Mini sleep lab

Its almost possible to create a mini at home sleep lab these days. You can outfit yourself with the following:

1. Data Capable APAP for monitoring breathing events (Recommend: PR System One)
2. CPAP data software such as Encore Pro/Viewer. (Maybe EPA for trends)
3. Recording Oximeter for monitoring SpO2 (SPO-7500 is popular, I use a Nonin WristOx)
4. Zeo for sleep stage monitoring.

Any other tools that are indispensable?

we are probably getting close to a CPAP with oxygen level reader that can diagnose sleep apnea and automatically adjust the pressure and so put all the sleep labs and sleep docs out of business

2 surveys showed that apnea sufferers, given a pressure adjustable CPAP were able to get near enough to their needed pressures

harry33 wrote:we are probably getting close to a CPAP with oxygen level reader that can diagnose sleep apnea and automatically adjust the pressure and so put all the sleep labs and sleep docs out of business

2 surveys showed that apnea sufferers, given a pressure adjustable CPAP were able to get near enough to their needed pressures

I think that if we could include a CO2 measuring device that can do both Oxygen sat & CO2 sat we would be getting close

There are units on the market that do both but they are still far too expensive. Beyond that the one really helpful measurement is
breathing effort. That is the one measurement that can make the difference between best guess vs observable facts.

This tech is though, moving ahead at a slick pace.

DSM

http://www.sleep-breathing.bc.ca/sleep.htm
#2 This website here describes the challenges of home sleep study & how it can be done today. Note the 'effort' data

EXTRACT ...

Home sleep monitoring can vary in complexity from oximetry alone to the recording of 6 or more parameters, including EEG, and EOG. Most systems do not include the EEG or EOG since sleep staging is not that important in diagnosing the typical patient with OSA. Treatment is based on clinical findings and the severity of the OSA as reflected by the AHI (Apnea/Hypopnea Index - see below). These patients have no difficulty falling asleep and fall back to sleep quite quickly even when waking up several times at night. Therefore, one can make the assumption that time in bed is nearly equal to time asleep when calculating the severity indices. Differentiation of REM from Non-REM sleep is important for the small number of patients who have so-called REM-Specific OSA. Some insurers will pay for home sleep monitoring, many do not. However, this situation will change dramatically in the near future with managed care. A large HMO in Puget Sound, Washington is already using home sleep monitoring as the principal method for diagnosing OSA.

At the Vancouver Sleep & Breathing Centre, we record the following parameters during home sleep monitoring (Channels are as shown in the sample recording above):

* Oxygen saturation (Channel 8 ),
* Heart rate (Channel 7 ),
* Snoring (Channel 3),
* Body position (Channel 2 ),
* Airflow from the nose and mouth (Channel 4 ),
* Chest/Abdomen movement (Channel 5 ),
* Single leg activity (Channel 1 ).

This allows us to confirm the diagnosis of OSA and grade the severity in terms of the Apnea/Hypopnea Index (AHI). The AHI is calculated by counting up the number of apneas and hypopneas that occur during the night and dividing by the time in bed. We make the assumption that time in bed is a good estimate of time asleep. This is a good assumption in patients with OSA who have no difficulty falling back to sleep even if they wake up several times during the night.

When the AHI is greater than 15, the patient is likely to complain of excessive daytime sleepiness.

When the AHI is greater than 30, the patient is at increased risk for cardiovascular complications. These patients are also likely to show rapid progression of their disease if left untreated.

The AHI must also be interpreted in the context of the individual patient. For example, a patient with heart disease who has an AHI of 20 needs closer follow-up than one who has no heart disease.

Sudden limb activity, oxygen desaturations, and sudden changes in heart rate when closely associated with apnea or hypopnea can provide useful measures for determining whether the patient is responding to treatment. The doctor can elect to monitor only the relevant parameters in the follow-up study.

Oximetry alone is often touted as a good way of screening patients for OSA. However, oximetry has the following limitations:

* it can fail to diagnose patients who have few apneas but who are very symptomatic,
* it can fail to diagnose patients who have apneas lasting only 10 -15 seconds,
* it will fail to diagnose patients who have frequent hypopneas which are not associated with oxygen desaturation,
* it does not indicate whether the drop in oxygen is due to a central or obstructive apnea,
* it does not provide other useful information such as body position and limb activity.

Not all oximeters are created equal. The oximeters which are commonly in use for screening for OSA use sampling intervals of 10 - 15 seconds. However, these long sampling intervals make the devices insensitive for the detection of brief apneas. The minimum acceptable sampling interval for oximeters used for this purpose should be 5 - 6 seconds. Most multiparameter home monitoring devices use oximeters with sampling intervals of 2 - 3 seconds.

It may be more difficult to determine whether changes in oxygen saturation are real or due to artifact when you are recording only the oxygen signal. Trying to make oximetry more sensitive by using a drop in oxygen saturation of 2 % as the criteria for detecting an abnormal event increases the chance of interference from movement artifacts.

At the Vancouver Sleep & Breathing Centre, we use oximetry to:

1. determine if treatment is effective in patients who showed significant desaturations on their home sleep study,
2. screen snorers:
* who do not have any symptoms of OSA,
* who have a normal Epworth Sleepiness Scale Score,
* who have a low pre-test probability of having OSA,
* who have none of the upper airway characteristics which predispose an individual to having apnea.

The last step is taken as an extra measure of safety for the patient who only snores. This is because no one can predict with absolute certainty who will have OSA. Those who show significant desaturations are recommended to have a more detailed sleep study.