Cryobiopsy Probe Tissue Sampling Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cryosurgical instruments are not suitable for obtaining tissue samples from tissue surfaces, particularly mucous membranes, and cause significant damage to the surrounding tissue, limiting their effectiveness and safety.
Innovation Solution
A cryosurgical instrument with a probe head that can be cooled to freeze tissue, a support tube for retracting the probe, and an accelerating device to apply a defined tear-off force, allowing for gentle and efficient sample retrieval by tearing the tissue along natural cell boundaries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cryoprobe is used to freeze and extract tissue samples, then tissue sampling capability is improved, but surrounding tissue damage increases
Solution Approach 1:
The instrument is divided into distinct functional segments: a probe for freezing tissue, a support tube for structural support and retraction, and an accelerating device for controlled tissue separation. This segmentation allows each component to perform its specific function efficiently while minimizing interference with surrounding tissue.
Solution Approach 2:
The probe head is frozen onto the tissue wall before retraction, creating a solid bond that allows for clean separation. The accelerating device is pre-loaded with elastic energy that is released at the precise moment needed to tear the tissue sample away, ensuring controlled and minimal damage extraction.
2Quantity of substance
If a lance-shaped probe head is used for coring tumors, then large tissue extraction capability is improved, but suitability for tissue surface sampling deteriorates
Solution Approach 1:
The probe head features a planar portion specifically designed for contacting tissue surfaces, with a curvature radius of 0.5mm to 2mm that matches the local geometry of mucous membranes. This localized adaptation allows the instrument to effectively sample from delicate tissue surfaces while maintaining the overall capability for larger tissue extraction when needed.
3Ease of operation
If manual probing is used to exert force on tissue, then operator control is improved, but force consistency and reliability deteriorate
Solution Approach 1:
The accelerating device is self-actuating through the release of pre-stored elastic energy in a spring element. When triggered, the spring automatically propels the support tube forward with consistent force, eliminating the need for the operator to manually control the force application. This self-service mechanism ensures reliable and repeatable force delivery across multiple procedures.
4Speed
If intensive cooling is applied to freeze tissue rapidly, then freezing speed is improved, but tissue damage from rapid cooling increases
Solution Approach 1:
The cooling system applies intensive cooling only to the probe head surface that contacts the tissue, rather than cooling the entire probe structure. This localized partial cooling achieves rapid freezing of the tissue sample while minimizing thermal damage to surrounding areas and reducing overall tissue stress from rapid temperature changes.
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
Enables reliable, minimally invasive tissue sampling with reduced tissue damage and improved sample preservation, ensuring consistent and safe biopsy procedures.
Implementation Method 1
The rapid and intensive cooling of the probe head (approx. −50° C.) is achieved by way of the Joule-Thomson effect. This effect draws on the fact that gas cools intensively when it can expand under high pressure through a small nozzle into a large space.
Implementation Method 2
The accelerating device accelerates the support tube relative to the probe. The striking of the accelerated support tube on the tissue wall releases a tear-off force, by means of which the probe head tears out a region of the tissue wall.
Data Source
AI summary
A cryosurgical instrument for separating a tissue sample from a biological tissue to be treated, for purposes of biopsy. The cryosurgical instrument includes a probe for bringing a probe head up to the biological tissue and a gas line for supplying cooling gas from a gas source of a cryosurgical apparatus to the probe head. The probe head cools a limited tissue region, by means of the supplied gas, for obtaining a tissue sample. The tissue sample can be separated from the surrounding tissue when frozen onto the probe head. The instrument has a support tube in which the probe is guided and which can be moved relative to the probe in such a way that the surrounding tissue can be supported by means of the support tube during the separating of the tissue sample. The instrument also includes an accelerating device that provides a predefined force for the separating process.