JPS6019113B2 - Rotating electrical supply device and method for tomography scanning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to medical diagnostic apparatus and methods, and more particularly to x-ray scanning apparatus of the type utilized in computed tomography.

It is an object of the present invention to be suitable for use almost continuously and rapidly in the diagnosis of a set of patients, and yet capable of causing the starting and stopping of several rotatable assemblies by continuous operation. It is an object of the present invention to provide a scanning device for use in computerized tomography equipment, etc., which avoids applying physical pressure to parts.

Another object of the invention is to provide a scanning device that can be used to create a series of successive cross-sectional views through the patient being diagnosed.

Yet another object of the present invention is to significantly improve the quality of the data generated, and thus the image reproduction ability, by incorporating a calibration circuit that compensates for drift in the electronic processing circuitry resulting from temperature or time-induced changes in the circuit components. The purpose is to provide equipment. Yet another object of the invention is to provide signal processing and conditioning circuitry that can be accommodated by bringing the signal processing conditioning circuitry into physical proximity to the detection elements of the rotating assembly of the scanning device, such as by circuitry connected to a radiation source used in the scanning device. It is an object of the present invention to provide a scanning device used in computer-processed tomography, etc., which minimizes the noise and spurious signals emitted.

Still another object of the present invention is to include a coupling means movable with the part of the scanning device that is rotated so that the rotation of the device can be stopped or reversed synchronously without the need to synchronously stop or reverse the rotation of the device. A computer-processed axial tomography device is used in which the various signals supplied with information and power and control signals for the radiation source are easily and effectively shuttled to the rotating parts of the device. An object of the present invention is to provide a scanning device.

Yet another object of the present invention is that by providing a circuit for compensating for differences in the levels of radiation intensity received by various detectors, the quality of the data generated, and thus the ability to simulate reproduction, can be significantly improved. An object of the present invention is to provide a scanning device.

In accordance with the present invention, the foregoing objects and other objects which will become apparent in the course of the following description provide an assembly rotatable about an axis extending along a central gateway formed therein; and means for positioning the region to be examined inside the central entrance such that the axis of rotation of the region is perpendicular to a thin, generally planar section of the region to be scanned.

A source of penetrating radiation, e.g. placed on the opposite side of the radiation to detect unabsorbed radiation across the portion to be scanned.Means are provided for rotating the assembly so that the fan beam impinges on the site from multiple directions of incidence. A signal processing conditioning means is mounted on the rotatable assembly and is movable with the lever assembly to receive output signals from nearby detectors.

This signal processing and conditioning means amplifies the signal applied to it and converts it into a digital signal. A slip ring connection means rotatable with the aforementioned assembly receives outputs from the signal processing and conditioning means and supplies these output signals to a computer control and image reproduction station.

The said connection means also receive control signals from and send control signals to a central control logic circuit "switch etc." in said station. Further slip ring means rotatable with said assembly are also provided. and serves as a connection means for supplying power and control inputs to a radiation source, typically an x-ray tube.

The aforementioned assembly is continuously rotatable, making sequential rotations of 360 degrees or less, and a series of diagnostics can be initiated at any selected point in the rotation of the assembly.

The detection means, which preferably comprises a plurality of separate elements, is provided with means for adjusting the relative gain of the channels connected to the detection elements in conjunction with patient diagnosis.

This compensates for drifts in the channel resulting from, for example, time- or temperature-induced changes in circuit components. FIG. 1 shows an external perspective view, which is a somewhat simplified view of a scanning device 10 according to the invention.
FIG. 1 should be considered simultaneously with FIGS. 2 and 3.
Apparatus 10' has an external cover 12 within which a frame 14 (FIG. 3) supports a rotatable assembly 16. Assembly 16 is clearly shown in FIG. The scanning device 10 forms part of a computerized tomography device (tomography device), the remaining parts of the latter device being explained in more detail in connection with FIG. , an image reproduction part, and an image display part, most of which include two control and reproduction stations. Apparatus 10 communicates with station 20 via various control leads, as indicated schematically in FIG. 1 by interconnect line 18. Therefore, the device 10'
The digital information obtained as a result of this scanning is sent to station 20'. This time, station 20 is connected to device 1.
0, as well as various power supply voltages of the radiation source, motor, and other components, for example, produce control information for operating the device 10. The rotatable assembly 16 includes an outer sill 22 of stainless steel or other metal and includes a motor 2.
8 about its central axis 26 in direction 24.

