Pressure Transducer Auto-Zeroing and Electronic Level Adjustment

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Solution Overview

Problem

Current vital signs monitoring systems require manual zeroing and leveling of pressure transducers, which are time-consuming, expose patients to contamination risks, and result in measurement errors due to zero drift and level differences, especially in urgent situations where time is critical.

Innovation Solution

An automatic zeroing and electronic level adjustment system using a circuit with two differential amplifiers and specific software to eliminate the need for manual zeroing and leveling, allowing for immediate monitoring initiation and accurate pressure measurement without exposing the transducer to atmospheric pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual zeroing and leveling procedures are performed, then measurement accuracy is improved, but time consumption and operational complexity increase

Engineering Contradiction:
Improvepressure measurement accuracyVSAvoidtime for zeroing and leveling procedures
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs automatic zeroing and leveling without requiring manual intervention. The microprocessor automatically executes zeroing by triggering a valve to expose the transducer to atmospheric pressure and calculates leveling based on patient data (height, weight, age) and transducer position, eliminating the need for manual procedures while maintaining measurement accuracy

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system performs zeroing automatically before pressure monitoring begins and recalibrates at predetermined intervals (e.g., every 8 hours). This preliminary and periodic action ensures measurement accuracy is maintained without requiring manual intervention at each calibration point, reducing time loss while preserving precision

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If manual zeroing is performed by opening the system to atmospheric pressure, then transducer calibration is achieved, but patient contamination risk increases

Engineering Contradiction:
Improvetransducer calibration accuracyVSAvoidpatient contamination risk
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

A valve is introduced as an intermediary component that controls the exposure of the transducer to atmospheric pressure. The valve can be automatically triggered to open briefly for zeroing and then automatically closed, isolating the patient's vascular system from the external environment. This intermediary mechanism enables necessary calibration while minimizing contamination risk by limiting exposure time and enabling automatic closure

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If transducer leveling is performed manually, then measurement accuracy is improved, but device complexity and ease of operation worsen

Engineering Contradiction:
Improvepressure measurement accuracyVSAvoidease of transducer positioning
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The manual mechanical leveling process is replaced with an electronic calculation system. The microprocessor calculates the required leveling adjustment based on patient anthropometric data (height, weight, age), transducer position relative to the patient, and gravitational acceleration. This substitution transforms a complex manual mechanical adjustment into a simple electronic calculation, improving ease of operation while maintaining measurement accuracy

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system changes from fixed mechanical leveling to dynamic electronic parameter adjustment. By using patient-specific parameters (height, weight, age) and transducer position data, the system calculates and applies customized leveling corrections. This parameter-based approach allows the same transducer to be accurately leveled for different patients and positions without manual reconfiguration, improving both ease of operation and measurement precision

Inventive Principle:
Principle #35Parameter changes

4Measurement precision

If frequent zeroing is performed to correct zero drift, then measurement accuracy is maintained, but productivity and time efficiency decrease

Engineering Contradiction:
Improvepressure measurement accuracyVSAvoidmonitoring system efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system performs automatic zeroing at predetermined periodic intervals (e.g., every 8 hours) rather than requiring frequent manual interventions. The microprocessor automatically triggers the zeroing sequence at these intervals, maintaining measurement accuracy by correcting zero drift while minimizing disruption to clinical workflow. This periodic automated action balances measurement precision requirements with productivity concerns by eliminating the need for frequent manual zeroing

Inventive Principle:
Principle #19Periodic action

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 prompt and accurate pressure monitoring without manual zeroing or leveling, reducing contamination risks and measurement errors, and allowing the transducer to be positioned anywhere, with automatic level correction during patient position changes or transportation.

Implementation Method 1

general pressure transducers are usually 'Wheatstone' bridge type

Methodology Applied
Scientific EffectWheatstone bridge: Wheatstone Bridge

Implementation Method 2

pressure transducers are usually 'Wheatstone' bridge type

Methodology Applied
Scientific EffectPiezoresistive effect: Piezoresistive Effect

Implementation Method 3

a differential type amplifier circuit is usually used, amplifying the difference between the voltages applied to its inputs

Methodology Applied
Scientific EffectDifferential amplification:

Data Source

PatentEP3520690B1System for automatic zeroing and electronic adjustment of pressure transducer level applied to vital sign monitors
Publication Date: 2024.09.25 ZAMMI INSTRAL
  • EP3520690B1 patent drawingFigure 1~2
  • EP3520690B1 patent drawingFigure 3~4
  • EP3520690B1 patent drawing

AI summary

The present invention provides automatic zeroing and electronic level adjustment of pressure transducer in relation to patient, applied to vital signs monitors, where the automatic zeroing of circuit of pressure consists of circuit and software able to remove the reference of virtual ground of pressure calculation, and the electronic level adjustment of transducer in relation to patient consists of offset, through software, of value in mmHg related to level difference in cmH2O informed by the user by means of monitor interface.