This PDF file contains the front matter associated with SPIE Proceedings Volume 11212, including the Title Page, Copyright information, Table of Contents, Author and Conference Committee lists.

Transperineal laser ablation (TPLA) is a novel minimal invasive treatment of benign prostatic obstruction. TPLA can be performed in an outpatient day-care setting under local anesthesia with optional conscious sedation. The mechanism is bases on thermoablation resulting in coagulative necrosis, which is induced by the laser light of 1064nm. Laser light is delivered in the prostate trough transperineal placed needles. This study aims to treat 20 men by TPLA to evaluate safety and feasibility, and voiding outcomes. TPLA has the potential to become an alternative for standard treatments with urethral approach that require general or spinal anesthesia and hospital admittance.

Although laser lithotripsy is now the preferred treatment option for urolithiasis due to shorter operation time and a better stone-free rate [1], the optimal laser settings for URS (Ureteroscopic lithotripsy) to enable shorter operating times remain unclear. This study aims to identify optimal laser settings for Ho:YAG laser-lithotripsy to maximize the ablation rate while minimizing the retropulsion, as well as to improve the discharge of fragments via the urinary tract. The net result will be an increase in treatment success and patient satisfaction by ameliorating the stone-free rate.

In vitro investigations of Ho:YAG laser-induced stone ablation and retropulsion were performed with a bench top model first introduced by Sroka’s group [2]. A commercial Ho:YAG laser system (Lumenis VersaPulse PowerSuite 100W, Lumenis Ltd., Yokneam, Israel) was used as the laser pulse source, with pulse energy from 0.2 J up to 1.5 J and repetition rate from 5 to 40 Hz. A DOE with two replicate points and two lack-of-fit points was performed on artificial BEGO stones of sample size 14 under reproducible experimental conditions (fiber size: 365 μm, S-LLF365 SureFlex Fiber, Boston Scientific Corporation, San Jose, CA, USA). The best fit to the experimental data was analyzed utilizing the design of experiment software, which can produce the numerical formulas for the response surfaces of ablation rate and retropulsion in terms of laser pulse parameters [3].

The coded numerical formulas for the response surfaces of ablation speed and retropulsion velocity are generated. The coded equation is useful for identifying the relative impact of the factors by comparing their coefficients. Upon examination of the laser ablation of stone phantoms (BEGO), the laser pulse energy is 1.4 times the impact of the frequency, and laser pulse peak power’s impact is the same as the frequency; while for retropulsion, the laser pulse energy is 5.8 times as the impact of the frequency, and laser pulse peak power’s impact is 13 times as the frequency; A series of laser settings for relatively efficient laser lithotripsy were identified in terms of laser pulse energy and peak power.

The laser pulse energy or peak power in reference to frequency has a higher impact coefficient to stone retropulsion as compared to stone ablation in Ho:YAG laser-lithotripsy. The most effective way to reduce stone retropulsion during laser lithotripsy is to reduce the laser pulse peak power (which has the highest impact coefficient in the coded response equation).

Background: Near infrared spectroscopy (NIRS) is used to quantify multiple physiologic measures; several of these are applied to optimize muscle training regimens in elite athletes. However, pelvic floor muscle training (PMFT), the definitive therapy for urge urinary incontinence (UUI) due to PFM damage/dysfunction in women, lacks quantifiable measures beyond simple pressure manometry. A NIRS interface able to transvaginally monitor the PFM bilaterally has been developed; we now describe a method to quantify oxygen kinetics in the PFM.

Methods: The NIRS interface (interoptode distance 20 mm) enables dual-channel monitoring at 10 Hz during PFM sustained maximal voluntary contraction (SMVC) with a 4-wavelength (766nm, 861nm, 906nm 971nm) continuous wave instrument. Changes in oxy and deoxy-hemoglobin concentration (O₂Hb/HHb) in the right and left PFM were used to derive HbDiff (O₂Hb - HHb). Established HbDiff half-recovery time (½RT) methodology was then applied to quantify PFM reoxygenation commencing on cessation of SMVC.

Results: SMVCs were monitored successfully in 15 asymptomatic women; contraction strength and duration varied; post- SMVC reoxygenation HbDiff (½RT) was quantified for both the right and left sides of the PFM.

Conclusions: Skeletal muscle recovery from exercise-induced oxygen deficit indicates oxidative capacity; this equates with muscular fitness. SMVC is a robust measure of muscle strength and endurance, and HbDiff in occlusion free ½RT analysis reflects metabolic changes within muscle better than O₂Hb. This pilot study shows the feasibility of using transvaginal NIRS data to derive a quantitative measure of PFM oxygen kinetics relevant to improving the evaluation PFM dysfunction in UUI and the efficacy in PMFT.

