Comparing the Performance and Efficacy of the 3B/BMC RESmart. Auto-CPAP with the ResMed S9 AutoSet

Transcription

1 3B MEDICAL, INC., US HIGHWAY 27, LAKE WALES, FL Comparing the Performance and Efficacy of the 3B/BMC RESmart Auto-CPAP with the ResMed S9 AutoSet Zhi Zhuang, PhD, Research and Development, BMC Medical Co., Ltd.

2 Comparing the Performance and Efficacy of the 3B/BMC RESmart Auto-CPAP with the ResMed S9 AutoSet Zhi Zhuang, PhD, Research and Development, BMC Medical Co., Ltd. Abstract There are several auto-adjusting CPAP systems on the market, each with its own proprietary algorithm that controls the pressure response to varied respiratory events. There are substantial benefits of auto-adjusting CPAP devices over fixed pressure CPAP devices. Patients undergoing auto-adjusting CPAP therapy generally report more restful sleep, better quality sleep, less discomfort from pressure, and less trouble getting to sleep. 1 Over the years there have been a few published attempts to evaluate the efficacy of one algorithm over another. 2 The 3B/BMC RESmart Auto-CPAP has been on the market globally in 120 countries since However, it s entry into the U.S. marketplace is recent and a comparative review is timely. This paper evaluates the performance and efficacy of the 3B/BMC auto-adjusting unit compared to the ResMed S9 Autoset. Introduction Both the ResMed AutoSet and the 3B/BMC RESmart Auto algorithm appear to rely on the same sensory input. ResMed's AutoSet algorithm monitors the patient on a breath-by-breath basis to maintain upper airway patency for any given breath. The AutoSet algorithm adjusts treatment pressure as a function of three parameters: inspiratory flow limitation, snore, and apnea. The 3B/BMC RESmart System uses Dual-Channel Quad-Phase technology to monitor all four upper-airway respiratory events: apnea, snore, flow limitation, and hypopnea. While the 3B/BMC and ResMed algorithms rely on similar sensory input (i.e. apnea hypopnea, snoring, and changes in inspiratory flow contour) the weighing and processing of each input is different, necessitating a comparative evaluation to determine whether the efficacy is equivalent for both algorithms. With the use of pressure and flow sensors, the 3B/BMC RESmart analyzes the state of the patient s upper airway on a breath-by-breath basis and adjusts the treatment pressure automatically. The device gradually reduces the pressure to the set minimum pressure as long as no further events occur so that upper airway patency is maintained with the minimum sufficient pressure. The reduced pressure, along with 3B/BMC s proprietary RESlex exhalation relief technology, improves patient comfort and acceptance of PAP therapy. P a g e 1

3 The aim of both the bench tests and the clinical trial was to determine the therapeutic efficacy of the 3B/BMC RESmart Auto CPAP System compared to the ResMed S9 Autoset. In bench testing both devices were presented with one normal and three disordered breathing patterns simulated with an INGMAR Active Servo Lung The resulting pressure changes in the Auto-CPAP units, as they were subjected to each pattern, were recorded. Bench testing was followed by a clinical trial involving 25 patients. The test patients were evaluated by polysomnograph (PSG) to diagnose OSA and to determine their baselines. The initial PSG was followed by PSG monitoring of treatment by both the 3B/BMC RESmart Auto-CPAP and the ResMed S9 Autoset. Clinical results were recorded, including analysis of AHI, SNI, blood oxygen desaturation, ODI, SpO2, and pulse rate. Results. Both the 3B/BMC RESmart Auto and the ResMed S9 Autoset were able to detect accurately apnea, hypopnea, and snore events and respond appropriately with pressure adjustments. Conclusion. The 3B/BMC RESmart and the ResMed S9 Autoset demonstrated comparable performance both generally as effective treatments for OSA and specifically in terms of responding to respiratory events as defined by the reduction of AHI to less than five. Validation Objective To compare the performance of the 3B/BMC RESmart Auto CPAP with the ResMed S9 Autoset for the treatment of Obstructive Sleep Apnea. P a g e 2

4 Comparative Bench Testing Both devices were presented with one normal and three disordered breathing patterns simulated by the Active Servo Lung The Active Servo Lung 5000 monitored and recorded the resulting pressure changes in the APAP units while they underwent each simulated breathing pattern. Clinical Trial: Patients were evaluated for an OSA diagnosis with polysomnography monitoring to establish a baseline. Patients were subsequently treated, while continuously monitored by PSG, with both the 3B/BMC RESmart Auto-CPAP and the ResMed S9 Autoset. Clinical results were recorded, including analysis of AHI, SNI, blood oxygen desaturation, ODI, SpO2, and pulse rate. Performance Bench Test Method Four breathing patterns, including normal breathing, apnea, flow limitation, and snore, were simulated by the Active Servo Lung 5000 (Figures 1-4). Figure 1 Normal Breathing Figure 2 Hypopnea (Flow Limited) P a g e 3

