Sleep Monitor is an app for iPhone or iPod Touch. It was originally designed for use in clinical settings, to gather positional data from clinical study patients who wear the device (suitably affixed on their torso) while sleeping. After months of clinical use, the app was released on the AppStore for more general use in Sleep Medicine studies or by individuals wishing to gather more information about their own sleep patterns. UCSD staff presented some clinical test results at the AVRO 2013 conference in Seattle, WA on May 5, 2013 - slides from the presentation are available here.
The design philosophy underlying Sleep Monitor stresses simplified operational use. Since the app must be operated by each individual, ease of use is essential in obtaining reliable data from a wide variety of participants, including those who may be physically disabled and/or inexperienced with use of mobile devices.
In operation, Sleep Monitor is first started at bed time, and the device is placed into an appropriate pouch/container so that it faces out, away from the torso, and fastened around the waist (ace bandages work well for this) while sleeping. On waking, the monitor is stopped by pressing the device's Home button. Then, when the app is restarted, the data is graphically displayed and transmitted to a (configurable) email address. For multiple night sampling, simply repeat the start-sleep-stop-send process.
iPhone/iPod touch preparation
Prior to first use, Sleep Monitor specific Settings should be setup on the device to support identification of the data source, and email destination addresses to direct data reporting to the monitoring staff (individuals would simply email to themselves).
Settings are accessed via the device's Settings app, which displays a scrollable list of app-specific selections. To access the Sleep Monitor specific Settings, select its element from the list.
The detailed settings information includes Identification, Email Addressing, and Data Attributes elements. The Data Identifier field is used by the app when composing email; whatever is specified in this setting is replicated within the data-reporting email as the device's ID.
The Email To: field is used to provide the email address of the primary data recipient. An additional recipient may be specified in the Email cc: field.
The Data Reduction switch is used to confine data reporting to two attachments: one RFC-4180 compliant (spreadsheet compatible) attachment, and one .pdf file containing the graphical data representation. When the switch is ON, the email body will contain only a brief summary including data start and end times, and number of samples. With the switch OFF, the email body will contain the summary, as well as additional lines for each data sample made during the sleep period. In either case (ON or OFF) all sample data will be included in the 2 attachments.
The Data Summary switch is used to specify if a graphical Data Summary screen (see below) is to be displayed prior to generating the email. A switch setting of ON means that the Data Summary will be shown. If set to OFF, Data Summary display will be bypassed. Clinical users may wish to keep this OFF to simplify operation by participants.
The Demo Mode switch should be set to OFF for normal operation. Its intended use is for quick familiarization with the app and device operation. When set to ON, Sleep Monitor will sample device position at 1-second (rather than the normal 1-minute) intervals. With this faster sampling rate, it is easier to observe the device in operation throughout a range of positions, and quickly gather data to display. Prior to an actual sleep monitoring run, be sure to set this switch to OFF. (If left ON, the monitoring run will self-terminate after about 39 minutes).
Operation of the Sleep Monitor app
When started, Sleep Monitor displays a monitoring screen showing the start time, begins sampling positional data, and logs each sample to the screen. Data collection includes each sample time, the "roll" position about a vertical axis (indicating whether the subject is laying flat on back or stomach, or is on left or right side), and the "pitch" position about a horizontal axis (indicating if body position is inclining or declining). All position samples are reported in degrees, from 0 thru +/- 179. With the device aligned to the subject's abdomen and facing outward, 0 degrees of "roll" describes laying flat, with positive angles indicating orientation on left side, and negative angles on the right. Similarly, 0 degrees of "pitch" indicates lying flat, with positive angles indicating head up orientation, and negative angles measuring a head-down/feet-up angularity.
A simple "How To Use" guide is supplied for the patient's review, accessible via the "info" button on the monitoring (above) screen.
After the sampling run has performed, and the app has been restarted (the beginning of STEP 3 in "How To"), Sleep Monitor will begin preparing data for viewing and emailing. If the Data Summary switch is set to ON, this screen will be displayed, otherwise it will be bypassed, and the emailing dialog screen (next, below) will be shown.
This Data Summary screen plots each positional data sample as a single colored line, with earliest samples appearing to the rear, and newer samples frontmost. The angularity of each colored line matches the angularity of the device at the time of sampling. If laying flat on back, the representational line will be horizontal (and light blue in color). Rolling onto the right side from flat is a counter-clockwise motion in this graphic (assuming head to back of screen, and feet to front). When the angularity has reached 22.5 degrees of roll, the line color is changed to green (on right side) or red (on left side). A key to the angular limits and colors used for back, left, right, and belly along with the percentage of time spent in each position is shown on the screen. Note that in this Data Summary depiction, there is only room for about 5 hours of sampling. The complete data set (up to 11 hours) is provided in the .pdf attachment file.
When finished viewing this screen, tapping the Done button will cause the emailing dialog screen to be shown.
Following the Data Summary presentation, this emailing dialog screen is presented. It is possible for the user to edit email addresses if necessary, though it shouldn't be necessary if Settings Email To: has been setup. When ready, tapping the Send button will initiate sending of the email and attachments. Should the device be in "Airplane Mode" when the send attempt is made, the email will be saved into an outbox for later transmission when cell or wifi network is available.
After the email dialog has been completed, the monitoring screen will be presented with instructions to exit Sleep Monitor by pressing the device's Home button.
The "dataBlimp" and "graphicsBlimp" screenshots below do not appear within the Sleep Monitor app. They are included here to show sample contents of the 2 email attachments. When saved after receiving the email, each file is available for viewing by specialized applications; dataBlimp.csv by spreadsheets such as Numbers or Excel, and graphicsBlimp.pdf by pdf viewers such as Preview or Acrobat.