Abstract
This study focused on inhalation therapy and measured the inhalation volume and inhalation rate using a flow sensor installed in a pMDI (pressurized metered-dose spray inhaler). As a result, there were many cases in which the injection of the agent was not properly timed. In order to solve this problem, two types of auxiliary systems that operate according to a set inhalation rate were produced and tested. One is the system with which the subject does not need to operate the injection lever, and the system injects automatically after reaching the set inhalation speed. The other is the system with which the subject holds the injection lever with a brake from the start of inhalation, the brake is released when the set inhalation speed is reached, and the system injects by the lever operation.
The results showed that both methods eliminated the need for well-timed injection and facilitated inhalation. However, there were some problems with automatic injections, such as inhalation stoppage and backflow when injected at unexpected times. In the system with a brake, subjects were able to recognize the lever operation and anticipate the injection, which reduced the number of cases of inhalation stoppage and backflow.
