3 3
New OSA Patient Simulator for Testing PAP Devices
Fig 2. Pressure trends for three different APAP devices tested during the initial 45-minute simulated wake period. Device A (black line) showed a mild pressure increase ( < 2 cmH 2 O), device I (dark grey line) showed a moderate pressure increase (2.5 – 3 cmH 2 O), while device D (light grey line) showed a high pressure increase ( > 7 cmH 2 O) in response to the breathing pattern simulating 45 minutes of wake period (blue line). E: erratic breathing; S: swallowing. doi:10.1371/journal.pone.0151530.g002
additional analysis (Table 4), the responses of the tested devices were relatively similar to the ones in the previous tests that included the 45-minute sleep onset phase. The largest change was seen in device D, where the residual AHI increased from 0.6 to 6 events per hour.
Discussion We successfully developed and carried out a proof-of-concept test of a novel optimized bench model easily adaptable to simulate different SDB patterns found in OSA, including periods of wake, periods representing different sleep stages and phases of more or less severe SDB events. This tool can be useful to objectively evaluate bench test performance of different APAP devices with realistic breathing patterns covering a wide range of patient phenotypes. In its “ Steady mode ” , the simulator could also assess the capacity of APAP, as well as CPAP, devices to estimate treatment duration and detect residual respiratory events of a fixed predefined dis- turbed breathing scenario. The presentation and severity of OSA varies greatly depending on patient characteristics such as gender, age, body mass index, and craniofacial structure [18,22]. Specific patient
Table 4. Results of device re-testing without the sleep onset period. Device P max , cmH 2 O P mean , cmH 2 O Residual AHI, /h Overcome events
Overcome fl ow limitation
Residual fl ow limitation, min (% sleep time)
D G H
14.6
8.95 9.25 7.35
6
Yes Yes
Yes
9 (4%)
11.65 11.45
2.6 6.6 9.6
No No No
164 (80%) 70 (34%) 107.5 (52%)
No
I
11.3
7.9
Yes
AHI: apnea-hypopnea index; NA: not available; P max : maximum positive airway pressure applied; P mean : mean positive airway pressure; D: Icon by Fisher & Paykel; G: Prisma 20A by Weinmann; H: System One by Respironics; I: iCH by Apex.
doi:10.1371/journal.pone.0151530.t004
PLOS ONE | DOI:10.1371/journal.pone.0151530 March 15, 2016
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