Garmin G1000 MFD

[jph]

Hi Keith, - Just a note,
if the text on your display is correct - do you mean CO as opposed to CO2 - Carbon monoxide (CO) as opposed to carbon dioxide (CO2)
If it is CO, which I actually thought may be more appropriate than CO2, then the use of the MG811 sensor is a bit confusing as this is more targeted to CO2.

There is a known issue with pulse oximetry with higher levels of carbon monoxide (CO) as it can mask the actual Sp02 levels.
It can saturate Haemoglobin cells and still keep them 'pink' .. leading to false readings.
it is one of the effects of the guy with the hosepipe in the car window from the exhaust being a nice healthy colour when pushing up daisies. as opposed to severe cyanosis . - hence a separate dedicated CO detector would be excellent.

If the display text you are using is correct, then they may be using the MG811 as a CO detector. It is certainly possible .. but ?
Where are you getting the page display details from Keith ? - I did a search on the G1000 and SpO2 etc / hypoxia and could find nothing.
Damn clever piece of kit though. !

[Keith Baxter]

Joe,

It is CO,

But here are some links.
https://www8.garmin.com/manuals/webhelp ... 7AD51.html

https://centuryavionics.co.za/shop/garm ... -delta-px/

Whilst this one is not Garmin it is compatible with most of the Garmin range.

https://www.guardianavionics.com/aero-4 ... d-aircraft


Keith

[Sling]

I think there is a little confusion here. Perhaps to do with where this conversation started and with the information presented here. To display CO you need a CO detector. CO is usually measured in ppm by a detector. They are fitted to protect against the hidden dangers associated with faulty or leaking exhaust systems. The Garmin units interface with the Guardian Avionics range of products. I've used these units before and will do so again. They started out just selling CO products but they now also do other stuff including a pulse oximeter which is something completely different to CO. As already mentioned this is to aid in the detection of hypoxia.

Some words from the net on pulse oximeters.
Pulse oximeters work by shining a light through a relatively transparent area of the skin. The light shines through to a detector positioned on the other side of the skin.
For example, when a pulse oximeter is clipped onto a finger, one side of the clip shines the light, and the other detects it.
The amount of light absorbed by the blood indicates the oxygen saturation. A pulse oximeter does not directly measure oxygen saturation but instead uses a complex equation and other data to estimate the exact level.

That box has different systems combined in a graphic wrapped into a systems category but in fact the information is coming from different types of sensors. You'll also notice an instrument vacuum reading there also.

Tony

[Keith Baxter]

Tony,

100% Correct. I want to build one of those boxes so that it can talk to the G1000 via Arduino and give readings.

Keith

[jph]

That's no problem Keith, and also thanks for the input Tony.
The MAX30100 / 30102 info I supplied is correct. The info Tony gives is also correct apart from a slight clarification with the position of the reflector. It used to be this way (ie - on opposite sides of the - for example - earlobe or finger) but now with the newer sensors the tx and rx are on the same chip on a single side as can be seen by looking at a MAX30100 / 30102 unit or datasheet I linked to. This means that the unit 'could' be placed directly onto an area with appropriately located high density supply of arterial and venous blood vessels in very close proximity to the surface and in high concentration. However, due to false readings from ambient light and scatter, and of course, practicality A 'clip on housing is used that blocks most ambient light. A pulse oximeter is NEVER used to detect C0 !. CO detection is always a separate sensor. Even CO2 levels are not directly measured with pulse oximetry, they can only be inferred but are of no real interest anyway. For a patient on O2 for Covid, or for a pilot in a non pressurised aircraft using O2, then one of the main uses for the device is to allow the pilot to adjust the flow rate of O2 to maintain a suitable saturation level and can be varied to suit the individual.
Ro SpO2, The sensor board containing the optical transmitter / detector, which is the module that attaches to a highly vascular skin area, sends its data on reflectivity to the arduini, the library I listed does does all the math for the conversion (that Tony mentions). to SpO2 / Pulse rate / regularity. In the second library, the output is a simple, easy to read value of Sp02 and also pulse. Pulse is determined by the regular rapid change in signal levels between heart beats from the optical sensors. The library does it all for you. It is actually accurate to say that a 'pulse oximeter' DOES measure SpO2 as the term 'pulse Oximeter' is generally used to refer to the whole unit with readout, whereas a 'sensor designed for use with pulse oximetry does not as it relies on the appropriate math to convert the optical readings.

