2006 OPEN FORUM Abstracts
A Bench Study to Compare the Performance Characteristics of Portable Oxygen Concentrators
R. Diesem, G. Voss, R. McCoy, RRT, FAARC
Background: With two new portable oxygen concentrators entering the market, there are now more options for patients who prefer the portability and efficiency that these type of devices offer. However, it is important for these patients, as well as physicians and therapists, to understand how these devices operate, what their performance capabilities are and what, if any, limitations of using the device are. Often times it is assumed that these products perform similarly, so purchasing decisions are then based on factors outside of actual product performance such as product warranty, additional non-therapeutic features, and price. The objective of this evaluation is to demonstrate the performance characteristics and differences between four portable oxygen concentrators currently on the market.
Methods: Using a Hans Rudolph Series 1101 breathing simulator to act as the patient, four different models of portable oxygen concentrators were tested and compared for performance in the following areas: Dose volume per breath, average dose volume per device setting, flow delivery profiles, FIO2, trigger sensitivity and calculated savings ratio. Data was obtained for each of these characteristics using four different breathing patterns with breath rates of 15, 20, 25 and 30 breaths per minute, respectively.
Results: Dose volumes at 15bpm ranged from 7.6 to 16.6mL at the 1 setting to 40.1 to 90.0mL at the highest device setting, and dose volumes at 30bpm ranged from 4.9 to 16.9mL at the 1 setting to 26.1 to 95.1mL at the highest device setting. Two of the four devices reduced the average amount of oxygen delivered per setting as the respiratory rate increased. All devices exhibited a drop in FIO2 at high breath rates / high device settings which, for three of the devices, suggests a drop in oxygen purity under these conditions. Sensitivity values across devices were consistent at each unit's most sensitive setting, ranging from a negative pressure of 0.09 to 0.11cmH2O. Calculated savings ratios were similar, ranging from 3.1:1 to 3.4:1.
Conclusion: Each portable oxygen concentrator had unique performance characteristics that patients, clinicians and therapists should be aware of before selecting a device for use. For example, a patient with a prescription for a high dose setting may not be able to maintain saturation at high breath rates on a portable concentrator due to the loss in oxygen purity under these conditions. It is important that all persons involved with the use of portable oxygen concentrators be aware of the performance capabilities and limitations as well as the differences between them.