Biopsy Forceps Double Hinge Rod Staggered Five-Bar Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing biopsy forceps used under endoscopes suffer from insufficient occlusal force, leading to tissue tearing and bleeding during sampling, which increases operation time, treatment costs, and patient discomfort due to the single-hole push-pull rod mechanism being close to the 'dead point' and having a smaller transmission angle.
Innovation Solution
A medical forceps design featuring a double hinge center push-pull rod structure with two connecting members arranged in a crossed manner, enhancing the occlusal force and flexibility by increasing the transmission angle, allowing for smoother and more efficient tissue sampling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a single-hole push-pull rod structure is used, then the device complexity is reduced, but the occlusal force is insufficient and the transmission angle is small
Solution Approach 1:
The push-pull rod is divided into two separate push-pull rods, each with its own hinge center. This segmentation allows each rod to independently transmit force through the connecting pieces to the forceps jaws, increasing the overall occlusal force while maintaining manageable structural complexity
Solution Approach 2:
The two push-pull rods and connecting pieces are combined to form a parallelogram linkage mechanism. This merging creates a coordinated system where both forceps jaws move simultaneously and maintain proper alignment, maximizing the transmitted occlusal force through geometric coordination
2Ease of operation
If a single-hole push-pull rod is used, then the structure is simpler, but the transmission angle is smaller affecting smoothness
Solution Approach 1:
The two push-pull rods are positioned asymmetrically relative to the forceps base, with different hinge center locations optimized for their respective motion paths. This asymmetric arrangement allows each rod to maintain an optimal transmission angle throughout its range of motion, ensuring smooth operation
Solution Approach 2:
The hinge centers are positioned to allow dynamic adjustment of transmission angles during the opening and closing cycle. As the forceps jaws move, the geometry of the linkage system dynamically maintains favorable transmission angles, ensuring smooth operation throughout the entire range of motion
3Reliability
If the forceps cup is closed with insufficient force, then the structure is simpler, but the tissue is torn and bleeding occurs
Solution Approach 1:
The forceps jaws are pre-loaded with elastic potential energy through the spring mechanism before engagement. When the forceps are activated, this stored energy is released to provide an immediate boost in occlusal force, ensuring sufficient gripping strength to prevent tissue tearing from the moment of engagement
Solution Approach 2:
The occlusal force is enhanced by changing the mechanical parameters of the linkage system, specifically the lengths and positions of the push-pull rods and connecting pieces. These parameter adjustments optimize the force multiplication effect, transforming the operator's input force into sufficiently high occlusal force at the jaws
4Productivity
If hemostasis treatment is required due to tissue bleeding, then the occlusal force was insufficient, but the operation time and treatment costs increase
Solution Approach 1:
The forceps incorporate a spring mechanism that pre-charges elastic potential energy, providing a cushion of stored force ready to be deployed upon activation. This beforehand cushioning ensures that sufficient occlusal force is immediately available to secure tissue without slipping or causing trauma that would require additional hemostasis procedures
Data Source
Figure 1~2
Figure 3~4
Figure 5~8
AI summary
Disclosed is a medical forceps, comprising a handle, a traction string, a the sleeve tube (5), a forceps base (4), a push-pull rod (3), connecting members (2) and forceps jaws (1).The sleeve tube (5) is connected to the forceps base (4). The traction string passes through the sleeve tube (5) and the forceps base (4), one end of the traction string is connected to the handle, and the other end thereof is connected to the push-pull rod (3). Middle parts of the two forceps jaws (1) are hinged by means of a hinge shaft, and the hinge shaft is mounted on the forceps base (4). A lower part of each forceps jaw (1) is hinged to one end of the respective connecting member (2), and the other end of the connecting member (2) is hinged to the push-pull rod (3). The push-pull rod (3) has two hinge centers for being respectively hinged to the two connecting members (2). The two connecting members (2) are arranged in a crossed manner. The push-pull rod (3) uses a structure having two hinge centers, and in this way, the forceps jaws (1), the connecting members (2) and the pull rod (3) form a staggered five-bar mechanism so as to enhance the occlusal force of the forceps while also ensuring the pushing flexibility, thereby improving the efficiency and accuracy of taking a tissue by means of biopsy forceps.