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FLEXIBLE STINGER FOR MRI LIQUID HELIUM BOTTOM FILL

IP.com Disclosure Number: IPCOM000236071D
Publication Date: 2014-Apr-04
Document File: 5 page(s) / 332K

Publishing Venue

The IP.com Prior Art Database

Abstract

The invention proposes a technique to utilize a flexible stinger used for magnetic resonance imaging (MRI) liquid helium bottom fill. The proposed technique creates a stinger with a flexible section which allows the stinger to be bent and fitted into the magnet under very tight clearance. A guiding sleeve, which is a part of the stinger set is used to ensure that flexible stinger stays in the rigid/straight status and is engaged in the bottom fill line inside the magnet.

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FLEXIBLE STINGER FOR MRI LIQUID HELIUM BOTTOM FILL

FIELD OF INVENTION

The invention generally relates to a magnetic resonance imaging (MRI) system and more particularly to a flexible stinger for MRI liquid helium bottom fill.

BACKGROUND OF THE INVENTION

In general, helium bottom fill is a preferred technique for reducing ramping quench and saving liquid Helium (LHe) transfer cost. However, there is a challenge and often impossible to practice bottom fill in magnetic resonance (MR) site with low ceiling height. The limited clearance above the magnet prevents use of extended stringer for bottom fill.

A conventional technique includes two short extension tubes of 7” and a short 7” stringer. 

An operator inserts first extension tube into the fill port first and keeps the first extension tube end above the fill port. The operator then threads the second extension tube onto the first piece making an extension 14 inches long. Then the 14” extension is to be threaded onto the short 7” stringer. As a result, the total length of stringer becomes 21” to ensure engagement with the bottom fill line.  See illustration below:

FIG. 1 depicts the conventional bottom fill technique

However, the above mentioned conventional technique has three major problems. The first problem is the safety of the operator. The operator works in a tight space with his face at the same height as that of the tube or stinger. A large volume of cold helium gas is venting out from the fill port when the fill port is open towards the face of the operator. Liquid helium is pushed out through the fill port by internal pressure resulting in serious damage to the operator. The second issue is safety of the magnet. The cold helium gas venting out through the fill port makes it very hard to see the small tubes while trying to join all the extension tubes together. Operator is required to wear cryogenic gloves during the process. There is a possibility that a short extension gets dropped into the magnetic vessel, which introduces many possible issues for the magnet and system. The third issue is the magnetic thermal performance. When the fill port is opened to atmosphere for an extended period of time, there is increase in chance of air letting into the cryostat vessel which creates icing or thermal issues.


Hence there exists a need for an efficient technique for MRI liquid helium bottom fill.

BRIEF DESCRIPTION OF THE INVENTION

The invention proposes a technique to utilize a flexible stinger used for magnetic resonance imaging (MRI) liquid helium bottom fill. The proposed technique creates a stinger with a flexible section which allows the stinger to be bent and fitted into the magnet under very tight clearance. A guiding sleeve, which is a part of the stinger set is used to ensure that flexible stinger stays in the rigid/straight status and is engaged in the bottom fill line inside the magnet.


DETAILED DESCRIPTION...