Abstract
The CPAP (Continuous Positive Airway Pressure) therapy is the gold standard to treat the obstructive sleep apnoea syndrome (OSAS). The CPAP-device generates a positive pressure to splint the upper respiratory tracts preventing an collapse of the tracts and the pharynx. It has been shown that many CPAP-devices cannot maintain the pressure set points adjusted by the medical staff, because the mask pressure is seriously influenced by the patient’s breathing. In this work a method is provided to estimate the breathing effort of the patient. Therefore a model of the breathing therapy system is introduced and the application of the Kalman filter is described. The estimated breathing effort could then be used in further control strategies to improve the control quality.
Zusammenfassung
Die CPAP (Continuous Positive Airway Pressure)-Therapie ist der Goldstandard, um das obstruktive Schlafapnoesyndrom (OSAS) zu behandeln. Das CPAP-Gerät erzeugt einen positiven Atemwegsdruck, um die oberen Atemwege pneumatisch zu schienen. Damit kann ein Verschluss der Atemwege und des Pharynx verhindert werden. Es hat sich gezeigt, dass viele CPAP-Geräte die vom Fachpersonal geforderten Therapiedrücke nur unzureichend einhalten, da der Druck in der Maske durch die Atmung des Patienten erheblich beeinflusst wird. In dieser Arbeit wird eine Methode vorgestellt, die Atemanstrengungen des Patienten zu schätzen. Dafür wird ein Modell des Atemtherapiegerätes vorgestellt und die Anwendung eines Kalman Filters beschrieben. Die geschätzte Atemanstrengung kann dann für weitere Regelungsstrategien verwendet werden, um damit die Regelgüte zu verbessern.
Funding statement: The author want to thank HOFFRICHTER GmbH for financial support and for the preparation of the test device.
About the authors
Mathias Scheel studied information technology and electrical engineering with focus on automation and mechatronic at the Hochschule Wismar-University of Applied Sciences, Technology, Business and Design from 2008 to 2013 and received his „Master of Engineering“ (M. Eng.) in 2013. Since 2013 he is a member of the Automation and Mechatronics Group at the Hochschule Wismar and started his doctoral project in cooperation with HOFFRICHTER GmbH. In 2016 he becomes a member of the technical committee “AUTOMED” in the German Society of Biomedical Engineering and the VDI/VDE in Germany. His research area is modeling, identification and control in artificial ventilation and breathing therapy.
Andreas Berndt studied electrical engineering with focus on communications engineering at the Hochschule Stralsund-University of Applied Sciences from 1996 to 2000 and received his degree Dipl.-Ing. (FH) in 2000. After his study he started his career at Siemens AG as a development engineer. 2010 he moved to HOFFRICHTER GmbH and worked as a development engineer for hardware. Since 2014 he is the head of development and in 2015 he assumed the task of a site manager of HOFFRICHTER GmbH in Schwerin.
Olaf Simanski studied electrical engineering at the University of Rostock in Germany from 1991 to 1996. After this he worked as scientific co-worker at the University of Rostock at the Institute of Automation. During this period he wrote 2002 his PhD-thesis and 2010 his “habilitation” in the field of measurement and control of biomedical, especially anesthesia systems. From 2002 to 2011 he was the leader of the “Medical Control Group” at the Institute of Automation at the University of Rostock. 2011 he moved to the Hochschule Wismar-University of Applied Sciences, Technology, Business and Design as chair of Automation. Since 2012 he is also the leader of the “Medical Control Group” at the “Control Application Centre” at the University of Rostock.
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