Airflow resistance of airflow-regulating devices described by independent coefficients.
Rehabilitation after laryngectomy includes more and more the use of airflow-regulating devices such as shunt valves (SVs), tracheostoma valves (TSVs), and heat and moisture exchange (HME) filters. In determining the quality of those devices, airflow resistance is a very important factor. It is currently defined as pressure drop divided by airflow. However, for most applications, this definition does not result in a pressure- and airflow-independent parameter. Therefore, a new set of parameters is defined and applied to pressure-airflow curves of airflow-regulating devices. Pressure drop over TSVs and HME filters appears to have a squared relationship with flow. In SVs, it has a linear relationship. The new set of parameters describes the pressure-airflow relationship properly for all considered devices. In conclusion, theoretical predictions of flow mechanics appear to be valid for SVs, TSVs, and HME filters. Only 2 coefficients are necessary to describe the pressure-flow characteristics of these airflow-regulating devices, independent of pressure drop over and flow through the device.
Verkerke
G J
GJ
Department of Biomedical Engineering, Faculty of Medical Sciences, University of Groningen, The Netherlands.
Geertsema
A A
AA
Schutte
H K
HK
D000403:Airway Resistance / Q000502:physiology*; D004867:Equipment Design; D005374:Filtration / Q000295:instrumentation*; D006801:Humans; D007825:Laryngectomy / Q000534:rehabilitation*; D011183:Postoperative Complications / Q000503:physiopathology; D012123:Pulmonary Ventilation / Q000502:physiology; D012134:Respiratory Protective Devices; D014139:Tracheostomy / Q000295:instrumentation*