Phacoemulsification Fluid Control for Stable Intraocular Pressure
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Solution Overview
Problem
Phacoemulsification procedures experience significant fluctuations in intraocular pressure, which can be dangerous due to the unpredictable loss of irrigation fluid through the puncture site during surgery, complicating the surgeon's view and increasing the risk of accidental needle puncture.
Innovation Solution
An ophthalmosurgical appliance with volumetric flow determination devices and a control system to detect and compensate for fluid leaks by adjusting irrigation fluid pressure, using differential volumetric flow signals to maintain stable intraocular pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional phacoemulsification is performed without advanced flow control, then the device complexity is low, but intraocular pressure fluctuates significantly causing safety issues and poor surgical visibility
Solution Approach 1:
The control device receives a differential volumetric flow signal from the difference element that continuously monitors the balance between irrigation fluid inflow and aspiration fluid outflow. Based on this feedback signal and the irrigation fluid setpoint pressure signal, the control device automatically adjusts the irrigation fluid control pressure signal to the first fluid pump, creating a closed-loop feedback system that maintains stable intraocular pressure despite fluid loss through the puncture site
Solution Approach 2:
The patent introduces a control device as an intermediary component that mediates between the volumetric flow determination devices and the fluid pumps. This intermediary processes the differential flow signal and generates appropriate control signals, acting as a bridge that translates flow measurements into pressure control actions without requiring direct complex coupling between sensors and actuators
2Reliability
If volumetric flow determination devices and control systems are added to monitor and compensate fluid loss, then intraocular pressure stability is improved, but the device complexity increases
Solution Approach 1:
The control device serves multiple functions: it receives the irrigation fluid setpoint pressure signal, processes the differential volumetric flow signal from the difference element, determines the irrigation fluid control pressure signal, and outputs control signals to the first fluid pump. This multi-functionality consolidates what could be multiple separate components into a single integrated control unit, reducing overall system complexity while maintaining reliability
Solution Approach 2:
The system automatically monitors volumetric flow in both irrigation and aspiration lines, detects imbalances indicating fluid loss through the puncture site, and self-corrects by adjusting irrigation fluid pressure through the control device and first fluid pump. This self-service capability eliminates the need for manual intervention or additional complex safety systems, as the system autonomously maintains pressure stability
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
Minimizes intraocular pressure fluctuations by detecting and compensating for fluid leaks, ensuring a stable surgical environment and reducing the risk of complications.
Implementation Method 1
a first fluid pump which is arranged, in the direction of flow, between the irrigation fluid container and the handpiece and which is configured to convey irrigation fluid to the handpiece
Implementation Method 2
a second fluid pump which is arranged, in the direction of flow, between the handpiece and the collecting container and which is configured to convey aspiration fluid to the collecting container
Implementation Method 3
a first volumetric flow determination device which is arranged, in the direction of flow, between the first fluid pump and the handpiece and which is configured to determine a first volumetric flow
Implementation Method 4
the control device is configured to determine, from the differential volumetric flow signal and the irrigation fluid setpoint pressure signal, a signal for an irrigation fluid control pressure and to supply this signal at an output of the control device for the first fluid pump
Implementation Method 5
a thin hollow needle (phaco needle) is inserted by a handpiece into the crystalline lens and is induced to vibrate by ultrasound
Implementation Method 6
the vibrating hollow needle emulsifies the crystalline lens in such a way that the resulting lens particles can be aspirated
Data Source
AI summary
An ophthalmosurgical appliance includes an irrigation fluid line through which irrigation fluid can flow from an irrigation fluid container to an ophthalmosurgical handpiece for phacoemulsification, a first fluid pump configured to convey the irrigation fluid to the handpiece, a first volumetric flow determination device configured to determine a first volumetric flow, an aspiration fluid line, a second fluid pump configured to convey aspiration fluid to the collecting container, a second volumetric flow determination device configured to determine a second volumetric flow, a difference element configured to form a difference from the first volumetric flow and the second volumetric flow to form a differential volumetric flow signal, and a control device configured to determine, from the differential volumetric flow signal and the irrigation fluid setpoint pressure signal, a signal for an irrigation fluid control pressure to supply this signal at an output of the control device to the first fluid pump.