Optical Blood Pressure Sensor Eliminates Cuff Occlusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing non-invasive blood pressure measurement techniques require calibration and temporarily restrict blood flow, which can be uncomfortable and inaccurate, especially in motion or for areas that cannot withstand restricted blood flow.
Innovation Solution
The use of light-based technology to measure pulse wave velocity (PWV) and instantaneous blood velocity without the need for calibration, allowing for self-calibrating non-invasive blood pressure systems that do not restrict blood flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a cuff is used to restrict blood flow for non-invasive measurement, then blood pressure can be measured without invasion, but circulation is temporarily stopped causing discomfort and potential damage
Solution Approach 1:
The patent replaces the mechanical cuff-based occlusion system with an optical measurement system using light sources and detectors. The system measures blood pressure by detecting changes in light absorption and reflection properties of blood vessels during the cardiac cycle, eliminating the need for mechanical compression and blood flow restriction while maintaining measurement capability
Solution Approach 2:
The patent introduces light as an intermediary medium to transfer information about blood pressure parameters. By measuring optical properties (absorption, reflection, scattering) of blood and surrounding tissues, the system indirectly determines blood pressure without direct mechanical contact or occlusion, serving as a non-invasive mediator between the measurement goal and the patient
2Object-affected harmful factors
If traditional non-invasive methods are used, then invasion is avoided, but motion of patient or equipment results in inaccurate measurements
Solution Approach 1:
The patent employs dynamic signal processing techniques that adapt to motion conditions in real-time. The system continuously tracks blood pressure parameters by analyzing dynamic changes in optical signals during the cardiac cycle, using differential measurements and signal differentiation to isolate true blood pressure variations from motion-induced artifacts, maintaining reliability during patient movement
3Measurement precision
If repeated cuff measurements are performed, then accurate blood pressure can be obtained, but time is required for multiple measurements with pauses between them
Solution Approach 1:
The patent implements continuous blood pressure monitoring by continuously measuring optical properties of blood vessels throughout the cardiac cycle. Unlike intermittent cuff measurements, the system provides uninterrupted real-time data streams, enabling continuous tracking of blood pressure changes without pauses or repeated application of measurement protocols, thereby improving measurement throughput and temporal resolution
4Measurement precision
If invasive measurement is used, then accurate blood pressure is obtained, but patient discomfort and risk of complications increase
Solution Approach 1:
The patent replaces invasive mechanical sensors that require insertion into blood vessels with non-invasive optical measurement systems. The system uses light sources and detectors placed on the skin surface to measure blood pressure through optical properties of blood and tissues, completely eliminating the need for vascular penetration while maintaining measurement accuracy
Solution Approach 2:
The patent uses optical fields as intermediaries to obtain blood pressure information without direct contact with blood or vessels. Light serves as a mediator that interacts with blood components (hemoglobin, plasma) and tissue structures to provide indirect but accurate measurement of hemodynamic parameters, avoiding all invasive procedures and associated risks
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
Enables accurate, continuous, and beat-to-beat monitoring of blood pressure without the need for calibration or blood flow restriction, improving patient comfort and measurement accuracy.
Implementation Method 1
a light source to emit light that passes through or reflects off tissues
Implementation Method 2
The reflected light waveform has a Doppler shift from the emitted light due to the reflection of the light from moving components of the patient's tissues
Implementation Method 3
a detector to detect the light and output a signal in response to and based on the detected light
Data Source
AI summary
Light-based non-invasive blood pressure measurement systems and methods that include a sensor having a light emitter and a light detector are disclosed. The light emitter emitting coherent or non-coherent light that is transmitted into and reflected from the tissues of the patient, including reflecting from moving blood. The light reflected from the moving blood being having a Doppler shift and detected by the light detector to generate a noninvasive blood pressure signal. The non-invasive blood pressure signal is processed to determine the instantaneous velocity of the blood. Additionally, pulse wave velocity data is obtained nearly, or substantially, simultaneously with the acquisition of the non-invasive blood pressure signal. Using the pulse wave velocity, the instantaneous velocity of the blood and a density of the blood, an instantaneous blood pressure can be determined.