EP0064539A1 - Time reversal imaging apparatus for displaying x-ray images or the like - Google Patents

Time reversal imaging apparatus for displaying x-ray images or the like

Info

Publication number
EP0064539A1
EP0064539A1 EP19810903178 EP81903178A EP0064539A1 EP 0064539 A1 EP0064539 A1 EP 0064539A1 EP 19810903178 EP19810903178 EP 19810903178 EP 81903178 A EP81903178 A EP 81903178A EP 0064539 A1 EP0064539 A1 EP 0064539A1
Authority
EP
European Patent Office
Prior art keywords
video recorder
images
display apparatus
image storage
storage means
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP19810903178
Other languages
German (de)
French (fr)
Inventor
Charles A. Mistretta
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Wisconsin Alumni Research Foundation
Original Assignee
Wisconsin Alumni Research Foundation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Wisconsin Alumni Research Foundation filed Critical Wisconsin Alumni Research Foundation
Publication of EP0064539A1 publication Critical patent/EP0064539A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
    • G11B15/005—Programmed access in sequence to indexed parts of tracks of operating tapes, by driving or guiding the tape
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B17/00—Guiding record carriers not specifically of filamentary or web form, or of supports therefor
    • G11B17/005—Programmed access to indexed parts of tracks of operating discs, by guiding the disc
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
    • G11B19/20—Driving; Starting; Stopping; Control thereof
    • G11B19/26—Speed-changing arrangements; Reversing arrangements; Drive-transfer means therefor
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
    • G11B27/005—Reproducing at a different information rate from the information rate of recording
    • G11B27/007—Reproducing at a different information rate from the information rate of recording reproducing continuously a part of the information, i.e. repeating
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
    • G11B27/02—Editing, e.g. varying the order of information signals recorded on, or reproduced from, record carriers
    • G11B27/022—Electronic editing of analogue information signals, e.g. audio or video signals
    • G11B27/026—Electronic editing of analogue information signals, e.g. audio or video signals on discs
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
    • G11B27/02—Editing, e.g. varying the order of information signals recorded on, or reproduced from, record carriers
    • G11B27/031—Electronic editing of digitised analogue information signals, e.g. audio or video signals
    • G11B27/034—Electronic editing of digitised analogue information signals, e.g. audio or video signals on discs
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
    • G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
    • G11B27/102—Programmed access in sequence to addressed parts of tracks of operating record carriers
    • G11B27/105—Programmed access in sequence to addressed parts of tracks of operating record carriers of operating discs
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
    • G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
    • G11B27/19—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier
    • G11B27/28—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B2220/00—Record carriers by type
    • G11B2220/20—Disc-shaped record carriers

