Cryobiopsy Probe Cooling With CO2 Canister Flow Control
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Solution Overview
Problem
Existing cryobiopsy devices face challenges in efficiently extracting biopsy samples using carbon dioxide as a refrigerant, particularly in terms of fluid delivery and probe cooling mechanisms.
Innovation Solution
A medical device with a handle and probe system that includes a chamber for a carbon dioxide canister, actuators for fluid release, and exhaust holes for efficient refrigerant distribution, allowing for rapid tissue freezing and sample extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If carbon dioxide is used to cool the distal tip of cryobiopsy devices, then tissue freezing capability is improved, but device complexity increases due to fluid delivery mechanisms
Solution Approach 1:
The device is divided into separate functional modules: a handle containing the carbon dioxide canister and valve mechanism, a shaft with lumens for fluid delivery, and a probe with a distal tip. This segmentation allows the cooling function to be isolated to specific components, reducing overall system complexity while maintaining effective tissue freezing capability at the distal tip.
Solution Approach 2:
Carbon dioxide serves as an intermediary substance that transfers thermal energy from the handle to the distal tip of the probe. The CO2 is stored as a liquid in the canister, then delivered through the shaft lumens to the distal tip where it evaporates, absorbing heat and achieving the required low temperatures for tissue freezing without requiring direct mechanical contact with the cooling source.
2Loss of time
If rapid tissue freezing is achieved for efficient biopsy extraction, then procedure time is reduced, but patient harm may increase due to thermal damage
Solution Approach 1:
The cooling effect is concentrated at the distal tip of the probe where it contacts the tissue, while the shaft and handle remain at ambient or higher temperatures. This localized application of cold ensures rapid freezing of only the targeted tissue sample without subjecting surrounding structures or the patient's body to harmful thermal effects. The insulating properties of the shaft and controlled delivery of CO2 further confine the thermal impact to the biopsy site.
Solution Approach 2:
The cryobiopsy device operates in periodic cycles: CO2 is delivered to freeze the tissue, then the freezing action is terminated and the probe is withdrawn. This periodic operation allows controlled thermal exposure that achieves rapid tissue freezing for efficient sample extraction while preventing excessive thermal damage through timely termination of the cooling phase.
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 enables efficient cryobiopsy procedures by rapidly cooling tissue for sample acquisition, reducing procedure time and minimizing patient harm.
Implementation Method 1
cryobiopsy devices use a cooled tip to acquire a tissue sample. Carbon dioxide may be used to cool the distal tip of such cryobiopsy devices
Implementation Method 2
The fluid contained in the canister may be pressurized carbon dioxide
Data Source
AI summary
Medical devices, systems, and methods described herein may be useful for performing a biopsy medical at a target tissue site within a patient and removing a biopsy sample from the target tissue site. The medical device includes a probe that includes a lumen, and a handle in fluid communication with the probe. The handle including a body defining a chamber coupled to the probe and configured to receive a canister containing a fluid, and an actuator configured to transition a valve from a closed position in which the probe is not in fluid communication with the handle and into an open position in which the probe is in fluid communication with the handle.