Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
  • A61B5/055—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R33/00—Arrangements or instruments for measuring magnetic variables
  • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
  • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
  • G01R33/283—Intercom or optical viewing arrangements, structurally associated with NMR apparatus

Definitions

• the invention relates to an MR whole-body tomograph with a magnet system which has a central tube suitable for accommodating a patient, and with an optical device which can be attached in front of the eyes of a patient in the tube for establishing a line of sight the environment outside the magnet system.
• the patient When examining with an MR whole-body tomograph, the patient is exposed to a strong magnetic field inside the bore of a magnet system is generated. This hole is limited by a central tube of the magnet system, the diameter of which is approximately 60 cm. The length of this tube is very much greater than the diameter and is approximately 180 cm in the embodiments of such tomographs which are mostly used in practice, correspondingly more in the case of superconducting magnet systems.
• the patient's body part to be examined must be approximately in the middle of the tube. Particularly when examinations are carried out in the head area, the head is accordingly located almost one meter from the ends of the central tube of the magnet system and the tube wall is also relatively close to the patient's face.
• an adjustable mirror system which has not proven itself in practice, is attached, with which the viewing direction of the patient can be deflected in the longitudinal direction of the tube, in order to enable the patient to make constant eye contact with a caregiver at the end of the tube .
• eye contact is usually not feasible and in many cases is not sufficient to prevent patient irritation, and certainly not to shorten the patient's long examination time.
• the invention is therefore based on the object of designing an MR whole-body tomograph in such a way that even long examination times are easy to endure for the patient.
• the optical device comprises an eyepiece that can be attached in front of the patient's eyes and a device for generating an image in the focal plane of the eyepiece.
• the design of the optical device according to the invention not only offers the patient theoretically like the known mirror system, but also in practice the possibility of maintaining constant eye contact with a caregiver, and in addition it actually allows contact in a variety of ways to the outside world.
• the device for generating an image can comprise an objective arranged outside the magnet system and an image guide which transmits the image produced by the objective into the focal plane of the eyepiece.
• the image guide can be formed, for example, by an optical lens system or also by a fiber guide, ie a bundle of optical fibers. In this way it is possible for the patient, with appropriate training and alignment of the lens, to have an overview of the entire treatment or operating room and to observe the people working in it. This significantly increases the patient's sense of security.
• Non-magnetic screens are all available today as liquid crystal screens (LCD screens), but it does not seem impossible that other types of suitable screens will become available over time.
• the TV set could be act as a television camera, which in turn is aimed at the surroundings of the tomograph, so that the patient can observe the processes in his surroundings.
• the television device can also be a television playback device, for example a television receiver or else a video recorder, from which the video signals are fed to the screen arranged inside the tube of the magnet system.
• the eyepiece and the device for generating an image in the focal plane of the eyepiece to the inside of the central tube in such a way that the eyepiece can be brought into the correct position in front of the patient's eyes.
• the patient would have to maintain a rigid head position in order to always have the correct view into the eyepiece.
• This type of positioning should have advantages due to the immobilization of the head during head measurements.
• the eyepiece is attached to the patient's head so that it does not change its position relative to the head.
• the eyepiece can be attached to a head coil similar to the mirror of the known device. However, this would limit the use of the optical device in head examinations.
• the eyepiece is provided with a holder that can be attached to the patient's head.
• This could be a spectacle-like holder, as is known, for example, from a double magnifying glass.
• the use of a screen arranged in the focal plane of the eyepiece would have the advantage that this screen could be firmly connected to the eyepiece, the electrical leads leading to the screen, which are necessary for the transmission of the video signal, sufficient could be flexible to allow head movements of the patient.
• the focal plane of the eyepiece can also be arranged essentially in a cross-sectional plane of the central tube and there is an optical deflection element in the beam path of the eyepiece, which is the patient's radial direction of view perpendicular to the focal plane aligns.
• the optical device can also be designed such that it provides the doctor with an observation of the patient, e.g. an eye diagnosis allows the direction of observation (the beam path) to be reversed.
• a suitable viewing device eyepiece, mirror, mon tor
• eyepiece, mirror, mon tor can be provided outside the tomograph.
• the optical device can be assigned an acoustic transmission device which makes it possible to transmit either the noises occurring in the vicinity of the tomograph or the sound belonging to an image program into the patient's listening area.
