Medical ultrasound has many properties that make it suitable for widespread use both as an imaging tool and as a ubiquitous biosensing technology. At present, however, wide deployment of medical ultrasound for disease detection and monitoring has been limited by rigid sensor geometries. On one hand, rigid sensor geometries are generally considered desirable, as known geometries facilitate coherent beamformation and image reconstruction. On the other hand, however, rigid sensors do not accommodate body surface curvature, necessitating the application of sensor pressure by a skilled operator during imaging. This compression-based process of image acquisition, termed “sonography,†requires considerable skill, in turn increasing interoperator variability. Moreover, the need to have an operator apply pressure is incompatible with wearable technology, greatly limiting the scope and utility of medical ultrasound technology. The aim of this proposed research is to address the core unmet need described above, which is the development of a novel class of conformable ultrasound systems that would enable insights into soft tissue biology presently not possible owing to a lack of suitable instrumentation. The system has the potential to complement mammographic imaging by providing tissue characterization data that would facilitate optimal use of scarce breast cancer care resources. This work will be particularly relevant to developing nations, where a shortage of qualified ultrasound operators and related infrastructure greatly limits access to care. The proposed interdisciplinary project will be integrated with educational and outreach activities, including development of new courses geared towards disseminating new microfabrication techniques outside of the traditional physics and material science communities to increase interest and engagement in STEAM fields and to proliferate the study of piezoelectric systems at the K-12, undergraduate, and graduate education levels.
Obtaining sufficient contact over soft surfaces of large areas (i.e., shoulder, breast) or small joints (i.e., finger joints, wrist joints) is not achievable, due to the rigid planar design of the ultrasound transducer versus the typical curvilinear shape of body parts. The human breast presents a particular challenge, as its geometry and deformability are highly variable not only between subjects but also at different times and ages within a given subject. At the same time, breast cancer is the most common cancer and such cancers are typically located within the expected penetration depth of sonography. As a result, there is an opportunity to develop technology for longitudinal imaging of breast lesions both for cancer diagnostic and early detection purposes and also serve as a new non-invasive window into the biological behavior of breast tumors. The primary goal of the proposed research is to develop conformable phased array ultrasound patches for soft tissue imaging over large-area, curvilinear regions by introducing a novel system design and microfabrication strategy, along with a framework and advanced algorithms to reconstruct spatiotemporally-accurate images that could be applied to any human body parts. The challenges that will be addressed during the course of the project include: 1) Development of large-area, conformable phased array transducer design, 2) Spatiotemporally-accurate 3-D image reconstruction from highly curvilinear body parts, 3) In vivo, real-time actuation and sensing on both in vitro on mock tissue phantoms and in vivo in a limited human trial focused on the detection, localization, and characterization of breast lesions. The proposed work will build upon the PI's interdisciplinary expertise and experience in piezoelectric, microfabricated biomedical devices and conformable systems. The proposed system will provide interfaces that enable next-generation features of wearable technologies, such as accurate, real-time and autonomous monitoring of any soft tissue for 3-D imaging, and machine learning strategies to detect disease progression in an objective manner.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
