Electrical Ureter Stimulation for Reliable Laparoscopic Identification

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Solution Overview

Problem

Current methods for identifying the ureter during minimally-invasive surgery are unreliable and costly, often leading to ureteral injuries and increased operating room times, and pre-operative ureteral stent placement introduces additional risks and costs.

Innovation Solution

An electrical stimulator that generates a low-level electrical current to stimulate ureteral muscles, causing them to contract and be visually identifiable, eliminating the need for pre-operative stent placement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pre-operative ureteral stent placement is used to identify the ureter, then ureter identification reliability is improved, but device complexity and cost increase

Engineering Contradiction:
Improveureter identification reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical stent placement system with an electrical stimulation system. Instead of inserting physical stents into the ureter, the invention uses electrical stimuli delivered through a catheter to trigger peristaltic contractions of the ureteral smooth muscle, making the ureter visually identifiable during surgery without requiring stent placement.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state and parameters of ureteral identification from static (visualizing a stent) to dynamic (observing peristaltic contractions). By applying electrical parameters (voltage, frequency, pulse duration) to stimulate the ureter, the system creates observable motion that identifies the ureter's location and path during surgery.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If pre-operative ureteral stent placement is used to identify the ureter, then ureter identification reliability is improved, but operating time increases

Engineering Contradiction:
Improveureter identification reliabilityVSAvoidoperating time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent performs preliminary electrical stimulation of the ureter during the surgical procedure itself, rather than requiring pre-operative stent placement. The electrical stimulator is introduced through the surgical site and immediately used to identify the ureter, eliminating the separate pre-operative stenting step and reducing total operating time.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If pre-operative ureteral stent placement is used to identify the ureter, then ureter identification reliability is improved, but cost increases

Engineering Contradiction:
Improveureter identification reliabilityVSAvoidcost
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent uses a disposable electrical stimulator catheter that is inexpensive compared to ureteral stents. The stimulator is a single-use device that delivers electrical pulses through its electrodes and is then discarded, eliminating the need for expensive stent materials and the associated placement and removal procedures.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Device complexity

If visual compression method is used to identify the ureter, then device complexity is reduced, but measurement precision deteriorates

Engineering Contradiction:
Improvedevice complexityVSAvoidureter identification precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces manual visual compression with an electrical stimulation system. Instead of relying on the surgeon to manually compress and observe the ureter, the electrical stimulator automatically delivers controlled stimuli that produce visible peristaltic contractions, providing more precise and reliable identification without requiring complex manual manipulation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

5Ease of operation

If manual ureter compression is used to identify the ureter, then ease of operation is improved, but reliability deteriorates

Engineering Contradiction:
Improveease of operationVSAvoidureter identification reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent makes the ureter self-identifying through its own peristaltic response to electrical stimulation. The ureter's natural smooth muscle contractions are triggered by the electrical stimuli, causing the ureter to move and become visible on its own without requiring the surgeon to manually compress or manipulate it, thereby improving reliability while maintaining ease of operation.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The electrical stimulator allows for reliable ureter identification, reducing the risk of injury and costs associated with pre-operative stent placement, while shortening operating times and improving surgical precision.

Implementation Method 1

an electrical stimulator which generates a low-level electrical current (preferably but not necessarily in a pulsatile form), such that when the tip of the electrical stimulator is positioned near the ureter, the low-level electrical current provided by the electrical stimulator will cause the ureteral muscles to contract

Methodology Applied
Scientific EffectElectrical stimulation: Electrical Impedance Tomography

Data Source

PatentEP3104798B1Apparatus for identifying the ureter during a minimally-invasive procedure
Publication Date: 2026.04.15 THE METHODIST HOSPITAL
  • EP3104798B1 patent drawingFigure 1
  • EP3104798B1 patent drawingFigure 2
  • EP3104798B1 patent drawingFigure 3

AI summary

A method for identifying a ureter during a medical procedure, the method comprising: providing an electrical stimulator comprising: a shaft having at least one electrode; and a power supply connected to the at least one electrode for providing an electrical signal to the at least one electrode; advancing the shaft so that the at least one electrode contacts tissue; operating the power supply so that the electrical signal is applied to the tissue; and visually observing the tissue to determine the presence of a ureter in the tissue.