Photopheresis Light Dose Control via Hematocrit and Thickness Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Delivering a precise light dose to cells suspended in a light-attenuating medium is challenging, especially when the medium is not transparent and target cells are not uniformly distributed, leading to inconsistent light energy delivery in phototherapy treatments.
Innovation Solution
A photopheresis system and method that use a disposable fluid circuit with a processing chamber and irradiation device, where the hematocrit and thickness of the cell suspension are controlled to ensure a predetermined light dose is delivered, based on therapeutic response rather than direct measurement, eliminating the need for hematocrit sensors and allowing for variations in light attenuating material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If light irradiation therapy is applied to cells in a light attenuating medium, then therapeutic effect is achieved, but light energy delivery becomes inconsistent due to attenuation and non-uniform cell distribution
Solution Approach 1:
The patent changes physical parameters of the suspension including hematocrit control (maintaining red blood cell concentration between 0-5%), suspension thickness control (maintaining between 3-6mm), and light dose adjustment based on these parameters to compensate for attenuation effects and ensure consistent light delivery to target cells
Solution Approach 2:
The patent implements feedback control by measuring hematocrit and suspension thickness, then using these measurements to calculate and adjust the emitted light dose to achieve the desired target dose, creating a closed-loop system that compensates for variations in light attenuation
2Measurement precision
If hematocrit sensors and complex algorithms are used to control light dose, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent employs disposable sensors and single-use processing chambers that are integrated into disposable blood processing kits, eliminating the need for complex reusable sensor systems and calibration mechanisms while maintaining measurement precision throughout the device lifecycle
Solution Approach 2:
The patent introduces simplified intermediary measurement approaches using disposable sensors that directly measure hematocrit and thickness parameters without requiring complex algorithmic processing, and uses lookup tables or simplified calculation methods to determine appropriate light doses based on measured parameters
3Ease of operation
If manual hematocrit measurement and adjustment is performed, then ease of operation is maintained, but manufacturing precision of light dose delivery deteriorates
Solution Approach 1:
The system automatically measures hematocrit and suspension thickness using integrated disposable sensors, then automatically calculates and adjusts the light dose parameters, eliminating the need for manual measurement and adjustment while ensuring precise control of the therapeutic light dose delivered to cells
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 ensures a consistent therapeutic effect by determining the required light dose through therapeutic response measurements, achieving precise light delivery even with varying amounts of light-attenuating material, thereby improving the efficacy of phototherapy treatments.
Implementation Method 1
a hematocrit sensor...to measure the hematocrit of the suspended mononuclear cells
Implementation Method 2
subjected to UV light to activate the 8-MOP molecules. The photoactivated 8-MOP alters the DNA of the pathogenic leukocytes
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method provided for determining a range for the amount of light-energy attenuating material that may be present in a suspension containing target cells (such as MNCs), light-energy attenuating matter (such as RBCs and plasma), and a light-energy activatable compound (such as psoralen) so that a desired therapeutic effect (such as the percentage of MNCs in which apoptosis occurs) is obtained when the suspension is subjected to a known amount of light energy. In a related aspect, a method is provided for preparing a suspension containing target cells, light-energy attenuating matter, and a light-energy activatable compound so that a desired therapeutic effect is obtained when the suspension is subjected to a known amount of light energy