Ophthalmic Surgical Control Module for Occlusion Detection

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Solution Overview

Problem

During phacoemulsification, occlusions can occur due to lens particles blocking the hollow needle, leading to high suction pressure and potential capsular bag puncture, causing complications, and existing detection methods are prone to misinterpretation due to noise in measurement signals.

Innovation Solution

An ophthalmic surgical control module device using convolution functions with different durations and threshold values to differentiate between occlusion and noise in irrigation fluid line measurement signals, providing a control signal to manage surgical parameters and reduce complications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If pressure or volume flow measurement signals are used to detect occlusion, then occlusion detection capability is improved, but measurement precision deteriorates due to noise in the signals

Engineering Contradiction:
Improveocclusion detection capabilityVSAvoidmeasurement signal accuracy
Core Design Contradiction:
Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent segments the measurement signal evaluation into multiple time windows, processing signals at different temporal resolutions. This allows differentiation between transient noise (short duration) and genuine occlusion events (sustained pattern), resolving the contradiction between detection capability and measurement precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary signal processing by convolving measurement signals with template functions before threshold comparison. This preliminary transformation enhances the signal-to-noise ratio and prepares the data for more accurate occlusion detection, addressing the measurement precision issue.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If high suction pressure is applied to remove lens particles, then occlusion removal efficiency is improved, but harmful factors worsen due to risk of capsular bag puncture

Engineering Contradiction:
Improveocclusion removal efficiencyVSAvoidcapsular bag puncture risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements real-time feedback control by continuously monitoring pressure and flow signals, detecting occlusion events, and automatically adjusting pump operation. When occlusion is detected, the system modulates suction pressure to remove the particle while preventing excessive pressure that could cause capsular bag puncture.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts suction pressure based on real-time signal analysis. Rather than maintaining constant high pressure, the system modulates pressure levels according to detected occlusion conditions, optimizing particle removal while minimizing harmful effects on the capsular bag.

Inventive Principle:
Principle #15Dynamics

3Productivity

If continuous suction is applied during phacoemulsification, then lens particle removal is improved, but harmful factors worsen due to anterior chamber fluid loss and eye collapse risk

Engineering Contradiction:
Improvelens particle removal efficiencyVSAvoidanterior chamber collapse risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system uses feedback from flow and pressure measurements to monitor anterior chamber conditions. When fluid loss approaches dangerous levels, the system automatically modulates or stops suction, preventing eye collapse while maintaining effective lens particle removal during safe operating windows.

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

This solution enables reliable detection of occlusions and their resolution, minimizing the risk of medical complications by accurately interpreting measurement signals and adjusting surgical parameters, thus ensuring safer phacoemulsification procedures.

Implementation Method 1

a first convolution function device (51), which is set up to receive at its input a first measurement signal (x(t)) detected on an irrigation fluid line (8) from a first measurement device (19), and at its output to output an amount of a time derivative of the first measurement signal folded by means of a first convolution function (513)

Methodology Applied
Scientific EffectConvolution:

Implementation Method 2

The beginning of an occlusion or the breaking up of an occlusion can be detected by detecting measurement signals in an ophthalmosurgical system. For example, a pressure or a volume flow can be detected in an irrigation fluid line or an aspiration fluid line.

Methodology Applied
Scientific EffectPressure detection:

Data Source

PatentEP4051194B1Ophthalmo-surgical control module assembly
Publication Date: 2023.08.16 CARL ZEISS MEDITEC AG
  • EP4051194B1 patent drawingFigure 1
  • EP4051194B1 patent drawingFigure 2
  • EP4051194B1 patent drawingFigure 3

AI summary

The invention relates to an ophthalmo-surgical control module assembly (96), comprising: - a first convolution function assembly (51), which is configured to receive, at the input (511) thereof, a first measuring signal acquired on an irrigation fluid line (8) from a first measuring assembly (19), and to output, at the output (512) thereof, a value, convoluted by means of a first convolution function (513), for a time derivation of the first measuring signal, wherein the first convolution function (513) has a first period (t1), - a first threshold assembly (61), with which a first threshold value (51) for the time derivation of the first measuring signal can be configured, - a first comparator assembly (71), which is configured to receive the value of the time derivation of the first measuring signal output by the first convolution function assembly (51) and to receive the first threshold value (51) and after a predefined first time to compare the value output for the time derivation of the first measuring signal and the first threshold value (51) with one another and to output a first comparison result, - a second convolution function assembly (52), - a second threshold assembly (62), - a second comparator assembly (72), which is configured to output a second comparison result, - a first evaluation assembly (81), which is configured to receive and to evaluate the first comparison result and the second comparison result and to output a first evaluation signal, - an actuation assembly (90), which is configured to receive the first evaluation signal and to provide, as a function of the first evaluation signal, a control signal (91) to control a parameter of an ophthalmo-surgical device (95).