No abstract

No abstract

The penetration depth of photoacoustic imaging in biological tissues has been fundamentally limited by the strong optical attenuation when light is delivered externally through the tissue surface. To address this issue, we previously reported internal-illumination photoacoustic imaging using a customized radial-emission optical fiber diffuser, which, however, has complex fabrication, high cost, and non-uniform light emission. To overcome these shortcomings, we have developed a new type of low-cost fiber diffusers based on a graded-scattering method in which the optical scattering of the fiber diffuser is gradually increased as the light travels. The graded scattering can compensate for the optical attenuation and provide relatively uniform light emission along the diffuser. We performed Monte Carlo numerical simulations to optimize several key design parameters, including the number of scattering segments, scattering anisotropy factor, divergence angle of the optical fiber, and reflective index of the surrounding medium. These optimized parameters collectively result in uniform light emission along the fiber diffuser and can be flexibly adjusted to accommodate different applications. We fabricated and characterized the prototype

No abstract

perspective. Factors important to patients for surgical success after stone surgery have not been explored. We looked to determine patient factors important for surgical success, changes in such factors before and after surgery, and the quantity of criteria reduction for surgical success.METHODS: Established stone patients scheduled for renal stone surgery completed a modified patient centered outcome questionnaire (PCOQ) before and 6-8 weeks after surgery. The modified PCOQ evaluated multiple domains including: pain, hematuria, urinary symptoms, infections, emotional distress, and activity of daily living impairment. Patients rated their current, desired, and expected levels within each domain as well as levels for surgical success. Patient were also queried on the importance of being stone free.RESULTS: Our cohort consisted of 59 patients, 68% female with a mean age of 54.9 years. Prior stone history was reported in 69% and 51% underwent prior stone surgery. Ureteroscopy was performed in 58% of patients and 42% underwent percutaneous nephrolithotomy. 62% of patients were stone free after surgery based on follow up renal ultrasound. 64% of patients rated pain as the most important factor for surgical success, while 13% rated being stone free as most important. The top 3 reported factors for success were pain (85%), activity of daily living impairment (44%) and stone free status (29%). Subjects who rated pain as their most important factor, on average, required a 78% reduction in symptoms for surgery to be considered successful. There was a statistically significant decrease in mean levels of symptoms for all domains after surgery (p < 0.0001).CONCLUSIONS: Success after stone surgery has long been synonymous with stone free rates, but the paradigm may be shifting. Definitions for surgical success for stone disease should now incorporate the patient perspective. Within our cohort, patients' definitions of success were varied and revolved around pain and symptom resolution with daily activities. Patients not only seek relief from symptoms, but large reductions are required for surgery to be considered successful. However, most patients did not require complete resolution of symptoms to consider treatment a success. Provider insight into individual patient's success criteria may help with shared decision making, preoperative counseling and postoperative patient satisfaction.