5 Figure 3 Apnea Figure 4 Snore Note: Snore was simulated by superimposing fluncations with a frequency of 50 Hz on normal inspiratory flow. Test Procedure 1. The test equipment was set up according to the description in Figure 5, respectively connected to the RESmart Auto and S9 Autoset according to Table The Active Servo Lung 5000 was powered on. The normal breathing pattern was run for five minutes before the Active Servo Lung 5000 began simulating the apnea pattern. The apnea ran for 15 minutes before reverting to normal breathing for the remainder of the test period. The total test period was 1 hour and 30 minutes. 3. This process was repeated with the snore and hypopnea breathing patterns. Figure 5 Test Equipment Connection P a g e 4

6 Table 1 Setting Parameters of the RESmart Auto & S9 Autoset RESmart Auto S9 Mode Auto-CPAP Mode AutoSet Min APAP 4.0 cmh2o Min Pressure 4.0 cmh2o Max APAP 15.0 cmh2o Max Pressure 15.0 cmh2o Ramp 0 min Ramp 0 min RESlex Off EPR Off Results As shown in Figures 6 and 7, the 3B/BMC RESmart Auto has the same level of response sensitivity to the three types of sleep events as the ResMed S9 Autoset. Both are most sensitive to apnea and least sensitive to snore. Furthermore, when a sleep event occurs, the higher the pressure setting the RESmart Auto delivers, the smaller the rate of rise in pressure will be. When the patient returns to normal breathing, the interval of pressure reduction increases, and the output pressure decreases. Figure 6 Auto-Adjusting Pressure Comparison of RESmart Auto on 3 Sleep Events P a g e 5

7 Figure 7 Auto-Adjusting Pressure Comparison of S9 on 3 Sleep Events Clinical Test Screening Test Subjects and Establishing Baselines Based on the standard of clinical assessment on Sleep Apnea Hypopnea Syndrome, test subjects were recruited based on a pool of patients previously diagnosed with OSA. The clinical trial included 25 patients, of which 23 were male and 2 were female. All patients were monitored by PSG to determine a baseline. The diagnosis results demonstrated that 13 patients had severe symptoms, 10 had moderate symptoms, and 2 had mild symptoms. Of the 25 patients, 15 of them had relatively severe snore. Contrast Test Method For the purposes of the clinical testing, the self-control method was performed, which required that the same patients take part in both the test group experiment and control group experiment. For the test group experiment, the patient is treated with the RESmart Auto and is simultaneously monitored using PSG for a minimum of 4 hours. The control group experiment required a separate night of monitored sleeping for a minimum of 4 hours while being monitored by PSG. Evaluation Standards Table 2 below contains the parameters by which to analyze the patient therapy. Table 2 Evaluation Standards Clinical Evaluation AHI (times/hour) SpO2 (%) Symptom Cured (ideal) < 5 > 90 Almost disappeared Significantly Effective < 20 and reduced by 50% - Obviously alleviated Effective Reduced by 25% - Alleviated Ineffective Reduced by < 25% - Without obvious change P a g e 6

8 Results As the raw clinical data in Figure 8 and Figure 9 shows, both the AHI and blood oxygen saturation of the test subjects were restored to a normal level with PAP therapy. Score of AHI Subjects ID PSG RESmart Auto S9 Figure 8 AHI Min SPO PSG RESmart Auto S9 Subjects ID Figure 9 Minimum SpO2 Table 3: Treatment Statistics Comparison Clinical effectiveness Cured Significantly effective Effective Ineffective Total Experimental group (n) Control group(n) The statistics show that the treatment efficiency ( cured, significantly effective and effective all count as effective) of both devices was 100%. There was no significant difference in the clinical effectiveness of the subject and predicate devices. P a g e 7

9 Conclusion Both comparative bench testing and clinical trials verify that the algorithm of the 3B/BMC RESmart Auto-CPAP provides for accurate detection and fast response to sleep events. The Resmart and the S9 Autoset had similar clinical results and displayed no significant variations in objectively measured vigilance, nocturnal breathing disturbances, or symptoms, indicating that neither treatment modality was superior to the other. 1 Clifford A. Massie, Nigel McArdle, Robert W. Hart, Wolfgang W. Schmidt-Nowara, Alan Lankford, David W. Hudgel, Nancy Gordon, and Neil J. Douglas. Comparison between Automatic and Fixed Positive Airway Pressure Therapy in the Home. American Journal of Respiratory and Critical Care Medicine. Vol. 167, No. 1 (2003), pp McCoy, Robert, Ryan Diesem, and Todd Eiken. Auto-Adjusting Positive Airway Pressure. Sleep Review [ Accessed December 12, B Medical, Inc., BMC Medical Co., Ltd. All rights reserved. P a g e 8