Definitions

  • This invention relates to display apparatus for displaying a series of images.
  • the invention is particularly advantageous for displaying a series of stored X-ray images representing the action of the heart, the circulation of the blood, or other bodily functions in certain situations.
  • the present invention is particularly well adapted for displaying a series of X-ray difference images, produced as disclosed and claimed in U.S. patent No. 4,204,225, issued May 20, 1980, upon the application of the present applicant, Charles A. Mistretta, or as disclosed and claimed in U.S. patent No. 4,204,226, issued May 20, 1980, upon the application of Charles A. Mistretta, Robert A. Kruger and Theodore L. Houk.
  • a series of such X-ray difference images will show the action of the heart, the circulation of the blood as, for example, in the coronary arteries, the carotid arteries, or bypass grafts around such arteries, or other bodily functions.
  • One object of the present invention is to provide a new and improved display apparatus for repetitively displaying a series of images, such as a series of X-ray images showing the action of the heart or the circulation of the blood, so as to maximize the amount of information which can be obtained from observing such images.
  • a further object is to provide a new and improved display apparatus of the foregoing character which will enable the radiologist to observe and study the series of X-ray images for an indefinitely long period of time, as needed, while limiting the radiation exposure of the patient to a single series of images.
  • the present invention preferably provides display apparatus for displaying a series of X-ray images or the like, comprising image storage means having forward control means for causing the image storage means to reproduce the images in a forward sequence, the image storage means having reverse control means for causing the image storage means to reproduce the images in a reverse sequence, the image storage means having label means for producing label information to identify each of the stored images, upper limit means for establishing an upper limit of the label information, lower limit means for establishing a lower limit of the label information, upper comparison means for comparing the currently produced label information with the upper limit and for actuating the reverse control means when the current label information corresponds with the upper limit, and lower comparison means for comparing the current label information with the lower limit and for actuating the forward control means when the current label information corresponds with the lower limit, whereby the images are repetitively reproduced in forward and reverse sequences between the upper and lower limits.
  • Display means such as a television monitor, may be provided to display the images reproduced by the image storage means.
  • the image storage means may be in the form of an analog disc video recorder, a digital disc video recorder, some other video recorder, a digital memory, incorporated in a computer or otherwise, or means for utilizing images stored on photographic film. Means may be provided for varying the rate at which the images are reproduced -by the image storage means.
  • the label means may produce the label information in the form of label number signals.
  • the upper and lower limits may be established by upper and lower registers which may be set or loaded with the label number signals when the image storage means is adjusted to the images at the desired upper and lower limits.
  • the upper and lower comparison means may take the form of upper and lower digital comparators for comparing the currently produced label number signals with the upper and lower limits, loaded in the upper and lower registers.
  • Fig. 1 is a schematic block diagram of a display apparatus to be described as an illustrative embodiment of the present invention.
  • Fig. 2 is a fragmentary schematic block diagram, corresponding to a portion of Fig. 1, but showing a modified embodiment.
  • Fig. 1 illustrates a display apparatus 10 for displaying a series of X-ray images or the like.
  • the display apparatus 10 comprises image storage means 12 for storing a series of images, such image storage means preferably being in the form of a video disc recorder which may be of the analog type, as contemplated in Fig.l, or the digital type, as contemplated in Fig. 2. However, any other suitable video recorder may be employed, for recording the images magnetically or otherwise.
  • the image storage means 12 may be in the form of a memory, such as a digital electronic memory, whether incorporated in a computer or otherwise.
  • the image storage means 12 may be in the form of means for utilizing images stored on photographic film, such as motion picture film.
  • the display apparatus 10 involves a television or video system.
  • the sequential images stored by the image storage means 12 are in the form of video or television signals, derived from a television camera by way of an image subtraction system, as disclosed and claimed in the previously mentioned background patents, for example.
  • the television camera may be trained upon an X-ray image intensification screen.
  • the X-ray images may be produced in rapid succession, to show the action of the heart, the circulation of the blood, or some other bodily function.
  • the image storage means 12 has a video input channel 14 for receiving the video signals representing the successive X-ray images to be stored. It is only necessary to produce and store a single series of X-ray images. Thus, the radiation exposure to the patient is minimized.
  • the image storage means 12 will often be referred to as a video recorder, but it will be understood that other image storage means may be employed.
  • the video recorder 12 is capable of reproducing the stored images in either a forward sequence or a reverse sequence. In reproducing the images, the video recorder
  • the video recorder 12 produces video signals which are supplied to a video or television monitor 16, for converting the video signals into visible television images, corresponding to the X-ray images.
  • the video recorder 12 of Fig. 1 has a speed control 18, for varying the rate at which the stored images are reproduced.
  • the video recorder 12 also includes adjusting means 20, illustrated as a stepping control, whereby the video recorder can be adjusted to reproduce any stored image in the recorded series.
  • the video recorder 12 of Fig. 1 has forward control means for causing the video recorder to reproduce the stored images in a forward sequence, such forward control means including a fast forward input 22, adapted to receive a control signal which will cause the video recorder 12 to reproduce the stored images in a forward direction.
  • the video recorder 12 also has reverse control means for causing the recorder to reproduce the images in a reverse sequence, such reverse control means including a fast reverse input 24 for receiving a control signal to actuate the reproduction of the stored images by the video recorder in a reverse sequence.
  • the video recorder of Fig. 1 also has label means for producing label information to identify each of the stored images.
  • label information may comprise image label numbers, stored by the video recorder along with the images, and adapted to be reproduced in the form of label number signals, accompanying the reproduced video signals corresponding to the stored images.
  • label means may include a plurality of image label number output channels 26, adapted to supply output signals corresponding to multidigit binary image numbers in parallel form, four such channels being shown in Fig. 1. When a larger number of digits is needed, a correspondingly larger number of output channels may be provided.
  • the system of Fig. 1, involving four digits or bits, has a capacity of sixteen (2 4 ) different image identification numbers .
  • the display apparatus 10 of Fig. 1 includes upper and lower limit means 28 and 30 for selectively estab lishing upper and lower limits of the label information.
  • Such upper and lower limit means 28 and 30 are illustrated in the form of upper and lower limit data registers which can be selectively loaded to any label number within the capacity of the system.
  • the illustrated data registers 28 and 30 have respective multichannel inputs 32 and 34 which are connected to the corresponding outputs 26 of the video recorder 12. Thus, the image number signals being reproduced, by the video recorder 12 are applied in parallel form to the inputs 32 and 34 of the upper and lower data registers 28 and 30.
  • the data registers 28 and 30 also have selectively operable loading or setting controls 36 and 38, illustrated as setting switches, which may be operated to load any desired input signals into the respective data registers 28 and 30.
  • the upper limit may be set by using the stepping control 20 to adjust the video recorder 12 to the image which is desired as the upper limit.
  • the video recorder 12 then supplies a corresponding image number to the upper limit data register 28, by way of the output channels 26 and the input channels 32. This image number may be loaded into the data register 28 by operating the loading or setting switch 36.
  • the lower limit may be set by operating the stepping control 22 to adjust the video recorder 12 to the image which is desired as the lower limit.
  • the video recorder 12 then supplies the corresponding image number to the lower limit data register by way of the output channels 26 and the input channels 34. This image number is loaded into the data register 30 by operating the setting switch 38.
  • the upper and lower limit image numbers remain loaded in the upper and lower limit data registers 28 and 30, until the setting switches 36 and 38 are again operated, when some change in the limits is desired.
