Blood Pump Control for Minimizing Substituate Infusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
During blood treatment, the reinfusion of a substituate into patients can be counterproductive as it infuses unwanted fluid, particularly detrimental for pediatric patients with smaller blood volumes, aiming to minimize blood cell loss but often resulting in the infusion of a substituate, which contradicts the therapeutic goal of removing water from the blood.
Innovation Solution
A method for operating a blood treatment apparatus with a blood filter and control unit that manages the operation of blood and ultrafiltration pumps to minimize the reinfusion of substituate by delaying the ultrafiltration pump's reactivation, allowing fresh blood to replace concentrated blood in the extracorporeal circuit, thereby reducing the hematocrit and ultrafiltration rate, and optimizing the flow rates and pressures to minimize substituate infusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If substituate is infused into the extracorporeal blood circuit to displace and reinfuse patient's blood, then blood cell loss is minimized, but unwanted fluid is infused into the patient which contradicts the therapeutic goal of removing water from blood
Solution Approach 1:
The blood pump is operated for a predetermined time period before ultrafiltration is stopped to allow fresh blood to displace concentrated blood in the extracorporeal circuit. This preliminary blood circulation action prepares the system so that when substituate is later infused for blood return, the amount of substituate required is minimized because the concentrated blood has already been diluted and displaced by fresh blood circulation.
Solution Approach 2:
The blood pump operates continuously throughout the blood return process, maintaining continuous blood circulation. This continuous operation ensures that fresh blood constantly displaces concentrated blood in the extracorporeal circuit, allowing the system to achieve complete blood return with minimal substituate infusion while maintaining the therapeutic benefit of water removal.
2Loss of time
If ultrafiltration is stopped immediately to begin blood return, then treatment time is reduced, but concentrated blood remains in the extracorporeal circuit requiring more substituate for effective displacement
Solution Approach 1:
Instead of stopping ultrafiltration immediately, the system performs a preliminary blood circulation phase where the blood pump operates for a predetermined time period before ultrafiltration cessation. This preliminary action displaces concentrated blood with fresh blood, reducing the substituate volume needed for subsequent blood return while adding only a brief, controlled time extension to the overall treatment.
3Productivity
If the blood pump operates at high flow rates to quickly return blood, then treatment efficiency is improved, but the risk of air embolism and circuit emptying increases
Solution Approach 1:
The blood pump flow rate is dynamically adjusted based on real-time monitoring of circulation parameters. The control unit modifies the pump operation to maintain optimal flow rates that ensure complete blood return while preventing air embolism and circuit emptying, adapting the system's operation to changing conditions throughout the blood return process.
Solution Approach 2:
The system employs feedback control where the control unit monitors circulation parameters and adjusts blood pump operation accordingly. This feedback mechanism ensures that the blood pump operates at flow rates that maximize blood return efficiency while maintaining circulation stability and preventing harmful conditions such as air embolism or circuit emptying.
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 approach reduces the amount of substituate infused during reinfusion, improves circulation stability, particularly for pediatric patients, minimizes blood loss, and enhances the effectiveness of blood return by reducing the vascular liquid intake and treatment time, ultimately improving patient well-being and reducing anemia and the need for erythropoietin drugs.
Implementation Method 1
The blood filter (19) includes a blood chamber (19a) and a dialysate chamber (19b), between which a membrane (19c) is arranged
Implementation Method 2
operating a blood pump from a time point tUF-stop, at which an ultrafiltration pump is stopped
Data Source
AI summary
A method for operating a blood treatment apparatus including an extracorporeal blood circuit having a blood filter with a blood chamber and a dialysate chamber, between which a membrane is arranged. The method encompasses operating a blood pump from a first time point, at which an ultrafiltration pump is stopped, at least until a second time point, at which at least one of the following conditions is met for the first time after the first time point: a time interval after has elapsed, the blood pump has conveyed a volume after, a measurement of a fluid in the extracorporeal blood circuit exceeds or falls below a threshold.