Blood Pressure Pulse Wave Measurement Using Tube Delay Elements
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing blood pressure pulse wave measurement apparatuses require significant labor and time to change tube lengths, necessitating adjustments to the measurement algorithm for accurate ankle-brachial index (ABI) and pulse wave velocity (PWV) measurements, as tube length changes affect pulse wave transmission time.
Innovation Solution
Incorporating delay elements, such as air tanks, in the tubes connecting cuffs to detection units, allowing the tubes' transfer characteristics to match predetermined reference lengths without altering the measurement algorithm, enabling easy length adjustments without affecting ABI and PWV calculations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the tube length connecting the cuff and detection unit is changed, then the apparatus can be miniaturized and attachment is easier, but the measurement algorithm must be changed which requires significant labor and time
Solution Approach 1:
A delay element is introduced as an intermediary component in the tube between the cuff and detection unit. This delay element compensates for the reduced pulse wave transmission time caused by shorter tube length, effectively decoupling the physical tube length from the measurement algorithm's reference length assumption, thereby allowing apparatus miniaturization without algorithm updates
Solution Approach 2:
The invention changes the physical parameter of tube length while maintaining the effective measurement parameter through the delay element. By adjusting the delay element's delay characteristic to match the difference between the actual tube length and reference length, the system maintains measurement accuracy despite physical dimension changes
2Ease of operation
If the tube length is reduced, then the apparatus becomes more compact and easier to handle, but the pulse wave transmission time changes affecting measurement accuracy
Solution Approach 1:
The delay element serves as a mediator that compensates for the changed pulse wave transmission characteristics. It introduces an artificial delay that matches the difference between actual and reference tube lengths, thereby maintaining the effective transmission time used in measurements despite the physically shorter tube
Solution Approach 2:
The delay element is designed with a predetermined delay characteristic that is calculated in advance based on the reference length. This preliminary design allows the tube length to be changed without requiring subsequent adjustments to the measurement system, as the compensation is already built into the delay element
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 easy attachment and potential miniaturization of the apparatus, allowing tube length changes without requiring updates to the measurement algorithm, thus reducing labor and time needed for measurements while maintaining accurate results.
Implementation Method 1
a first delay element which delays a transfer characteristic of the first tube so that the transfer characteristic of the first tube matches a transfer characteristic of a tube having a predetermined first reference length; a second delay element which delays a transfer characteristic of the second tube so that the transfer characteristic of the second tube matches a transfer characteristic of a tube having a predetermined second reference length
Data Source
AI summary
A blood pressure pulse wave measurement apparatus includes: first and second cuffs for pressing upper and lower limbs of a measurement subject; first and second detection units configured to detect first and second pulse waves transmitted from the cuffs through first and second tubes; and a control unit configured to calculate an ankle-brachial blood pressure ratio and a pulse wave velocity using the pulse waves. First and second delay elements are provided at specific positions in the lengthwise directions of the tubes. The first delay element delays a transfer characteristic of the first tube so the transfer characteristic of the first tube matches a transfer characteristic of a tube having a predetermined first reference length, and the second delay element delays a transfer characteristic of the second tube so the transfer characteristic of the second tube matches a transfer characteristic of a tube having a predetermined second reference length.