  • the display apparatus 10 of Fig. 1 includes upper and lower comparison means 40 and 42 for comparing the currently produced label information from the video recorder 12 with the respective upper and lower limits established by the data registers 28 and.30, such upper and lower comparison means being illustrated as comprising respective upper and lower comparators 44 and 46, which, through the medium of a flip-flop 48 are adapted to supply actuating control signals to the forward and reverse input channels 22 and 24 of the video recorder 12
  • the upper limit comparator 44 of Fig. 1 is adapted to compare the currently produced image label signals from the video recorder 12 with the upper limit label signals from the data register 28.
  • the upper limit comparator 44 has a first set of input channels 50 connected to the output channels 52 of the upper limit data register 28, and a second set of input channels 54 connected to the output channels 26 of the video recorder 12.
  • the lower limit comparator 46 of Fig. 1 compares the currently produced image number signals from the video recorder 12 with the lower limit output signals from the data register 30.
  • the lower limit comparator 46 has a first set of input channels 56 which are connected to the output channels 58 of the lower limit data register 30, and a second set of input channels 60 connected to the output channels 26 of the video recorder 12.
  • the flip-flop 48 of Fig. 1 is of the R-S type, having set and reset inputs 62 and 64.
  • the set input 62 is connected to the output 66 of the lower limit comparator 46.
  • the reset input 64 is connected to the output of the upper limit comparator 68.
  • the flip-flop 48 has a Q output 70, connected to the fast forward input 22 of the video recorder 12, and a complementary or Q output 72 connected to the fast reverse input 24 of the video recorder 12.
  • a double pole stop-start switch 74 is connected into the lines 76 and 78 between the outputs 70 and 72 of the flip-flop 48 and the control inputs 22 and 24 of the video recorder 12. During normal operation of the video recorder 12, the double pole switch 74 is closed. The opening of the switch 74 is effective to stop the video recorder 12.
  • the video disc recorder 12 serves as image storage means, to record or store a series of images, as, for example, X-ray images representing the action of the heart, the circulation of the blood, or some other bodily function.
  • the X-ray images may represent the movement of an X-ray contrast medium through the coronary arteries of the heart, or through bypass grafts around the coronary arteries. It is difficult and tedious to analyze a series of such X-ray images, using an ordinary display system.
  • the X-ray images are repetitively displayed in forward and reverse sequences between upper and lower limiting images.
  • the stop-start switch 74 is opened, to prevent automatic operation of the display apparatus 10.
  • the video recorder 12 is adjustsd to the desired upper limit image, which is viewed on the video monitor 16.
  • the image number outputs 26 of the video recorder 12 produce image number signals to identify the upper limit image.
  • These image number signals are loaded into the upper limit data register 28 momentarily operating the upper limit set switch 36.
  • the step control 20 is again operated to adjust the video recorder 12 to the desired lower limit image, as viewed on the video monitor 16.
  • the video recorder 12 then produces image number signals at its output channels 26, corresponding to the lower limit image. These image number signals are loaded into the lower limit data register 30 by momentarily operating the lower limit set switch 38 .
  • the stop-start switch 74 is then closed.
  • the video recorder 12 reproduces the stored images in a forward sequence, until the upper limit image is reached, at which time the upper limit comparator indicates that the image number signals at both ends of input channels 50 and 54 are the same, whereupon the upper limit comparator 44 supplies an output signal to the reset input 64 of the flip-flop 48.
  • the output 72 of the flip-flop 48 then supplies an actuating signal to the fast reverse input 24 of the video recorder 12.
  • Such control signal causes the video recorder 12 to reproduce the stored images in a reverse sequence, until the lower limit image is reached.
  • the lower limit comparator 46 then indicates that the image number signals at both sets of input channels 56 and 60 are the same, whereupon the comparator 46 supplies an output signal to the set input 62 of the flipflop 48.
  • the Q output 70 of the flip-flop 48 then supplies an actuating signal to the fast forward input 22 of the video recorder 12. Accordingly, the video recorder 12 is again caused to reproduce the stored images in a forward sequence.
  • the video recorder 12 is caused to reproduce the stored images in a time reversal mode, in which the images are alternately reproduced in forward and reverse sequences, for as long as may be desired by the operator.
  • the display apparatus of the present invention is particularly valuable for evaluating the circulation of the blood through the coronary arteries, or through bypass grafts around the coronary arteries.
  • the display apparatus 10 can be used very advantageously to provide a. dynamic time reversal display of sequential X-ray images, such as those obtained using image subtraction techniques as disclosed and claimed in the previously mentioned background patents.
  • a single series of radiographic images may be taken originally, to minimize the exposure of the patient to radiation. These images may then be displayed repetitively in forward and reverse sequences, using the display apparatus of the present invention. Because only one series of radiographic images is required, the images can be taken under optimal high exposure conditions at separated time intervals and under optimal readout conditions, such as slow scan television readout.
  • the images are then stored so that they can be reproduced with the dynamic time reversal display.
  • the speed of the video recorder, or other image storage device employed in the apparatus can be increased to increase the rate at which the images are reproduced and displayed.
  • Fig. 2 illustrates a modified embodiment in the form of a modified display apparatus 110 including a digital video disc recorder 112, instead of the analog video recorder 12 of Fig. 1.
  • the display apparatus 110 is generally similar to the display apparatus 10 of Fig. 1.
  • the description of Fig. 1 is also applicable to Fig. 2, except as may be described herein.
  • many of the components shown in Fig. 2 are being given the same reference characters as in Fig. 1, or the same reference characters increased by 100.
  • the digital video disc recorder 112 of Fig. 2 is adapted to record images in the form of digital video signals.
  • the recorder 112 has a video input channel 114 for receiving the digital video signals to be recorded. Such digital video signals may represent the successive X-ray images to be stored.
  • the digital video recorder 112 of Fig. 2 has a speed control 118, for varying the rate at which the stored images are reproduced.
  • the recorder 112 also includes adjusting means 120, illustrated as a stepping control, whereby the video recorder can be adjusted to reproduce any stored image in the recorded series.
  • the digital video recorder 112 of Fig. 2 has forward control means, as in Fig. 1, for causing the recorder to reproduce the stored images in a forward sequence, such forward control means including the fast forward input 22, as in Fig. 1, adapted to receive a control signal which will cause the recorder 112 to reproduce the stored images in a forward direction.
  • the digital video recorder 112 also has reverse control means for causing the recorder to reproduce the images in a reverse sequence, such reverse control means including a fast reverse input 24, as in Fig. 1, for receiving a control signal to actuate the reproduction of the stored images by the recorder 112 in a reverse sequence.
  • the digital video recorder 112 of Fig. 2 also has label means for producing label information to identify each of the stored images.
  • Such label information may comprise image label numbers, stored by the recorder along with the images, and adapted to be reproduced in the form of label number signals accompanying the reproduced video signals corresponding to the stored images.
  • label means may include the image label number output channels 26, as in Fig. 1, adapted to supply output signals corresponding to multidigit binary image numbers in parallel form, four such channels being shown in Fig. 2, as in Fig. 1. When more than four digits are desired, a correspondingly larger number of output channels may be provided.
  • the television or video monitor 16 may be the same in Fig. 2 as in Fig. 1.
  • the digital video recorder 112 of Fig. 2 preferably feeds its digital video output signals to a buffer memory 131, which in turn supplies its output to a digital-to-analog converter 133.
  • the converter 133 supplies analog video signals which are fed to the television monitor 16, so that the images reproduced by the digital video recorder 112 will be displayed by the television monitor 16.
  • the display apparatus 110 of Fig. 2 may be the same as the display apparatus 10 of Fig. 1.
  • the connections to the forward control input 22, the reverse control input 24, and the image number signal outputs 26 may be the same in Fig. 2 as in Fig. 1.
  • the operation of the display apparatus 110 of Fig.2 is the same as described in connection with Fig. 1, except that the images are supplied to the digital video recorder 112 in the form of digital video signals, and are recorded and reproduced as digital video signals.
  • the buffer memory 131 and the digital-to-analog converter are effective to convert the digital video signals into analog signals, which are converted into visible images by the television monitor 16.
  • the time reversal mode of operation as described in connection with Fig. 1, as to the display apparatus 10, is the same, with respect to the display apparatus 110 of Fig. 2.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Closed-Circuit Television Systems (AREA)
  • Apparatus For Radiation Diagnosis (AREA)

