A FPGA-based wearable ultrasound device for monitoring obstructive sleep apnea syndrome

Abstract

Obstructive sleep apnea (OSA) a breathing disorder characterized by repetitive collapse of the pharyngeal airway during sleep can cause intermittent hypoxemia and frequent arousal Many studies have demonstrated that the deformation of tongue base plays an important role in OSA Currently several medical imaging modalities have been used to record the airway changes such as cine MRI and ultrafast CT However most of them are difficult to be used widely in clinical diagnosis for continuous recording the deformation of tongue in real-time particularly during sleeping In order to overcome these problems a wearable ultrasonic device was developed for real-time monitor of the dynamic change of the tongue base in this study The device includes a custom-designed 3-MHz ultrasonic array transducer an ultrasound pulser/receiver high speed analog-to-digital converter and a FPGA board The ultrasound pulse repetition frequency and pulse center frequency are controlled by the programmable FPGA board Since this device exhibits non-invasive real time imaging portable and non-ionizing radiation it can be used to detect the airway situation during natural sleeping with various postures This new information will help physicians to diagnose the symptoms The anthropometric measurement was carried out for verifying the system performance Results demonstrated that the dynamic variation of tongue base can be clearly distinguished by using this wearable system It has the potential to be incorporated into polysomnography and to provide information about retroglossal airway behavior during natural sleep Furthermore it is very important in devising applying and determining the effectiveness of tailor-made treatment modalities

Date of Award	2016 Aug 15
Original language	English
Supervisor	Chih-Chung Huang (Supervisor)