Air Force 1: Innovative Cost-Effective Ureteroscopic Force Sensor "Presentation" - Bruce Gao
August 14, 2024
At the World Congress of Endourology and Uro-Technology, Bruce Gao presents the development and evaluation of a cost-effective force sensor for ureteroscopic applications called the Air Force 1. This device uses readily available materials to measure insertion forces during ureteral access sheath placement, aiming to prevent high-grade ureteral injuries. Dr. Gao concludes that this inexpensive method reliably measures clinically relevant forces during ureteroscopic procedures.
Biographies:
Bruce Gao, MD, Urologist, Department of Urology, University of California, Irvine, CA
Biographies:
Bruce Gao, MD, Urologist, Department of Urology, University of California, Irvine, CA
Read the Full Video Transcript
Bruce Gao: Dear UroToday viewers, my name is Bruce Gao. I am an endourology fellow at the University of California, Irvine, and I'm excited to present our project titled Development and Initial Evaluation of a Cost-Effective Force Sensor for Ureteroscopic Application: The Air Force 1. Prior work at our university using a novel force sensor has shown that ureteral access sheath insertion force greater than eight Newtons risks high-grade ureteral injury. To provide urologists around the world the ability to measure force, we developed an easily assembled and cost-effective force sensor using materials present in all operating rooms.
The device, dubbed Air Force 1, is based on the specific amount of force required to compress an air-filled occluded 1 mL syringe with a plunger starting at 1 mL. Three brands of 1 mL medical-grade syringes were tested: the Luer-Lok Syringe and Luer Slip Syringe by Becton Dickinson and the Tuberculin Syringe by Berpu. After setting the plunger at 1 mL, the syringe was occluded, and the syringe plunger was compressed at a constant rate with the UCI-Force Sensor. As the plunger was compressed, forces of four, six, and eight Newtons, as measured in hundredths of a Newton, were correlated with the milliliter graduations on the syringe. Testing was performed in quintuplicates, and 225 readings were recorded.
Four, six, and eight Newtons were precisely identified as 0.3, 0.2, and 0.15 milliliters, respectively, on the Becton Dickinson 1 mL Luer-Lok syringe. The Tuberculin and Luer Slip syringes were less precise; however, compression to 0.25 and 0.2 milliliters corresponded to six and eight Newtons, respectively. A method for applying this clinically was developed with an overall cost of less than $4. As demonstrated here on the right, the plunger of a 1 mL syringe is set to the 1 mL marking and then occluded with a cap and adhesive. Next, the occluded 1 mL syringe is placed into the barrel of a 20 mL syringe and secured with a Kelly clamp. The guidewire over which the access sheath has already been passed is then threaded through the 20 mL syringe. The surgeon then advances the access sheath by pushing on the plunger of the 1 mL syringe and is thereby able to monitor the applied force during access sheath insertion. The Air Force 1 has now been used successfully in over 20 patients without incurring a single high-grade ureteral injury.
In conclusion, based on volume changes, benchtop testing indicates that four, six, and eight Newton force measurements can be reliably and reproducibly achieved using an occluded 1 mL syringe. Furthermore, we have now developed an effective and inexpensive method for applying this information in the clinical setting. Thank you.
Bruce Gao: Dear UroToday viewers, my name is Bruce Gao. I am an endourology fellow at the University of California, Irvine, and I'm excited to present our project titled Development and Initial Evaluation of a Cost-Effective Force Sensor for Ureteroscopic Application: The Air Force 1. Prior work at our university using a novel force sensor has shown that ureteral access sheath insertion force greater than eight Newtons risks high-grade ureteral injury. To provide urologists around the world the ability to measure force, we developed an easily assembled and cost-effective force sensor using materials present in all operating rooms.
The device, dubbed Air Force 1, is based on the specific amount of force required to compress an air-filled occluded 1 mL syringe with a plunger starting at 1 mL. Three brands of 1 mL medical-grade syringes were tested: the Luer-Lok Syringe and Luer Slip Syringe by Becton Dickinson and the Tuberculin Syringe by Berpu. After setting the plunger at 1 mL, the syringe was occluded, and the syringe plunger was compressed at a constant rate with the UCI-Force Sensor. As the plunger was compressed, forces of four, six, and eight Newtons, as measured in hundredths of a Newton, were correlated with the milliliter graduations on the syringe. Testing was performed in quintuplicates, and 225 readings were recorded.
Four, six, and eight Newtons were precisely identified as 0.3, 0.2, and 0.15 milliliters, respectively, on the Becton Dickinson 1 mL Luer-Lok syringe. The Tuberculin and Luer Slip syringes were less precise; however, compression to 0.25 and 0.2 milliliters corresponded to six and eight Newtons, respectively. A method for applying this clinically was developed with an overall cost of less than $4. As demonstrated here on the right, the plunger of a 1 mL syringe is set to the 1 mL marking and then occluded with a cap and adhesive. Next, the occluded 1 mL syringe is placed into the barrel of a 20 mL syringe and secured with a Kelly clamp. The guidewire over which the access sheath has already been passed is then threaded through the 20 mL syringe. The surgeon then advances the access sheath by pushing on the plunger of the 1 mL syringe and is thereby able to monitor the applied force during access sheath insertion. The Air Force 1 has now been used successfully in over 20 patients without incurring a single high-grade ureteral injury.
In conclusion, based on volume changes, benchtop testing indicates that four, six, and eight Newton force measurements can be reliably and reproducibly achieved using an occluded 1 mL syringe. Furthermore, we have now developed an effective and inexpensive method for applying this information in the clinical setting. Thank you.