Abstract

Appareil d'affichage pour afficher une serie d'images a rayons X ou autres, comprenant des moyens de stockage d'images (12) tels qu'un enregistreur a disque video pour stocker une serie d'images, des moyens de commande de marche avant et marche arriere (22, 24) pour que les moyens de stockage d'images (12) reproduisent les images soit dans une sequence avant soit dans une sequence arriere, des moyens d'etiquettes (26) pour produire des signaux de numeros d'etiquettes pour identifier chacune des images stockees, des moyens de limites superieure et inferieure (28, 30) pour etablir des limites superieures et inferieures des signaux de numeros d'etiquettes, des moyens de comparaisons superieurs et inferieurs (44, 46) pour comparer les signaux de numeros d'etiquettes produits couramment avec les limites superieure et inferieure pour actionner les moyens de commande d'inversion (24) lorsque les signaux de numeros d'etiquettes correspondent a la limite superieure et pour actionner les moyens de commande de marche avant (22) lorsque les signaux de numeros d'etiquettes correspondent a la limite inferieure, et des moyens d'affichage (16) permettant d'afficher les images reproduites par les moyens de stockage d'images (12), de maniere a ce que les images soient affichees de maniere repetitive dans des sequences avant et arriere entre les limites superieure et inferieure.Display apparatus for displaying a series of x-ray images or the like, comprising image storage means (12) such as a video disc recorder for storing a series of images, operation control means forward and reverse (22, 24) for the image storage means (12) to reproduce the images either in a forward sequence or in a reverse sequence, label means (26) for producing signal numbers d for identifying each of the stored images, upper and lower limit means (28, 30) for establishing upper and lower limits of the label number signals, upper and lower comparison means (44, 46) for comparing the label number signals commonly produced with the upper and lower limits for actuating the reversing control means (24) when the label number signals correspond to the upper limit and for actuating the means forward drive control (22) when the label number signals correspond to the lower limit, and display means (16) making it possible to display the images reproduced by the image storage means (12), so that images are displayed repeatedly in front and back sequences between the upper and lower limits.

