Helical Heat Exchange Catheter Pulsatile Flow Cooling
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Solution Overview
Problem
Current endovascular heat exchange systems are inefficient in rapidly inducing hypothermia prior to reperfusion in ischemic events such as myocardial infarction or ischemic stroke, and struggle to overcome the body's natural temperature regulation mechanisms, leading to slower temperature changes and potential re-warming to normothermia.
Innovation Solution
A heat exchange catheter system with a heat exchange catheter and fluid cooling apparatus that uses pulsatile flow through a helically configured heat exchange balloon to enhance heat exchange efficiency, capable of lowering core body temperature by 3 degrees Celsius in 30 minutes or less, and incorporates detectors for precise positioning within the vasculature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional endovascular heat exchange systems are used, then body temperature can be altered, but the rate of temperature change is slow and the body's natural temperature regulation mechanisms interfere with achieving target temperatures
Solution Approach 1:
The patent employs pulsatile flow of cooling fluid through the heat exchange catheter, creating periodic action that enhances heat transfer efficiency. The pulsatile nature of the flow generates dynamic pressure variations and fluid movement patterns that disrupt thermal boundary layers, thereby increasing the rate of heat exchange and overcoming the body's natural temperature regulation mechanisms more effectively than continuous flow systems.
Solution Approach 2:
The system dynamically adjusts flow rate, pressure, and temperature parameters of the cooling fluid to optimize heat exchange efficiency. By changing these parameters in response to measured temperature and pressure conditions, the system achieves faster and more reliable temperature control despite the body's thermoregulatory responses.
2Productivity
If higher cooling power is applied to rapidly induce hypothermia, then target temperature is reached faster, but the risk of excessive cooling and loss of temperature control increases
Solution Approach 1:
The patent incorporates temperature sensors and pressure sensors that continuously monitor the patient's core temperature and system pressure. This feedback is used by the control system to dynamically adjust the cooling fluid flow rate and temperature, enabling the system to deliver high cooling power when needed while preventing excessive cooling. The feedback loop ensures precise temperature control by reducing cooling intensity as target temperature approaches.
Solution Approach 2:
The system transitions from static, fixed-parameter cooling to dynamic, adaptive cooling where flow rate, pressure, and temperature are continuously adjusted based on real-time measurements. This dynamic approach allows the system to optimize cooling power delivery while maintaining precise control over the rate and extent of temperature change.
3Ease of operation
If heat exchange catheter is positioned in the vasculature, then endovascular cooling can be achieved, but precise positioning is difficult and time-consuming
Solution Approach 1:
The patent replaces manual, mechanical catheter positioning with automated positioning using detectors and imaging guidance. The system uses radiopaque markers visible under fluoroscopy, impedance sensing, or other detection methods to automatically determine catheter location and guide advancement to the optimal position, eliminating the need for time-consuming manual positioning and reducing procedural time.
4Power
If conventional heat exchange catheters are used, then cooling can be provided, but the cooling efficiency is insufficient to overcome physiological temperature regulation
Solution Approach 1:
The pulsatile flow mechanism creates periodic disturbances in the cooling fluid that disrupt thermal boundary layers at the catheter surface and within the blood. This periodic action enhances convective heat transfer coefficients, thereby increasing cooling efficiency to a level sufficient to overcome the body's natural thermoregulatory mechanisms that would otherwise prevent rapid temperature reduction.
Solution Approach 2:
The pulsatile flow generates mechanical vibrations and pressure fluctuations that enhance mixing and reduce thermal boundary layer thickness. This mechanical vibration effect increases the surface area and efficiency of heat exchange between the cooling fluid and blood, enabling the system to deliver sufficient cooling power to overcome physiological temperature regulation.
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 system effectively induces cardio-protective, neuro-protective, or renal-protective levels of hypothermia prior to reperfusion, overcoming the body's temperature regulation mechanisms and maintaining target temperatures with improved cooling or warming power compared to prior art.
Implementation Method 1
a heat exchange catheter and a fluid cooling apparatus useable to cool a thermal exchange fluid and to circulate that cooled thermal exchange fluid through the heat exchange catheter
Implementation Method 2
thermal exchange fluid of precisely controlled temperature is circulated through the catheter's heat exchanger
Implementation Method 3
uses pulsatile flow through a helically configured heat exchange balloon to enhance heat exchange efficiency
Data Source
AI summary
Devices and methods for warming or cooling blood flowing through the vasculature of a human or animal subject so as to alter or control the temperature of all or part of the subject's body. Heat exchangers are positioned within the subject's vasculature and heated or cooled heat exchange fluid is circulated through the heat exchanger. For certain therapeutic applications, the heat exchanger and associated elements of the system have sufficient power to lower the subject's body temperature by at least 3 degrees C. in less than 30 minutes.