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RE: DIY ResMed S10 Air Inlet UVC Bug Killing System - Brazen - 10-17-2022
As a nurse, I wish you the very best through surgery and recovery.
With your history of sleep apnea, I suspect many of your nurses will try to keep the head of your bed as high as post-surgery doctor's orders and your comfort allow.
I've witnessed a 15-20° angle be enough to improve apnic breathing.
You will also likely be on continuous o2 monitoring, every hospital I've worked require it post-surgery, some for as long as you're receiving IV opiates.
If your cpap isn't enough, nurses will throw oxygen on you. Many patients choose oxygen over cpap. (for a while we also weren't allowed patient's own cpap and had no other option)
How are covid numbers there?
If you have any conditions that reduce your immune system, you could politely request a negative pressure room. There might not be one available but covid lead many hospitals to fit many more than we had pre-covid so it might be worth asking if they aren't currently overrun with covid hospitalizations.
Negative pressure rooms filter the air at a much higher rate than non-pressurized.
I hope you receive great care. I hope your hospital has enough staff.
Current state in my part of the world is not enough nurses/aids and those still standing are giving their entire being. They are exhausted and truly believe in giving their all, because patients need them. They are all heart.
The PTSD is real.
RE: DIY ResMed S10 Air Inlet UVC Bug Killing System - Nightynite - 10-17-2022
Beers, Your Idea is actually what we have on our new home air conditioner. In the AC industry they call it a “ Air Scrubber “. It a UV light mounted in the duct work next to the filter. When the units running, the UV light comes on and it zaps the viruses and bacteria. So they say. You can even buy them on Amazon.
RE: DIY ResMed S10 Air Inlet UVC Bug Killing System - MoreBeers - 10-18-2022
Hello Brazen!
Many thanks for your comments and for the kind best wishes.
>> With your history of sleep apnea, I suspect many of your nurses will try to keep the head of your bed as high as post-surgery doctor's orders and your comfort allow.
I've witnessed a 15-20° angle be enough to improve apnic breathing. <<
All being well, I should be brought around in Theatre, so should be awake by the time I get to Recovery, and then the Ward (or ICU if the Operation did not go as well as hoped). But I will try and let them know before going under that elevated is the best position to avoid Apnoeas.
Just to very briefly describe myself, I am 62, and physically quite disabled from the waist down, all due to old motorcycle injuries, then HM Forces, then Farming plus a lot of heavy manual work as part of our other businesses. That little lot combined has comprehensively damaged all joints from hips down, compounded by mislignment issues wearing joints out faster than usual.
However, I was very fit, and still have very good upper arm strength. So, I am not in bad shape from the waist up, but from the waist down is just a dumpster fire!
Sadly, lack of mobility has seen my weight creep up (my fine wife now has me on a high protein diet to try and improve that!), but I have recently been able to strap myself into a Static Rowing machine (getting on and off it has been the most painful part, seems I am OK once on it!), and have gradually managed to improve my fitness.
I had to do an NHS Pre-Operative Fitness Test, and stunned the Anaesthetist conducting the test! I hobbled in on crutches, so he was not optimistic that I would score very well at all. But once actually on the special cycle machine, and hooked up to Oxygen/CO2 mask analysis, ECG and Blood Oxygen devices, I happily cycled as the machine increased the load, and to his obvious amazement, all of my scores were very good. Aerobic to Anaerobic conversion point was good, and I was basically right on the numbers all of the way. He was highly amused to show me all of the various graphs afterwards, and pointed out how well I had done. He found it very funny, and had left some amusing comments in my notes, because others reading them also chuckle and comment that I had been a very good boy and done well!
Clever old me! But, the point I am really making is that I seem to be on the right side of the numbers when going into this, which is one good thing at least. Just wish I could walk properly!
The Rowing has really helped there, and I am now trying to do that twice a day right up until the Surgery. I monitor my heart when doing this, and Row to my heart's limits rather than trying to win any prizes. My instinct is to try and beat my last score, but the key has been to stop myself getting carried away, and instead behave like an adult, and stick to my heart rate limits instead.
For the benefit of others in a similar position, Rowing is well worth doing, because it exercises so many muscles, and if you keep a close eye on your heart rate limits, and stick to those like glue, then your fitness should gradually improve and do so very safely. Just start slow, and let things improve.