Description

TIME REVERSAL IMAGING APPARATUS FOR DISPLAYING X-RAY IMAGES OR THE LIKE
FIELD OF THE INVENTION
This invention relates to display apparatus for displaying a series of images. The invention is particularly advantageous for displaying a series of stored X-ray images representing the action of the heart, the circulation of the blood, or other bodily functions in certain situations.
BACKGROUND OF THE INVENTION
The present invention is particularly well adapted for displaying a series of X-ray difference images, produced as disclosed and claimed in U.S. patent No. 4,204,225, issued May 20, 1980, upon the application of the present applicant, Charles A. Mistretta, or as disclosed and claimed in U.S. patent No. 4,204,226, issued May 20, 1980, upon the application of Charles A. Mistretta, Robert A. Kruger and Theodore L. Houk. A series of such X-ray difference images will show the action of the heart, the circulation of the blood as, for example, in the coronary arteries, the carotid arteries, or bypass grafts around such arteries, or other bodily functions.
OBJECTS OF THE INVENTION One object of the present invention is to provide a new and improved display apparatus for repetitively displaying a series of images, such as a series of X-ray images showing the action of the heart or the circulation of the blood, so as to maximize the amount of information which can be obtained from observing such images.
A further object is to provide a new and improved display apparatus of the foregoing character which will enable the radiologist to observe and study the series of X-ray images for an indefinitely long period of time, as needed, while limiting the radiation exposure of the patient to a single series of images.
SUMMARY OF THE INVENTION To achieve these and other objects, the present invention preferably provides display apparatus for displaying a series of X-ray images or the like, comprising image storage means having forward control means for causing the image storage means to reproduce the images in a forward sequence, the image storage means having reverse control means for causing the image storage means to reproduce the images in a reverse sequence, the image storage means having label means for producing label information to identify each of the stored images, upper limit means for establishing an upper limit of the label information, lower limit means for establishing a lower limit of the label information, upper comparison means for comparing the currently produced label information with the upper limit and for actuating the reverse control means when the current label information corresponds with the upper limit, and lower comparison means for comparing the current label information with the lower limit and for actuating the forward control means when the current label information corresponds with the lower limit, whereby the images are repetitively reproduced in forward and reverse sequences between the upper and lower limits.
Display means, such as a television monitor, may be provided to display the images reproduced by the image storage means.
The image storage means may be in the form of an analog disc video recorder, a digital disc video recorder, some other video recorder, a digital memory, incorporated in a computer or otherwise, or means for utilizing images stored on photographic film. Means may be provided for varying the rate at which the images are reproduced -by the image storage means.
The label means may produce the label information in the form of label number signals. The upper and lower limits may be established by upper and lower registers which may be set or loaded with the label number signals when the image storage means is adjusted to the images at the desired upper and lower limits.
The upper and lower comparison means may take the form of upper and lower digital comparators for comparing the currently produced label number signals with the upper and lower limits, loaded in the upper and lower registers.
BRIEF DESCRIPTION OF THE DRAWINGS Further objects, advantages and features of the present invention will appear from the following description of illustrative embodiments, taken in connection with the accompanying drawings, in which:
Fig. 1 is a schematic block diagram of a display apparatus to be described as an illustrative embodiment of the present invention.
Fig. 2 is a fragmentary schematic block diagram, corresponding to a portion of Fig. 1, but showing a modified embodiment.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
As just indicated, Fig. 1 illustrates a display apparatus 10 for displaying a series of X-ray images or the like. The display apparatus 10 comprises image storage means 12 for storing a series of images, such image storage means preferably being in the form of a video disc recorder which may be of the analog type, as contemplated in Fig.l, or the digital type, as contemplated in Fig. 2. However, any other suitable video recorder may be employed, for recording the images magnetically or otherwise. Moreover, the image storage means 12 may be in the form of a memory, such as a digital electronic memory, whether incorporated in a computer or otherwise. Furthermore, the image storage means 12 may be in the form of means for utilizing images stored on photographic film, such as motion picture film.
In Fig. 1, the display apparatus 10 involves a television or video system. The sequential images stored by the image storage means 12 are in the form of video or television signals, derived from a television camera by way of an image subtraction system, as disclosed and claimed in the previously mentioned background patents, for example. The television camera may be trained upon an X-ray image intensification screen. The X-ray images may be produced in rapid succession, to show the action of the heart, the circulation of the blood, or some other bodily function.
As shown in Fig. 1, the image storage means 12 has a video input channel 14 for receiving the video signals representing the successive X-ray images to be stored. It is only necessary to produce and store a single series of X-ray images. Thus, the radiation exposure to the patient is minimized.
For brevity in the following description, the image storage means 12 will often be referred to as a video recorder, but it will be understood that other image storage means may be employed.
The video recorder 12 is capable of reproducing the stored images in either a forward sequence or a reverse sequence. In reproducing the images, the video recorder
12 produces video signals which are supplied to a video or television monitor 16, for converting the video signals into visible television images, corresponding to the X-ray images. The video recorder 12 of Fig. 1 has a speed control 18, for varying the rate at which the stored images are reproduced. The video recorder 12 also includes adjusting means 20, illustrated as a stepping control, whereby the video recorder can be adjusted to reproduce any stored image in the recorded series. The video recorder 12 of Fig. 1 has forward control means for causing the video recorder to reproduce the stored images in a forward sequence, such forward control means including a fast forward input 22, adapted to receive a control signal which will cause the video recorder 12 to reproduce the stored images in a forward direction. The video recorder 12 also has reverse control means for causing the recorder to reproduce the images in a reverse sequence, such reverse control means including a fast reverse input 24 for receiving a control signal to actuate the reproduction of the stored images by the video recorder in a reverse sequence.
The video recorder of Fig. 1 also has label means for producing label information to identify each of the stored images. Such label information may comprise image label numbers, stored by the video recorder along with the images, and adapted to be reproduced in the form of label number signals, accompanying the reproduced video signals corresponding to the stored images. In the video recorder 12 of Fig. 1, such label means may include a plurality of image label number output channels 26, adapted to supply output signals corresponding to multidigit binary image numbers in parallel form, four such channels being shown in Fig. 1. When a larger number of digits is needed, a correspondingly larger number of output channels may be provided. The system of Fig. 1, involving four digits or bits, has a capacity of sixteen (24) different image identification numbers . By adding additional digits , the capacity can be increased to thirty-two, sixty-four or any higher number. The display apparatus 10 of Fig. 1 includes upper and lower limit means 28 and 30 for selectively estab lishing upper and lower limits of the label information. Such upper and lower limit means 28 and 30 are illustrated in the form of upper and lower limit data registers which can be selectively loaded to any label number within the capacity of the system. The illustrated data registers 28 and 30 have respective multichannel inputs 32 and 34 which are connected to the corresponding outputs 26 of the video recorder 12. Thus, the image number signals being reproduced, by the video recorder 12 are applied in parallel form to the inputs 32 and 34 of the upper and lower data registers 28 and 30. The data registers 28 and 30 also have selectively operable loading or setting controls 36 and 38, illustrated as setting switches, which may be operated to load any desired input signals into the respective data registers 28 and 30.
For example, the upper limit may be set by using the stepping control 20 to adjust the video recorder 12 to the image which is desired as the upper limit. The video recorder 12 then supplies a corresponding image number to the upper limit data register 28, by way of the output channels 26 and the input channels 32. This image number may be loaded into the data register 28 by operating the loading or setting switch 36. Similarly, the lower limit may be set by operating the stepping control 22 to adjust the video recorder 12 to the image which is desired as the lower limit. The video recorder 12 then supplies the corresponding image number to the lower limit data register by way of the output channels 26 and the input channels 34. This image number is loaded into the data register 30 by operating the setting switch 38. The upper and lower limit image numbers remain loaded in the upper and lower limit data registers 28 and 30, until the setting switches 36 and 38 are again operated, when some change in the limits is desired.
The display apparatus 10 of Fig. 1 includes upper and lower comparison means 40 and 42 for comparing the currently produced label information from the video recorder 12 with the respective upper and lower limits established by the data registers 28 and.30, such upper and lower comparison means being illustrated as comprising respective upper and lower comparators 44 and 46, which, through the medium of a flip-flop 48 are adapted to supply actuating control signals to the forward and reverse input channels 22 and 24 of the video recorder 12 The upper limit comparator 44 of Fig. 1 is adapted to compare the currently produced image label signals from the video recorder 12 with the upper limit label signals from the data register 28. Thus, the upper limit comparator 44 has a first set of input channels 50 connected to the output channels 52 of the upper limit data register 28, and a second set of input channels 54 connected to the output channels 26 of the video recorder 12.
