Forced Oscillation Technique Measurement Apparatus Using Fan-Speaker Hybrid

The number of patients suffering from asthma and chronic obstructive pulmonary disease (COPD) increases due to deteriorating air quality and smoking. A measurement technique known as the forced oscillation technique (FOT) helps physicians to assess the current state of their patient's lungs. Measurement devices based on either fans or speakers have been developed in the past that can carry out this measurement, but their performance and/or robustness often fall short. This article proposes a combination of a fan- and speaker-based measurement apparatus that employs the FOT to help physicians diagnose patients with these diseases. First, we discuss the currently available measurement devices and their specific problems. Next, a fan-speaker hybrid measurement apparatus is proposed. This fan-speaker hybrid FOT measurement apparatus is then characterized and its performance is improved with a feed forward compensation. Finally, measurements on two test subjects with the proposed measurement apparatus are shown and discussed.