The drive mechanism 30 of the motor 28 is supported by a drive collar 32 that is fixed around the cylinder 22. Drive theory 3
It includes a 0G rubber surface 34, etc., and is effective in preventing rotational slippage of the cylinder 22 due to its high coefficient of friction. As will become apparent by comparing FIGS. 1 and 2, the central opening □ 36 of the rotatable assembly 16
0 serves to transport a patient 54 to be diagnosed inside the hospital.

A sleeve 38, made of plastic or the like, is fixed to the cover 12 and forms a fixed reference frame. Sleeve 38 has several advantages, particularly a positive psychological impact on the patient placed inside the entrance 36. While the device 10 is in use, the patient 54 is placed on the top surface 42 of the positioning platform 40. Top surface 42 is movable along central axis 26 to allow patient 54 to be brought into the interior of device 10 . A laser beam source 44 is connected to the device 1 to assist in properly positioning the patient during the diagnostic process.
The laser beam impinges on the patient in the head position (Fig. 3). Cover the laser beam source again! 2 can also be installed.
The positioning platform 4 has actuating means for gradually advancing the platform 40 to facilitate continuous lateral scanning through the body of the patient 54, as will be explained in more detail below with respect to FIG.
This actuating means also moves table 40 in other directions to facilitate patient positioning. The front end of the assembly 16 carries a plate 48 around which a radiation source 50 is mounted.

The radiation source 5 preferably comprises an X-ray source capable of projecting an X-ray pattern in the form of a fan-shaped beam 52. The fan beam 52 is formed in a known manner by a collimator (not shown) placed in front of the OX-ray source. The fan beam 52 is preferably at least as wide as the object to be examined, which in the present example is of course the patient 54. Detection means, designated generally at 56, are mounted diametrically opposite the radiation source 50, ie towards the opposite end of the plate 48.

Although the detection means may also use detectors suitable for use with X-rays and similar exposure 40 magnetic radiation, such as crystal scintillators in combination with photomultipliers, photodiodes, etc. Preferably, it consists of an array of ionization chambers, such as xenon-krypton detectors. The individual cells 58 of the detector array are connected to the collimator plate 6
They are separated by 0'. Collimator plate 60 cells 5
8 are oriented with increasing slope toward the radiation source 50 as one progresses toward the ends of the array. A beam such as beam 62 is therefore actually incident on the appropriate cell along the axis of that cell. In accordance with one important feature of the invention, the detection means 56 is in close physical proximity to the signal processing and conditioning means, indicated generally at 64.

In fact, in the device shown these two blocks 56 and 64 are back to back to each other. Such physical proximity provides important advantages to the present invention, as the proximity of these blocks, which are typically rotatable with assembly 16, minimizes the possibility of spurious signals being introduced into the various detection channels. . This is particularly important in this embodiment. This is because high voltages applied to x-ray sources and the like increase the likelihood of introducing such spurious signals. In addition to including several of the previously mentioned components, assembly 16 includes several reinforcing members, such as reinforcing ring 66 and cross struts 682.

The purpose of these components is to increase the overall strength of the assembly 16 to a practical degree, thereby reducing the effects of vibration and the possibility of undesirable deflection. Both of these vibrations and deflections are particularly harmful to the sensing structure because they can produce undesired outputs by applying pressure to some of the sensing structures and changing the electrical response characteristics of the sensing means. In the case of X-ray diagnostics, the thickness of the fan beam 52 determined by the collimator is typically between 1 in 30 and 15 ribs at the center of the object. When the radiation source and detector array are rotated relative to the patient for approximately 1 to 18 ins (continuously rotated when performing precision reconstructions), the amount of absorbed radiation is detected. Measured by means 56 3 days.

