OuSense: Electronic-Photonic System-on-Chip for Real-time Endoscopic Ultrasound 3D Imaging

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

For decades, ultrasound imaging has been one of the most indispensable tools in numerous medical disciplines ranging from oncology to cardiology and from dermatology to ophthalmology because of its portability and ease of use. However, in endoscopic, intravascular and catheterized applications, i.e., inside the body imaging systems, which constitute a huge part of the Point-of-Care spectrum of applications, traditional ultrasonic imagers have demonstrated serious shortcomings in terms of power dissipation and being too large in size. A unique platform developed by the Principal Investigator's research team, which enables tight co-integration of high-performance photonic devices with fast sophisticated transistors will serve as the vehicle towards achieving the goal of personalized, portable diagnostic systems that can shine new light INTO human physiology. Such a system, with highly sensitive, micro-scale optical sensors in its core, can be ultra-low power and size, ensuring safe operation inside the human body without sacrificing key system attributes. These optical sensors can provide 3D imaging in real time and pave the way towards the realization of a first of its kind miniaturized optical ultrasonic reception probe. The photonic nature of this system will also enable the applications such as ultrasound photoacoustic imaging that can assist the diagnosis and treatment of a wide range of important diseases from breast cancer to cardiovascular. This framework, along with associated educational materials and experiences will help create a new crop of engineers who are capable of tackling the complex, multidisciplinary nature of biomedical imaging and sensing systems. The proposed research will develop first of its kind optical ultrasound probe with thousands of sensor elements, capable of real-time 3-D imaging with high power and area efficiency (target: <0.5W, <5mm3. Transduction of the ultrasonic signal in the optical domain will remote the power hungry receive electronics outside the probe tube, and consequently the human body. Thus, more power will be externally available to lower receiver noise, without contributing to probe heat-up. The micro-ring resonators that will be used as the main sensing element have been proven to mitigate the sensitivity-bandwidth tradeoff of their piezo and CMUT counterparts. Replacing electrical transducers will also greatly simplify packaging, eliminating most electrical connections and interfaces, relying on extremely compact optic fiber arrays instead of micro-coax cables to carry the ultrasonic modulation. Electronic-photonic co-design will result in ultra-efficient thermal tuning control circuitry placed on-chip, in close proximity to the optics. The result of this effort will be the first optical ultrasound reception system simultaneously interrogating multiple optical sensors. Dense packing of thousands of sensing elements enables targeting the emerging applications like photoacoustic imaging, which require high sensitivity, frequency and resolution. This work will investigate an all-optical multi-modal ultrasound imaging, combining traditional ultrasound with photoacoustics to generate high contrast images that can assist the diagnosis and treatment of a wide range of important diseases from breast cancer to cardiovascular. 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.