Eyelid Microcirculation Monitoring via Interferometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current patient monitoring technologies face challenges in accurately determining the microcirculation state of blood vessels, particularly in extremities like fingers and ears, due to factors such as cold temperatures, patient movement, and poor perfusion, which can lead to inaccurate readings and difficulties in monitoring microcirculation effectively.
Innovation Solution
A patient monitor and sensor system that utilizes a light source and photodiode detector placed on the eyelid to assess microcirculation by emitting red and infrared wavelengths, calculating oxygen saturation and perfusion index, and comparing ratios to determine the microcirculation state, with features like alarm generation and compensation for anomalous readings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a pulse oximetry sensor is attached to an extremity (finger, toe, ear lobe) to monitor blood oxygen saturation, then the monitoring can be performed at a convenient location with pulsatile blood flow, but the readings become inaccurate due to cold temperatures, patient movement, and poor perfusion in these extremities
Solution Approach 1:
The patent uses the eyelid as an intermediary tissue site between the traditional extremity locations and the core body. The eyelid provides accessible positioning while having better blood supply and less sensitivity to temperature and movement effects, thereby mediating between ease of placement and measurement accuracy
Solution Approach 2:
The patent changes the monitoring location parameter from extremities (fingers, toes, ear lobes) to the eyelid. This parameter change shifts the measurement environment to one with more stable perfusion characteristics, reducing the impact of temperature and movement while maintaining accessibility
2Duration of action of stationary object
If traditional pulse oximetry is used in cold environments or with poor perfusion, then the sensor can remain in place, but the microcirculation state cannot be accurately determined due to blocked blood vessels
Solution Approach 1:
The eyelid serves as a mediator that is less affected by the harmful factors (cold temperature, poor perfusion) that impact extremities. The better blood supply and vascular characteristics of the eyelid mediate against the negative effects of cold and poor perfusion, maintaining measurement accuracy while allowing continuous monitoring
3Measurement precision
If the sensor is placed on the eyelid to avoid temperature and movement effects, then measurement accuracy improves, but the device complexity increases due to additional monitoring features and algorithms
Solution Approach 1:
The monitoring system is designed with multi-functionality, using the same sensor platform to perform both traditional pulse oximetry and microcirculation state monitoring. This universal approach allows the system to handle multiple monitoring needs without proportionally increasing complexity, as the same hardware infrastructure supports multiple measurement modes
Solution Approach 2:
The system incorporates feedback mechanisms that automatically adjust monitoring parameters and trigger alarms based on detected microcirculation states. This feedback approach allows the system to maintain high measurement precision while managing complexity through automated responses rather than requiring complex manual intervention systems
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 accurate and reliable monitoring of microcirculation, reducing the impact of temperature and movement, and effectively differentiates between normal and blocked microcirculation states, aiding in the detection of conditions like cyanosis and sepsis.
Implementation Method 1
A patient monitor and sensor system that utilizes a light source and photodiode detector placed on the eyelid to assess microcirculation by emitting red and infrared wavelengths
Data Source
AI summary
A patient monitor capable of measuring microcirculation at a tissue site includes a light source, a beam splitter, a photodetector and a patient monitor. Light emitted from the light source is split into a reference arm and a sample arm. The light in the sample arm is directed at a tissue site, such as an eyelid. The reflected light from the tissue site is interfered with the light from the reference arm. The photodetector measures the interference of the light from both the sample arm and the reference arm. The patient monitor uses the measurements from the photodetector to calculate the oxygen saturation at the tissue site and monitor the microcirculation at the tissue site.