MEASURINGsleep What choices are available for sleep testing?
HST devices fall into two basic categories: Screeners and Home Sleep Diagnostic devices. A screener (type IV: 1 or 2 channels usually using oximetry as 1 of the parameters) is designed to provide enough information to identify that the patient has sleep disordered breathing but without enough information to establish a treatment pathway. Data driven discussions of sleep quality initiated by patients using portable and wearable sleep tracking devices is a very new trend in patient education. It goes without saying that the 1994 guidelines couldn’t predict this recent trend. The wearable sleep tracker device revolution has really started to get into the Type IV sleep screener arena with products that are steadily improving in accuracy and usability. The Apple Watch, for example, has a sophisticated heart rate monitor that is capable of acting as a pulse oximeter. This feature is turned off in the device so it is a product for the future. It remains to be seen if the Apple Watch will qualify as a level IV device. Based on the current guidelines and the computing power of the Apple Watch, the product may eventually have the feature set to reach Level III Home Sleep Diagnostic Device capability. Mattress manufacturers have started pursuing sleep quality data as a way of encouraging mattress choices based on style data. The Beddit 3 Sleep Tracker for example is a thin flexible sensor that lies across the mattress reading heart rate, breathing, temperature, humidity and even snoring. The folks at Sleep Number have released a product, Sleep IQ, that tracks sleep quality and connects to your favorite health and wellness apps. Is it possible that diagnostic mattresses will test the line between screener and diagnostic device? Today wearable devices like Jawbone, Fitbit or bedside monitors like the S+ from ResMed are designed to provide data about sleep efficiency and sleep quality. In general, these devices provide excellent sleep quality data. They cannot provide data that can be used to determine appropriate treatment pathways, and reliability and accuracy have been concerns. Wearable trackers may record the subject to be asleep when they are
simply sitting and watching TV. Clearly, there is still some work to do in this area. The big question when working with patients who use fitness trackers is how to use the reams of information that the patient presents with. To date there are no standards in the “wellness” field, which is where the trackers are rated by the FDA. Many patients realize that the sleep tracker is not a medical grade device however when compared to the fee for a sleep study some patients are willing to compromise on accuracy in favor of low cost. The clinician, however, cannot work with the data regardless of the amount of detail in the Excel spreadsheet. There just isn’t a lot of medical information to be gleaned from number of steps in a day or how restless the patient was over the last week. This presents a relationship dilemma requiring more skills and often more clinic time to merge the patient’s expectations with clinical reality. The key to success with level IV devices rests with moving the patient into a home sleep diagnostic device so that a therapy can be prescribed and delivered in a way that can be objectively monitored, titrated and managed. The Home Sleep Diagnostic Devices category (Type III limited channel devices 4-7 channels) is much more crowded and the decisions are complicated by insurance reimbursement and other factors. The guidelines used today were established by a task force in 2007 by the American Academy of Sleep Medicine (AASM). The guidelines for portable monitoring state that at minimum a device must record airflow, effort and oximetry, biosensors conventionally used for in lab PSG. This leaves a tremendous range of equipment capability, from units with few measured parameters like the ARES from SleepMed or the WatchPat from Itamar, to devices with 18 channels or more like the
Type III home sleep diagnostic device
Randy Clare is a sales and business development manager for Carefusion, and is based in Yorba Linda, California. He has been involved with the development and distribution of sleep therapy products including CPAP supplies, oral appliances and sleep diagnostic devices for over 20 years. He can be reached at email@example.com. For more information, follow thesleepandrespiratoryscholar.com.