@article{kreager_wu_chang_moon_mitchell_peng_huang_muller_tian_jiang_2024, title={High-Performance PMN-PT Single-Crystal-Based 1-3 Composite Transducer Integrated with a Biopsy Needle}, volume={14}, ISSN={["2079-6374"]}, url={https://www.mdpi.com/2079-6374/14/2/74}, DOI={10.3390/bios14020074}, abstractNote={To address the need for high-resolution imaging in lung nodule detection and overcome the limitations of the shallow imaging depth associated with high-frequency ultrasound and the complex structure of lung tissue, we successfully integrated 50 MHz ultrasound transducers with 18-gauge biopsy needles. Featuring a miniaturized size of 0.6 × 0.5 × 0.5 mm3, the 50 MHz micromachined 1-3 composite transducer was tested to perform mechanical scanning of a nodule within a lung-tissue-mimicking phantom in vitro. The high-frequency transducer demonstrated the ability to achieve imaging with an axial resolution of 30 μm for measuring nodule edges. Moreover, the integrated biopsy needle prototype exhibited high accuracy (1.74% discrepancy) in estimating nodule area compared to actual dimensions in vitro. These results underscore the promising potential of biopsy-needle-integrated transducers in enhancing the accuracy of endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNA) for clinical applications.}, number={2}, journal={BIOSENSORS-BASEL}, author={Kreager, Benjamin C. and Wu, Huaiyu and Chang, Wei-Yi and Moon, Sunho and Mitchell, Josh and Peng, Chang and Huang, Chih-Chung and Muller, Marie and Tian, Jian and Jiang, Xiaoning}, year={2024}, month={Feb} } @article{moon_xue_ganesh_shukla_kreager_cai_wu_zhu_sharma_jiang_2024, title={Ultrasound-Compatible Electrode for Functional Electrical Stimulation}, volume={12}, ISSN={["2227-9059"]}, url={https://doi.org/10.3390/biomedicines12081741}, DOI={10.3390/biomedicines12081741}, abstractNote={Functional electrical stimulation (FES) is a vital method in neurorehabilitation used to reanimate paralyzed muscles, enhance the size and strength of atrophied muscles, and reduce spasticity. FES often leads to increased muscle fatigue, necessitating careful monitoring of the patient's response. Ultrasound (US) imaging has been utilized to provide valuable insights into FES-induced fatigue by assessing changes in muscle thickness, stiffness, and strain. Current commercial FES electrodes lack sufficient US transparency, hindering the observation of muscle activity beneath the skin where the electrodes are placed. US-compatible electrodes are essential for accurate imaging and optimal FES performance, especially given the spatial constraints of conventional US probes and the need to monitor muscle areas directly beneath the electrodes. This study introduces specially designed body-conforming US-compatible FES (US-FES) electrodes constructed with a silver nanowire/polydimethylsiloxane (AgNW/PDMS) composite. We compared the performance of our body-conforming US-FES electrode with a commercial hydrogel electrode. The findings revealed that our US-FES electrode exhibited comparable conductivity and performance to the commercial one. Furthermore, US compatibility was investigated through phantom and in vivo tests, showing significant compatibility even during FES, unlike the commercial electrode. The results indicated that US-FES electrodes hold significant promise for the real-time monitoring of muscle activity during FES in clinical rehabilitative applications.}, number={8}, journal={BIOMEDICINES}, author={Moon, Sunho and Xue, Xiangming and Ganesh, Vidisha and Shukla, Darpan and Kreager, Benjamin C. and Cai, Qianqian and Wu, Huaiyu and Zhu, Yong and Sharma, Nitin and Jiang, Xiaoning}, year={2024}, month={Aug} } @article{wu_kreager_chen_zhang_abenojar_exner_jiang_2023, title={Intravascular sonothrombolysis with nanobubbles : in-vitro study}, volume={2023-July}, ISSN={["1944-9380"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85173598275&partnerID=MN8TOARS}, DOI={10.1109/NANO58406.2023.10231295}, abstractNote={Thrombosis-related morbidity and mortality pose a significant global health challenge. Existing approaches for thrombolysis, such as administering fibrinolytic agents or performing mechanical thrombectomy, come with prolonged treatment duration and risks of complications. Recent research proposes a more effective and safer alternative with contrast agents mediated ultrasound thrombolysis. Nonetheless, effectively treating retracted clots remains problematic due to their dense structure. To tackle this issue, we introduce an innovative method utilizing a stacked transducer for intravascular sonothrombolysis for higher lysis efficiency, employing a mixture of nanobubbles (NB) and microbubbles (MB). The inclusion of nanobubbles serves to enhance cavitation and improve the breakdown of clot structures. In our study, we employed a 470 kHz transducer with an aperture size of $1.4\times 1.4$ mm2 integrated in a 9-Fr catheter. Preliminary results indicate that NB- and MB/NB-mediated sonothrombolysis led to a 31% and 65% higher lysis rate, respectively, compared to MB-mediated sonothrombolysis in the case of retracted clots. These findings demonstrate the significant potential of nanobubbles in the field of sonothrombolysis applications.}, journal={2023 IEEE 23RD INTERNATIONAL CONFERENCE ON NANOTECHNOLOGY, NANO}, author={Wu, Huaiyu and Kreager, Ben and Chen, Mengyue and Zhang, Bohua and Abenojar, Eric and Exner, Agata A. and Jiang, Xiaoning}, year={2023}, pages={376–379} } @article{kreager_moon_mitchell_wu_peng_muller_huang_jiang_2023, title={Lung nodule biopsy guided using a 30 MHz ultrasound transducer: in vitro study}, volume={12488}, ISBN={["978-1-5106-6083-0"]}, ISSN={["1996-756X"]}, DOI={10.1117/12.2658585}, abstractNote={Ultrasound is often favored in biopsy guidance since it is non-ionizing, inexpensive, portable, and has a high frame rate. However, imaging probes that operate at a low frequency may not be able to differentiate between tiny targets and surrounding tissues clearly, and at a high frequency, it suffers from tissue scattering and signals attenuation, which is hard to image deeper targets such as lung tissues. In this study, we developed a biopsy needle (with a size of 18 G) integrated with a 30 MHz high-frequency ultrasound transducer (axial resolution: ~ 100 µm) for the lung nodule biopsy in vitro test. To mimic contrasting biological tissues, a melamine foam-gelatin phantom was developed. With an advancing step of 0.5 mm, the distance from the biopsy needle to the gelatin-foam boundary was estimated by the speed of sound in gelatin and the time-of-flight of the echo signal. The results showed that the 30 MHz ultrasound transducer can map the geometry of the gelatin-foam boundary, indicating the capability of distinguishing tumor and healthy lung tissue with this ultrasound-guided biopsy technique.}, journal={HEALTH MONITORING OF STRUCTURAL AND BIOLOGICAL SYSTEMS XVII}, author={Kreager, Ben and Moon, Sunho and Mitchell, Josh and Wu, Huaiyu and Peng, Chang and Muller, Marie and Huang, Chih-Chung and Jiang, Xiaoning}, year={2023} }