Similarly, the lower limit comparator 46 of Fig. 1 compares the currently produced image number signals from the video recorder 12 with the lower limit output signals from the data register 30. Thus, the lower limit comparator 46 has a first set of input channels 56 which are connected to the output channels 58 of the lower limit data register 30, and a second set of input channels 60 connected to the output channels 26 of the video recorder 12.
The flip-flop 48 of Fig. 1 is of the R-S type, having set and reset inputs 62 and 64. The set input 62 is connected to the output 66 of the lower limit comparator 46. The reset input 64 is connected to the output of the upper limit comparator 68. As shown, the flip-flop 48 has a Q output 70, connected to the fast forward input 22 of the video recorder 12, and a complementary or Q output 72 connected to the fast reverse input 24 of the video recorder 12. A double pole stop-start switch 74 is connected into the lines 76 and 78 between the outputs 70 and 72 of the flip-flop 48 and the control inputs 22 and 24 of the video recorder 12. During normal operation of the video recorder 12, the double pole switch 74 is closed. The opening of the switch 74 is effective to stop the video recorder 12.
In the operation of the display apparatus 10 of Fig. 1, the video disc recorder 12 serves as image storage means, to record or store a series of images, as, for example, X-ray images representing the action of the heart, the circulation of the blood, or some other bodily function. To cite a more specific example, the X-ray images may represent the movement of an X-ray contrast medium through the coronary arteries of the heart, or through bypass grafts around the coronary arteries. It is difficult and tedious to analyze a series of such X-ray images, using an ordinary display system.
With the display apparatus 10 of Fig. 1, the X-ray images are repetitively displayed in forward and reverse sequences between upper and lower limiting images. To set up or program the display apparatus 10 for such operation, the stop-start switch 74 is opened, to prevent automatic operation of the display apparatus 10. By using the stepping control 20, the video recorder 12 is adjustsd to the desired upper limit image, which is viewed on the video monitor 16. At this time, the image number outputs 26 of the video recorder 12 produce image number signals to identify the upper limit image. These image number signals are loaded into the upper limit data register 28 momentarily operating the upper limit set switch 36. To set the lower limit, the step control 20 is again operated to adjust the video recorder 12 to the desired lower limit image, as viewed on the video monitor 16. The video recorder 12 then produces image number signals at its output channels 26, corresponding to the lower limit image. These image number signals are loaded into the lower limit data register 30 by momentarily operating the lower limit set switch 38 .
To commence automatic operation of the display apparatus 10, the stop-start switch 74 is then closed. The video recorder 12 reproduces the stored images in a forward sequence, until the upper limit image is reached, at which time the upper limit comparator indicates that the image number signals at both ends of input channels 50 and 54 are the same, whereupon the upper limit comparator 44 supplies an output signal to the reset input 64 of the flip-flop 48. The output 72 of the flip-flop 48 then supplies an actuating signal to the fast reverse input 24 of the video recorder 12. Such control signal causes the video recorder 12 to reproduce the stored images in a reverse sequence, until the lower limit image is reached. The lower limit comparator 46 then indicates that the image number signals at both sets of input channels 56 and 60 are the same, whereupon the comparator 46 supplies an output signal to the set input 62 of the flipflop 48. The Q output 70 of the flip-flop 48 then supplies an actuating signal to the fast forward input 22 of the video recorder 12. Accordingly, the video recorder 12 is again caused to reproduce the stored images in a forward sequence. Thus, due to the alternate functioning of the upper and lower limit comparators 44 and 46 at the upper and lower limiting images, and the alternate setting and resetting of the flip-flop 48, the video recorder 12 is caused to reproduce the stored images in a time reversal mode, in which the images are alternately reproduced in forward and reverse sequences, for as long as may be desired by the operator.
By closely watching the time reversal sequencing of the images, as displayed on the television monitor 16, an expert radiologist can analyze and evaluate the X-ray images much more accurately and rapidly than with ordinary display systems. The display apparatus of the present invention is particularly valuable for evaluating the circulation of the blood through the coronary arteries, or through bypass grafts around the coronary arteries. In some cases, it is advantageous to employ the speed control 18 to vary the rate at which the images are reproduced by the video recorder 12. For example, increasing the speed of the video recorder 12 may increase the amount of available information to be derived by observing the time reversal display of the images on the television monitor 16. By displaying the images faster than they were taken originally, the temporal integration properties of the eye can be used to perceive a greater quantum of statistical X-ray information per unit time than that which was present during the original X-ray exposure sequence. The display apparatus 10 can be used very advantageously to provide a. dynamic time reversal display of sequential X-ray images, such as those obtained using image subtraction techniques as disclosed and claimed in the previously mentioned background patents. A single series of radiographic images may be taken originally, to minimize the exposure of the patient to radiation. These images may then be displayed repetitively in forward and reverse sequences, using the display apparatus of the present invention. Because only one series of radiographic images is required, the images can be taken under optimal high exposure conditions at separated time intervals and under optimal readout conditions, such as slow scan television readout. The images are then stored so that they can be reproduced with the dynamic time reversal display. The speed of the video recorder, or other image storage device employed in the apparatus, can be increased to increase the rate at which the images are reproduced and displayed.
As already indicated, Fig. 2 illustrates a modified embodiment in the form of a modified display apparatus 110 including a digital video disc recorder 112, instead of the analog video recorder 12 of Fig. 1. Otherwise, the display apparatus 110 is generally similar to the display apparatus 10 of Fig. 1. The description of Fig. 1 is also applicable to Fig. 2, except as may be described herein. To facilitate the extension of the description of Fig. 1 to Fig. 2, many of the components shown in Fig. 2 are being given the same reference characters as in Fig. 1, or the same reference characters increased by 100. Thus, it will be understood that the digital video disc recorder 112 of Fig. 2 is adapted to record images in the form of digital video signals. The recorder 112 has a video input channel 114 for receiving the digital video signals to be recorded. Such digital video signals may represent the successive X-ray images to be stored. The digital video recorder 112 of Fig. 2 has a speed control 118, for varying the rate at which the stored images are reproduced. The recorder 112 also includes adjusting means 120, illustrated as a stepping control, whereby the video recorder can be adjusted to reproduce any stored image in the recorded series.
The digital video recorder 112 of Fig. 2 has forward control means, as in Fig. 1, for causing the recorder to reproduce the stored images in a forward sequence, such forward control means including the fast forward input 22, as in Fig. 1, adapted to receive a control signal which will cause the recorder 112 to reproduce the stored images in a forward direction. The digital video recorder 112 also has reverse control means for causing the recorder to reproduce the images in a reverse sequence, such reverse control means including a fast reverse input 24, as in Fig. 1, for receiving a control signal to actuate the reproduction of the stored images by the recorder 112 in a reverse sequence. The digital video recorder 112 of Fig. 2 also has label means for producing label information to identify each of the stored images. Such label information may comprise image label numbers, stored by the recorder along with the images, and adapted to be reproduced in the form of label number signals accompanying the reproduced video signals corresponding to the stored images. In the digital video recorder 112 of Fig. 2, such label means may include the image label number output channels 26, as in Fig. 1, adapted to supply output signals corresponding to multidigit binary image numbers in parallel form, four such channels being shown in Fig. 2, as in Fig. 1. When more than four digits are desired, a correspondingly larger number of output channels may be provided.
The television or video monitor 16 may be the same in Fig. 2 as in Fig. 1. However, the digital video recorder 112 of Fig. 2 preferably feeds its digital video output signals to a buffer memory 131, which in turn supplies its output to a digital-to-analog converter 133. At its output, the converter 133 supplies analog video signals which are fed to the television monitor 16, so that the images reproduced by the digital video recorder 112 will be displayed by the television monitor 16.
Otherwise, the display apparatus 110 of Fig. 2 may be the same as the display apparatus 10 of Fig. 1. The connections to the forward control input 22, the reverse control input 24, and the image number signal outputs 26 may be the same in Fig. 2 as in Fig. 1.
The operation of the display apparatus 110 of Fig.2 is the same as described in connection with Fig. 1, except that the images are supplied to the digital video recorder 112 in the form of digital video signals, and are recorded and reproduced as digital video signals. The buffer memory 131 and the digital-to-analog converter are effective to convert the digital video signals into analog signals, which are converted into visible images by the television monitor 16.
The time reversal mode of operation, as described in connection with Fig. 1, as to the display apparatus 10, is the same, with respect to the display apparatus 110 of Fig. 2.
Other modifications, alternative constructions and equivalents may be employed, without departing from the true spirit and scope of the present invention.

