Data transmission system for computed tomography scanners

Abstract

Device for transmitting data between a rotating part and a stationary part of a computed tomography scanner, wherein the rotating part has at least one data source and the stationary part comprises at least one data sink for evaluating the data, wherein at least one transmitting device and a first slotted waveguide (102, 108) fed by the transmitting device are provided in the rotating part, and the transmitting device is configured to receive data from the data source and to convert this data into an electromagnetic signal for transmission or coupling into the slotted waveguide (102, 108), wherein at least one receiving device is provided in the stationary part, which is configured to receive the signal from the second slotted waveguide (102, 108).to decouple, to convert the signals for forwarding to the data sink, and wherein the two slotted waveguides (102, 108) are arranged circularly around a common axis of rotation.

Description

Technical area

[0001] The invention relates to a data transmission system for transmitting data between the rotating part and the stationary part of a computer tomograph by means of modulated radio frequency / RF transmission. State of the art

[0002] US Pat. No. 6,433,631 discloses a device for data transmission in computed tomography scanners. A stripline in the rotating part is supplied with the transmitter signal. A tap is provided on the stationary part, which is positioned at a short distance, approximately 1 mm, from the stripline.

[0003] The transmission systems known from the state of the art are limited to data rates of max. 10 Gbit / s. Description of the invention

[0004] The object of the invention is to present a data transmission system which allows data transmission rates of up to several 100 GBit / s and can be integrated into computer tomographs with little mechanical effort.

[0005] An inventive solution to this problem is specified in the independent claims. Further developments of the invention are the subject of the dependent claims. Description of the drawings

[0006] The invention is described below without limiting the general inventive concept by means of exemplary embodiments with reference to the drawings. Fig. 1 shows schematically the arrangement of transmitting and receiving devices and waveguide. Fig. Figure 2 shows schematically the arrangement of transmitting and receiving devices and waveguide in detail.

[0007] A device according to the invention for transmitting data between the rotating part and the stationary part of a CT scanner comprises at least one data source on the rotating part and at least one data sink on the stationary part. A data source can be, for example, an X-ray detector or the data acquisition system (data processing system), or a control device or computer. A data sink can be a computer for evaluating and processing the data, but also another control unit or FPGA, etc.

[0008] Furthermore, at least one transmitting device and a first slotted waveguide 102, 108 fed by the transmitting device are provided in the rotating part. Such a first transmitting device receives data from the data source and converts it into a corresponding electromagnetic signal for transmission or coupling to the first slotted waveguide 102, 108. Furthermore, at least one receiving device is provided in the stationary part, which receives or couples the signal from a second slotted waveguide 102, 108. The receiving device converts the signals for forwarding to the data sink.

[0009] Signal transmission from the rotating to the stationary part occurs via coupling between the first slotted and second slotted waveguides, resulting in signal coupling of the electromagnetic waves through the slots from one waveguide to the other. The signals or waves propagating in the primary mode or in higher-order modes within the preferably rectangular waveguide 102, 108 escape through the slots of the first slotted waveguide 102, 108 of the transmitter and are collected by the slots of the second slotted waveguide 102, 108 of the receiver, resulting in the excitation of waves within the preferably rectangular waveguide 102, 108 of the receiver.

[0010] The signals can be modulated and / or encoded by the transmitter device according to the state of the art.

[0011] In the invention, each slotted waveguide 102, 108 is a hollow guide having discrete slots along the longitudinal axis at a defined distance from each other. Both slotted waveguides are arranged at a small distance from each other, movable around a central rotation axis. This is referred to as a slotted waveguide system.

[0012] The waveguide can have a round or square cross-section, depending on the required transmission properties, with the square cross-section being preferred.

[0013] One embodiment of the invention provides at least one transmitting device in the stationary part and at least one receiving device in the rotating part. This embodiment also enables communication from the stationary part to the rotating part.

[0014] A further embodiment of the invention provides for a plurality of transmitting devices and a plurality of receiving devices, which are either each arranged on one of a plurality of parallel slotted waveguide systems 101 or are arranged on a slotted waveguide system 101 divided into a plurality of segments.