Data acquisition occurs during one 360° relative rotation of the device. The device also allows sufficient time to acquire data for several revolutions, which increases the amount of data and provides superior images. The data 40 from the detection means 56, after being suitably processed and conditioned, is fed to the station 20', weighed, suitably stored, and later back-projected with other data to the thus diagnosed patient 54. An output image is obtained that is a replica of a thin cross-sectional portion of the image. The data does not necessarily have to be converted into a visually discernible image, but can also be expressed in other analytical forms, ie numerical values, etc. To illustrate another feature of the invention with reference to FIG. 3, electrical connections to all portions of assembly 16 are made through a slip ring assembly, designated generally by the numeral 70.

Specifically, high voltage input lines 72 and 74 are connected to assembly 7.
0 is provided in the cover portion 76 of 0. This cover part 76 is stationary. The slip ring assembly 70 is connected to the radiation source 501 through cables 78, 80 extending from the cover portion 82 of the assembly 70, as will be described in connection with FIGS. 6 and 7. This makes it possible to apply the necessary energizing voltage. The cover portion 82 rotates with the assembly 16 which is supported on a bearing 85 between the reinforcing ring 66 and the frame ring 86. Similarly, for the detection output of various low voltage control signals for the electrical elements mounted on the plate 48 and for the radiation source 50
The various low voltage connections for the low voltage input (for the anode rotor) are all made by slip ring connections contained within section 88 of slip ring assembly 70.

Some of the outer connections 90 are exposed in section 88, and the outer cover of section 88 is of course stationary. The details of the slip ring assembly 70 are as described above.
and will be explained later in connection with FIG. The schematic electrical block diagram of FIG. 4 illustrates the interrelationship of the various parts of the device.

FIG. 4 also illustrates the relationship between apparatus 10 and its associated components, and the various operating parts of a fully computer-processed axial tomography apparatus 92 utilized with apparatus 10. Tomography apparatus 92 generally includes a machine/patient area 94 and a control and image reproduction station 20 communicating with this area. Region 94 contains the components previously described in connection with FIGS. 1-3. The parts of the tomography apparatus 92 that are attached to and move together with the assembly 16 are shown entirely within the dashed lines designated by the same reference numeral 16, and the detector array 5
6. a radiation source 50 in the form of an It includes control logic 100 and an analog-to-digital converter 102 for receiving the output from block 98 and transmitting it in digital form to control and reproduction station 20'.

All connections to assembly 16 are made through slip ring assemblies as previously described.

Specifically, the output of the transducer 102 is provided via a slip ring assembly 104 to an input/output direct memory access control means 106. Similarly, the central control panel/logic circuit 108 at station 2,
Connections to the detector electronic control logic 100 are made through a slip ring assembly 110. Similarly, X-ray tube 5
All of the zero supply voltage and excitation voltage are obtained through a series of slip rings 112, 114, 116 and 118. Slip ring 112 connects an x-ray starter 120 to initiate and sustain rotation of the anode, slip ring 114 provides high voltage from power source 122, and slip ring 116 connects x-ray grid controller 124. The slip ring 118 also connects the filament circuit power supply 126. The various power inputs to the x-ray tube 50 etc. originate from stationary, essentially conventional equipment located at the control and image reproduction station 20 or machine/patient area 94 but not forming part of the rotating assembly 16. .

