Vitrectomy Probe Pneumatic Valve Displacement Pump
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Solution Overview
Problem
Vitrectomy procedures often result in traction on the retina due to the pulling of vitreous humor, which can lead to retinal injury or detachment, as existing vitrectomy probes lack effective mechanisms to minimize this traction during tissue removal.
Innovation Solution
The design incorporates internal valves within the vitrectomy probe to create a displacement pump, utilizing pneumatic pressure to control the movement of the inner cutting assembly, thereby reducing traction by managing the aspiration of vitreous humor in a controlled, incremental manner, eliminating the need for a downstream vacuum source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a downstream vacuum source is used to aspirate vitreous humor, then the vitreous removal efficiency is improved, but the retinal traction increases due to continuous pulling
Solution Approach 1:
The patent employs pneumatic pressure differentials to control the aspiration process. A pneumatic valve regulates the flow of vitreous humor into the cutter, using pressure control rather than continuous vacuum suction. This allows the vitreous to be drawn in gradually and controlledly, reducing the pulling force on the retina while maintaining efficient removal.
Solution Approach 2:
The patent implements periodic cutting cycles where the cutter alternates between extending and retracting positions. During the retraction phase, the pneumatic valve closes to trap and expel the cut vitreous in controlled increments. This periodic action prevents continuous traction by pausing the aspiration process between cuts, allowing the retina to recover briefly.
2Productivity
If the cutter operates at high cycle rate, then the vitreous removal speed is improved, but the retinal traction increases due to frequent pulling
Solution Approach 1:
The pneumatic valve system allows the cutter to operate at high cycle rates while maintaining controlled aspiration. The pressure differential mechanism ensures that vitreous is drawn in only when needed and expelled in controlled increments, preventing excessive traction even during rapid cycling. The pneumatic control decouples the cutting frequency from the aspiration force.
3Object-affected harmful factors
If a displacement pump mechanism is used to control vitreous aspiration, then the retinal traction is reduced, but the device complexity increases
Solution Approach 1:
The patent merges the pneumatic valve control mechanism with the existing cutter assembly. The valve is integrated into the cutter structure, and the pneumatic system shares components with the motor assembly. This consolidation reduces the overall device complexity compared to adding a separate displacement pump system, while still achieving controlled vitreous aspiration.
Solution Approach 2:
The pneumatic valve mechanism is designed to automatically regulate vitreous flow based on pressure differentials and mechanical position. The system self-regulates the aspiration process without requiring external complex control systems, using the inherent properties of the pneumatic and mechanical components to achieve traction-free vitreous removal.
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 significantly reduces retinal traction by controlling the amount of vitreous humor drawn per cutting cycle, independent of the cycle rate, and allows for precise control of vitreous removal without increasing traction on the retina.
Implementation Method 1
The diaphragm may be displaced into the retracted position by a first pneumatic pressure
Implementation Method 2
The valve may be configured to close in response to the first pneumatic pressure
Implementation Method 3
The design incorporates internal valves within the vitrectomy probe to create a displacement pump, utilizing pneumatic pressure to control the movement of the inner cutting assembly
Data Source
AI summary
Apparatuses, systems, and methods are described for selectively generating an aspiration flow within a surgical instrument. Particularly, the disclosure describes example vitrectomy probes operable to selectively generate an aspiration flow in relation to operation of the cutter of the vitrectomy probe. In some instances, one or more valves may be used to form a barrier or closure and create a piston effect in order to selectively generate an aspiration flow.