Heater-Cooler System Using Biocidal Fluid and Cold Storage
Solution Overview
Problem
Current heater-cooler systems used in medical/surgical procedures face contamination risks and health hazards due to the potential for microbial transmission, especially during setup and removal, and disrupt laminar air curtains with compressor cooling fans.
Innovation Solution
A closed loop heat transfer fluid circuit with a cold storage unit using non-water-based phase change materials and a biocidal heat transfer fluid to prevent bacterial growth and contamination, while eliminating the need for compressor cooling by providing cooling from the cold storage unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional water-based heater-cooler systems are used, then heating and cooling performance is delivered, but contamination risks and health hazards increase due to microbial transmission
Solution Approach 1:
The patent changes the chemical composition parameter of the heat transfer fluid from water-based to non-water-based (using biocidal fluids), which fundamentally alters the fluid's properties to prevent microbial growth while maintaining thermal transfer capabilities
Solution Approach 2:
The patent creates an inert environment by using non-water-based biocidal fluids that are inherently resistant to microbial contamination, effectively eliminating the biological contamination pathway while preserving the thermal function
2Temperature
If compressor cooling fans are used for refrigeration units, then cooling capability is provided, but laminar air curtains are disrupted
Solution Approach 1:
The patent extracts and removes the compressor cooling fan from the surgical environment, relocating the refrigeration unit outside the operating theatre or positioning it where it does not interfere with the laminar air curtain, thereby eliminating the source of air disruption
Solution Approach 2:
The patent introduces a cold storage unit as an intermediary thermal energy storage device that decouples the refrigeration process from the immediate cooling demand, allowing the compressor to operate remotely without disrupting the surgical field's air curtain
3Reliability
If sealed flow systems are used to prevent contamination, then contamination transfer during use is prevented, but setup and removal still release microbes into the environment
Solution Approach 1:
The patent changes the fundamental nature of the heat transfer fluid from water-based to non-water-based biocidal fluid, which inherently prevents microbial growth and eliminates the contamination hazard that would be released during setup and removal
Solution Approach 2:
The patent converts the potential harm of water-based fluids (which support microbial growth) into a benefit by using non-water-based biocidal fluids that actively prevent contamination, turning a previously problematic property into a protective feature
4Temperature
If refrigeration units with compressors are used, then cooling is provided, but the system complexity and potential contamination points increase
Solution Approach 1:
The patent implements preliminary action by using a cold storage unit that is pre-charged with cold thermal energy before the surgical procedure begins, allowing the system to operate without an active compressor during surgery and reducing overall system complexity
Solution Approach 2:
The patent extracts the compressor from the immediate surgical environment and relocates it outside the operating theatre, simplifying the in-theatre system configuration and reducing potential contamination points while maintaining cooling capability through the cold storage unit
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 solution effectively reduces contamination risks, maintains temperature control without disrupting laminar air curtains, and provides efficient heating and cooling for extracorporeal perfusion systems.
Implementation Method 1
The cold storage unit may comprise a chamber containing a liquid that freezes at a temperature above that to which the heat transfer fluid is cooled by the refrigeration unit
Implementation Method 2
a cold storage unit using non-water-based phase change materials
Implementation Method 3
a refrigeration unit for cooling a flow of heat transfer fluid to a use temperature
Implementation Method 4
a closed loop heat transfer fluid circuit
Implementation Method 5
flow circuitry is further configured to direct heat transfer fluid through the cold storage unit to cool the heat transfer fluid for use in the extracorporeal perfusion system without the heat transfer fluid being cooled by the refrigeration unit
Implementation Method 6
a biocidal heat transfer fluid to prevent bacterial growth and contamination
Data Source
AI summary
A heater-cooler apparatus of an extracorporeal perfusion system comprises at least one fluid circuit 102, 104 providing a supply of a heat transfer fluid to the perfusion system, a cold storage unit 266, and a refrigeration unit 250 for charging the cold storage unit 266. The cold storage unit 266 comprises a chamber 312 containing a liquid that freezes at a temperature above that to which the heat transfer fluid is cooled by the refrigeration unit 250, and a passage through which the heat transfer fluid is conveyed, the passage extending through the chamber 312. This allows a more effective cold storage unit to be provided.