Blood Purification Fluid-Pump Calibration During Priming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The flow rate of fluid replacement pumps in hemodialysis devices is often displaced from the set rate at the start of therapy, affecting the accuracy of dialysis fluid, replacement fluid, and waste fluid pumps.
Innovation Solution
A blood purification apparatus with a controller that measures and adjusts the flow rates of replacement, dialysis, and waste fluid pumps using a scale to calculate correction values, ensuring accurate flow rates by measuring weight changes during priming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fluid replacement pump is operated during dialysis therapy, then the replacement fluid is delivered to the blood circuit, but the flow rate of the pump is displaced from the set rate at the start of therapy
Solution Approach 1:
The patent performs flow rate calibration during the priming phase before dialysis therapy begins. The controller measures the actual flow rate of the fluid replacement pump by monitoring fluid volume changes in the blood circuit during priming, calculates a correction value, and applies it to ensure accurate flow rate delivery from the start of therapy without requiring separate calibration time
2Measurement precision
If the flow rate of the fluid replacement pump is calibrated during priming, then the pump delivers accurate flow rate at start of therapy, but additional measurement and control mechanisms are required
Solution Approach 1:
The system uses the existing blood circuit and fluid storage chambers as measurement vessels during priming. The controller leverages the built-in scale to measure fluid volume changes and automatically calculates correction values for the pump flow rate, eliminating the need for external measurement devices or manual calibration procedures
3Reliability
If the dialysis fluid pump and waste fluid pump are operated simultaneously, then the dialysis process functions properly, but the flow rates of both pumps may be displaced from set rates at start of therapy
Solution Approach 1:
The controller continuously monitors the actual flow rates of both the dialysis fluid pump and waste fluid pump during priming by measuring fluid volume changes. Based on these measurements, the controller calculates correction values and adjusts the pump operations to ensure both pumps deliver accurate flow rates simultaneously, maintaining proper dialysis function while ensuring precision
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
Ensures that each pump operates at the correct flow rate at the start of therapy, preventing errors and enabling precise fluid management.
Implementation Method 1
a scale, and a controller. The scale measures weight change of the first fluid storage portion and the second fluid storage portion as a whole
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
In a first step (S1), a controller actually measures a substantial replacement fluid flow rate of a replacement fluid pump from weight change measured by a scale and calculates a replacement fluid correction value which is a difference between a set replacement fluid flow rate and the substantial replacement fluid flow rate. In a second step (S2), the controller actually measures a substantial dialysis fluid flow rate of a dialysis fluid pump from weight change measured by the scale and calculates a dialysis fluid correction value which is a difference between a set dialysis fluid flow rate and the substantial dialysis fluid flow rate. In a third step (S3), the controller actually measures a difference between a substantial waste fluid flow rate of a waste fluid pump and the substantial dialysis fluid flow rate of the dialysis fluid pump from weight change measured by the scale, calculates the substantial waste fluid flow rate from this difference and the substantial dialysis fluid flow rate actually measured in the second step, and calculates a waste fluid correction value which is a difference between a set waste fluid flow rate and the substantial waste fluid flow rate.