Specifically, a high voltage control device 128 is provided;
The controller provides control signals to high voltage power supply 122 through conductor 130. Both of these parts are external to the rotating assembly 16, as already indicated. High voltage control device 1
32 is connected to a high voltage control device 128. A known exercise device is provided and is shown schematically at 1.34.
The same high voltage controller 132 also controls the operation of the x-ray starter 120 through a control line 136. Power is supplied to the filament circuit power supply 126 through a conductor 138 and a regulating means 140. The adjustment means 140 is powered by an input lead 142, suitable for a phase control device 144. Such a phase control device 144 is used in conjunction with the energization of the filament circuit to avoid non-uniform temperature distribution in the filament circuit. Phase controller 144 also provides input to central control panel logic circuit 108 through conductor 146. This input is used in connection with the operation of the x-ray grid controller 124, ie according to the phase of the current flowing through the conductor 148. An x-ray grid controller 124 periodically pulses the x-ray tube grid to emit x-rays in pulses during the operating cycle of the apparatus. The x-ray pulses are typically at a rate of one pulse for each rotation of the assembly 16, but may be at a rate of two or more pulses for each rotation of the assembly 16. Furthermore, other pulse configurations can also be used. In accordance with an important aspect of the present invention, the need to periodically stop rotation of assembly 16 is avoided by using slip rings on all connections. In practice, in a preferred mode of operation of the device, the assembly 1
6 rotation is constantly maintained. For example, such rotation may continue while a series of cross-sectional scans are performed on a single patient. Alternatively, such rotations may continue during sequential scanning of multiple patients. This has the important advantage of not only saving time and minimizing motion, but also eliminating the physical stress placed on the parts of the device by stopping and starting the assembly. These stresses include stresses that are applied to the very heavy structural parts of the assembly, stresses that are applied to the high-altitude rotating anode portion of the x-ray tube, and vibrational stresses that are particularly harmful to the detector. A 3600 scan is initiated by an operator entering a command for such a scan into the central control panel logic 108.

As already explained, since the rotations are continuous, the scanning cycle for the patient can be performed at any point in the rotation of the assembly 16, i.e. regardless of the particular angular setting at which the series of scans is started. , it is also desirable to be able to start. This is important for reasons explained below. In typical operation of the device, a complete 36
00 scans, 1 complete revolution of assembly 16, is 1
It takes less than 6 seconds. This is a very short amount of time compared to the time taken by conventional devices for the same purpose. However, during such zero scan cycles, it is desirable for the patient to hold his breath to avoid blurring the image.
If the scan cycle could be initiated at only one point in the rotation of the assembly 16, it is possible that the scan would not begin for as long as six seconds after the start of operator action. Therefore, the total time the patient has to hold his breath may be 12 seconds. This is relatively undesirable, especially when frail patients are being diagnosed. For this reason, the book bag box is provided with a center position detector 150. The detector 15 includes a light emitting source 152 (eg, a light emitting diode), and a photodetector. It consists of a simple optically coupled switch containing a photodetector element such as transistor 154.
A projection 156 attached to plate 48 is rotatable with assembly 16 and traverses the optical path between light emitting source 152 and phototransistor 154 only once during each rotation of the assembly. The output of detector 150 is provided to position counter 160 via lead 166. Central control panel/logic circuit 1
When the scan cycle begins at 08, a start signal advances on conductor 162 which starts counter 160. During continuous rotation, pulse control signals provided from central control panel and logic 108 to grid controller 124 are also provided to position counter 160' via conductor 164. Upon reaching the center position, protrusion 156 crosses the optical path at detector 150 and a stop signal is transmitted through lead 166 to counter 160.
'This will be supplied. Next, the count value of the counter 160 is
8 to a central control panel and logic circuit 108. From this count, circuit 108 determines an information stream indicative of the absolute angular position of each sheet of scan data acquired by the detector during the scan. Rotation of assembly 16 is effected by motor 28 as previously described. This motor 28 is provided with an interlocking device 170. The motor 28 is activated and deactivated by a central control panel and logic circuit 108. Detector array 5
6 includes 301 separate detection elements in the typical example.
All of these sensing elements produce very low level analog output signals. A corresponding array of signal processing conditioning channels amplifies and integrates these signals and provides them to multiplexer 192. Multiplexer 192 multiplexes the signals and provides them to analog-to-digital converter 102 . By using these techniques, the multiple input signals from the detector can be significantly reduced to a relatively small A
A D converter, ie a 16-bit AD converter, can be used. As a result, a single output line 174 carries data streams from multiple channels. A relatively small number of output lines, such as output line 174, are used to provide data from assembly 16 to control and replay station 20. Only two of the hundreds of channels are actually shown in FIG. In practice, for example, around 20 output lines 114 can typically serve a total of 301 channels. In the circuit shown in FIG. 4, the amplifier array 18 consists of a plurality of operational amplifiers 176, with a series of FET switches 178 feeding into a series of integrators 182 forming part of an integrator array 184. Pass the output of or prevent it from passing.

