital signs from a patient down the hall....instead of MY PATIENT.
Does that explain the concern??
Gordon
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Sorry for being clueless but where physically in the system is there a need for an airtight connector? I believe that the valve connectors are exterior and I thought from your last P sensor post that the sensor body is connected by a tube and so is also exterior to the pressurized area.
???? Bob
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The Bosch MCP 280 pressure sensor does not have a Farb. It only has a whole
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On Mar 26, 2020, at 11:45, KD8CGH <rkayakr@...> wrote:
?Sorry for being clueless but where physically in the system is there a need for an airtight connector? I believe that the valve connectors are exterior and I thought from your last P sensor post that the sensor body is connected by a tube and so is also exterior to the pressurized area.
???? Bob
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Thank to your post I saw that. I proposed in the P sensor topic making a cover that includes a barb over the orifice. If I have the case and flange dimensions I can whip up something quickly that can be printed anywhere.
??? Bob
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It doesn't have a barb or nipple suitable for connecting to a thin plastic hose; it was made to measure AMBIENT pressure so it only has an opening into its case.
Gordon
On Thu, Mar 26, 2020 at 1:42 PM Gordon Gibby via Groups.Io <docvacuumtubes= [email protected]> wrote: The Bosch MCP 280 pressure sensor does not have a Farb. It only has a whole ?Sorry for being clueless but where physically in the system is there a need for an airtight connector? I believe that the valve connectors are exterior and I thought from your last P sensor post that the sensor body is connected by a tube and so is also exterior to the pressurized area.
???? Bob
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Gordon
?? I assume you were typing when my 2:31 post 219 appeared. Is that solution acceptable?
?????? Bob
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?airway pressure can vary between -20?cmH2O to 60 or even 80 cmH2O in the event that the over-pressure relief valve fails.??
Pressure sensor should not be destroyed by being exposed to twice that amount.??
The BMP280 sensor datasheet that I see?is inadequate for this pressure range.??
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It doesn't have a barb or nipple suitable for connecting to a thin plastic hose; it was made to measure AMBIENT pressure so it only has an opening into its case.
Gordon
On Thu, Mar 26, 2020 at 1:42 PM Gordon Gibby via Groups.Io <docvacuumtubes= [email protected]> wrote:
The Bosch MCP 280 pressure sensor does not have a Farb. It only has a whole
?Sorry for being clueless but where physically in the system is there a need for an airtight connector? I believe that the valve connectors are exterior and I thought from your last P sensor post that the sensor body is connected by a tube and
so is also exterior to the pressurized area.
???? Bob
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Hi,
Shouldn't the pressure sensor be a differential sensor; sensing the difference in airway pressure against the ambient pressure.?
It looks like you are trying to accurately measure tenths of a PSI against a background ambient pressure of 14 PSI. The ambient pressure is going to vary with altitude or if a storm front moves in. If you have a second pressure sensor to measure the ambient pressure (forgive me if I missed that in the design) will the two sensors track accurately?
It looks like?1000 hPa =?14.503773773 psi.
Tom, wb6b
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Marcelo Varanda
Bob Benedict, KD8CGH