Bio


Ning Lu received a joint Ph.D. degree in Biomedical Engineering and Scientific Computing from the University of Michigan, Ann Arbor, USA, in 2023. Previously, she earned a B.S.E. degree (highest honors) in Biomedical Engineering from Southeast University, Nanjing, China, in 2018. From May 2022 to September 2022, she worked at Meta (formerly Facebook) Reality Labs as a research scientist intern on ultrasonic eye tracking for AR/VR wearable devices, in Redmond, Washington, USA. Her research interests include ultrasound instrumentation, ultrasound therapy, ultrasound imaging algorithms, and AI in healthcare.

Stanford Advisors


All Publications


  • Treatment envelope of transcranial histotripsy: challenges and strategies to maximize the treatment location profile. Physics in medicine and biology Lu, N., Yeats, E., Sukovich, J., Hall, T. L., Pandey, A., Xu, Z. 2024

    Abstract

    A 750kHz, 360-element ultrasound array has been built for transcranial histotripsy applications. This study aims to evaluate its performance to determine whether this array is adequate for treating a wide range of brain locations through a human skull. Treatment location profiles in 2 excised human skulls were experimentally characterized based on passive cavitation mapping. Full-wave acoustic simulations were performed in 8 human skulls to analyze the ultrasound propagation at shallow targets in skulls with different properties. Results showed that histotripsy successfully generated cavitation from deep to shallow targets within 5 mm from the skull surface in the skull with high SDR and small thickness, whereas in the skull with low SDR and large thickness, the treatment envelope was limited up to 16 mm from the skull surface. Simulation results demonstrated that the treatment envelope was highly dependent on the skull acoustic properties. Pre-focal pressure hotspots were observed in both simulation and experiments when targeting near the skull. For each skull, the acoustic pressure loss increases significantly for shallow targets compared to central targets due to high attenuation, large incident angles, and pre-focal pressure hotspots. Strategies including array design optimization, pose optimization, and amplitude correction, are proposed to broaden the treatment envelope. This study identifies the capabilities and limitations of the 360-element transcranial histotripsy array and suggests strategies for designing the nextgeneration transcranial histotripsy array to expand the treatment location profile for a future clinical trial. .

    View details for DOI 10.1088/1361-6560/ad8d9f

    View details for PubMedID 39481233

  • In Vivo Cavitation-Based Aberration Correction of Histotripsy in Porcine Liver. IEEE transactions on ultrasonics, ferroelectrics, and frequency control Yeats, E., Lu, N., Stocker, G., Komaiha, M., Sukovich, J. R., Xu, Z., Hall, T. L. 2024; 71 (8): 1019-1029

    Abstract

    Histotripsy is a noninvasive ablation technique that focuses ultrasound pulses into the body to destroy tissues via cavitation. Heterogeneous acoustic paths through tissue introduce phase errors that distort and weaken the focus, requiring additional power output from the histotripsy transducer to perform therapy. This effect, termed phase aberration, limits the safety and efficacy of histotripsy ablation. It has been shown in vitro that the phase errors from aberration can be corrected by receiving the acoustic signals emitted by cavitation. For transabdominal histotripsy in vivo, however, cavitation-based aberration correction (AC) is complicated by acoustic signal clutter and respiratory motion. This study develops a method that enables robust, effective cavitation-based AC in vivo and evaluates its efficacy in the swine liver. The method begins with a high-speed pulsing procedure to minimize the effects of respiratory motion. Then, an optimal phase correction is obtained in the presence of acoustic clutter by filtering with the singular value decomposition (SVD). This AC method reduced the power required to generate cavitation in the liver by 26% on average (range: 0%-52%) and required ~2 s for signal acquisition and processing per focus location. These results suggest that the cavitation-based method could enable fast and effective AC for transabdominal histotripsy.

    View details for DOI 10.1109/TUFFC.2024.3409638

    View details for PubMedID 38837932

  • Neuronavigation-Guided Transcranial Histotripsy (NaviTH) System. Ultrasound in medicine & biology Choi, S. W., Komaiha, M., Choi, D., Lu, N., Gerhardson, T. I., Fox, A., Chaudhary, N., Camelo-Piragua, S., Hall, T. L., Pandey, A. S., Xu, Z., Sukovich, J. R. 2024

    Abstract

    The goal of the work described here was to develop the first neuronavigation-guided transcranial histotripsy (NaviTH) system and associated workflow for transcranial ablation.The NaviTH system consists of a 360-element, 700 kHz transmitter-receiver-capable transcranial histotripsy array, a clinical neuronavigation system and associated equipment for patient-to-array co-registration and therapy planning and targeting software systems. A workflow for NaviTH treatments, including pre-treatment aberration correction, was developed. Targeting errors stemming from target registration errors (TREs) during the patient-to-array co-registration process, as well as focal shifts caused by skull-induced aberrations, were investigated and characterized. The NaviTH system was used in treatments of two <96 h post-mortem human cadavers and in experiments in two excised human skullcaps.The NaviTH was successfully used to create ablations in the cadaver brains as confirmed in post-treatment magnetic resonance imaging A total of three ablations were created in the cadaver brains, and targeting errors of 9, 3.4 and 4.4 mm were observed in corpus callosum, septum and thalamus targets, respectively. Errors were found to be caused primarily by TREs resulting from transducer tracking instrument design flaws and imperfections in the treatment workflow. Transducer tracking instrument design and workflow improvements reduced TREs to <2 mm, and skull-induced focal shifts, following pre-treatment aberration correction, were 0.3 mm. Total targeting errors of the NaviTH system following the noted improvements were 2.5 mm.The feasibility of using the first NaviTH system in a human cadaver model has been determined. Although accuracy still needs to be improved, the proposed system has the potential to allow for transcranial histotripsy therapies without requiring active magnetic resonance treatment guidance.

    View details for DOI 10.1016/j.ultrasmedbio.2024.04.001

    View details for PubMedID 38789304