Front-Handle Dermatome Inversion for Precision Skin Excision
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Solution Overview
Problem
Prior power operated dermatomes require operators to move away from the cutting area, reducing visibility and precision due to the handle's rearward placement, leading to less precise control during skin tissue removal.
Innovation Solution
The design features an annular rotary knife blade with a central axis of rotation, a frustoconical lower blade portion, and a depth gauge assembly that allows for precise adjustment of the cutting depth, enabling the dermatome to be used closer to the body while maintaining visibility and improving control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the handle is disposed rearward of the cutting direction, then the dermatome can be operated with a standard hand-held configuration, but the operator must move away from the cutting area resulting in reduced visibility and less precise control
Solution Approach 1:
The patent inverts the conventional dermatome configuration by placing the handle at the front (leading edge) rather than the rear. This inversion allows the operator to position their hand closer to the cutting area, improving visibility and control precision while maintaining the hand-held operational configuration.
2Ease of operation
If the operator moves away from the cutting area to use the dermatome, then the hand-held configuration can be maintained, but visibility of the skin area to be removed is reduced
Solution Approach 1:
By inverting the handle position to the front of the dermatome, the operator's hand naturally positions closer to the cutting area, thereby improving visibility of the skin surface without requiring the operator to lean in or position their body closer to the patient.
3Ease of manufacture
If a reciprocating cutting blade is used at the front edge, then the cutting function is achieved, but the operator cannot maintain close proximity to the body due to handle placement
Solution Approach 1:
The patent maintains the reciprocating cutting blade at the front edge for effective skin removal while inverting the handle position to allow the operator to keep their hand close to the body, thereby resolving the conflict between cutting functionality and operator proximity.
Solution Approach 2:
The dermatome is segmented into distinct functional zones: the front handle area for operator control, the middle cutting zone with the reciprocating blade, and the rear operational handle. This segmentation allows each zone to optimize its function while working together as an integrated system.
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 precision and consistency in skin excision, reducing operator skill dependency and improving the reliability of skin grafting operations by allowing for accurate and repeatable thickness removal.
Implementation Method 1
an annular rotary knife blade rotatable about a central axis of rotation... the inner wall of the lower blade portion and the outer wall of the lower blade portion converging in a direction proceeding toward the bottom surface of the lower blade portion, an intersection of the bottom surface and the inner wall of the lower blade portion forming a cutting edge
Implementation Method 2
the outer wall of the upper body portion including a bearing race extending radially inwardly into the outer wall
Implementation Method 3
the upper body portion including a driven gear
Data Source
Figure 1
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AI summary
An exemplary hand-held, power operated dermatome (100) comprises a blade housing assembly (400), a skin deflector (440), an annular rotary knife blade (300), a cutting plane (702), and a depth gauge (600). The rotary knife blade (300) has an inner region (301), an upper body portion (302), and a lower cutting portion (304). The lower cutting portion (304) has an inner surface (354), an outer surface (356), and a bottom surface (362). A cutting edge (360) of the rotary knife blade is formed by the intersection between the inner surface (354) and the bottom surface (362) of the lower cutting portion. The cutting plane (702) of the dermatome is defined by the cutting edge (360) of the rotary knife blade, and the depth gauge (600) is disposed within the inner region of the rotary knife blade (301).