Pulse Wave Signal Processor Contact Pressure Determination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pulse wave signal processors face challenges in determining appropriate contact pressure without a pressure sensor, as the pressure sensor and light-emitting/receiving elements are often mounted at different locations, leading to inconsistent contact pressure readings.
Innovation Solution
A pulse wave signal processor that calculates a pulse wave feature related to the steepness of rise of a pulse wave, allowing it to determine whether the contact pressure is within an appropriate range without the need for a pressure sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pressure sensor is attached to determine contact pressure, then contact pressure can be measured, but device size increases and components are mounted at different locations leading to measurement inaccuracies
Solution Approach 1:
The patent extracts the pressure sensing function from a separate pressure sensor and integrates it into the photoplethysmographic sensor structure. By making the light-emitting and light-receiving elements press against the measurement site, the system determines contact pressure through the pulse wave signal characteristics themselves, eliminating the need for a separate pressure sensor and its associated mounting complexities.
Solution Approach 2:
The photoplethysmographic sensor serves multiple functions: it measures pulse waves for physiological information and simultaneously determines contact pressure through the same pulse wave signal analysis. This multi-functionality eliminates the need for separate dedicated components for pressure measurement, reducing device complexity while maintaining measurement accuracy.
2Adaptability or versatility
If pressure sensor and light-emitting/receiving elements are mounted at different locations, then component layout is flexible, but contact pressure readings become inconsistent
Solution Approach 1:
The patent merges the pressure measurement function with the photoplethysmographic measurement function by using the same light-emitting and light-receiving elements at the same location. The pulse wave signal obtained from this unified measurement point reflects the contact pressure at that specific location, ensuring consistent and reliable pressure readings.
3Volume of moving object
If device is miniaturized, then device size decreases, but attaching additional components like pressure sensors becomes difficult
Solution Approach 1:
The patent removes the separate pressure sensor component entirely and extracts the pressure measurement capability into the pulse wave signal analysis of the photoplethysmographic sensor. This eliminates the need for additional components that would be difficult to attach in miniaturized devices.
Solution Approach 2:
The photoplethysmographic sensor is designed to perform both physiological measurement and contact pressure determination simultaneously. This multi-functionality allows miniaturized devices to maintain comprehensive measurement capabilities without adding separate pressure sensing components that would increase device volume.
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 configuration enables reliable determination of appropriate contact pressure, improving the accuracy of physiological information measurement and allowing for miniaturization of the device, while eliminating the need for a pressure sensor.
Implementation Method 1
light is emitted from a light-emitting element onto a measurement site such as a finger, and when the light is reflected from or transmitted through the measurement site, the light is detected by a light-receiving element
Implementation Method 2
a convenient method for measuring pulse waves is to use a photoplethysmographic sensor
Data Source
AI summary
A pulse wave feature calculator is provided that calculates a value of a pulse wave feature based on a steepness of a rise of a pulse wave measured with a photoplethysmographic sensor. Based on the value of the pulse wave feature calculated by the pulse wave feature calculator, a contact pressure determinator determines whether a contact pressure, which is a pressure with which the photoplethysmographic sensor is pressed against a measurement site, is within a range, such as an appropriate range.