A5046034446- Ultrasound Imaging and Elastography
- Ultrasonics and Acoustic Wave Propagation
- Wireless Power Transfer Systems
- Optical Coherence Tomography Applications
- Photoacoustic and Ultrasonic Imaging
- Photoreceptor and optogenetics research
- Neuroscience and Neural Engineering
- Piezoelectric Actuators and Control
- Advanced Thermoelectric Materials and Devices
- Antenna Design and Analysis
- Acoustic Wave Resonator Technologies
- Wireless Body Area Networks
- Microfluidic and Bio-sensing Technologies
- Antenna Design and Optimization
- Thermal Radiation and Cooling Technologies
- Corneal surgery and disorders
- Retinal Imaging and Analysis
- Thermal properties of materials
- Orbital Angular Momentum in Optics
- Ultrasound and Hyperthermia Applications
- Lung Cancer Diagnosis and Treatment
- Hematopoietic Stem Cell Transplantation
- Flow Measurement and Analysis
- Advanced Thermodynamic Systems and Engines
- Microwave Imaging and Scattering Analysis
University of Southern California
2017-2024
Southern California Eye Institute
2020-2022
Ultrasonic Technologies (United States)
2020
LAC+USC Medical Center
2017-2018
Huazhong University of Science and Technology
2014
Korea Atomic Energy Research Institute
2001
Thermoelectric generators (TEGs) provide a unique solution for energy harvesting from waste heat, presenting potential green energy. However, traditional rigid and flexible TEGs cannot work on complex dynamic surfaces. Here, we report stretchable TEG (S-TEG) (over 50% stretchability of the entire device) that is geometrically suitable various surfaces heat sources. The S-TEG consists hot-pressed nanolayered p-(Sb2Te3) n-(Bi2Te3)-type thermoelectric couple arrays exploits wavy serpentine...
Abstract Electronic visual prostheses, or biomimetic eyes, have shown the feasibility of restoring functional vision in blind through electrical pulses to initiate neural responses artificially. However, existing prostheses predominantly use wired connections electromagnetic waves for powering and data telemetry, which raises safety concerns couples inefficiently miniaturized implant units. Here, we present a flexible ultrasound-induced retinal stimulating piezo-array that can offer an...
Bionic multifunctional structural materials that are lightweight, strong, and perceptible have shown great promise in sports, medicine, aerospace applications. However, smart monitoring devices with integrated mechanical protection piezoelectric induction limited. Herein, we report a strategy to grow the recyclable healable Rochelle salt crystals 3D-printed cuttlebone-inspired structures form new composite for reinforcement devices. In addition its remarkable performance, growth mechanisms,...
Abstract Retinal degeneration, a leading cause of irreversible low vision and blindness globally, can be partially addressed by retina prostheses which stimulate remaining neurons in the retina. However, existing electrode-based treatments are invasive, posing substantial risks to patients healthcare providers. Here, we introduce completely noninvasive ultrasonic prosthesis, featuring customized ultrasound two-dimensional array allows for simultaneous imaging stimulation. With synchronous...
p-type Sb2Te3/poly(3,4-ethylenedioxythiophene) (PEDOT) thermoelectric composites are fabricated by embedding PEDOT into Sb2Te3 matrix. The grains of in the found to be micron degree and keep plate-like shapes. measurements properties show that thermal conductivity κ is about 0.14 W m−1 K−1 temperature range 300–523 K, much lower than compounds. maximum dimensionless figure merit reaches 1.18 at 523 which highest value for reported Sb2Te3/organic composites. It suggested embedded PEDOTs may...
Objective: The choroidal vessels, which supply oxygen and nutrient to the retina, may play a pivotal role in eye disease pathogenesis such as diabetic retinopathy glaucoma. In addition, retrobulbar circulation that feeds choroid shows an important pathophysiologic myopia degenerative myopia. Owing light-absorbing retinal pigment epithelium (RPE) optically opaque sclera, vasculature were difficult be observed using clinically accepted optical coherence tomography angiography (OCT-A)...
Tiled modular 2-D ultrasound arrays have the potential for realizing large apertures novel diagnostic applications. This work presents an architecture fabrication of tileable array modules implemented using 1-3 composites high-bandwidth (BW) PIN-PMN-PT single-crystal piezoelectric material closely coupled with high-voltage CMOS application-specific integrated circuit (ASIC) electronics buffering and multiplexing functions. The module, which is designed to be operated as a λ -pitch 1.75-D...
Acoustic radiation force optical coherence elastography (ARF-OCE) has been successfully implemented to characterize the biomechanical properties of soft tissues, such as cornea and retina, with high resolution using single-element ultrasonic transducers for ARF excitation. Most currently proposed OCE techniques, air puff ARF, have less capability control spatiotemporal information induced region deformation, resulting in limited accuracy low temporal shear wave elasticity imaging. In this...
Ultrasound medical imaging is an entrenched and powerful tool for diagnosis. Image quality in ultrasound mainly dependent on performance of piezoelectric transducer elements, which further related to the electromechanical constituent materials. With rising need materials with better low cost, a highly <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\langle 001\rangle $ </tex-math></inline-formula> textured...
