Patent Grant
7280638
This invention relates generally to medical imaging systems, and more particularly to cooling of portable of medical imaging devices.
Through-put and turnaround of patients is a key economic metric of the productivity of X-ray imaging devices. X-ray imaging devices have a high fixed cost that the owners and operators of the X-ray imaging devices seek to either reduce and/or the owners and operators seek to derive the greatest amount of productivity from the devices, in order to obtain the greatest return-on-investment from the X-ray imaging device.
One way to derive the greatest amount of productivity from the X-ray imaging device is to increase the number of subjects or patients that are imaged in an amount of time. However, the amount of time needed to image a subject is limited to some extent by the amount of time that is required in between imaging sessions to cool the X-ray tube that is in the X-ray imaging device.
An X-ray tube typically converts more than 99% of all the energy supplied to the X-ray tube into heat as an unwanted by-product of producing the desired X-rays. The effective management of X-ray tube heat is a key element in the design of X-ray tube housings.
Improving the transfer of heat energy away from the X-ray tube facilitates increased use of the system and is more efficient for the user since less time is spent waiting for the X-ray tube to cool.
Conventional liquid cooled X-ray tube designs include a pump and a heat exchanger mounted on the X-ray tube. The pump circulates oil from inside the X-ray tube housing through a heat exchanger that cools the oil by either forced air convection or by an external liquid cooler.
Other conventional solutions have incorporated secondary external or internal plumbing lines into the X-ray tube housing, through which a coolant is circulated. The cooling lines typically route the coolant to a radiator near the X-ray tube and a fan cools the plumbing lines in or on the X-ray tube housing.
Mobile X-ray equipment needs to minimize weight and power requirements. Existing cooling solutions have resulted in increased weight and power requirements at the X-ray tube. Any increased weight at the X-ray tube is particularly undesirable due to the counter balancing required for the gantry, and the use of a fan restricts use of the system in some surgical environments.
Conventional X-ray tube housings require a complex design with many parts to integrate the secondary plumbing and customized cooling solutions within the X-ray tube housing which result in high manufacturing and assembly costs.
For the reasons stated above, and for other reasons stated, there is a need in the art for an X-ray tube cooling system that has the weight at the X-ray head. There is also a need to reduce the use of fans at the X-ray tube; to reduce the power requirements at the X-ray tube; and to improve the heat transfer from the X-ray tube housing.
The above-mentioned shortcomings, disadvantages, and problems are addressed herein, which will be understood by reading and studying the following specification.
In one aspect, passages are integrated into the walls of the X-ray tube housing, through which a substance having a temperature that is less than the operating temperature of the X-ray tube is circulated, and the heat is transferred from the X-ray tube housing to an external cooler. In some embodiments, the substance is liquid.
In another aspect, the integrated cooling passages are included about the perimeter of the X-ray tube housing as the X-ray tube housing is formed. In some embodiments using a rotating anode X-ray tube and an oil coolant, the path of heat transfer is from the anode to the glass insert and oil by the means of radiation. The oil that is in contact with the glass insert conducts heat away form the insert to the X-ray tube housing which is then cooled by the integrated cooling passages located within the X-ray tube housing through which fluid is passed to an external fluid cooling system.
Apparatus, systems, and methods of varying scope are described herein. In addition to the aspects and advantages described in this summary, further aspects and advantages will become apparent by reference to the drawings and by reading the detailed description that follows.
In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments which may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments, and it is to be understood that other embodiments may be utilized and that logical, mechanical, electrical, and other changes may be made without departing from the scope of the embodiments. The following detailed description is, therefore, not to be taken in a limiting sense.
The detailed description is divided into four sections. In the first section, a system level overview is described. In the second section, apparatus of embodiments are described. In the third section, embodiments of methods are described. Finally, in the fourth section, a conclusion of the detailed description is provided.
By integrating cooling passages 102-108 directly into the walls of the X-ray tube housing 100, a liquid or gas coolant heat exchange can be externally mounted and connected by flexible pipe to the X-ray tube, avoiding excessive weight and power requirements at the X-ray tube and allowing any fan to be safely situated far from the X-ray tube.
Building cooling passages 102-108 directly into the X-ray tube housing 100 allows efficient heat exchange from the internal coolant surrounding the X-ray tube inside the X-ray tube housing 100 to an externally-located liquid or gas coolant heat exchange.
