Surgical Instrument Detection via Dual Electromagnetic Sensors

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Solution Overview

Problem

Current surgical navigation systems face challenges in accurately detecting and distinguishing between different types of surgical instruments within the body, particularly in minimally invasive procedures, due to limitations in sensor alignment and orientation detection, which affects precise instrument positioning and image overlay during surgeries.

Innovation Solution

A detection system utilizing two electromagnetic sensors with a field generator, where the sensors are strategically aligned within surgical instruments like hollow needles and endoscopes to determine their type and position, allowing for precise angular orientation and position detection, enabling automatic recognition and correct image representation on a surgeon's monitor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single electromagnetic sensor is used to detect surgical instruments, then the device complexity is reduced, but the measurement precision of instrument position and orientation cannot be achieved

Engineering Contradiction:
Improveinstrument position and orientation detectionVSAvoidsensor unit structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The detection system divides the sensing function into two separate electromagnetic sensors positioned at different locations within the instrument shaft. One sensor detects the electromagnetic field at its position while the other detects the field at a different position, allowing the system to calculate both position and orientation through coordinate transformations based on the known fixed distance and angular relationship between the sensors.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If sensors are fixed rigidly in surgical instruments, then the measurement precision is improved, but the adaptability to different instrument types is reduced

Engineering Contradiction:
Improvesensor position detectionVSAvoidinstrument type recognition
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The sensor unit is designed with a universal configuration that can be adapted to different surgical instrument types. The two electromagnetic sensors are positioned at fixed locations with a known angular relationship, and the system uses coordinate transformations to calculate instrument orientation relative to the instrument's own coordinate system. This allows the same sensor unit to detect both rotationally symmetric instruments (like needles) and non-symmetric instruments (like endoscopes) by adjusting the reference orientation based on instrument type.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of operation

If optical sensors are used for navigation, then the ease of operation is improved, but radiation exposure increases and image quality is affected

Engineering Contradiction:
Improvesurgeon freedom of movementVSAvoidradiation exposure
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The system replaces optical sensing mechanisms with electromagnetic field-based detection. Electromagnetic sensors detect the position and orientation of surgical instruments by measuring electromagnetic field characteristics rather than using optical lines of sight. This eliminates the need for optical cameras and radiation-based imaging during the surgical procedure, reducing radiation exposure while maintaining surgeon freedom of movement.

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

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

Enables accurate detection and display of surgical instruments' positions and orientations within the body, enhancing surgical precision by providing clear, instrument-specific image overlays on CT, MRI, or X-ray images, thereby improving surgical navigation and instrument placement.

Implementation Method 1

A detection system is proposed which utilizes two electromagnetic sensors (1.1, 1.2) with a field generator (2.1)

Methodology Applied
Scientific EffectElectromagnetic field: Electromagnetic Induction

Data Source

PatentEP3500152B1Detection system for automatically detecting surgical instruments
Publication Date: 2023.10.18 JOIMAX GMBH
  • EP3500152B1 patent drawingFigure 1
  • EP3500152B1 patent drawingFigure 2
  • EP3500152B1 patent drawingFigure 3

AI summary

In relation to the automatic detection of surgical instruments in respect of their type and their location, the invention provides a detection system having at least two surgical instruments, which each have at least one cavity extending along a longitudinal axis of the instrument and a proximal entry region to the cavity, wherein an angle of the proximal entry region in relation to the longitudinal extent of the cavity is different in the at least two instruments, having a sensor unit with two electromagnetic sensors that is insertable into the cavity, one sensor thereof being arranged extending axially in the cavity, the other sensor thereof being arranged in the entry region, having a field generator for producing an electromagnetic field, and having an evaluation unit for evaluating signals transmitted to the evaluation unit from the sensors according to their position in the field of the field generator.