Blood Processing Apparatus Pump Positioning for Cavitation Control
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Solution Overview
Problem
Existing blood processing apparatuses face challenges in reliably measuring hematocrit values of incoming and outgoing blood due to the risk of gas bubbles forming from cavitation, which can distort measurements.
Innovation Solution
The blood processing apparatus positions the pump mechanisms upstream of the chamber elements, ensuring they operate on the pressure side, minimizing cavitation and allowing for accurate hematocrit measurement by using ultrasonic and infrared sensors integrated into a holder device for precise temperature and density analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pump mechanisms are positioned downstream of chamber elements, then blood flow can be maintained, but gas bubbles form from cavitation which distort hematocrit measurements
Solution Approach 1:
The patent inverts the conventional arrangement by positioning the pump mechanisms upstream of the chamber elements rather than downstream. This reversal ensures that blood is pumped through the chamber elements on the pressure side of the pump, eliminating the negative pressure conditions that cause cavitation and gas bubble formation, thereby preventing measurement distortion while maintaining blood flow
2Productivity
If chamber elements are positioned on the suction side of pump mechanisms, then blood flow is maintained, but cavitation effects generate gas bubbles that interfere with measurements
Solution Approach 1:
The patent applies inversion by reversing the positional relationship between pumps and chamber elements. Instead of placing chamber elements on the suction side (conventional arrangement), the patent positions them on the pressure side upstream of the pumps. This maintains adequate blood flow while eliminating cavitation-induced gas bubbles that would compromise measurement reliability
3Measurement precision
If chamber elements are positioned on the pressure side of pump mechanisms, then gas bubble formation is minimized, but additional positioning complexity is required
Solution Approach 1:
The patent resolves the positioning complexity by inverting the conventional arrangement. By placing chamber elements upstream of the pumps on the pressure side, the design achieves gas bubble minimization while the inverted topology naturally simplifies the positioning requirements, as the pump-driven flow direction becomes the guiding principle for component arrangement
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
This configuration reduces the occurrence of gas bubbles, enabling reliable determination of hematocrit values in both incoming and processed blood, facilitating effective control and optimization of the blood processing parameters.
Implementation Method 1
A first ultrasonic sensor (92) is arranged on the bottom wall (803) of the first chamber element (80) and a second ultrasonic sensor (93) is arranged on the bottom wall (813) of the second chamber element (81)
Implementation Method 2
a first infrared sensor (94) which in the inserted position of the measurement device faces a circumferential wall of the first chamber element and a second infrared sensor (95) which in the inserted position of the measurement device faces a circumferential wall of the second chamber element
Data Source
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AI summary
A blood processing apparatus (1) comprises a measurement device (8) having a first chamber element (80) for measuring a haematocrit value of a blood fluid, the first chamber element (80) comprising a first inlet port (800) connectable to a first reservoir container (2) for allowing a flow from the first reservoir container (2) into the first chamber element (80) and a first outlet port (801) for allowing a flow out of the first chamber element (80), and the second chamber element (81) comprising a second inlet port (810) for allowing a flow into the second chamber element (81) and a second outlet port (811) connectable to a second reservoir container (3) for allowing a flow out of the second chamber element (81) towards the second reservoir container (3). The blood processing apparatus furthermore comprises a first pump mechanism (600) for pumping a blood fluid in a flow direction (F1) from the first reservoir container (2) towards the blood processing apparatus (1), and a second pump mechanism (610) for pumping a blood fluid in a flow direction (F2) from the blood processing apparatus (1) towards the second reservoir container (2). Herein, the first pump mechanism (600) is located upstream of the first inlet port (800) of the first chamber element (80) and the second pump mechanism (610) is located upstream of the second inlet port (810) of the second chamber element (81). In this way a blood processing apparatus comprising a measurement device is provided which in an easy and reliable manner allows for a measurement of in particular a haematocrit value in the incoming blood flow as well as the outgoing blood flow.