Ultrasound single-beam acoustic tweezer system has attracted increasing attention in the field of biomechanics. Cell biomechanics play a pivotal role leukemia cell functions. To better understand and compare mechanics cells, herein, we fabricated an in-house connected with 50-MHz high-frequency cylinder ultrasound transducer. Selected cells (Jurkat, K562, MV-411 cells) were cultured, trapped, manipulated by single beam, which was transmitted from transducer without contacting any cells. The...
Large aperture ultrasonic arrays can be implemented by tiling together multiple pretested modules of high-density acoustic with closely integrated multiplexing and buffering electronics to form a larger high yield. These modular used implement large 1.75D array apertures capable focusing in elevation for uniform slice thickness along the axial direction which improve image contrast. An important goal is obtaining yield sensitivity while reducing extraneous artifacts. We have been developing...
High element density and strict constraints of the element's size have significantly limited design fabrication 2-D ultrasonic arrays, especially fully sampled arrays. Recently, 3-D printing technology has been one most rapidly developing fields. Along with great progress technology, complex detailed structures become readily available a short iteration cycle, which allows us to reduce complexity routing helps ameliorate assembly problems in ultrasound array fabrication. In this work, we...
Tiled large aperture 1.75D/2D transducer arrays with closely integrated ASIC electronics have the potential for implementing high channel count ultrasound probes novel applications, however they must yield a number of elements to maintain good image quality. This constraint can be addressed by tiling together smaller array modules build up larger aperture. In this work we present recent imaging results apertures multiple tiled integrating 2D wide bandwidth PIN-PMN-PT 1-3 composite piezo...
Tiled modular 2D ultrasound arrays have the potential for realizing large apertures novel diagnostic applications. Here we present results of recent work fabrication a tileable array module implemented using 1-3 composite high bandwidth PIN-PMN-PT material closely coupled with voltage CMOS ASICs buffering and multiplexing functions. The transducer is supported by 3D printed conducting acoustically attenuating interposer backing which links to PCB housing interface ASICs. A low temperature...
High channel count, large area ultrasound arrays at fine pitch require close integration of transducer elements and ASIC electronics. Composites single crystal material non-conducting epoxy filler can be used to increase bandwidth. Direct bonding the composite leads acoustic mismatch excessive ringing. A collimated connection block (i.e. an interposer) between array their respective connections provide both attenuation electrical interconnection. Here we present implementation interposer...
Argus II retinal prosthesis is the US Food and Drug Administration (FDA) approved medical device intended to restore sight a patient’s blind secondary degeneration (i.e., retinitis pigmentosa). However, most reported prostheses require invasive surgery implant electrodes in eye. Recent studies have shown that focused ultrasound can be developed into non-invasive technology. Ultrasound energy on neurons trigger activities of with high spatial-temporal resolution. This paper introduces novel...
In this paper, we describe process development and initial results for a tileable 2D array module implementation of large area arrays. The is based on 1-3 composite single crystal PIN-PMN-PT transducer material which benefits from improved electromechanical coupling coefficient k <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">33</sub> ' increased Curie temperature. backing the consists novel 3D printed acrylic frame that filled with conducting...
Current shear wave elastography methods primarily focus on 2D imaging. To explore mechanical properties of biological tissues in 3D, a four-dimensional (4D, x, y, z, t) ultrasound is required. However, 4D still challenging due to the limitation hardware standard acquisition systems. In this study, we introduce novel method achieve elastography, named sequential-based excitation (SE-SWE). This can implemented by 1024-element array with 256-channel system.
In a significant proportion of patients screened for Hepatocellular Carcinoma (HCC) using ultrasound the quality images obtained is below requirements diagnostic classification. Detection small, low contrast lesions impaired in with abdominal wall thickness greater than 2.5 cm due to image contrast. To address this need we have been developing large 1.75D array apertures composed multiple tiled subarrays modules. The modules include custom buffering and switching ASICs multiplexing number...
Hepatocellular carcinoma is difficult to diagnose reliably using ultrasound in patients with thick abdominal walls. An important consideration for improving diagnosis these increased contrast noise resolution (CNR) which directly dependent on elevation focus and can be improved by a large electronically scanned elevational aperture. Here we present recent work integrating ASIC electronics modules area 64 × 16 element 1.75D acoustic array module. The pitch of the 650 µm azimuth 1000...
High frequency arrays (>10 MHz) have potential utility in clinical settings for ophthalmology, breast cancer, and skin cancer diagnosis, been used extensively small animal imaging would benefit from the use of 1.75D electronic focus elevation to improve contrast resolution cyst differentiation detection. Here we report a array that utilizes novel high pitch-changing interposer backing maps 70 μm×150 μm transducer element grid 150 ASIC assembly facilitate access 2D elements. A PIN-PMN-PT...
We have been developing highly-integrated and modular large aperture multi-row 1.75D linear arrays interfaced to a configurable ultrasound system (Verasonics Vantage 32LE) using custom ASIC multiplexing electronics with the goal improve detection of liver cancer deep in body. The array consists multiple rows which are capable an elevation for realization synthetic focusing imaging both azimuthal elevational planes. addresses 1,024 acoustic elements <tex...