Pneumothorax (PTX) is an acute respiratory condition in which air accumulates between the lung and chest wall. PTX can become life threatening if not identified and treated; therefore, early detection and prompt intervention are critical for patients at risk. Lung ultrasound (LUS) is a real-time, portable imaging modality suitable for bedside use. In contrast to chest X-ray for PTX detection, LUS does not use ionizing radiation and has demonstrated superior diagnostic performance. However, the operator dependence of handheld ultrasound probes limits the feasibility of continuous PTX monitoring which would enable early detection of PTX and be particularly beneficial for patients at ongoing risk, such as those under mechanical ventilation or aeromedical transport. We have developed a flexible, lightweight, and thin wearable ultrasonic sensor (WUS) for motion mode (M-mode) ultrasound image acquisitions. The WUS consists of a single-element ultrasonic transducer made of a polyvinylidene difluoride piezoelectric polymer film. Its simple fabrication and component materials make it low-cost and suitable for disposable use. The WUS is well-suited for long-term, continuous monitoring due to its hands-free operation. In this study, we demonstrate the feasibility of the WUS for PTX detection by using M-mode image features with lung tissue-mimicking phantoms and in-vivo human subjects. Work supported by the Natural Sciences and Engineering Research Council of Canada.
Ono et al. (Wed,) studied this question.