Vitrectomy Cutter With Segmented Lateral Openings
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Solution Overview
Problem
Existing surgical cutting instruments for vitrectomies, such as those described in U.S. Pat. No. 5,630,827 and WO 98/52502, face limitations in cutting performance due to the frequency of back-and-forth movement of the inner tube and generate significant pressure and vacuum fluctuations in the eye, leading to potential damage.
Innovation Solution
The device features an inner tube with at least one lateral opening near the free end equipped with additional outer cutting edges, allowing multiple cuts per stroke and maintaining a constant cross-sectional flow to prevent pressure fluctuations by controlling the movement and arrangement of openings in both tubes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the inner tube is moved back and forth with a single cutting edge, then the device can cut tissue, but the work speed is limited by the frequency of movement and throughput is restricted
Solution Approach 1:
The inner tube is segmented with multiple lateral openings (first, second, and third openings) distributed along its length, each equipped with cutting edges. This segmentation allows multiple cutting actions to occur simultaneously at different positions along the tube during a single back-and-forth movement, thereby increasing cutting throughput without requiring higher movement frequency.
2Productivity
If the inner tube has multiple lateral openings with cutting edges, then multiple cuts per stroke are achieved, but the device complexity increases
Solution Approach 1:
The inner tube with multiple openings and cutting edges is nested within the outer tube that also contains multiple openings and cutting edges. This nested configuration allows the cutting edges of both tubes to work cooperatively during the back-and-forth movement, achieving multiple simultaneous cuts while maintaining a compact structure that does not excessively increase overall device complexity.
3Quantity of substance
If the inner tube alternately closes and opens the suction openings, then tissue can be suctioned, but significant pressure and vacuum fluctuations are generated in the eye
Solution Approach 1:
The suction function is segmented across multiple openings distributed along the inner and outer tubes. During the back-and-forth movement, different openings are opened and closed at different times, which distributes the suction action over a longer period and reduces abrupt pressure changes in the eye, thereby minimizing harmful pressure fluctuations while still achieving effective tissue 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 configuration enhances cutting performance by allowing multiple cuts per stroke without increasing the frequency of inner tube movement and prevents pressure fluctuations, ensuring safer and more efficient tissue removal during vitrectomies.
Implementation Method 1
The cutting edges work together with a cutting function when the inner tube is slid
Implementation Method 2
The cutting edges work together with a cutting function when the inner tube is slid
Implementation Method 3
the tissue can be suctioned out of the interior of the device—more precisely stated, through the inner tube
Data Source
AI summary
An apparatus for cutting and aspirating tissue from the human body or animal body, particularly for application in vitrectomies, for retinal detachment, etc., having an outer tube (1) and an inner tube (5) which can slide back and forth concentrically in the outer tube (1) with minimal play, wherein the outer tube (1) is closed on the free end (2) thereof, and has a lateral opening (3) near the free end (2), with at least one inner cutting edge (4), wherein the inner tube (5) is open on the free end and has an outer cutting edge (6) at that position, and wherein the cutting edges (4, 6) work together in a cutting manner when the inner tube (5) is displaced, characterized in that the inner tube (5) has at least one lateral opening (7) with at least one further outer cutting edge (8) near the free end.