Publications by authors named "Lauren Shepard"

Inorganic fillers play an important role in improving the ionic conductivity of solid composite electrolytes (SCEs) for Li-ion batteries. Among inorganic fillers, perovskite-type lithium lanthanum titanate (LLTO) stands out for its high bulk Li conductivity on the order of 10 S cm at room temperature. According to a literature survey, the optimal LLTO filler should possess the following characteristics: i) a single-crystal structure to minimize grain boundaries; ii) a small particle size to increase the filler/polymer interface area; iii) a 1D morphology for efficient interface channels; and iv) cubic symmetry to facilitate rapid bulk Li diffusion within the filler.

View Article and Find Full Text PDF

Introduction: With the advancement of surgical technology, the opportunity to integrate novel surgical preparation is imperative to improve patient outcomes and enhance safety.

Methods: Patient specific perfused kidney phantoms including the tumor, parenchyma, artery, vein, and calyx were fabricated using 3D-printing and hydrogel injection molding from scans of 25 patients scheduled for robotic partial-nephrectomy (RAPN). Models are validated for anatomical accuracy, mechanical, functional properties and surrounded by the other models of relevant anatomy in a body cast for a simulated surgical rehearsal.

View Article and Find Full Text PDF

Introduction: With advancements in laser technology, urologists have been able to treat urinary calculi more efficiently by increasing the energy delivered to the stone. With increases in power used, there is an increase in temperatures generated during laser lithotripsy. The aim of this study was to evaluate the thermal dose and temperatures generated with four laser settings at a standardized power in a high-fidelity, anatomic model.

View Article and Find Full Text PDF

As laser technology has advanced, high-power lasers have become increasingly common. The Holmium: yttrium-aluminum-garnet (Ho:YAG) laser has long been accepted as the standard for laser lithotripsy. The thulium fiber laser (TFL) has recently been established as a viable option.

View Article and Find Full Text PDF

Purpose: To evaluate the thermal profiles of the holmium laser at different laser parameters at different locations in an in vitro anatomic pelvicalyceal collecting system (PCS) model. Laser lithotripsy is the cornerstone of treatment for urolithiasis. With the prevalence of high-powered lasers, stone ablation efficiency has become more pronounced.

View Article and Find Full Text PDF

Introduction: With advancements in laser technology, urologists have been able to treat urinary calculi more efficiently by increasing the energy delivered to the stone. With increases in power used, there is an increase in temperatures generated during laser lithotripsy. The aim of this study was to evaluate the thermal dose and temperatures generated with four laser settings at a standardized power in a high-fidelity, anatomic model.

View Article and Find Full Text PDF

Objective: To compare equivalency of remote to in-person training during simulated transrectal ultrasound-guided prostate biopsy, we combined three technologies (mixed reality [MR] software, smart glasses, and hydrogel simulation model). Taken together, telemonitoring harnesses data streaming to provide real-time supervision and technical assistance for surgical procedures from an expert at a remote geographical location.

Methods: Nineteen students were randomized into two groups (MR-first and in-person-first) and proctored to measure prostate volume and perform 14-biopsies over seven sessions: pretest, two MR/in-person-guided training sessions, mid-test, crossover into two in-person/MR-guided training sessions, and post-test.

View Article and Find Full Text PDF

Holmium laser enucleation of the prostate (HoLEP) has emerged as a new gold standard for treatment of benign prostatic hyperplasia; however, its steep learning curve hinders generalization of this technique. Therefore, there is a need for a benchtop HoLEP simulator to reduce this learning curve and provide training. We have developed a nonbiohazardous HoLEP simulator using modern education theory and validated it in a multicenter study.

View Article and Find Full Text PDF

Introduction: Machine learning methods have emerged as objective tools to evaluate operative performance in urological procedures. Our objectives were to establish machine learning-based methods for predicting surgeon caseload for nerve-sparing robot-assisted radical prostatectomy using our validated hydrogel-based simulation platform and identify potential metrics of surgical expertise.

Methods: Video, robotic kinematics, and force sensor data were collected from 35 board-certified urologists at the 2022 AUA conference.

View Article and Find Full Text PDF

Introduction: Open transplant nephrectomy for failed renal allograft is an invasive procedure associated with significant perioperative morbidity and mortality. Minimally invasive surgical approaches have improved a variety of patient outcomes for many surgeries. Thus, robotic assisted transplant nephrectomy (RATN) potentially offers significant patient benefit.

View Article and Find Full Text PDF

Background: 3D printed patient-specific coronary models have the ability to enable repeatable benchtop experiments under controlled blood flow conditions. This approach can be applied to CT-derived patient geometries to emulate coronary flow and related parameters such as Fractional Flow Reserve (FFR).

Methods: This study uses 3D printing to compare such benchtop FFR results with a non-invasive CT-FFR research software algorithm and catheter based invasive FFR (I-FFR) measurements.

View Article and Find Full Text PDF

We developed three-dimensionally (3D) printed patient-specific coronary phantoms that are capable of sustaining physiological flow and pressure conditions. We assessed the accuracy of these phantoms from coronary CT acquisition, benchtop experimentation, and CT-FFR software. Five patients with coronary artery disease underwent 320-detector row coronary CT angiography (CCTA) (Aquilion ONE, Canon Medical Systems) and a catheter lab procedure to measure fractional flow reserve (FFR).

View Article and Find Full Text PDF

Purpose: 3D printed patient specific vascular models provide the ability to perform precise and repeatable benchtop experiments with simulated physiological blood flow conditions. This approach can be applied to CT-derived patient geometries to determine coronary flow related parameters such as Fractional Flow Reserve (FFR). To demonstrate the utility of this approach we compared bench-top results with non-invasive CT-derived FFR software based on a computational fluid dynamics algorithm and catheter based FFR measurements.

View Article and Find Full Text PDF

3D printing has been used to create complex arterial phantoms to advance device testing and physiological condition evaluation. Stereolithographic (STL) files of patient-specific cardiovascular anatomy are acquired to build cardiac vasculature through advanced mesh-manipulation techniques. Management of distal branches in the arterial tree is important to make such phantoms practicable.

View Article and Find Full Text PDF

Purpose: Accurate patient-specific phantoms for device testing or endovascular treatment planning can be 3D printed. We expand the applicability of this approach for cardiovascular disease, in particular, for CT-geometry derived benchtop measurements of Fractional Flow Reserve, the reference standard for determination of significant individual coronary artery atherosclerotic lesions.

Materials And Methods: Coronary CT Angiography (CTA) images during a single heartbeat were acquired with a 320×0.

View Article and Find Full Text PDF