I am now pulling far more work in terms of distance and calories burnt, but at either the same or a lower heart rate than when I first started, so I think that is a good measure of cardio-vascular fitness.
My Sleep Apnoea is a complex mix of position and pain, the lower joint pain means I wiggle around too much at night seeking relief, so I go in and out of the best positions for Sleep Apnoea, and have little control over that.
I can see that pain is a much bigger factor than I had realised, and many nights my Sleep Apnoea is fully controlled, but my rate of Pulse Changes are high, which I can see is linked to pain and wriggling around, and not remaining in a single position because it's hard to find a good one.
Some nights, the position issue can lead to a dense cluster of Obstructives and Hypopnoeas when on my back, and so nearly always due to position. Once I wriggle into a better position, Apnoeas are again controlled.
Unfortunately, flat on my back with my head flat, is the worst position, so as you say, the key will be to persuade them to elevate the pillow end of the bed. This should be easy, as the beds are now motorised.
One advantage of the pain killers needed for surgery, should be that they should also kill limb joint pain, so I should be quite comfortable, which should hopefully stop me wanting to move position and onto my side. I know I won't be allowed on my side for a couple of weeks, to allow the internal re-plumbing time to fully heal.
I think it's all doable, provided I get to convey these concerns before they put me under!
>>You will also likely be on continuous o2 monitoring, every hospital I've worked require it post-surgery, some for as long as you're receiving IV opiates.
If your cpap isn't enough, nurses will throw oxygen on you. Many patients choose oxygen over cpap. (for a while we also weren't allowed patient's own cpap and had no other option)<<
Yes, I agree. The in-line Filter I have bought for my CPAP does have an Oxygen Tap provision, so they could do both if they wish, just by connecting Oxygen to that.
But provided the pillow end of the bed is raised, then I may be OK on just Oxygen. I will chat about that with the Anaesthetist again. He seemed keen last time to make sure I was on CPAP by Recovery and/or Ward, but I will chat about the position issue, and he may opt for just Oxygen.
>>How are covid numbers there?<<
Hard to say, I don't trust the tests, too much political and financial meddling going on, so it's hard to split arguably manipulated Case numbers from actual infections. Last that I checked, it seemed actual/genuine infections were going down.
>> If you have any conditions that reduce your immune system, you could politely request a negative pressure room. There might not be one available but covid lead many hospitals to fit many more than we had pre-covid so it might be worth asking if they aren't currently overrun with covid hospitalizations.
Negative pressure rooms filter the air at a much higher rate than non-pressurized. <<
Thankfully I do not have any other issues, and my immune system has always seemed to be robust. I keep myself as fit as possible from a cardio-vascular perspective, and fuel my system with sensible things like Vitamin C, D3, K2, B12, Zinc and Magnesium. My blood tests are all OK, and after a spell of Atrial Fibrillation caused by my CPAP Strap constricting the Vagus Nerves in my neck, my heart was checked out fully and is functionally normal.
I have a Thread that covers that but, long story short, I worked out what was causing the Atrial Fibrillation, and made up a foam rear and side pad for my ResMed F20 Mask, and the Atrial Fibrillation stopped that same night, after 3.5 Months of it! It has not come back.
I mentioned that during the NHS Fitness Test, and the Doctor said my heart did not miss a beat, even when under load. So I am 99.9% sure it was a Strap issue that caused the earlier Atrial Fibrillation (see my other Thread for more details).
>> I hope you receive great care. I hope your hospital has enough staff. <<
Thanks, I think they are reasonably well staffed, and the Colorectal Unit seem well switched on and capable.
MoreBeers
RE: DIY ResMed S10 Air Inlet UVC Bug Killing System - MoreBeers - 10-18-2022
Hello Nightynite!
>> Beers, Your Idea is actually what we have on our new home air conditioner. In the AC industry they call it a “ Air Scrubber “. It a UV light mounted in the duct work next to the filter. When the units running, the UV light comes on and it zaps the viruses and bacteria. So they say. You can even buy them on Amazon. <<
Yes, that is indeed what I have in mind.
The key is to make sure the UVC LEDs do actually produce UVC and at the 260 nm wavelength so as to both work, and not produce Ozone.
As I understand it, it is only UVC below 200 nm that generates Ozone, but I am no expert, that is just what I have gleaned so far.
