Clinical Evaluation of a Fiber-optic Sensor System for Monitoring Respiration Activity and Heart Work During MRI Examinations

The main purpose of the study is to determine the possibility of assessing the level of anxiety by means of the respiration curve and/or ballistocardiographic (BCG) signal acquired from MRI patients using a fiber-optic sensor system. In many patients, the MRI examination causes enormous stress due to limited space in the scanner, isolation during the examination and high noise levels. Usually, anxiety or stress triggers an increase in respiration rate (RR), leading to hyperventilation in extreme cases. There are also frequent cases of disturbances in heart rate (HR). Thus, the symptoms of claustrophobia can be detected by monitoring respiration activity and heart work.

The fiber-optic sensor system consists of a sensor mat, an interrogator and a personal computer (PC), and records respiratory and BCG signals in patients during MRI. The metal-free sensor mat is placed under the patient's back, does not pose a threat to the patient and has no influence over the quality of imaging. The interrogation module detects the optical signal including vital signs, and the PC with software developed for signal processing and visualization enable the MRI operator to monitor patient's RR and HR.

Up to 200 MRI patients in different age, weight, and gender will be participated in the study. They will be asked to complete the State Trait Anxiety Inventory (STAI) questionnaire in order to estimate anxiety level before and after the MRI scanning. Relations between the STAI X-1 scores and the mean RR and/or HR values recorded at the beginning and the end of the MRI scanning will be analyzed using descriptive statistic methods. The research scheme includes also the collection of the STAI X-2 scores before the MRI scanning. Finally, the values of the physiological parameters, which may indicate a dangerous level of anxiety will be determined. Positive results of the clinical evaluation will predestine the fiber-optic sensor system to be implemented in routine MRI procedures.