Various operations on the detection signal processing conditioning channel are under the control of logic circuit 100.

After the detection signal is amplified and integrated to raise the signal,
The multiplexer 192 time-multiplexes the signals. Multiplexer 192 significantly relaxes the requirements on the transmission channel and provides the multiplexed signal to analog-to-digital converter 102 as previously described. The signal is then passed through slip ring assembly 104 to input/output/direct memory access control means 106. Control means 1
06 is connected to the computer 188 through a conductor 190. The detected data is then stored in a suitable storage location, for example on disk 191 or other storage element, connected to computer 188. Computer 188 is preferably a well-known digital computer suitable for use in this application. Various other components serve to display and process the information provided to the computer 188, such as an image display 194 connected to a camera 195, an electrostatic printer 196, a printer 198, and a CRT.
Terminal 200 and magnetic tape recording means 202 are followed by tomography device 92 .

The operation of these components is well known in data processing systems, so there is no need to explain them in detail here.
In order to sequentially scan the patient 54 in a series of transverse planes, the top surface 42 of the positioning table is configured to gradually advance the top surface 42 axially toward the central gateway 36 and to rotate the top surface 42 in another direction to orient the patient in the appropriate direction. It has already been mentioned that means are provided for moving in the direction. As shown in FIG. 4, this is simply accomplished by a movement motor 204 driving a positioning platform movement means 206. Motor 204 is gradually driven by motor drive means 208 . The motor drive means 208 receives a signal from the central control panel/logic circuit 108 at the end of each rotational scan;
Central control panel/logic circuit i08 through control line 210
It is activated periodically by A central control panel and logic circuit 108 steps the motors. The upper surface 42 of the positioning platform is then gradually moved by the mechanical linkage, for example, gradually towards the opening 36. Referring now to FIG. 2, during the process of scanning a patient, the outer beams of fan beam 52, such as beam 62, are typically thinner than the more central beams, such as beam 61. pass through the organization.

Instead of or in addition to a physical compensator (i.e., a radiation absorber) and for the purpose of improving the performance of the signal processing conditioning channel, the various detection signal channels can be connected to different detection signal channels, e.g., in the gain channel, with two different value resistors. It is possible to have different gain characteristics by using different amplifiers. Therefore, channels connecting to detectors of outer beams, such as beam 62, have less gain than channels processing signals originating from highly absorbed central beams, such as beam 61. A preferred circuit configuration for use as amplification multiplexing block 98 in FIG.
As shown in the figure.

The circuit shown in FIG. 5 is particularly effective in solving two problems associated with the present apparatus. Firstly,
The large differences in path density typically encountered during scanning of parts of the human body (this accounts for the fact that some of the end beams of the fan beam 52 pass entirely outside the body, or partially through the body) ), the difference in the output of the detector array 56 is large. Furthermore, these levels are first of all very low. The range of detected outputs typically experienced in typical situations ranges from 1pA to 300mA. This in turn means that the signal processing circuitry is not only very sensitive, but also relatively sensitive to signals with a very wide range of variation. In addition, drift creates another serious problem with the device.

This drift occurs in the detection signal processing channel during the course of long-term operation of the device. Because the effects of drift vary from channel to channel, imbalances can occur over long periods of time, resulting in erroneous data. The circuit of FIG. 5 completely solves both of the aforementioned problems. Specifically, the circuit of FIG. 5 recalibrates the various detection signal processing channels in conjunction with patient scanning. Detector row 56 at the beginning of the day's operation including genuine copying
Multiple channels originating from are calibrated.

