Smart Kidney Stone Basket: A Proof of Concept With Digital Feedback Force Monitoring

Abstract

Ureteroscopy with stone extraction devices is a common treatment for urolithiasis but carries risks, such as ureteral wall avulsion due to excessive withdrawal forces. These forces arise from friction between the stone basket and the ureteral wall, and existing devices lack real-time feedback, relying on the surgeon's tactile judgment, which may lead to preventable injuries. This study addresses this gap by developing a system to measure and monitor withdrawal forces during stone retrieval. The system integrates a linear variable differential transformer (LVDT) sensor, Arduino microcontroller, calibrated spring mechanism, and a kidney stone basket, providing force feedback categorized into safe, cautionary, and high-risk zones. Bench-top trials demonstrated its reliability, with force measurement accuracy (variance ±0.05 N) and classification into safe (<5.396 N), cautious (5.396 N–9.809 N), and dangerous (>9.809 N) zones, in line with thresholds for tissue damage reported in literature. The system demonstrated force control within safe thresholds, reducing excessive withdrawal force incidents by an estimated 30% compared to conventional tactile-based extraction, potentially lowering the risk of ureteral injuries such as perforation and avulsion. Additionally, this feedback mechanism can be incorporated into ureteroscopy simulators and surgical training programs, allowing residents to visualize force applications in real-time and develop safer extraction techniques. By providing quantitative force thresholds, the system enables objective skill assessment and structured training exercises, helping residents refine techniques before performing procedures. Future research will focus on clinical validation and expanding the system's capabilities to improve surgical outcomes.