Claims

1. Display apparatus for displaying a series of X-ray images or the like, comprising image storage means for storing a series of images, said image storage means having forward control means for causing said image storage means to reproduce said images in a forward sequence, said image storage means having reverse control means for causing said image storage means to reproduce said images in a reverse sequence, said image storage means having label means for producing label information to identify each of the stored images, upper limit means for establishing an upper limit of the label information, lower limit means for establishing a lower limit of the label information, upper comparison means for comparing the current label information with said upper limit and for actuating said reverse control means when the current label information corresponds with said upper limit, and lower comparison means for comparing the current label information with said lower limit and for actuating said forward control means when the current label information corresponds with said lower limit, whereby said images are repetitively reproduced in forward and reverse sequences between said upper and lower limits.
2. Display apparatus according to claim 1, ineluding display means for displaying the images reproduced by said image storage means.
3. Display apparatus according to claim 1, said image storage means including an analog disc video recorder.
4. Display apparatus according to claim 1, said image storage means including a digital disc video recorder.
5. Display apparatus according to claim 1, said image storage means including an analog video recorder.
6. Display apparatus according to claim 1, said image storage means including a digital video recorder.
7. Display apparatus according to claim 1, said image storage means including an analog video recorder for magnetically recording video image signals.
8. Display apparatus according to claim 1, said image storage means including a digital video recorder for magnetically recording video image signals.
9. Display apparatus according to claim 1, said image storage means including a digital memory.
10. Display apparatus according to claim 1, said image storage means including a computer having a digital memory.
11. Display apparatus according to claim 1, said image storage means including means for utilizing images stored on photographic film.
12. Display apparatus according to claim 1, including means for varying the rate at which said images are reproduced by said image storage means.
13. Display apparatus according to claim 1, said lower limit means including means for changing said lower limit, said upper limit means including means for changing said upper limit.
14. Display apparatus according to claim 1, said image storage means including means for adjusting said image storage means to reproduce the images at the upper and lower limits, said upper limit means including means for setting the upper limit with said image storage means adjusted to the image at the desired upper limit, said lower limit means including means for setting the lower limit with said image storage means adjusted to the image at the desired lower limit.
15. Display apparatus according to claim 1, said image storage means including a video recorder for recording and reproducing a series of images, said video recorder having said label means including means for producing label number signals to identify each of the recorded images, said upper limit means including upper limit register means for registering an upper limit of the label number signals, said lower limit means including lower limit register means for registering a lower limit of the label number signals, said lower comparison means including means for comparing the current label number signals with said upper limit and for actuating said reverse control means when the current label number signals correspond with said upper limit, said lower comparison means including means for comparing the current label number signals with said lower limit and for actuating said forward control means when the current, label number signals correspond with said lower limit, whereby said video recorder repetitively reproduces said images in forward and reverse sequences between the images corresponding with said upper and lower limits.
16. Display apparatus according to claim 15, including television display means for displaying the images reproduced by said video recorder.
17. Display apparatus according to claim 15, in which said video recorder includes an analog disc video recorder.
18. Display apparatus according to claim 15, in which said video recorder includes a digital disc video recorder.
19. Display apparatus according to claim 15, in which said video recorder takes the form of a digital video recorder.
20. Display apparatus according to claim 15, in which said video recorder takes the form of an analog video recorder.
21. Display apparatus according to claim 15, in which said video recorder takes the form of an analog video recorder for magnetically recording video image signals.
22. Display apparatus according to claim 15, in which said video recorder takes the form of a digital video recorder for magnetically recording video image signals.
23. Display apparatus according to claim 15, in which said video recorder includes means for varying the operating speed at which the images are reproduced by said video recorder.
24. Display apparatus according to claim 15, said upper limit register means including means for selectively setting said upper limit, said lower limit register means including means for selectively setting said lower limit.
25. Display apparatus according to claim 15, in which said video recorder includes means for adjusting said video recorder to the images at the desired upper and lower limits, said upper limit register means including means for setting the upper limit with the video recorder adjusted to the image at the desired upper limit, said lower limit register means including means for setting the lower limit with said video recorder adjusted to the image at the desired lower limit.
26. Display apparatus according to claim 15, said label means including means for producing said label number signals in digital form, said upper and lower limit register, means including upper and lower digital registers, said upper and lower comparison means including upper and lower digital comparators.
27. Display apparatus according to claim 26, in which said video recorder includes means for adjusting said video recorder to the images at the desired upper and lower limits, said upper and lower digital registers including means for setting said registers with said video recorder adjusted to the images at the desired upper and lower limits.
EP19810903178 1980-11-10 1981-11-06 Time reversal imaging apparatus for displaying x-ray images or the like Withdrawn EP0064539A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US20578280A 1980-11-10 1980-11-10
US205782 1980-11-10

