Expandable Trocar Blades for Low-Force Tissue Penetration
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Solution Overview
Problem
Current medical penetration devices, such as trocars, are limited by their small size, requiring significant force to advance through tissue and often failing to accommodate larger devices needed for procedures, especially when transitioning between body lumens, as they cannot easily enlarge the penetration size.
Innovation Solution
The development of trocars with radially expandable blades that automatically open as they exit the endoscope sheath, allowing for a larger tissue penetration without the need for additional force, and featuring a combination of sharpened cutting edges and atraumatic designs for safe tissue interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the penetrating member is made larger to provide a larger penetration, then the penetration size is improved, but the force required to advance the tool through tissue increases significantly
Solution Approach 1:
The penetrating member is divided into a small delivery component that passes through tissue with minimal force and a larger expandable component (blades or cutting elements) that is deployed after penetration to create the larger opening. This segmentation allows the initial penetration to be performed with a small profile while achieving a large final penetration size.
Solution Approach 2:
The larger cutting blades or penetrating elements are nested within the smaller delivery sheath or catheter during advancement. Once the delivery component penetrates the tissue, the nested blades are deployed outward to enlarge the penetration. This nesting principle allows a small delivery device to deliver a larger functional component.
2Adaptability or versatility
If the penetrating member size is increased to accommodate larger devices, then device compatibility is improved, but the ability to advance through narrow sheaths deteriorates
Solution Approach 1:
The penetrating member transitions from a static small diameter configuration during delivery to a dynamic expanded configuration at the target site. The blades or cutting elements can be deployed radially outward after penetration, allowing the device to accommodate large-bore catheters and stents while maintaining compatibility with narrow endoscopic sheaths during advancement.
3Reliability
If significant force is applied to advance the tool through tissue, then penetration is achieved, but tissue trauma increases
Solution Approach 1:
A sharp puncture tip or cutting edge is provided on the delivery component to preliminarily penetrate the tissue wall with minimal force. Once the initial penetration is achieved, the larger blades are deployed to complete the penetration and create the final opening. This preliminary action allows the majority of the penetration to be achieved with minimal force application.
Data Source
AI summary
A trocar has an elongate body and a tissue-penetrating tip. One or more radially extending blade(s) are provided near the tissue-penetrating tip of the trocar body so that they automatically open as the trocar is advanced through tissue. The blades will enlarge the penetration which was formed by the tip of the trocar.