The main issue seems to be to make sure the volume of the UVC box is sufficiently large to ensure the air flowing through it is slow moving, so that the UVC has time to zap any bugs as they slowly pass through.
I am hoping that will not need a huge void, I mean relative to the size of the ResMed S10's inlet aperture and Filter. That is only around 30mm x 50mm, the size of the Filter, so the key is to funnel all air towards that from a relatively larger void, not necessarily a large void in the real sense.
It may only need to be about the same size as the whole side of the S10, and maybe 100mm in width or less.
I will make it as small as possible so that it can be neatly bolted to the side of the S10.
I may also add an On/Off Switch, so it can be disabled in the event of any issues affecting the operation of the CPAP.
I want it tamper-proof and robust, to cope with mishandling, and so as not to expose anyone to any UVC "light", which is invisible. I may add purple LEDs as well, just to indicate where the UVC is.
The UVC LEDs may include a purple warning LED component, as many do just to flag when they are on.
In theory, this could work, and as I say, I only need this for maybe 5-10 days at most, so provided the UVC won't cause any plastic reactions in that time, then it'll do.
I will try to keep this Thread posted on my progress.
Budget is tight this Month, so I may not start getting the components until early next Month. In the interim, I will just research the components, and try to calculate an optimum target size. I also need to look at how to power it, and if I can take a spur off the ResMed's wiring without affecting the operation of the CPAP.
MoreBeers
RE: DIY ResMed S10 Air Inlet UVC Bug Killing System - Crimson Nape - 10-18-2022
MoreBeers - You got me thinking about the size of your light chamber that might work. Using the weighted average value of the OSCAR Tidal Volume value (ml/min) and multiplying by the Respiration Rate's 95%-tile value, and dividing by 1000 to obtain the liters per minute of breath. Now, add in 2x (for a safety margin) the leak rate, (24 l/min), yields a padded average displacement for 1 minute. Since 1 liter = 1000 cubic centimeters of space, you will need the enclosure to have a minimum area of this value. To calculate the enclosure size in a cube, use the Excel formula, "=Value ^ (1/3)" to obtain the size per side in centimeters.
Example:
Values:
Tidal Volume Avg: 500 ml/min per breath
95%-tile Respiration rate: 20
2x Resmed leak rate (24/l min x 2) = 48 liters (rounded to 50 liters for ease)
Calculation:
RR (20) x TV (500) = 10000 ml/min (10000 ml /1000 = 10 liters)
Breath (10 L) + Leak (50 L) = 60 liters = 600003 centimeters
Result:
Using Excel's cube root calculation: "60000 ^ (1/3)" = 39.15 centimeters per side for a cubic enclosure. (Imperial: 39.15 cm = 15.4 inches)
A cylinder close to the same size (607143 cm), would have a diameter of 30.5 centimeters by 83.1 centimeters in height. (Imperial: 12 in x 32-3/4 in) Note: Since a cube design will have dead airspace in its corners, a cylinder would be the preferred shape.
Disclaimer:
Of course, the port placements and the air intake port location relative to the room space will be a major determining factor as to its efficiency. The closer you get to the floor, there is almost a logarithmic increase in particulate matter per cubic meter.
Please check my math. It will give you something to do.
Please post your results.
- Red
RE: DIY ResMed S10 Air Inlet UVC Bug Killing System - Gideon - 10-18-2022
You mentioned a link between being on your back and clusters of obstructive events, you seem to have a handle on that but you implied being restricted to back sleeping for a week or two and thus possibly being unable to manage that. Consider a soft cervical collar for those weeks post surgery, just the recovery period for now. We have found the collar to be very effective at managing clustered positional events, typically from chin tucking. Ask them for a collar to assist with your sleep and your positions being limited.
RE: DIY ResMed S10 Air Inlet UVC Bug Killing System - MoreBeers - 10-18-2022
Hello Red!
Many thanks, I will look at the figures ASAP, but first glance I can see what you are seeking to achieve.
The other factor that needs to be addressed, is the time a particle needs to be under UVC of a given intensity to kill it.
A container, either box or cylinder of the size that your calculations suggest, may need a huge number of UVC LEDs, or more powerful ones, to ensure the whole air mass is exposed to sufficient UVC.
