Wearable Perfusion Index via Occlusion Baseline
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current devices for monitoring peripheral blood flow provide relative measurements that are difficult to interpret clinically, especially when a 'healthy' baseline cannot be obtained, and are affected by skin color, leading to inconsistent measurements.
Innovation Solution
A method and system for monitoring peripheral blood flow using a wearable device that involves monitoring blood flow under two different physiologic conditions, generating a dimensionless relative index based on these measurements, and outputting an indication of this index.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If relative measurements are used for monitoring peripheral blood flow, then device complexity is reduced, but measurement precision deteriorates due to difficulty in clinical interpretation
Solution Approach 1:
The patent transforms the measurement parameter from absolute blood flow values to a dimensionless relative index by introducing a reference measurement (occlusion baseline). This parameter transformation enables clinical interpretation while maintaining device simplicity, as the index represents blood flow as a percentage of the reference state rather than requiring complex absolute quantification
2Measurement precision
If absolute blood flow measurements are implemented, then measurement precision improves, but device complexity increases due to requirements for healthy baseline acquisition
Solution Approach 1:
The system performs self-calibration by using the patient's own occluded state as the reference baseline, eliminating the need for external healthy baseline data. The device automatically establishes its own reference point through the occlusion maneuver, making the system self-sufficient and removing dependencies on external calibration sources
3Ease of operation
If traditional blood loss estimation methods are used, then ease of operation is maintained, but measurement precision deteriorates due to underestimation of blood loss
Solution Approach 1:
The patent replaces visual estimation (mechanical observation) with optical measurement using photodetectors and light sources. This substitution maintains operational simplicity as the device automatically performs measurements and calculations, while dramatically improving precision by providing objective quantitative data on blood flow changes and blood loss
4Device complexity
If skin color effects are not compensated, then device complexity remains low, but measurement precision deteriorates due to inconsistent measurements across different skin tones
Solution Approach 1:
The patent introduces an intermediary reference measurement (occlusion baseline) that serves as a mediator between the light source and the blood flow measurement. This reference state captures the skin's optical properties under known conditions, allowing the system to compensate for skin color variations by comparing measurements against this personalized reference rather than requiring complex skin tone detection algorithms
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 solution provides subject-specific perfusion range measurements that are not affected by skin color, enabling accurate monitoring of peripheral blood flow and early detection of conditions like postpartum hemorrhage.
Implementation Method 1
a photodetector to detect the intensity of light transmitted through the tissue
Data Source
AI summary
A method for monitoring peripheral blood flow of a patient using a wearable device includes monitoring peripheral blood flow of the patient under a first physiologic condition and monitoring peripheral blood flow of the patient under a second physiologic condition different than the first physiologic condition. A dimensionless relative index of the monitored peripheral blood flow of the patient i) under the second physiologic condition based on the monitored peripheral blood flow under the first physiologic condition, or ii) under the first physiologic condition based on the monitored peripheral blood flow under the second physiologic condition is generated. An indication of the dimensionless relative index is output.