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Purpose: Retrograde intrarenal surgery is the gold-standard treatment for most kidney stones. During ureteroscopy, ureteral access sheath insertion at forces greater than 8.0 Newtons (N) risks high-grade ureteral injury. To monitor force, our institution utilizes a unique, Bluetooth-equipped device (i.e., the University of California—Irvine Force Sensor). Given the unique nature of the force sensor, we sought to develop an inexpensive and accessible force sensor based on Boyle's law and the specific amount of force required to compress an occluded 1.0 mL syringe. Materials and Methods: We evaluated three brands of 1.0 mL syringes. After setting the plunger at 1.0 mL, the syringe was occluded, and the syringe plunger was compressed. The syringe volume was recorded when the applied force on the plunger reached 4.0 N, 6.0 N, and 8.0 N. Multiple trials were performed to assess reliability and reproducibility. A method for applying this clinically was also developed. Results: The precise force thresholds identified for a 1.0 mL Luer-Lok™ Syringe (Becton Dickinson, Franklin Lakes, NJ) were 0.30 mL for 4.00 N, 0.20 mL for 6.00 N, and 0.15 mL for 8.00 N. The 1.0 mL Tuberculin Syringe and 1.0 mL Luer Slip Syringe were less precise, but compression from 1.0 to 0.40 mL, 0.25 mL, and 0.20 mL corresponded to force sensor readings that did not exceed 4.00 N, 6.00 N, and 8.00 N, respectively. Conclusions: Based on volume changes, 4.00 N, 6.00 N, and 8.00 N of force can be reliably and reproducibly achieved using an occluded 1.0 mL syringe. [ABSTRACT FROM AUTHOR]

Formatively-measured constructs are increasingly applied in information system research models. Recent work shows that exogenous formatively-measured constructs suffer from a number of problems that include interpretational confounding and a lack of external consistency. Yet replacement by reflectively-measured constructs can lead to bias if not theoretically appropriate. One solution may be to use a MIMIC construct composed of the formative measures as well as two additional reflective measures. A simulation study indicates that a MIMIC so composed mitigates the problems of interpretational confounding and poor external consistency allowing use broader use in a variety of structural models. [ABSTRACT FROM AUTHOR]