Urothelial carcinoma (UC) is the most common type of bladder cancer, and its treatment depends from both tumour invasiveness (stage) and aggressiveness (grade). The gold standard for detecting UC is white-light cystoscopy, followed by tissue biopsy and histopathological examination; however, such process is invasive, time-consuming, operatordependent and prone to sampling errors. In this framework, optical spectroscopy techniques can provide a fast, label-free and non-invasive tool for improving diagnosis. Thus, we combined auto-fluorescence, diffuse reflectance and Raman spectroscopy in a compact and transportable setup based on an optical fibre-bundle probe. This experimental setup was used for studying fresh biopsies of urothelial tumour (129 samples) and healthy bladder (40 samples) collected from 78 patients undergoing Transurethral Resection of Bladder Tumours (TURBT). The recorded data were analysed using Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) for obtaining an automated classification of the examined samples based on the intrinsic spectral information provided by all three techniques. We found that healthy and diseased tissues showed significant spectral differences for each technique, resulting in high accuracy (up to 90%) from PCA-LDA routines. While fluorescence spectroscopy seems sensitive enough for detecting UC, we found that a multimodal approach is crucial for obtaining high discriminating capability (<80%) in grading and staging tumour biopsies. In conclusion, the presented strategy generates results similar to gold standard histology, but in a fast and labelfree way, offering the potential for endoscopic in vivo applications.

The bladder urothelium is usually considered as an impermeable barrier to urine, but recent reports pointed that it was not only a passive impermeable membrane but also has some sensory and signaling functions. While aquaporin expression has been found in the urothelium, which implicits water transportation through the urothelium, it has never been observed directly the process of water transportation through the urothelium. We describe here for first time how water is transported through the urothelium through osmosis.

Delayed graft function occurs in 40% of kidney transplantation cases, and is not apparent until after surgery has concluded. To understand changes in donor kidney tissue before transplantation, spatial frequency domain imaging (SFDI) was used to measure absorption and reduced scattering coefficients in excised porcine kidneys as they underwent a standard period of cold ischemic time (CIT). SFDI indicated an increase in reduced scattering and absorption. The scattering b parameter increased until 24 hours, then returned towards baseline. These results suggest that continued investigation may lead to the development of a noninvasive assessment for graft viability.

We devised a method to continuously measure the distance from fiber tip to stone surface based on the reflectance of an aiming beam back into the fiber during a popcorning scenario to determine how often the stone is close to the laser fiber when firing. Continuous light was coupled into a 200 µm fiber taped immediately next to the holmium fiber. Fibers were placed into a test tube with 5 BegoStones. Reflected light back into the fiber passed through the coupler to a biased photodiode. The fraction of time a stone was within 0.5 mm varied from 5%-18%.

Numerical Simulations of Bubble Dynamics in Laser Lithotripsy Steven Peng1; Thomas Hasenberg1; Timothy Harrah2; James Zhang1; Dongyul Chai1; Hyun Wook Kang3 1Boston Scientific Corporation, 150 Baytech Dr., San Jose, CA, USA 95134 2Boston Scientific Corporation, 100 Boston Scientific Way, Marlborough, MA 01752 3Department of Biomedical Engineering and Center for Marine-integrated Technology (BK21Plus), Pukyong National University, Busan 48513, Korea Abstract: Laser lithotripsy has been clinically implemented to treat kidney stone disease by using the Holmium:YAG (λ = 2.12 μm) for two decades. The medical procedure involves bubble formation during delivery of infrared laser energy in water (saline). Bubble dynamics plays an important role of optimization of laser power delivery for best stone fragmentation and dusting effects. A high speed camera image system has been used to observe vapor bubble formation in a water tank, but this method faces more challenge to observe bubble dyna

The objective of this study was to map parameter boundaries for thermally safe laser and irrigation settings. The experimental system consisted of models simulating ureter, renal calyx, and renal pelvis placed in a water bath maintained at 37°C. Thermal dose for each trial was calculated based on Dewey and Sapareto t43 methodology. A parameter safety boundary was established by plotting the maximal safe power level for each irrigation rate. The boundary was found to be linear for each scenario with the renal pelvis able to tolerate the highest laser power and renal calyx the least power without injury.

The present research proposed a combination of a chemical (glutaraldehyde - GTA) with either 808 nm or 405 nm laser light to disinfect bacterial biofilms (both gram-positive and gram-negative bacteria) inside polytetrafluoroethene tubes that mimic the working channels of the flexible ureteroscopes. The combination of (GTA+405 nm) was hypothesized to be more effective than the combination of (GTA+ 808 nm) for ureteroscope reprocessing to prevent any secondary infection in the urinary tract during the ureteroscopy.