Wearable Ultrasound for Respiratory Monitoring in the Intensive Care Unit

Abstract

Elongated mechanical ventilation is associated with ventilator-induced lung injury (VILI), diaphragmatic muscle atrophy, patient discomfort, increased mortality rates and higher healthcare costs. However, hospitals are lacking in user-friendly, affordable and accurate methods to measure the decline the respiratory condition. Computed tomography (CT) is often used for visualization of the thorax, but it is expensive, time-consuming and uses unsafe ionizing radiation. Healthcare staff from the LUMC has expressed their need for a monitoring device using user-friendly, safe, affordable and accurate technology.
Current developments in ultrasound technology are resulting in smaller, cheaper and higher quality ultrasound devices. Micro-electro-mechanical (MEMS) ultrasound also allows for wearable solutions, such as patches attached to the skin. Besides, ultrasound does not use ionizing radiation and is therefore safer to use than CT.
Since ultrasound patches are already in development for other applications, for instance hemodynamic and bladder monitoring, the possibility of using it for respiratory monitoring for mechanically ventilated patients is investigated. In this report, the possibilities of using ultrasound patches for continuous respiratory monitoring for mechanically ventilated patients are explored. The focus points are usability and workflow design.
The design of a placing system is proposed, which allows the user to properly place the patches on the right location. This system is based on using an existing ultrasound transducer, in this case the Philips Lumify L12-4, to generate a full image. Then, the patch can be placed. This system allows for the use of both imaging and non-imaging patches. The electronics are reusable. The other parts can be adapted for the use with different transducers and applications, beyond respiratory monitoring.