Implantable Oil-Filled Pressure Sensor Diameter Reduction
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Solution Overview
Problem
Existing oil-filled pressure sensors are too large for human body implantation and have a diaphragm welding ring that creates a dead zone in pressure transmission, making them unsuitable for medical applications.
Innovation Solution
A pressure sensor design with a body having a cavity for liquid, a planar mounting surface, and a diaphragm that transmits external pressure to the liquid, along with a pressure detection chip and circuit board mounted on the surface, eliminating the need for a welding ring and allowing for a smaller diameter suitable for implantation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the circuit board is horizontally mounted on the top of the metal shell extending in the radial direction, then the pressure sensor can be manufactured with conventional structures, but the diameter of the sensor becomes necessarily large (greater than 6.9 mm)
Solution Approach 1:
The circuit board is reoriented from a horizontal mounting extending radially to a vertical mounting extending axially. This dimensional change allows the circuit board to be positioned within the axial length of the sensor body rather than increasing the radial diameter, thereby reducing the sensor diameter to less than 5 mm while maintaining manufacturability.
2Reliability
If a diaphragm welding ring is used to seal the pressure transmission medium, then the sealing is ensured, but a dead zone is formed in the flow of the pressure transmission medium
Solution Approach 1:
The welding ring structure is completely removed from the design. Instead of using a separate sealing ring component, the diaphragm is directly welded to the inner wall of the pressure transmission cavity, eliminating the dead zone while maintaining effective sealing and pressure transmission.
Solution Approach 2:
The sealing function and pressure transmission function are merged into a single continuous interface where the diaphragm directly contacts the pressure transmission medium without interruption from welding rings, ensuring uniform pressure distribution and eliminating dead zones.
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
The design enables a pressure sensor with a diameter of less than 5 mm, allowing for implantation in the human body, such as blood vessels, while eliminating the dead zone for effective pressure detection.
Implementation Method 1
a diaphragm attached to the body for transmitting an external medium pressure to the liquid in the cavity
Implementation Method 2
a pressure detection chip mounted on the mounting surface of the body for detecting a pressure of the liquid within the cavity
Data Source
AI summary
An implantable pressure sensor is disclosed that has a small diameter and eliminates any dead zone in the flow of the pressure transmission medium, and is thus particularly adapted for implantation. In one embodiment the pressure sensor comprises a body including a cavity for receiving a liquid, and a planar mounting surface extending in an axial direction of the body. A diaphragm is attached to the pressure sensor body for transmitting an external medium pressure to the liquid in the cavity. A pressure detection chip is mounted on the mounting surface of the pressure sensor body for detecting a pressure of the liquid within the cavity, and a circuit hoard is mounted on the planar mounting surface of the body and is electrically connected to the pressure detection chip resulting in a device of smaller diameter particularly suited for implantation.