Implantable Pressure Sensor with Fluid Cavity for Cardiac Monitoring

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Implantable medical devices, such as leadless cardiac pacemakers, face challenges in accurately monitoring cardiac activity and delivering therapy due to limitations in sensing pressure and cardiac cycle phases, which can affect the effectiveness of treatments for heart conditions like arrhythmias and inefficient heart contractions.

Innovation Solution

Incorporating a pressure sensor with a diaphragm responsive to external pressure, coupled with circuitry that communicates pressure measurements and cardiac signals to determine cardiac cycle phases, allowing for precise monitoring and therapy delivery, including cardiac resynchronization therapy (CRT) optimization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a pressure sensor is integrated into the implantable medical device housing, then measurement precision of cardiac pressure is improved, but device complexity increases

Engineering Contradiction:
Improvepressure sensing accuracyVSAvoiddevice structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The pressure sensor is integrated directly into the housing structure of the implantable medical device, combining the housing and sensor into a single unified component. This eliminates the need for separate sensor housings and reduces overall device complexity while maintaining measurement precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The housing serves multiple functions: it provides structural protection for internal components and simultaneously acts as the pressure sensing element through the integrated pressure sensor. This multi-functionality reduces the number of separate components needed, thereby reducing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If a diaphragm is added to transmit pressure from external environment to the pressure sensor, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvepressure transmission accuracyVSAvoiddevice structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

A diaphragm made of flexible material is used to transmit pressure from the external environment to the pressure sensor. The diaphragm's flexibility allows it to deform in response to pressure changes while maintaining a simple, thin-film structure that does not significantly increase device complexity.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The diaphragm acts as an intermediary element between the external environment and the pressure sensor, enabling accurate pressure transmission while isolating the sensor from direct exposure to the external environment. This simple intermediary structure resolves the contradiction by providing necessary pressure coupling without adding complex mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If fluid-filled cavity is used to communicate pressure measurements, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvepressure signal transmissionVSAvoiddevice structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

A fluid-filled cavity is used to transmit pressure measurements from the diaphragm to the pressure sensor. The fluid acts as a hydraulic medium, efficiently transmitting pressure signals with high fidelity. This approach maintains measurement precision while using a simple fluid-filled space rather than complex mechanical transmission mechanisms.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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

Enhances the ability to monitor cardiac activity and deliver targeted therapies, improving heart function and reducing arrhythmias by accurately sensing pressure and cardiac cycle phases, thereby optimizing treatment outcomes.

Implementation Method 1

The diaphragm may be responsive to a pressure applied to the diaphragm by the environment outside of the housing

Methodology Applied
Scientific EffectPressure sensing:

Implementation Method 2

A pressure sensor may be within the housing may have a pressure sensor diaphragm that is responsive to a pressure applied to the pressure sensor diaphragm and provides a pressure sensor output signal that is representative of the pressure applied to the pressure sensor diaphragm

Methodology Applied
Scientific EffectPressure measurement:

Implementation Method 3

A fluid filled cavity may be in fluid communication with both the diaphragm of the housing and the pressure sensor diaphragm of the pressure sensor. The fluid filled cavity may be configured to communicate a measure related to the pressure applied by the environment to the diaphragm of the housing to the pressure sensor diaphragm of the pressure sensor

Methodology Applied
Scientific EffectFluid communication:

Data Source

PatentEP3532161B1Implantable medical device with pressure sensor
Publication Date: 2023.08.30 CARDIAC PACEMAKERS INC
  • EP3532161B1 patent drawingFigure 1
  • EP3532161B1 patent drawingFigure 2
  • EP3532161B1 patent drawingFigure 3

AI summary

An implantable medical device (IMD) is configured with a pressure sensor. The IMD includes a housing, a pressure sensor and a fluid filled cavity. The housing has a diaphragm that is exposed to the environment outside of the housing. The pressure sensor has a pressure sensor diaphragm that is responsive to a pressure applied to the pressure sensor diaphragm and provides a pressure sensor output signal that is representative of the pressure applied to the pressure sensor diaphragm. The fluid filled cavity is in fluid communication with both the diaphragm of the housing and the pressure sensor diaphragm of the pressure sensor. The fluid filled cavity is configured to communicate a measure related to the pressure applied by the environment to the diaphragm of the housing to the pressure sensor diaphragm of the pressure sensor.