Development of Proportional Valve for Respiratory Training System BreathForce

• Published in: 2018 IEEE International Symposium on Signal Processing and Information Technology (ISSPIT) pp. 063 - 067
• Main Authors: Melvin, Alexa M., Ackermann, Eli, Tran, Kevin, Yangsheng Chen, Ovechkin, Alexander, Roussel, Thomas J.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.12.2018
• Subjects: Gears; Muscles; Pressure sensors; respiration; respiratory muscle training; Servomotors; spinal cord injuries; Testing; Training; Valves
• DOI: 10.1109/ISSPIT.2018.8642785

Respiratory Training (RT) is an essential aspect of rehabilitation for patients with compromised respiratory function including individuals with spinal cord injury (SCI) above T5. In this population, respiratory and cardiovascular problems are the main cause of morbidity and mortality. With the help of RT, patients are able to regain a percentage of their prior lung and cardiovascular capacity and capabilities. However, current RT devices are based on manually adjusted air pressure threshold or resistance; they do not have a data collection option; and they do not provide biofeedback during training session. BreathForce RT technology eliminates the need for the patient to be in a clinical setting during data recording and provides monitoring of the functional changes over the course of training. BreathForce is a portable RT system with an integrated pressure sensor, system actuated proportional control valve, and touchscreen interface that allows the patient to undergo therapy at their convenience according to the individually developed training protocol. However, the first prototype required manual adjustment of the pressure threshold valves. This study investigated the use of a program actuated ball valve driven by a servo motor. 3D printed gears with a 5:3 ratio, with the larger gear on the ball valve, were mounted onto the ball valve and servo. This configuration proportionally controls the amount of air flowing through the device depending on the patient's desired level of inspiratory and expiratory loads. Through preliminary data obtained from one test subject, the proportional valve demonstrated the ability to automatically change the resistance which in turn altered the amount of breathing work. Overall, BreathForce is an inexpensive, effective, and innovative alternative to existing RT devices which will allow patients suffering from respiratory-cardiovascular deficits to perform controlled therapy at home.