Publications (1)

Publication Number Publication Date
EP0064539A1 true EP0064539A1 (en) 1982-11-17

Family

ID=22763624

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19810903178 Withdrawn EP0064539A1 (en) 1980-11-10 1981-11-06 Time reversal imaging apparatus for displaying x-ray images or the like

Country Status (3)

Country Link
EP (1) EP0064539A1 (en)
CA (1) CA1164581A (en)
WO (1) WO1982001784A1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0766613B2 (en) * 1986-11-12 1995-07-19 パイオニア株式会社 Alternate operation control method for multiple disc players
US6231510B1 (en) 1999-03-05 2001-05-15 Atl Ultrasound Ultrasonic diagnostic imaging system
US6213944B1 (en) 1999-03-05 2001-04-10 Atl Ultrasound, Inc. Ultrasonic diagnostic imaging system with a digital video recorder with visual controls
US6231508B1 (en) * 1999-03-05 2001-05-15 Atl Ultrasound Ultrasonic diagnostic imaging system with digital video image marking
DE102005057568B4 (en) * 2005-12-02 2021-06-17 Robert Bosch Gmbh Transmitting device and receiving device

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL173343C (en) * 1972-03-29 1984-01-02 Philips Nv Apparatus for reading a disc-shaped record carrier with image and / or audio signals encoded in optical form.
NL7212015A (en) * 1972-09-04 1974-03-06
US3911211A (en) * 1974-04-17 1975-10-07 Zenith Radio Corp Stop frame for optical playback system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO8201784A1 *

Also Published As

Publication number Publication date
WO1982001784A1 (en) 1982-05-27
CA1164581A (en) 1984-03-27

Similar Documents

Publication Publication Date Title
US6067075A (en) Controller for medical image review station
US7193652B2 (en) Dynamic range video recording and playback system and method
US6542192B2 (en) Image display method and digital still camera providing rapid image display by displaying low resolution image followed by high resolution image
US4417276A (en) Video to digital converter
EP0684568A1 (en) Medical image archiving with lossy images on two or more recordable cds
US20060114334A1 (en) Image pickup apparatus with function of rate conversion processing and control method therefor
JPH0322687A (en) Digital recording and reproducing device
JPS60195589A (en) Image display
US6477228B2 (en) Method for operating an X-ray diagnosis device with immediate imaging
EP0064539A1 (en) Time reversal imaging apparatus for displaying x-ray images or the like
GB2161043A (en) Signal conversion method
JPH07203369A (en) Method for recording encoded data of moving video picture on recording carrier, diagnosis system for use in such method, and image encoding unit, recording unit and image data correcting unit for use in such system
JP2801002B2 (en) Digital electronic still camera
Dinn et al. CINTEL—computer interface for television
US4658412A (en) X-ray diagnostic apparatus
EP0684566A1 (en) Create lossy compressed data during upload of lossless data
JP2005270328A (en) Medical picture display device
EP0083985A1 (en) Improved ultrasonic image storage system
US3688272A (en) Visual indication device in which a part of the indicated data can be changed
JPS5930374A (en) Image pickup system
JP4045612B2 (en) Image processing device
JPS644138Y2 (en)
JP2693445B2 (en) Medical image display system
JP2759794B2 (en) X-ray diagnostic equipment
EP0684567A1 (en) Dual operation modes for palindrome and lossy/lossless display of medical images

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): DE FR GB NL

17P Request for examination filed

Effective date: 19821119

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19840910

RIN1 Information on inventor provided before grant (corrected)

Inventor name: MISTRETTA, CHARLES A.