As for C0, (as opposed to Co2) then use a different sensor, not the MG811
The MQ-7 is fine -
https://www.aliexpress.com/item/3257392 ... hweb201603_

this is a suitable library for the MQ-7
https://github.com/swatish17/MQ7-Library

To make that with an arduino and the two sensors / libraries I linked to would be no worries.

For carbon monoxide in the aircraft - I used to use the simple carboard 'dot' sensors lol - if they changed colour, then the CO was too high

Joe

[jph]

Also guys - where you mentioned 'confusion' Tony -
if you are possibly referring to -

"There is a known issue with pulse oximetry with higher levels of carbon monoxide (CO) as it can mask the actual Sp02 levels.
It can saturate Haemoglobin cells and still keep them 'pink' .. leading to false readings.
it is one of the effects of the guy with the hosepipe in the car window from the exhaust being a nice healthy colour when pushing up daisies. as opposed to severe cyanosis . - hence a separate dedicated CO detector would be excellent.

This is accurate. Haemoglobin and O2 levels (oxyhaemoglobin) reflect the optical reading of oximetry to calculate SpO2,

CO (carbon Monoxide), if present can give totally false readings as CO has a VERY high affinity for binding with haemoglobin to produce Carboxyhaemoglobin. This offers a VERY similar 'colour' of the reflected signal from oximetry - while at the same time the body is getting increasingly reduced levels of oxygen to the cells.

As I mentioned before, this is why a person suffering from high levels of carbon monoxide poisoning will still appear 'pink' and ' seemingly healthy' as far as skin tone etc, as opposed to low SpO2 caused by inadequate O2 levels or a problem with the functioning of the body's transfer system of O2 / CO2.

IN this respect, high levels of CO (Carbon MONOxide) can severely trick the oximeter and bugger up the readings. - hence that is why a separate Carbon MONOxide sensor is used - but only in situations where CO may well be an issue - such as a closed loop monitoring in an area with potential for high CO - AND- simultaneous SpO2 level readings - as in an aircraft cabin. It is not a fault of the oximeter - is is at a celular level. - again, why a separate sensor is used for CO.

In a person with LOW SpO2, then they will be evidence of skin colour change and cyanosis (blue tinges to highly vascular areas - lips etc) as well as the mental impairment which varies from individual. The 'colour' of the vascular areas will change to a more 'bluish' hue with increasing CO2 Carbon dioxide levels.

There is a huge difference.
I doubt many here have seen people who have suffered from Carbon MONOXIDE poisoning, but I assure you, they can be VERY dead and have the skin tone and colour of an otherwise healthy person - and this is purely due to the affinity for CO to bond with Haemoglobin as opposed to CO2 which does not. And, I have seen more than I would care to remember.
The Affinity of CO to bond to Haemoglobin is so high that one of the treatments in severe cases is to use a hyperbaric chamber as the only method to overcome that affinity.

[end of medical notes/] lol

[Keith Baxter]

Hi,


Traffic Page taking shape.



Keith

[Keith Baxter]

Hi,

OK so i started this Discord to discuss this instrument. The tipping point was the lack of data available to do a complete generic instrument. No fault of AM .

Air Manager is a superb product and will always remain the main focus of this Discord.

For now it will remain as a separate communication channel.

All the G1000 build notes and development will become OPEN SOURCE including how to create your own vector map and where to source that data. Air Manager is a power house and the possibility for real instrument creation is not impossible.

I invite all interested in contributing and sharing to join. Lets grow the knowledge base and pass on info to your copilots.

Say Hi to us here

https://discord.gg/GunAFpc5vv


Keith

[cyberguerro]

@Keith Baxter , have you got any estimated date for pushing into the store?
I hope to use it on my Android tablet with X-Plane's Cessna 172 SP asap.

[jph]

Hi,

OK so i started this Discord to discuss this instrument. The tipping point was the lack of data available to do a complete generic instrument. No fault of AM .

Air Manager is a superb product and will always remain the main focus of this Discord.

For now it will remain as a separate communication channel.

All the G1000 build notes and development will become OPEN SOURCE including how to create your own vector map and where to source that data. Air Manager is a power house and the possibility for real instrument creation is not impossible.

I invite all interested in contributing and sharing to join. Lets grow the knowledge base and pass on info to your copilots.

Say Hi to us here

https://discord.gg/GunAFpc5vv


Keith

Excellent stuff Keith. Nice work,
Joe