MR Airway Pressure Devce CAE UsersMR气道压力装置CAE用户.pptVIP

Abstract An airway pressure device was designed for use in an MR imager. This device will assist our client in studying CSF flow during Valsalva maneuvers performed by children with Chiari I malformation. Current research suggests that CSF flow decreases during Valsalva maneuvers in these patients. The final product consists of a rigid mouthpiece, pressure transducer, and compressed air operated valve system. Motivation Dr. Haughton is radiologist at UW-Hospital with a specialty in neuroradiology Research interest in CSF disorders Device needed to measure airway pressure during MR imaging Current devices are not MR compatible Problem Statement Our client needs a device to monitor exhalation pressure exerted during a Valsalva maneuver Specifically for studying CSF flow Images of the spine will be taken using MR imaging Research will be focused on children with Chiari I malformation Current studies show that CSF flow decreases during Valsalva maneuvers in these patients This causes patient symptoms to worsen Pressure measurement would be beneficial for data analysis and accuracy Client Specifications ?Needs to be MR compatible ?Pressure must be measured from beginning of Valsalva through mid expiration ?Small to minimize dead air space ?Usable by both alert and anesthetized patients Chiari I Malformations Valsalva Maneuver Expiratory effort against a closed glottis Increases pressure within the thoracic cavity MR Requirements Utilizes strong magnetic fields (1-3 T) Non-magnetic materials No metal touching the patient Must not affect image quality Comply with geometric constraints of GE Signa scanners and single channel head coil Final Design Components Rigid mouthpiece Silicon diaphragm pressure transducer End cap with tubing barb Features Device can be autoclaved Transducer can be sterilized Functions using compressed air and vacuum Device is small to minimize dead air space Can be used during normal breathing as well as during a Valsalva maneuver