RF Tissue Resection Device with Fluid Vaporization Propulsion
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Solution Overview
Problem
Conventional hysteroscopic resection devices for uterine fibroids are often too large in diameter, requiring anesthesia and cervical dilation, making them unsuitable for minimally invasive procedures through small diameter hysteroscopes.
Innovation Solution
A tissue resecting device with an RF electrode and a fluid management system that vaporizes liquid to propel resected tissue through a small extraction lumen, using a reciprocating inner sleeve and projecting element to resect and capture tissue, reducing the lumen diameter and preventing clogging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If conventional resecting instruments are used for hysteroscopic resection, then effective tissue resection can be achieved, but the instrument diameter is too large requiring anesthesia and cervical dilation
Solution Approach 1:
The resecting instrument is divided into multiple functional components: an outer sheath, an inner resecting sleeve, a receding element, and an RF electrode. This segmentation allows each component to perform a specific function while maintaining a compact overall diameter that can pass through small cervical openings without requiring dilation or anesthesia.
Solution Approach 2:
The inner resecting sleeve is nested within the outer sheath, and the RF electrode is positioned within the sleeve structure. This nested configuration minimizes the external diameter of the instrument while containing all necessary resection components, enabling passage through small diameter hysteroscopes and cervical canals without trauma or requiring anesthesia.
2Length of moving object
If smaller diameter instruments are used to avoid anesthesia, then minimally invasive procedure is achieved, but tissue extraction may be blocked by clogging
Solution Approach 1:
The receding element dynamically adjusts its position within the extraction lumen during the resection cycle. It extends forward to push captured tissue toward the lumen opening, then retracts to allow the sleeve to advance and capture the next tissue segment. This dynamic motion prevents tissue from blocking the small lumen diameter continuously, maintaining extraction efficiency without requiring a large bore.
Solution Approach 2:
The RF electrode vaporizes a small volume of fluid captured in the extraction lumen, generating expansive force that automatically propels resected tissue forward through the lumen and out of the instrument. This self-propulsion mechanism eliminates the need for manual irrigation or large lumen diameter to prevent clogging, as the tissue is actively ejected by the vaporization-driven expansion.
3Manufacturing precision
If RF electrode is advanced past tissue-receiving window to sever tissue, then precise resection is achieved, but device complexity increases
Solution Approach 1:
The resection and tissue capture functions are merged into a single reciprocating motion of the inner sleeve. As the sleeve advances past the tissue-receiving window, the RF electrode simultaneously severs the tissue and the sleeve captures it in the same continuous motion. This merging eliminates the need for separate resection and capture mechanisms, reducing overall device complexity while maintaining precise resection capability.
Solution Approach 2:
The inner resecting sleeve serves multiple functions: it guides the RF electrode during tissue severing, captures the resected tissue through its movement, and facilitates tissue ejection through the receding element. This multi-functionality reduces the number of separate components needed, simplifying the device structure while achieving precise tissue resection and removal.
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 effective resection and removal of uterine fibroids through a small diameter hysteroscope, reducing the need for anesthesia and cervical dilation, while preventing tissue clogging in the extraction lumen.
Implementation Method 1
energy is applied to the fluid in order to cause rapid expansion, e.g., vaporization, in order to propel the resected tissue strip through the extraction lumen
Implementation Method 2
Exemplary embodiments of the tissue resecting device comprise an RF electrode, wherein the electrode can be advanced past a tissue-receiving window on the device in order to sever a tissue strip
Data Source
AI summary
Tissue is resected and extracted from an interior location in a patient's body using a probe or tool which both effects resection and causes vaporization of a liquid or other fluid to propel the resected tissue through an extraction lumen of the resecting device. Resection is achieved using an electrosurgical electrode assembly including a first electrode on a resecting member and a second electrode within a resection probe or tool. Over a first resecting portion, radio frequency current helps resect the tissue and over a second or over transition region, the RF current initiates vaporization of the fluid or other liquid to propel the tissue from the resection device. In one embodiment, an extending element extends from a housing and into a channel in a resecting member as the resecting member moves toward a distal position.