Automated Citrate Anticoagulation Control in CRRT

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Solution Overview

Problem

Current CRRT therapies lack a consensus on optimizing citrate flow rates, leading to variability and potential life-threatening electrolyte imbalances, such as hypocalcemia or hypomagnesemia, due to the lack of a standardized method for controlling citrate anticoagulation in continuous renal replacement therapy.

Innovation Solution

A system comprising a blood flow detector, electrolyte sensor, citrate pump, and a controller executing algorithms to calculate optimal citrate flow rates based on blood flow, electrolyte concentrations, and citrate concentration, ensuring precise control of citrate and electrolyte supplementation in the blood filtration circuit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If citrate is used as an anticoagulant in CRRT, then blood coagulation is prevented, but electrolyte depletion occurs leading to hypocalcemia or hypomagnesemia

Engineering Contradiction:
Improveanticoagulation effectivenessVSAvoidelectrolyte depletion
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system continuously monitors electrolyte levels (calcium, magnesium) and citrate consumption in real-time, using this feedback to dynamically adjust the citrate infusion rate. This closed-loop control prevents both over-anticoagulation and electrolyte depletion by automatically modulating citrate delivery based on actual patient response and consumption patterns.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes the citrate infusion rate parameter based on real-time measurements of electrolyte levels, blood flow rate, and citrate consumption. By continuously adjusting this parameter rather than using a fixed rate, the system optimizes anticoagulation effectiveness while preventing electrolyte depletion.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If fixed citrate flow rate guidelines are used, then anticoagulation is provided, but variability in electrolyte levels occurs across different CRRT protocols

Engineering Contradiction:
Improveanticoagulation protocol simplicityVSAvoidelectrolyte level stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The system performs self-adjustment by automatically calculating and modifying the citrate infusion rate based on real-time patient-specific parameters including blood flow rate, electrolyte levels, and measured citrate consumption. This eliminates the need for manual protocol adjustments and ensures optimal anticoagulation with stable electrolyte levels for each individual patient.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system transitions from static fixed-rate citrate administration to dynamic rate adjustment. The citrate infusion rate is continuously modified in response to changing patient conditions, blood flow rates, and electrolyte levels, ensuring optimal anticoagulation effectiveness while maintaining electrolyte stability throughout the CRRT treatment.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If manual adjustment of citrate rate is performed, then some optimization is achieved, but significant variability and time loss occur

Engineering Contradiction:
Improvecitrate flow rate precisionVSAvoidadjustment time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The system replaces manual mechanical adjustment of citrate rates with an automated electronic control system. The processor continuously calculates the optimal citrate infusion rate based on real-time data from sensors and monitors, automatically adjusting the pump rate without manual intervention. This eliminates time loss associated with manual adjustments and achieves precise control of citrate delivery.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system provides continuous monitoring and adjustment of citrate infusion rates throughout the entire CRRT treatment. Rather than periodic manual checks, the system continuously measures electrolyte levels, blood flow rates, and citrate consumption, making real-time adjustments to maintain optimal anticoagulation and electrolyte balance without interruption or time loss.

Inventive Principle:
Principle #20Continuity of useful action

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 consistent and optimized citrate flow rates, maintaining stable electrolyte levels in patients undergoing CRRT, reducing the risk of electrolyte imbalances and ensuring effective anticoagulation, with minimal variance across different CRRT types and blood flow rates.

Implementation Method 1

Through osmosis or differential pressure, the hemofilter allows migration of soluble waste and water from the blood across the membrane and into the dialysate solution.

Methodology Applied
Scientific EffectOsmosis: Osmosis

Implementation Method 2

Through osmosis or differential pressure, the hemofilter allows migration of soluble waste and water from the blood across the membrane and into the dialysate solution.

Methodology Applied
Scientific EffectDifferential pressure: Pressure Gradient

Implementation Method 3

Hemodialysis involves convective diffusion of solutes from blood across a semi-permeable membrane into a volume of dialysate flow.

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 4

Hemofiltration operates without a dialysate, and instead uses a positive hydrostatic pressure to drive water and solutes across a more porous membrane.

Methodology Applied
Scientific EffectHydrostatic pressure: Pressure Gradient

Data Source

PatentEP1926510B1Automation and optimization of CRRT treatment using regional citrate anticoagulation
Publication Date: 2015.11.04 NIKKISO CO LTD
  • EP1926510B1 patent drawingFigure 1
  • EP1926510B1 patent drawingFigure 2
  • EP1926510B1 patent drawingFigure 3

AI summary

A system or method automates and optimizes citrate anticoagulant supplementation in a blood filtration circuit during CRRT. A processor-based control system interfaces with a blood filtration circuit to detect patient blood flow into the circuit, detect fluid loss through a hemofilter, and sense vital electrolyte concentrations in the blood flow, and in response, control the addition of citrate, substitution fluid, and electrolyte supplements to ensure stability of plasma concentrations in post-dilution flow returned to the patient. The controller executes the method embodied as process control algorithms for calculating an optimal citrate flow rate as a function of selected, detected, and calculated system parameters. Citrate may be added to the circuit separately, or as part of a substitution solution or a dialysate.