JMIR Publications

ABSTRACT

Background:

Ambulatory oxygen therapy is prescribed for patients with chronic lung diseases who experience exertional hypoxemia. However, the available ambulatory oxygen therapy devices may not adequately meet users’ requirements and their performance characteristics are heterogeneous.

Objective:

To identify devices available for delivery of ambulatory oxygen therapy, the technologies that they utilize to generate oxygen, the performance characteristics of each device, and the current status of the development.

Methods:

Peer-reviewed papers and grey literature (including white papers, technical reports in military medicine or space exploration, patent information) were searched. Documents that described a device that can deliver oxygen in an ambulatory context written in English were included. Search results were screened for inclusion by two independent reviewers.

Results:

We identified 32 portable oxygen concentrators (POCs, 29 commercially available), 10 oxygen cylinders, and 6 portable liquid oxygen (LOX). The POC products showed a trade-off between portability and oxygen delivery capacity (maximum flow rate ranging 2.0 to 6.0 L/min, device weight ranging 1.0 to 9.1 kg). Pressure swing adsorption (PSA) with zeolite were the most common oxygen generation technologies in POCs on the market. The mean maximum continuous operating time of POCs was 3.8 hours. Two prototype POCs with a maximum flow rate of 4 - 6 L/min and device weight of 8 - 9 kg have been developed in the field of space exploration using modified adsorbents. Liquid oxygen devices were the lightest and had the longest continuous operating time among the devices. Innovations in delivery included the downsizing of a POC by using nanozeolite as adsorbent, improving flow rate using rapid pressure swing adsorption (RPSA), and SpO₂-targeted automatic adjustment of oxygen delivery, all reported in scientific papers and patents but not yet available to consumers.

Conclusions:

This scoping review mapped the current ambulatory oxygen devices. POCs available to consumers may not meet the needs of patients in terms of oxygen flow rate, portability, and operating time. LOX offered superior performance but is limited by high costs. Technological innovation in this field has been limited over the past decade. Future development should involve users to ensure that new devices are aligned with patient needs. Clinical Trial: Open Science Framework (10.17605/OSF.IO/QS7FX)