In this illustrative embodiment, cooling passages 102-108 are built into the X-ray tube housing 100 using an extrusion former to enable the manufacture of the X-ray tube housing 100 and cooling passages 102-108 as a single form. The number of cooling passages is limited only by the capability of the extrusion former and the design of the housing.
Integrating the cooling passages 102-108 into the X-ray tube housing 100 simplifies the complexity of the X-ray tube housing assembly by obviating separate secondary plumbing and assists in the external lactation of the heat exchanger. The internal plumbing in this invention is built into the walls of the housing and thus gives the required strength from the metalwork being used to provide the main housing. Integrating plumbing within the X-ray tube housing gives strength to allow the external piping to an external cooling system by increasing the strength of the X-ray tube housing 100 and including the cooling passages 102-108 permits the external mounting of the heat exchanger and cooling system. The X-ray tube housing 100 also obviates mounting a cooling fan at the X-ray tube that allows the use in more surgical environments.
The X-ray tube housing 100, by integrating coolant passages 102-108, also obviates many separate cooling parts within the X-ray tube housing, thereby lowering assembly cost by removing the requirement for additional pipework that needs to be separately manufactured. Not only is the additional miniature pipework not required, but the required mounting problems are avoided and the corresponding assembly issues previously involved in connecting the pipework to the external cooler are eliminated because the housing already contains the pipe within the single piece.
The X-ray tube housing 100 also solves the need in the art to mount the cooling unit directly at the X-ray tube and allows the use of an external cooler not on the gantry holding the X-ray tube, thus reducing the weight of that cooler and removing the need for additional power lines to the X-ray tube housing. The integration of the coolant pipes into the housing avoids the need to minimize stress upon that pipework because the housing itself provides the superior strength such that any torque applied at the connection point to the external cooler can be distributed across the entire housing. This resistance to torque allows the use of external tubing, which will exert such force, whereas the prior art use of internal, discrete, piping would place all such torque upon the mounting point which would not be able to withstand the strain and thus require the use of a cooling unit directly attached to the X-ray tube housing.
While the integration of the cooling passages 102-108 into the X-ray tube housing 100 is not limited to any particular number of coolant passages, for sake of clarity a simplified design using four passages is described. Depending upon the competing requirements of the strength, weight, and coolant flow any number of passages could be used from a single larger passage with high coolant flow through to a large number of passages that would allow more uniform heat dissipation.
Openings 110 and 122 are coupled to one another through fittings 206 (
Flow within the X-ray tube housing 100 is directed as follows: coolant from an externally located coolant heat exchange (i) enters through fitting 202; (ii) passes through fitting 116 and though coolant passage 102; (iii) passes through fitting 206, pipe 210, and fitting 208 to coolant passage 108; (iv) through coolant passage 108, pipe 212, and fitting 106 to coolant passage 106; (v) through coolant passage 106, fitting 214, pipe 218, and fitting 220 into coolant passage 104; and (vi) out fitting 204 to the externally located heat exchange.
In an alternative embodiment, the flow of coolant through the X-ray tube housing 100 is in the opposite direction. Within the X-ray tube housing 100 is sealed the primary coolant 222 which is oil in this illustration. The actual X-ray tube 224 is mounted within the X-ray tube housing 100 in a conventional manner.
In the previous section, embodiments of apparatus are described. In this section, embodiments of methods are described.
An X-ray tube housing with integrated cooling passages is described. Although specific embodiments are illustrated and described herein, any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments shown. This application is intended to cover any adaptations or variations. For example, although described as using four cooling passages within the X-ray tube housing, implementations can be made using 1, 2, 6, 8, or any other number of cooling passages that provides the required function.
In particular, the names of the methods and apparatus are not intended to limit embodiments. Furthermore, additional methods and apparatus can be added to the components, functions can be rearranged among the components, and new components to correspond to future enhancements and physical devices used in embodiments can be introduced without departing from the scope of embodiments. Embodiments are applicable to future imaging devices, different medical devices, and new examination equipment.
The terminology used in this application with respect to X-ray tube housing tubes is meant to include all imaging housings and secondary cooling environments and alternate technologies which provide the same functionality as described herein.
| Number | Name | Date | Kind |
|---|---|---|---|
| 2900543 | Heuse | Aug 1959 | A |
| 6426998 | Hell et al. | Jul 2002 | B1 |
| Number | Date | Country |
|---|---|---|
| 2004-103568 | Apr 2004 | JP |
