Pd42-10 a Smart Kidney Stone Basket With Force Feedback

Abstract

to receive treatment with low power/high frequency settings of 0.2 J-0.4 J and 50 Hz [LP/HF group] or with conventional laser settings of 0.5 J-1.0 J and 5-10 Hz [conventional group]. Patient demographics and perioperative parameters were assessed.RESULTS: Of 103 patients, 52 patients were in the LP/HP group and 51 were in the conventional group. The mean age was 60 years (26-85) [LP/HF] and 57 years (25-91) [conventional]. The mean aggregate stone diameter/burden was 1.6 cm (0.5-4.5 cm) [LP/HF] and 1.0 cm (0.4-3.5 cm) [conventional]. All stones were treated with a 200 micron holmium laser fiber. In 13 cases (25%) using LP/HF settings, the energy level was increased from 0.2 J to 0.3 J-0.4 J. In 2 additional cases (3.8%), conventional settings (0.5 J-1.0 J, rate 5-10 Hz) were used due to harder stone compositions. Stone compositions included: calcium oxalate/mixed composition (54%), calcium oxalate monohydrate (26%), uric acid (10%), struvite (8%), and cystine (2%). The mean operative time was 64.4 min [LP/ HF] and 57.4 min [conventional] (P ¼ 0.37), and the total energy usage was 5.42 W [LP/HF] and 1.96 W [conventional] (P < 0.01).No trimming of the laser fiber tip was required in the LP/HF group as compared to 24% of cases that required trimming in the conventional group. Complete stone fragmentation into fine dust was achieved in 7 cases (13.4%) [LP/HF] obviating the need for stone basketing. No bleeding complications or gross ureteral perforations were encountered during any procedures. Subjectively, there was decreased visibility due to bleeding during 5 cases (9.8%) using conventional settings.CONCLUSIONS: Selecting energy settings of 0.2 J-0.4 J and 50 Hz results in effective stone fragmentation into fine dust, thus reducing the use of stone baskets to achieve stone-free status. These settings can be adjusted to work well for all stone compositions. Additionally, these settings serve to reduce laser fiber tip degradation and minimize stone retropulsion without increasing operative time.

A fluid‐structure interaction (FSI)‐based numerical investigation of peristalsis in an obstructed human ureter

“…However, even this technique can lead to complications in basketing and also injury to the ureter in some cases . The current authors are involved in an effort towards developing an intelligent kidney stone extraction basket, which measures excessive forces on the ureter while extracting stones using a force sensor . The device records safe and unsafe zones using experimental values of force during perforation and avulsion.…”