In detail, a so-called phantom, a block of known material such as homogeneous polyethylene, is first thinned into the device and a test scan run is performed with such material using X-ray scanning to establish a baseline. The computer 188 is effectively used to equalize or smooth the gains of the various channels.
Measurements are also made of the intensity of the X-ray beam that is not absorbed at all. In other words, this also includes the transmission properties at the edges of the phantom. The purpose of this work is to effectively indicate the absolute intensity of the X-ray source for later comparison. Referring to FIG. 5, which illustrates a typical channel, the output of the detection ionization chamber 212 is sent to an integrator 214 during the scan, and the output of the integrator 214 is sent to a sample Hall circuit 216, which is then sent to an analog - Sent to multiplexer 218 and finally analog.
The signal is sent to digital converter 220'. The output of integrator 214 is also sent through lead 222 to level detector 224. The output of level detector 224 becomes one input of JK flip-flop 226. JK flip flop 226
The other input is obtained from a crystal reference frequency source 228. This reference frequency is also sent to the corresponding flip-flops of all other detection channels. The K gate of flip-flop 226 is supplied with a high beta digital signal from 230. The signal from the detection ionization chamber 212 is integrated by an integrator 214, and its output is a waveform 232.
is actually a negative signal as indicated by .

When a sufficiently weakened negative level 234 is obtained, a signal is generated in the level 0 detector 224, which activates the flip-flop 226 when the next clock pulse occurs. Flip-flop 226 in turn provides pulses to counter 236, the output of which is strobed into latch 238 at the end of each measurement period. Latch 238
The output is digital. Multiplexer 2401 and then computer 88 are provided. signal level 23
4, a pulse from flip-flop 226 energizes discharge circuit 242. This discharge circuit 24
2 has an FET switch and a constant current source. This discharge circuit resets integrator 214 to the high level 244 of waveform 232. Counter 236, latch 238 and digital
The branch of the circuit of FIG. 5 that includes multiplexer 240 effectively serves as a direction determining circuit.

That is, the number of counts thus measured indicates the direction of the output level of the detection ionization chamber 212. Similarly, integrator 214, samples. Hold circuit 216, analog multiplexer 218 and analog to digital converter 22
This effectively configures a precision measurement branch of the output of the river detection ionization chamber 212. Of course, the illustrated circuit arrangement has a very wide dynamic response range. The circuit of FIG. 5 further allows calibration for the aforementioned purposes.

Specifically, a high reference source 246 and a low reference source 248 common to all detection channels are provided which are connected to the integrator 252 by a branch 252 containing a high resistor 254.
A common point 2501 is connected in front of 14. The alternation of the high reference source 246 and the low reference source 248 (which is grounded) is connected to the control line 25 connected to the computer 88.
6. Switch 258 is actually the lead
It constitutes a switch, and its control element is a computer 8.
Operated by 8. The operation for calibrating the circuit described above is performed as follows.

The patient is placed in a predetermined position, for example as shown in FIG. 3, the X-ray source is turned off and rotated further. This rotation is a calibration operation. During this calibration operation, the switch 258 switches between the high reference source 246 and the low reference source 2.
It switches sequentially between 48 positions. As a result of this operation, relative gains are determined for each of the plurality of channels. That is, a relative gain is determined between one high reference input and the other low reference input. To perform the same standardization that was done at the beginning of the day's operation, the computer then adjusts the effective gains of the various channels to equalize or standardize them. Adjacent channels therefore yield virtually the same relative gain when a high reference input is used on one side and a low reference input on the other. Of course, this does not require any adjustment of the electronic components in the channel, but merely a change in the computer-processed values. As already mentioned in connection with the initial calibration at the beginning of the day's operation, edge measurements are also taken.

The purpose of this is to determine the absolute intensity of the X-ray source at the start of operation and the
In addition to the operations described above, the computer also compares the output of the analog-to-digital converter 220 with the output of the analog-to-digital converter 220. Determine the exact multiple between digital multiplexers 240.

