From teenage i suffered a strange problem my first part of my whole sleep used to be nightmarish, or less relaxing. If i slept 6 hrs starting 1-2 hrs are mostly bad.
After many years of suffering one reason i found time gap between dinner and sleep. If gap is very high i.e. 6+ hours then sleep was much better. Every person has different body and has different weak and strong parts in body. From teenage my gut was not great and from that time this problem started. I ate lots of sugar in childhood, i abused meal timing very much, not eating for long and this type of behavior led to poor digestive health. But later i tried to fix almost every bad routine like sleeping late night to eating on time.
Today (2023) we have powerful technology at hand at low cost. Using which we can monitor some factors effecting sleep. I read about sleep apnea and thought i could be suffering this problem at some level for some reason. So i decided to test my sleep.
I tried smart watches to monitor sleep but they are definitely not good for serious sleep monitoring. The reasons are inaccurate sensors, high polling time of sensor data etc. Smart watches poll sensor data at high time gap. For example pulse is checked every 1-5 minutes and spo2 is checked every 10-30 minutes. What if spo2 was low during 2 consecutive polls? For this reason i shifted to oximeter.
I found many oximeters which could monitor the pulse and oxygen every second. This is far far ahead of smart watches. Some oximeters are Beurer PO 80, Miditive MPO-04. Many oximeters have Bluetooth which can log sensor data to phone.
Software for Bluetooth based oximeter have very bad rating on stores due to various issues like Bluetooth disconnected, data not logged after some time etc. Beurer oximeter has complaints of outdated pc software and data loss after saving sleep data to pc. Means the data was erased after download into pc. The cost of this oximeter is high and considering the limitations and lack of software support this oximeter doesn't fit for cost and features.
Then a very low budget solution was available to me which is M-170 oximeter. This is mass produced in China and rebranded by many companies. I got it at Rs900 i.e. ~USD11. In bulk it can even cost $2.
Here are some links for this oximeter -
This oximeter is just rebranded and has unique feature of maximum 8 hours of recording. The recording is split into 15 minutes parts. 4 hours of sleep is split into 16 pages. It can be used to monitor 15 minutes or even lesser data but should be for non sleep tests only. I will recommend to buy any cheaper oximeter from any brand because all are same. The model must be M-170 with 8 hours recording. There are some models which look same but don't offer recording. Old models had RR (respiratory rate) feature. Updated models have ODI (oxygen desaturation index).
Below are images of oximeter i took after my 4 hours sleep recording. I slept more but removed the oximeter.
My spo2 went down to 93 but that time i was awake after a sleep of 1.5hrs. The oximeter was loose and my left hand was pressed and blood flow went down. I learned many critical things by using it. Many false readings can happen due to many reasons. Like oximeter is loose, blood flow reduced to the hand, battery is not full, fingers are not clean and clear, fingers are rough, skin is very hard, very dark pigments etc. Its important to ensure these kind of things are not causing bad values in oximeter.
The graph is generated between minimum and maximum values read by oximeter. If minimum is 90 and max is 99 then the graph shows how values have chaned between these two. This makes it easier to analyze values despite low resolution screen of device and almost less visible data.
Page 1/16 means the first 15 minutes of sleep. Each page is 15 minutes of sleep. Total 16 pages means 4hrs of sleep data. Maths 15 minute page X 16 pages = 240 minutes of data. Even if total pages are different and don't match with 15min/page then it can be calculated using same maths. The low spo2 was caused by myself which i fixed and slept again. I will record more and then make any conclusion. It will help me monitor my sleep after different routine of day. What i ate, when i slept etc to remove activities that harm my sleep.
This monitor can also be used to check spo2 and pulse during physical activities e.g. 30 minute walk. But oximeter must not be loose and sweat etc things can also affect the reading. ODI value must be counted for sleep tests only. And sleep must be standard not a little nap.
Special note: Last recording of this oximeter doesn't erase even after removing batteries.
I hope this will help into your sleep monitoring.