[0015] A further embodiment of the invention provides a slotted waveguide system 101 that transmits one or more signals from the rotating part to the stationary part and / or from the stationary part to the rotating part. The signals can use different carrier frequencies and / or be differently modulated and / or differently encoded.

[0016] The modulation can be, for example, amplitude or frequency modulation or a mixture of both, such as QAM or similar.

[0017] In the case of simultaneous transmission of several signals in a slotted waveguide system 101, a signal splitter or similar device must be provided in both the transmitting device and the receiving device, which ensures decoupling between the signals and transmission directions by suitable measures such as frequency, phase selection or direction selection.

[0018] In a further embodiment of the invention, the transmission signal is adjusted based on one or more selection parameters. The selection parameters can be, for example, signal strength, signal quality such as noise, amplitude, jitter, etc.

[0019] In another embodiment, the invention is implemented as a phased array. Such a phased array comprises several slotted waveguides 102, 108, which are fed with signals that are in a defined relationship to one another in order to obtain a specific radiation pattern as a whole.

[0020] Such a phased array can be designed with fixed phase relationships between the individual radiators, or with variable phase relationships.

[0021] A further advantageous embodiment of a phased array arrangement is that the patterns of the individual slotted waveguides 102, 108 are determined depending on the relative position of the rotating part to the stationary part. This allows, for example, preprogrammed radiation patterns to be retrieved depending on the position. A learning device is also possible here, which, for example, measures the transmission ratios during transmission pauses and stores them for later transmission tasks.

[0022] In one embodiment, a control unit is provided which, if present, adjusts or selects individual slotted waveguide segments and the associated transmit and receive units according to predetermined parameters. The predetermined parameters for adjustment or selection include, for example, signal level, signal-to-noise ratio, bit error rate, propagation time, and / or phase shift relative to a reference signal or a position signal.

[0023] The waveguides 102, 108 are constructed as hollow guides made of conductive material, such as metal, or of a carrier material coated with conductive material, e.g. plastic.

[0024] A further embodiment of the invention consists in that an additional control unit is provided for controlling a bidirectional communication based on time windows, which control unit specifies the time frame for each communication direction.

[0025] A further embodiment of the invention consists in that at least one circuit for clock and / or data recovery (clock data recovery) is provided.

[0026] A further embodiment of the invention comprises a signal processor or FPGA in the transmitting unit, which divides the data into several slotted waveguide systems 101 and an electronic circuit, e.g. also based on a signal processor or FPGA, in the receiving unit, which combines the data again into a data stream.

[0027] A further embodiment of the invention comprises a receiving amplifier directly on the coupler in front of the receiving unit, wherein the gain of the amplifier is variable and the gain is adjusted based on measured or predetermined parameters.

[0028] A further embodiment of the invention comprises a discrete or integrated evaluation circuit which, based on various quality criteria, such as the error rate, selects the receiving unit for forwarding the signal which best meets the quality criteria when there are several receiving units.

[0029] To simplify the illustration, this document refers to a transmission from the rotating part to the stationary part of a CT scanner. Of course, a device according to the invention can also be used in the opposite direction. Likewise, a device according to the invention can also be used in other applications for rotary transmission and also for the linear transmission of two units moving relative to each other.

[0030] The transmission direction according to claim 1 was chosen from the rotor to the stator, as this corresponds to the most common application. However, transmission in the opposite direction or even bidirectional is also possible. List of reference symbols 101 circular slotted waveguide system 102 slotted waveguide 103 and 104 RF transmitters 105 and 106 waveguide termination 107 common rotation axis of the circularly arranged waveguides 108 slotted waveguide 109 possible directions of wave propagation 110 RF receivers QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 6,433,631

[0002]

