Oxygenator Intermediate Spacer Prevents Lumen Collapse
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Solution Overview
Problem
Conventional oxygenators with hollow fiber membranes experience decreases in heat exchange and gas exchange rates due to lumen collapse when partition sections are inserted between the heat exchange and gas exchange units during assembly.
Innovation Solution
An oxygenator design featuring an inner and outer cylinder unit formed by winding hollow fiber membranes, with a cylindrical intermediate spacer that creates a gap between the units to prevent lumen collapse, allowing the partition sections to engage radially and support the outer cylinder unit independently, thereby maintaining the heat and gas exchange rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If partition sections are inserted between the heat exchange unit and gas exchange unit during assembly, then the housing is properly partitioned into heat medium flow path and gas flow path, but the lumen of the hollow fiber membranes collapses and heat exchange rate and gas exchange rate decrease
Solution Approach 1:
The patent applies preliminary action by pre-forming grooves on the outer peripheral surface of the heat exchange unit and protrusions on the inner peripheral surface of the gas exchange unit before assembly. These pre-formed structural features guide the partition section into proper engagement during assembly, preventing lumen collapse while enabling proper partitioning of the housing into heat medium flow path and gas flow path.
Solution Approach 2:
The partition section acts as an intermediary element that mediates between the heat exchange unit and gas exchange unit. By designing the partition section with specific engagement features (grooves and protrusions), it enables proper housing partitioning without directly compressing the hollow fiber membranes, thus maintaining exchange rates while achieving functional separation.
2Device complexity
If the second hollow fiber membrane is wound around the outer surface of the first hollow fiber membrane, then the gas exchange unit is formed, but the end portions are pushed in the radial direction by the partition section causing lumen collapse
Solution Approach 1:
The patent applies local quality by creating localized engagement features (grooves on the heat exchange unit surface and corresponding protrusions on the gas exchange unit surface) at specific locations rather than uniform engagement across the entire structure. This localized approach allows the partition section to engage precisely where needed without applying radial compression to the hollow fiber lumens, maintaining manufacturing precision while enabling assembly.
Solution Approach 2:
The partition section is segmented into distinct functional zones: engagement portions that interface with the grooves and protrusions, and partitioning portions that separate the flow paths. This segmentation allows the partition section to perform multiple functions independently, enabling housing partitioning without compromising lumen patency in the wound cylindrical structure.
Data Source
AI summary
In manufacturing an oxygenator (10), an intermediate spacer (18) is arranged between an inner cylinder unit (13) configured by winding a first hollow fiber membrane (14a) and an outer cylinder unit (15) configured by winding a second hollow fiber membrane (16a) so that a first gap (100a) is formed between one end portions of the inner cylinder unit (13) and the outer cylinder unit (15), and a first partition section (62a) is inserted into the first gap (100a). A first end portion (18a) of the intermediate spacer (18) is located at a region which does not overlap the first partition section (62a) in a radial direction. The intermediate spacer (18) independently supports the outer cylinder unit (15) in a state in which a gap (Sa) is formed between an inner peripheral surface of the intermediate spacer (18) and an outer peripheral surface of the inner cylinder unit (13).