If the required UVC exposure time is not too long, then a far smaller area may work, depending on the air flow rate needed to feed the ResMed S10 at the same rate that its inlet is fed via a normal room.
So there is a flow rate issue v UVC exposure time.
Basically, the volume your calculations suggest, will need a certain flow rate for that volume to pass into the S10 over a given time, depending upon the size of the restriction that any proposed UVC device imposes. Ideally, a large air mass gets zapped, but that may not be necessary, or may be unworkable without something the size of a laser printer!
For example, we know the approximate size of the S10's inlet and, without measuring that, it's about 30mm x 50mm roughly, so all of the air needed passes through that anyway.
I can't say that I have heard my S10 sucking like a vacuum cleaner, so it may be possible, for example, to simply extend that shape by, say, 100mm, using a box section tube or circular tube that is say, 60mm x 80mm if square section.
That is then where the UVC LEDs act, and it can be made reflective with mirror plastic, and have UVC LEDs added along the length, in all four planes.
Then all of the air has to pass along that, and it will be a case of working out the air flow, and then working out the time duration that a particle will spend entering one end, and departing the other.
Will that be sufficient time to damage the particle's DNA?
That I do not know, but if that cannot do it, it may suggest that many of the devices sold that claim to sterilise air over much shorter distances, won't work either.
I just do not yet know if it is even possible.
Many thanks, this is useful data.
MoreBeers
RE: DIY ResMed S10 Air Inlet UVC Bug Killing System - MoreBeers - 10-18-2022
Hello Gideon!
>> You mentioned a link between being on your back and clusters of obstructive events, you seem to have a handle on that but you implied being restricted to back sleeping for a week or two and thus possibly being unable to manage that. Consider a soft cervical collar for those weeks post surgery, just the recovery period for now. We have found the collar to be very effective at managing clustered positional events, typically from chin tucking. Ask them for a collar to assist with your sleep and your positions being limited. <<
Many thanks for this.
Indeed, I had already been using a collar, a few different ones in fact, and had to stop using them when I was having the issue of Atrial Fibrillation that I am certain was caused by the ResMed F20 Mask Strap constricting the Vagus Nerves in my neck.
One of my other Threads covers that issue, and how I fixed it with a Foam Pad across the back and sides. The Atrial Fibrillation stopped that same night, and has never come back.
But, at that time, it took a while for related knock-on ectopic beats to fade away, and I noted when I wore the collar, they were worse, and when I removed the collar they became less frequent, so I dumped the collar just to make sure nothing was impacting my Vagus Nerves whilst they healed.
I don't think I have noted any major changes with, or without the collar, so have not gone back to wearing one.
I may revisit that but, at the moment, I cannot risk the Vagal Atrial Fibrillation coming back, because it can take a few weeks to make all of the knock-on effects go away again if it does.
My Operation is now within 4 weeks now, so I just do not have the time to risk introducing the Atrial Fibrillation back into the mix.
But, well said. When I am past the Surgery, I can try the collars again. The rear Foam Pad now protects my Vagus Nerves, so the collar should not, in theory, cause any such issues. Time is just against me to experiment with anything that might re-trigger an irregular heart rate.
The Surgery is said to take the same out of you as running a Marathon, which may be a bit of an overstatement, but my body is certainly going to be put under a huge strain, so I just need my ticker beating normally before I go in to that!
Appreciate the advice nevertheless.
MoreBeers
RE: DIY ResMed S10 Air Inlet UVC Bug Killing System - Crimson Nape - 10-18-2022
I looked for some standard that may address a time/volume measurement per power unit. I found this paper, https://www.ashrae.org/file%20library/technical%20resources/covid-19/si_s16_ch17.pdf that has the following reference:
Also, I found this reference to calculate duct size / exposure time:
https://www.amca.org/educate/articles-and-technical-papers/amca-inmotion-articles/uv-c-for-hvac-air-and-surface-disinfection-2.html
I hope they may help.
- Red
RE: DIY ResMed S10 Air Inlet UVC Bug Killing System - MoreBeers - 10-18-2022
Hello Red!
Great stuff, that is very useful indeed.
I will ponder that tomorrow, to see what I can make of it.
If nothing else, this project may show it's pointless over short distances if the air flow is too rapid, or it may show some benefit.
If there is any benefit, and it is not de minimis, then it's worth a shot, because it might just zap the critter that has my name on it!
MoreBeers