Robotic Ultrasonic Tissue Resection With AC Signal Feedback

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Solution Overview

Problem

Current surgical procedures for removing or altering structures within the body, such as discectomies and pedicle screw insertions, rely heavily on manual techniques and visual feedback, lacking precision and invasiveness.

Innovation Solution

A robotic surgical system with a robotically controlled ultrasonic instrument that uses AC drive signals to vibrate a tip against tissue, combined with surgical navigation and tracking, to precisely resect target tissue while avoiding non-targeted areas, utilizing a robotic manipulator for controlled movement and haptic feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If freehand techniques are used for tissue removal, then the procedure can be performed with simple manual tools, but surgical precision and reliability are insufficient

Engineering Contradiction:
Improvesurgical precisionVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

A robotic manipulator serves as an intermediary between the surgeon's commands and the ultrasonic instrument, enabling precise control of tissue resection while reducing direct manual manipulation. The robotic system translates surgical intent into accurate instrument positioning and movement.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system continuously monitors characteristics of the AC drive signal during ultrasonic vibration to detect tissue contact and resection status. This real-time feedback enables closed-loop control, allowing the robotic manipulator to adjust its movements based on actual tissue interaction, thereby improving surgical precision.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If surgical navigation is used to track tool position, then location information becomes more precise, but the system complexity and operational difficulty increase

Engineering Contradiction:
Improvelocation precisionVSAvoidoperational ease
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The robotic manipulator autonomously positions and controls the ultrasonic instrument based on pre-programmed surgical paths and real-time feedback, reducing the need for continuous manual adjustment and navigation interpretation by the surgeon. The system performs self-positioning and self-correction during the procedure.

Inventive Principle:
Principle #25Self-service

3Reliability

If manual tools are used for tissue resection, then the procedure is less invasive in terms of equipment, but the reliability and consistency of tissue removal are insufficient

Engineering Contradiction:
Improvetissue resection reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system replaces manual mechanical control with an automated robotic manipulator that uses sensors and control algorithms to regulate ultrasonic vibration and tissue resection. This substitution of manual mechanical operation with an automated electromechanical system improves reliability and consistency of tissue removal.

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

Solution Approach 2:

Real-time monitoring of AC drive signal characteristics provides feedback on tissue contact and resection progress, enabling the robotic manipulator to adjust its movements and force application dynamically. This closed-loop control ensures reliable and consistent tissue removal according to the planned surgical path.

Inventive Principle:
Principle #23Feedback

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

Enhances surgical precision and reduces invasiveness by enabling precise tissue resection and sensing, improving procedural accuracy and reducing the learning curve for surgeons.

Implementation Method 1

driving the ultrasonic instrument with an AC drive signal to induce vibrations in a tip of the ultrasonic instrument, and positioning the ultrasonic instrument so that a distal region of the tip is vibrating against a portion of the patient tissue

Methodology Applied
Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Data Source

PatentEP4691387A1Robotically controlled ultrasonic instrument
Publication Date: 2026.02.11 STRYKER CORP
  • EP4691387A1 patent drawingFigure 1
  • EP4691387A1 patent drawingFigure 2
  • EP4691387A1 patent drawingFigure 3

AI summary

Systems and methods for operating a robotic manipulator coupled to an ultrasonic instrument to control movement of the ultrasonic instrument to resect a target volume of patient tissue. The ultrasonic instrument is driven with an AC drive signal that induces vibrations in a tip of the ultrasonic instrument, and is positioned so that a distal region of the tip is vibrating against a portion of the patient tissue. A characteristic of the AC drive signal is obtained when the distal region of the tip is vibrating against the tissue portion, and a determination is made of whether the tissue portion corresponds to the target volume based on the determined characteristic. The robotic manipulator is operated to control movement of the ultrasonic instrument relative to the patient tissue based on the determination.