• FIG. 1 is a schematic representation of an MR whole body Tomographs according to the invention partly in a schematic side view and partly in section and
• the patient must assume such a position that the body section to be examined is located in the area of the longitudinal center of the magnet system 1.
• an eyepiece 7 is arranged within the cylinder 5 in front of the patient 6 in the focal plane by means of a lens optical device an image is generated.
• This optical device comprises an image generator 8 and a device 9 for transferring the image into the focal plane of the eyepiece 7.
• FIGS. 2 to 4 show several options for the design of the optical device.
• a lens 11 is used as the device for image generation, which generates a real image 13 of the scene symbolized by arrow 12.
• This real image is transmitted through a light guide formed by lens 14, 15 into the focal plane 16 of the eyepiece 17, which is arranged in front of the patient's eye 18.
• the eyepiece 17 generates, in a known manner, a parallel beam of rays from the image present in its focal plane 16, which in turn leads to the creation of an image on the mesh of the eye when the eye 18 is set to infinity.
• the lens 11 is net angeord outside of the magnet system and directed towards the treatment room, so that ' the patient can observe at any time what is happening in his environment.
• the image guide formed by the lenses 14, 15 serves to transmit the image into the focal plane 16 of the eyepiece.
• the structure of such image guides formed by lens systems is known per se.
• the number of lenses used therein depends, among other things, on the distance to be bridged by the image guide. Since the end of the image guide formed by the lenses 14, 15 is located in a cross-sectional plane of the tube 5, an optical deflection element 20 in the form of a mirror is arranged in the beam path of the eyepiece 17, through which the radial to the tube 5 Direction of vision of the patient is directed perpendicular to the end of the image guide.
• FIG. 3 differs from the embodiment of FIG. 2 essentially only in that there is between the lens 11 for observing the through the Arrow 12 symbolizes the scene and the focal plane 16 of the eyepiece 17 is a fiber optic image guide 19, the ends of which lie in the image plane 13 of the objective and in the focal plane 16 of the eyepiece.
• a fiber optic image guide 19 the ends of which lie in the image plane 13 of the objective and in the focal plane 16 of the eyepiece.
• FIG. 4 finally shows an embodiment in which an LCD screen 23 is located directly in the focal plane of the eyepiece 22 arranged in front of the eye 21 of a patient and is connected via a cable 24 to a television camera 25 arranged outside the magnet system.
• the LCD screen 23 can be arranged directly perpendicular to the visual axis 26 of the eye 21, so that an optical deflection element can be saved, or can be provided outside the magnet, so that 10
• a deflection mirror 20 as in the embodiments according to FIGS. 2 and 3 is present.
• a loudspeaker 27 is provided outside the magnetic field, to which audio signals from a microphone 28 attached to the television camera 25 are likewise supplied via the cable 24.
• the video camera 25 can be used to observe the room in which the MR whole-body tomograph is located, so that the patient is informed about the processes in his environment.
• the invention is not limited to the exemplary embodiments shown, but many deviations are possible without leaving the scope of the invention.
• the television camera 25 could be operated by a television receiver or by a video recorder to be replaced in this way to offer the patient entertainment while in the tube 5 of the magnet system and thereby shorten the long examination time.
• the lens could be directed to the screen of a television or the like instead of to the space surrounding the magnet system.
• the acoustic device can of course also include a microphone arranged in the area of the patient's head, which enables the patient to communicate with the surroundings in a linguistic manner.
• a system consisting of mirrors can also be provided, in particular a focusing mirror can be used instead of a lens. It is also expediently avoided that metal parts of the system are provided in the HF range and magnetizable parts are provided in the field.
• the television camera 25 arranged outside the field area can be arranged to be movable, in particular pivotable, and for example by a transmission device, e.g. can be moved by the patient from within the tomograph by means of a mechanical lever transmission, so that the patient can adjust his field of vision as desired.
• a device can also be provided in the area of the patient's hands with which the patient can select programs from a video recorder.

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• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Physics & Mathematics (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Heart & Thoracic Surgery (AREA)
• Surgery (AREA)
• Biophysics (AREA)
• Pathology (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• High Energy & Nuclear Physics (AREA)
• Medical Informatics (AREA)
• Molecular Biology (AREA)
• Radiology & Medical Imaging (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• General Physics & Mathematics (AREA)
• Magnetic Resonance Imaging Apparatus (AREA)

Applications Claiming Priority (2)

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Citations (6)

• 1988
  • 1988-12-31 DE DE3844482A patent/DE3844482C1/de not_active Expired - Lifetime
• 1989
  • 1989-12-21 WO PCT/DE1989/000783 patent/WO1990007301A1/de unknown

Patent Citations (6)

Non-Patent Citations (2)

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