Torque-Cable Rotary Transducer Catheter for Corrosion-Resistant Ultrasound Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current ultrasound catheters face challenges such as corrosive coupling media, reduced torque output due to fluid contact with piezoelectric motors, and limitations in achieving accurate three-dimensional imaging within small body conduits, leading to inefficiencies and potential risks during medical procedures.
Innovation Solution
The design includes a catheter with a rotating transducer and drive shaft, a non-rotating wire guide, and a torque cable system that allows for precise rotation and torque transmission, along with a slip ring assembly for electrical connectivity, enabling efficient fluid injection and improved imaging capabilities, including three-dimensional data acquisition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If saline coupling medium is used, then cost is reduced and acoustic transmission is improved, but corrosion of metallic components occurs reducing reliability
Solution Approach 1:
A sealed coupling medium reservoir containing the transducer is introduced as an intermediary system. This reservoir is filled with coupling medium (saline or other) and sealed to prevent the medium from contacting external metallic components. The reservoir acts as a mediator that allows acoustic coupling while isolating corrosive elements from sensitive components, thereby maintaining reliability while enabling the use of effective coupling media.
2Ease of operation
If piezoelectric motors are used to rotate the transducer, then precise rotation control is achieved, but fluid contact reduces torque output
Solution Approach 1:
A sealed reservoir containing the piezoelectric motor and coupling medium is introduced as an intermediary system. The reservoir allows the motor to operate in a controlled environment where coupling medium is present but cannot escape to contact external components. This enables the motor to maintain torque output while achieving precise rotation control of the transducer within the sealed environment.
Solution Approach 2:
A sealed flexible or rigid membrane enclosure is used to contain the coupling medium and motor assembly. This seal prevents fluid leakage while allowing the motor to function with the coupling medium present. The seal acts as a barrier that maintains the motor's torque capability by preventing fluid contamination of external mechanical interfaces.
3Ease of operation
If wire guide channels are included in the catheter, then wire guide placement is enabled, but acoustic window is blocked reducing imaging quality
Solution Approach 1:
The wire guide channel is repositioned from a central location that blocks the acoustic window to a peripheral location along the catheter shaft. This spatial reconfiguration in another dimension (radial position) allows the wire guide to be placed and guided while maintaining an unobstructed central acoustic window for optimal ultrasound imaging. The wire guide channel is positioned laterally rather than centrally.
4Length of moving object
If catheter size is reduced for small body conduits, then access to narrow vessels is enabled, but space for ultrasound hardware and fluid injection is limited
Solution Approach 1:
The coupling medium reservoir is designed as a nested structure where the reservoir wall itself forms part of the catheter wall structure. The transducer, wire guide channel, and fluid injection lumens are arranged concentrically and radially within the catheter cross-section, maximizing space utilization. This nesting allows multiple functions (imaging, wire guidance, fluid injection, coupling) to coexist in a compact configuration suitable for small body conduits.
Solution Approach 2:
The catheter wall and reservoir structure serve multiple functions simultaneously: providing structural support, containing coupling medium, enabling fluid injection through integrated lumens, and housing the transducer and wire guide. This multi-functionality reduces the need for separate components, allowing the catheter to maintain small diameter while providing all necessary imaging and intervention capabilities.
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 enhances the accuracy and efficiency of ultrasound imaging within the body, reduces the risk of corrosion, and allows for real-time, precise navigation and positioning of medical devices, improving the overall effectiveness of ultrasound procedures.
Implementation Method 1
The transducer transmits and/or receives ultrasound waves
Implementation Method 2
a torque cable offset a distance from the longitudinal axis, the torque cable operably connected to the drive shaft and a motor so that the drive shaft rotates in response to the torque cable
Data Source
AI summary
Disclosed are embodiments of devices and methods for imaging the inside of a body part, such as a blood vessel. In particular embodiments, a catheter has a chamber within which is a transducer. A wire guide channel extends throughout the length of the catheter. The transducer is rotatable about the wire guide channel and the transducer is driven by a cable or other device that is connected to a motor which is located outside the catheter. In one form, a torque cable connects the transducer to the motor. In other embodiments, a pusher piece having a plurality of lumens is positioned in the catheter. Each of the lumens is sized to receive a cable, wire, and/or flushing fluid. The lumens maintain the orientation and separation of the cables, wires, and/or to flushing fluid.