Therapy Pad Countercurrent Heat Exchanger for Uniform Cooling
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Solution Overview
Problem
Existing cold therapy systems face challenges in temperature control, with some devices providing uncomfortable chilling levels and inefficient thermal management, leading to rapid ice melt and uneven temperature distribution across therapy pads.
Innovation Solution
A heat exchanging therapy pad composed of three layers, with an outer and inner layer being thicker than the middle layer, forming countercurrent heat exchanger chambers to maintain even temperature profiles, and a variable or fixed flow restrictor system to control fluid flow and temperature, ensuring consistent skin contact temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a variable flow restrictor is used to control water flow for temperature control, then temperature control capability is improved, but device complexity increases
Solution Approach 1:
The system uses the patient's own body heat to automatically regulate the cooling pad temperature. The warm blood flowing through the pad naturally heats the chilled water, eliminating the need for external flow restrictors or control mechanisms. The temperature control is self-regulating based on the temperature differential between the pad and patient skin.
Solution Approach 2:
The patent replaces mechanical flow restrictors with a thermal field-based control mechanism. Instead of using valves or restrictors to control water flow, the system relies on thermal conduction and convection principles where the patient's body heat automatically regulates the cooling effect, substituting mechanical control with thermal physics.
2Temperature
If ice is used for cooling therapy, then cooling effect is improved, but ice melts too quickly expending thermal potential
Solution Approach 1:
The system changes the temperature parameter of the cooling medium from solid ice (0°C) to chilled water (32-40°F). This parameter change allows the cooling medium to maintain a lower temperature without rapidly changing phase, extending the duration of effective cooling therapy while avoiding the quick melting issue of ice.
Solution Approach 2:
The patent introduces chilled water as an intermediary cooling medium between the cold source and the patient's body. Instead of direct ice contact, the chilled water circulates through the pad, serving as a thermal mediator that provides sustained cooling without the rapid phase change losses associated with direct ice application.
3Temperature
If traditional cooling pads are used, then cooling capability is provided, but temperature distribution is uneven across the pad
Solution Approach 1:
The cooling pad is divided into multiple independent chambers or zones that are filled with chilled water. This segmentation allows each zone to be filled and cooled independently, ensuring uniform temperature distribution across the entire pad surface and preventing temperature gradients that occur in traditional single-chamber designs.
Solution Approach 2:
The patent transitions from a two-dimensional surface cooling approach to a three-dimensional volumetric cooling approach. By filling the pad with chilled water throughout its entire volume rather than just on the surface, the system achieves uniform temperature distribution from all directions, improving manufacturing precision of temperature uniformity.
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 provides safe and effective thermal management with consistent temperature across the therapy pad surface, allowing for precise temperature control and efficient heat exchange, addressing issues of rapid ice melt and temperature unevenness.
Implementation Method 1
The heat exchanging therapy pad is made from three layers sealed or welded together... The thinness of the middle layer makes that layer a good heat exchanger... The three layers are sealed, e.g., radio frequency ('RF') welded, along the entire perimeter of the shape or profile of the therapy pad
Implementation Method 2
The middle layer can be five mils (0.005 inch or 0.13 mm thick)... The thinness of the middle layer makes that layer a good heat exchanger
Implementation Method 3
The discharge end of the flowpath through the chilled-water chamber, however, becomes the entrance end of the flowpath through patient-contacting chamber. In this manner, the heat exchanger is a countercurrent heat exchanger, with the warmest water about to leave the therapy pad to return to a cooling bath meeting the coldest chilled water just entering the therapy pad
Implementation Method 4
The three layers are sealed, e.g., radio frequency ('RF') welded, along the entire perimeter of the shape or profile of the therapy pad
Data Source
AI summary
A cold therapy system includes (i) a cooling bath structured to chill and hold chilled water; (ii) a pump positioned and arranged to pump the chilled water; (iii) a to-pad line positioned and arranged to hold chilled water pumped by the pump from the cooling bath; (iv) a from-pad line positioned and arranged to hold water returning to the cooling bath; and (v) a therapy pad in fluid communication with the to- and from-pad lines, the therapy pad including a patient-contacting chamber that is in heat exchange communication with a chilled-water chamber residing outside of the patient-contacting chamber when the therapy pad is donned.