Variable-Rigidity Surgical Gripper Using Vacuum Jamming Sheets
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Solution Overview
Problem
Existing surgical gripping instruments lack the ability to vary rigidity, leading to inefficiencies in gripping and separating soft tissues due to either small gripped surface area with high rigidity materials or movement with low rigidity materials, and existing devices utilizing the 'jamming transition phenomenon with powder fillers lack strength against load stripping.
Innovation Solution
A device with variable rigidity comprising two flexible sheets covered by a bag-shaped cover, featuring a vent hole for fluid suction, friction materials, and low rigidity portions, utilizing the jamming transition phenomenon to achieve immediate rigidity variation without heat generation, and reinforced by extending materials to suppress deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a gripping instrument is made of high rigidity material such as stainless steel, then the structural strength is improved, but the gripped surface area becomes small and the organ may be damaged
Solution Approach 1:
The gripping instrument employs a rigidity variable structure that can dynamically transition between soft and rigid states. The friction material's rigidity is adjusted based on operational requirements: remaining soft during approach to conform to tissue contours and maximize contact area, then becoming rigid upon activation of the rigidity variation mechanism to maintain gripping force and prevent slippage during cutting operations.
2Area of stationary object
If a gripping instrument is made of low rigidity material, then the gripped surface area increases and the organ can be gripped in shape, but the rigidity is insufficient and the organ may move during separation
Solution Approach 1:
The gripping instrument employs a rigidity variable structure that can dynamically transition between soft and rigid states. The friction material's rigidity is adjusted based on operational requirements: remaining soft during approach to conform to tissue contours and maximize contact area, then becoming rigid upon activation of the rigidity variation mechanism to maintain gripping force and prevent slippage during cutting operations.
Solution Approach 2:
The friction material's rigidity parameter is changed from a fixed value to a variable parameter that can be adjusted between soft and rigid states. This is achieved through the rigidity variation mechanism which modifies the physical or mechanical properties of the friction material, allowing the gripping force and structural stiffness to be optimized for different phases of the surgical procedure.
3Strength
If powder filler is used for jamming transition phenomenon, then the rigidity can be increased by suction, but the strength against load stripping is not retained
Solution Approach 1:
The friction material's rigidity parameter is changed from a fixed value to a variable parameter that can be adjusted between soft and rigid states. This is achieved through the rigidity variation mechanism which modifies the physical or mechanical properties of the friction material, allowing the gripping force and structural stiffness to be optimized for different phases of the surgical procedure.
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
The device provides a wide range of rigidity variation through a simple structure, allowing efficient gripping and manipulation of tissues without generating heat, and maintaining negative pressure for secure adhesion and manipulation.
Implementation Method 1
a vent hole that enables suction of a fluid, which is between the flexible sheets and within the cover, from an exterior of the cover
Implementation Method 2
devices based on the 'jamming transition phenomenon' in which a fine powder is filled into a bag-shaped container formed of a soft material and the air in the interior is sucked so as to increase the rigidity
Implementation Method 3
the two flexible sheets are covered by a bag-shaped cover in a state in which the friction materials face one another
Data Source
AI summary
In order to provide a device with variable rigidity and a surgical gripping device that make it possible to increase the range of change in rigidity by means of a simple structure, this device with variable rigidity is configured so as to comprise two flexible sheets (12, 14) that include: a base material (20) formed using a sheet-like elastic material and having a plurality of recesses (20B) and a plurality of protrusions (20A) formed on one surface thereof; a low rigidity section (22) that is formed using an elastic material with a lower modulus of elasticity than the base material (20) and that is arranged in the recesses (20B) and joined to the recesses (20B) so that one surface of said low rigidity section (22) becomes flat; and a friction material (24) provided to the one surface. In addition, the two flexible sheets (12, 14) are covered by a bag-like cover with the two pieces of friction material (24) facing each other and are configured so as to have a ventilation port (18) whereby it is possible to suction the air within the flexible sheets (12, 14) and the cover (16) from the exterior of the cover (16).