Claims

[1] Device for transmitting data between a rotating part and a stationary part of a computer tomography scanner, wherein the rotating part has at least one data source and the stationary part comprises at least one data sink for evaluating the data, wherein at least one transmitting device and a first slotted waveguide (102, 108) fed by the latter are provided in the rotating part and the transmitting device is designed to receive data from the data source and to convert this data into an electromagnetic signal for conduction or coupling into the slotted waveguide (102, 108), wherein at least one receiving device is provided in the stationary part and is designed to receive the signal from the second slotted waveguide (102, 108).to couple out the signals for forwarding to the data sink and, wherein the two slotted waveguides (102, 108) are arranged in a circle around a common axis of rotation. [2] Device according to claim 1, which is designed so that the propagation of waves in the main mode or in higher order modes takes place within a preferably rectangular waveguide (102, 108) and the waves escape through the slots of the waveguide (102, 108) on the side of the transmitting device and are collected by the slots of the waveguide (102, 108) on the side of the receiving device. [3] Device according to one of the preceding claims, which is designed so that the signals are modulated and / or encoded by the transmitter device and demodulated and / or decoded by the receiver device. [4] Device according to one of the preceding claims, wherein the waveguides (102, 108) are hollow guides which are slotted along the longitudinal axis such that the slots of the two waveguides (102, 108) are arranged opposite one another and wherein the slotted waveguides (102, 108) are movable relative to one another with a gap to one another. [5] Device according to one of the preceding claims, wherein at least one slotted waveguide (102, 108) acts as a transmitter, which is connected at one end to the transmitting device and at the other end to a termination (105, 106). [6] Device according to one of the preceding claims, wherein at least one slotted waveguide (102, 108) acts as a receiver, which is connected at one end to a receiver system and at the other end to a termination (105, 106). [7] Device according to one of the preceding claims, wherein at least one slotted waveguide (102, 108) acts as a receiver, which is connected at one end to a receiver system. [8] Device according to one of the preceding claims, wherein the waveguide has a round, oval or square cross-section. [9] Device according to one of the preceding claims, wherein the gap between the two slotted waveguides (102, 108) is filled with air or with a dielectric material transparent to the electromagnetic wave to be transmitted. [10] Device according to one of the preceding claims, wherein a plurality of transmitting devices and a plurality of receiving devices are provided, which are each arranged either on one of a plurality of parallel waveguides (102, 108) or on a waveguide (102, 108) divided into a plurality of segments. [11] Device according to one of the preceding claims, wherein the waveguides (102, 108) are designed to transmit one or more signals from the rotating to the stationary part and / or from the stationary to the rotating part, wherein the signals may use different carrier frequencies and / or be differently modulated and / or differently encoded. [12] Device according to one of the preceding claims, wherein for the simultaneous transmission of a plurality of signals in the divided waveguide (102, 108), both the transmitting device and the receiving device have a signal switching means which is designed to provide decoupling between the signals and transmission directions, preferably via frequency, phase and / or direction selection. [13] Device according to one of the preceding claims, wherein the device is designed to adapt the transmission signal based on one or more selection parameters, preferably the signal strength and / or the signal quality. [14] Device according to one of the preceding claims, wherein several parts of the slotted waveguides (102, 108) are designed as a phased array. [15] Device according to one of the preceding claims, wherein a control unit is provided which is designed to set or select individual waveguide segments and the associated transmitting and receiving units according to parameters, wherein the parameters for setting or selection preferably include the signal level, the signal-to-noise ratio, the bit error rate, the propagation time and / or the phase shift relative to a reference signal or also a position signal. [16] Device according to one of the preceding claims, wherein the waveguide (102, 108) is constructed as a hollow guide made of an electrically conductive material, preferably metal or a carrier material coated with conductive material. [17] Device according to one of the preceding claims, wherein at least one circuit for clock and / or data recovery (clock data recovery) is provided. [18] Device according to one of the preceding claims, wherein a plurality of slotted waveguide systems (101) are arranged next to one another and preferably the transmitting unit comprises a signal processor or FPGA which is designed to divide data between a plurality of slotted waveguide systems. [19] Device according to one of the preceding claims, a receiving amplifier is provided directly on a coupler in front of the receiving unit, which is designed so that the gain is variable and can be adjusted on the basis of measured or predetermined parameters. [20] Device according to one of the preceding claims, wherein a discrete or integrated evaluation circuit is provided which is designed to select, on the basis of various quality criteria, preferably the error rate, from a plurality of receiving units, that receiving unit for forwarding the signal which best meets the quality criteria. [21] Device according to one of the preceding claims, wherein in the case of bidirectional communication between the rotating part and the stationary part, a control unit is provided which is designed to specify time windows for the communication in the respective direction. [22] Computer tomograph comprising a device according to one of the preceding claims.

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