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Stationary Computed Tomography using Rotating Electron Source

IP.com Disclosure Number: IPCOM000011788D
Publication Date: 2003-Mar-14
Document File: 6 page(s) / 111K

Publishing Venue

The IP.com Prior Art Database

Abstract

The present invention is aimed at solving the technical challenges resulting from the need for a rotating electron source inside a CT scanner system. This is accomplished by only rotating the most important unit, the electron source assembly and by eliminating the need for rotating heavy and large x-ray tubes and their accessories.

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FIELD OF TECHNOLOGY:

X-Ray Tubes

INVENTION TITLE: 

Stationary Computed Tomography using Rotating Electron Source

PROBLEM/BACKGROUND:

Current Computed Tomography (“CT”) scanners use x-ray tubes, which are rotating inside a CT gantry. In order to provide higher-powered x-ray equipment, the x-ray tube and its accessories (generators, cables, etc.) must be designed with a larger physical size and heavier weight. Rotating a large and heavy x-ray tube and its accessories inside a gantry is becoming a costly, technical challenge.

In addition to the increased power, the scanning speed demand is increasing, from 0.5 seconds per revolution to 0.35 seconds per revolution. The increased speed brings more technical challenge to rotate large, heavy x-ray source at high speed.

The proposed invention claims that by using a rotating or moving electron source, which only consists of electron source or cathode cup assembly, the need for a rotating mass could be eliminated. This method can be used to develop a CT system where the only rotating part is a very light weight electron source assembly. The rotation of x-ray source is created by rotating the electron source around a stationary anode (target). The rotating electron source assembly consists of an electron source (filaments), grid/bias electrodes, a magnetic circuit for rotation, and connecting brushes/rollers to power supply rails. The movement is similar to a linear motor used for rails. The Grid/Bias circuit is a programmable switching circuit designed to switch ON/OFF the electron sources (filaments or any other electron sources) to generate the required x-ray at the desired location and time.

INVENTION DESCRIPTION: 

Figure 1 shows the main concept for a stationary CT using a rotating electron source  (x-ray source).

The system consists;

1.      A CT gantry

2.      A rotating electron source assembly, which includes cathode cup with filaments or any other form of electron sources, grid/bias electrodes, rotation magnetic circuit, brush or roller connectors to stationary rails

3.      An auxiliary rotation circuit, which can be a single rotating unit or segmented and placed on the circumference of the gantry

4.      A stationary target/anode

5.      A stationary detector system

This invention is aimed at solving the technical challenges resulting from the need for a rotating electron source inside a CT scanner system. This is accomplished by only rotating the most important unit, the electron source assembly and by eliminating the need for rotating heavy and large x-ray tubes and their accessories. The limiting factor for fast scanning time is reduced by the light-weight and compact rotating parts of this invention. So faster scanning, if required, can be achieved.

In a stationary CT, using a rotating electron source, the rotating electron source assembly generates electrons as it rotates along the circumference of the CT gantry and produces x-rays using a stationary target/anode. The electron source motion/rotation is prod...