This is done by using as the high reference source 246 a signal that produces an average of N+1/2 pulses from the discharge circuit 242. Comparing the two outputs then indicates the aforementioned multiple, thereby allowing precise compensation of the detected output by the computer. All of the foregoing calibration procedures are performed with the patient 54 in place and immediately before or after scanning the patient.

The calibration procedure is initiated manually by an operator entering a command into the logic circuit 108. Alternatively, the calibration procedure proceeds automatically under the control of logic circuit 108. Important features of the invention, as well as some of the features of the invention already noted, including continuous rotation of the assembly 16, are realized by both the biasing connection to the x-ray tube and the control connection to the apparatus 10.
It has already been mentioned that it is the use of a slip ring assembly TO that allows for various connections that can be used to route other control inputs to and outputs from the device 10 to the outside world.

A general overview of slip ring assembly 70 has been previously described in connection with FIG. Details of slip ring assembly 70 will now be described with reference to FIGS. 6 and 7. Referring first to FIG. 6, rotation of cover portion 82 is effected integrally with cylinder 22 through link 2601.

Link 260 is fixed to cover portion 82 and is connected to pin 2.
62. The pin 262 is located on the rear side 2 of the cylinder 22.
It stands out from 64. FIG. 7 shows the high voltage input lines 72 and 74 coming from the power supply 122, as well as the high voltage cable 80 connecting the X-ray tube. Also shown is a series of connectors 90 for low voltage inputs and outputs. These are attached to a cover part 88 which is a fixed part. That is, various connecting lines emanating from the connector 90 are connected to the control and image reproduction station 20, in some cases to low voltage inputs, for example from the X-ray starter 120, and to the signal processing conditions of the assembly 16. connected to the AC power supply for the attached circuit. Referring now primarily to the cross-sectional view of FIG. 7, a slip ring assembly provided in portion 88 of assembly 70 is conventionally utilized to transmit low voltage inputs to rotating machinery. Being of a general type, it is not shown in great detail in this figure.

A set of low voltage cables 266 connect tube 26 of assembly 70.
It is passing through 8.

The tube 268 is mounted inside a central member 270 made of an insulating material such as transparent synthetic resin. Center member 270 extends from front plate 272 to a point 274 proximate rear bearing support 276 and bearing support ring 278. Front plate 272, center member 270 and ring 28 rotate with assembly 16, as do high voltage cables 78,80. As can be seen by comparing FIG. 3, the cover portion 76 does not rotate. This cover portion carries the high voltage input lines 74 and 72 already mentioned. These high voltage input lines are supplied with high voltage from an X-ray power supply connected to the tomography device 92. Electrical connection between cable 266 and connector 90 is made through conventional rotor 2861. Rotor 286 carries a slip ring 288 in contact with brushes 290. Brush 29
It is electrically connected to the river connector 90, and only one wire is required for the output of 301 detectors. ring 28
0 and various other parts of the cover part 82 on the one hand and parts of the cover part 76 on the other hand are enabled by a bearing 282 between the two said parts.

An oil seal 284 is also provided between the cover parts 76 and 82 of the assembly 70 so that the entire interior 291 of the cover parts 76 and 82 is filled with oil 315 or a similar substance with very high insulating properties. The high voltage slip ring electrical contact piece consists of a set of ring back pieces 292.

Ring saddle 292 is attached to flange 294 on center member 270.
, 296 and 298. These flanges are also insulated, of course. 1 set of conduits 300
, 302, 304, and 306 extend from these electrical pieces and pass through appropriate closures 305, 308, 310 in flanges 294, 296, 298, and 312, 31.
The high voltage cable 78, 8 is connected at a point like 4.

These cables 78, 80 connect to the x-ray tube. Various excitation voltages for typical operation are written in the figure. Contact with the rotating slip ring is made through a set of brushes 316. The brush 316 is composed mainly of graphite or other known compositions.

