Development and Initial Evaluation of a Cost-Effective Force Sensor for Ureteroscopic Application.

Area of Science:

• Urology
• Medical Devices
• Surgical Innovation

Background:

• Retrograde intrarenal surgery is standard for kidney stones.
• Ureteral access sheath insertion exceeding 8.0 N risks injury.
• Current force monitoring devices are unique and not widely accessible.

Purpose of the Study:

• To develop an inexpensive and accessible force sensor.
• To utilize Boyle's law and 1.0 mL syringes for force measurement.
• To establish force thresholds for safe ureteral access sheath insertion.

Main Methods:

• Evaluated three brands of 1.0 mL syringes.
• Occluded syringes and compressed plungers to specific forces (4.0 N, 6.0 N, 8.0 N).
• Recorded volume changes and assessed reliability and reproducibility.

Main Results:

• A 1.0 mL Luer-Lok™ Syringe showed precise volume changes at 4.0 N (0.30 mL), 6.0 N (0.20 mL), and 8.0 N (0.15 mL).
• Other 1.0 mL syringe types demonstrated less precision but reliable force correlation.
• Volume changes in occluded 1.0 mL syringes reliably indicate applied forces of 4.0 N, 6.0 N, and 8.0 N.

Conclusions:

• An occluded 1.0 mL syringe can serve as a reliable and reproducible force sensor.
• This method offers an inexpensive alternative for monitoring forces during ureteroscopy.
• Potential to enhance patient safety by preventing ureteral injury during stone treatment.