[Brief explanation of drawings]

1 is a schematic perspective view of a scanning device according to the invention, FIG. 2 is a schematic perspective view of the rotatable assembly of FIG. 1, and FIG. 3 is a partial cutaway of the device of FIGS. 1 and 2. It is a partial cross-sectional side view. FIG. 4 is a schematic electrical block diagram of the control parts and circuit components utilized in the devices of FIGS. Figure 2 shows the relationship to the rest of the computerized tomography device. FIG. 5 is a schematic electrical block diagram of a preferred form of an amplification/multiplexing circuit that can be used in the present invention and performs detection signal channel calibration in conjunction with patient diagnosis; FIG. FIG. 7 is a front view of the slip ring assembly section taken along line 7--7 of FIG. 6; DESCRIPTION OF SYMBOLS 10... Scanning device, 12... Cover, 16... Rotatable assembly, 20... Control and post-regeneration station tongue, 36...
・Central opening □, 40...Positioning table, 50...X-ray source, 52...Fan beam, 54...Patient, 56...
Detector array, 64... Signal processing conditioning means, 70.
... Slip ring assembly, 76, 82 ... Cover part, 92 ... Tomography device, 94 ... Machine.
Megumi 0 person area, 98...Amplification multiplexing block, 100...
・Detector electronic control logic circuit, 102 ・Analog・
Digital converter, 104... slip ring assembly,
106... Input/output/direct memory access control means, 108... Central control panel/logic circuit, 1
10...Slip ring assembly. FIG. l FIG. 2 FIG. 3 FIG. 5 FIG. 6 FIG. 4 FIG. 7

Claims (1)

[Scope of Claims] 1. In a scanning device for obtaining data that can be reproduced in order to produce a cross-sectional view of a portion passing through an object to be examined, the scanning device is positioned and forms a planar lamellar beam of radiation. means for rotating said beam about an axis along said object, and means for detecting said beam after passing through an object during said rotation of said beam, all said means for rotating said beam the beam is rotatable to perform a plurality of 360 degree rotations in a single direction of rotation; and (b) a rotating electrical supply device is provided, the device comprising: a first canopy carrying an annular electrical contact member; a second canopy portion holding an electrical contact member in sliding contact with the annular electrical contact member; a second canopy portion connecting the first canopy portion and the second canopy portion relative to each other; a support member and a fluid seal member that are rotated to
and an insulating liquid contained in the connected covering member, c. a central portion, a first end portion rotatably connected to the central portion, and an outer side non-rotatably connected to the central portion. a second end portion having a cover, a high voltage annular electrical contact disposed within the central portion and supported from the first end portion, a high voltage annular electrical contact engaged with the annular electrical contact and supported from the central portion; a high voltage electrical contact member disposed within the second end portion and non-rotatably connected to the first end portion, the outer cover being in sliding contact with the low voltage slip ring. retaining dynamically engaging contacts, d) the first end portion is coupled to the assembly, the high voltage annular electrical contact is connected to the radiation source, and the low voltage slip ring is coupled to the assembly; A rotary electricity supply device for a tomography scanning device, characterized in that it is connected to the detection means. 2. Device according to claim 1, characterized in that it includes means by which the rotational position of the radiation beam can be ascertained at any time during the rotation of the radiation beam so that scanning can be started at any time during the rotation of the radiation beam. 3. Apparatus according to claim 1 or 2, characterized in that said means for rotating said beam comprises a high voltage slip ring for powering said means for forming a radiation beam. 4. A scanning device for obtaining data that can be reproduced to produce a cross-sectional view of a section through an object to be examined, said object forming a planar lamellar beam of radiation along which said object is positioned. means for rotating said beam about an axis; and means for detecting said beam after impacting an object during said rotation of said beam;
A method of operating an apparatus wherein the means for rotating the beam is adapted to rotate the beam to perform a plurality of 360 degree rotations, all in a single direction of rotation, wherein a plurality of objects are A method comprising constantly rotating said beam in said single direction while being scanned sequentially within an apparatus. 5. Constantly rotating the beam in the single direction while the object is scanned in one cross-section, moved in the direction of a rotation axis, and scanned in other cross-sections. The method described in section.