Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
  • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
  • A61B5/683—Means for maintaining contact with the body
  • A61B5/6835—Supports or holders, e.g., articulated arms
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
  • A61B5/1036—Measuring load distribution, e.g. podologic studies
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
  • A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb
  • A61B5/1126—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb using a particular sensing technique
  • A61B5/1127—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb using a particular sensing technique using markers
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
  • A61B6/44—Constructional features of apparatus for radiation diagnosis
  • A61B6/4429—Constructional features of apparatus for radiation diagnosis related to the mounting of source units and detector units
  • A61B6/4435—Constructional features of apparatus for radiation diagnosis related to the mounting of source units and detector units the source unit and the detector unit being coupled by a rigid structure
  • A61B6/4441—Constructional features of apparatus for radiation diagnosis related to the mounting of source units and detector units the source unit and the detector unit being coupled by a rigid structure the rigid structure being a C-arm or U-arm
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
  • A61B6/44—Constructional features of apparatus for radiation diagnosis
  • A61B6/4476—Constructional features of apparatus for radiation diagnosis related to motor-assisted motion of the source unit
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
  • A61B6/50—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications
  • A61B6/508—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications for non-human patients
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
  • A61B6/54—Control of apparatus or devices for radiation diagnosis
  • A61B6/541—Control of apparatus or devices for radiation diagnosis involving acquisition triggered by a physiological signal
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
  • A61B6/54—Control of apparatus or devices for radiation diagnosis
  • A61B6/547—Control of apparatus or devices for radiation diagnosis involving tracking of position of the device or parts of the device
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
  • A61B6/58—Testing, adjusting or calibrating thereof
  • A61B6/587—Alignment of source unit to detector unit
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
  • A61B6/08—Auxiliary means for directing the radiation beam to a particular spot, e.g. using light beams

Definitions

• the invention relates to an apparatus and a method for detecting images of moving anatomical parts.
• the invention regards a dynamic-radiology system for acquiring images to be used for purposes of diagnosing pathological conditions of joints in mammals, whether humans or animals.
• Dynamic radiology responds fundamentally to two categories of medical requirements that regard investigation both of the so-called "ghost lesions”, i.e., lesions that are difficult to detect using conventional radiological techniques, and of the stability of the instruments for fixating the ends of fracture or of prostheses.
• WO2006042211 illustrates a dynamic image- acquisition system comprising a first robotized arm and a second robotized arm, each carrying a source of penetrating radiation emitted towards the limb in motion to be examined and a detector for capturing the images resulting from passage of radiation through the limb.
• the two arms are moreover moved in a co-ordinated way by means of a motion sensor pointed on the limb, which enables alignment of the radiation source and the detector to be constantly maintained.
• the continuous detection of the images can then be used for acquiring a succession of tomographic images and reconstructing a 3D model of the limb in motion.
• US6435715 shows a radiographic device in which an x-ray source and an x-ray receiver are set on robotized arms for moving in space under the control of a control unit that maintains the relative alignment of the source and the receiver.
• a further drawback is represented by the amount of data received and their processing complexity.
• a further drawback is represented by the difficulty of taking into account the optical barriers that sometimes are present around the platforms or the treadmills used for enabling movement of the limbs of the animal or of the person to be examined.
• the purpose of the present invention is to overcome the drawbacks of the solutions already known and to propose an image-acquisition apparatus that is relatively simple and reliable to produce, and suitable for use even in the presence of marked accelerations of the limb to be examined, for example, in the case of a horse that is galloping.
• a further purpose is to propose an apparatus suitable for use in the presence of optical barriers set between the limb to be examined and the radiation source.
• a first advantage of the invention consists in the greater constructional simplicity as compared to known solutions.
• a second advantage consists in the possibility of carrying out radiological investigations of anatomical parts in motion even with accelerations of a high value, for example the limbs of a horse that is galloping.
• a third advantage consists in the reduction of the exposure of the subject to the x rays.
• a further advantage consists in the fact that the motion of the unit for movement of the radiological unit can be rendered independent of the movement of the subject being examined, whilst maintaining the diagnostic capacity required and simplifying the mechanical structure necessary as compared to known solutions.
• FIG. 1 shows a general view of a first embodiment of the invention applied to investigation of a limb of a horse
• FIG. 2 shows a general view of a second embodiment of the invention applied to investigation of a lower limb of a human being
• FIG. 4 shows a block diagram representing the method of the invention
• FIG. 5-7 show a detection device that can be used in an apparatus according to the invention
• FIG. 9 shows a preferred linear system for movement of the radiation source of the apparatus
• FIGS. 10 and 1 1 show, respectively, a front perspective view and a rear perspective view of an apparatus according to the invention provided with the movement system of Figure 9;
• FIG. 12 and 13 show perspective views of a general view of the apparatus of Figures 10 and 1 1 applied to investigation of the limb of a horse;
• FIG. 16 shows a flowchart with three different choices that the physician can decide to select when using the apparatus
• Figure 17 and 18 show, respectively, the apparatus of Figures 12 and 13 applied to a human patient.
• the apparatus comprises:
• radiological detector device 2 preferably comprising a number of digital detectors for acquiring the radiological images resulting from the radiation that has passed through the anatomical part irradiated;
• the tracing unit 3 is provided for continuous acquisition of data regarding the positions assumed by said anatomical part A in a first complete movement, or cycle of movements, important for the diagnostic examination to be carried out.
• the unit 7 On the basis of the acquisition made during the first movement, the unit 7 is used, automatically or under control of an operator, in such a way as to select one or more discrete positions Ps of the anatomical part detected by said tracing unit 3 during said first movement and significant for the purposes of the diagnostic examination.
• the unit 7 issues a command to the unit 4 for carrying out one or more displacements of the radiation source 1 into the positions Ps assumed by the anatomical part A, and at the same time sends a command to the source 1 for issuing one or more radiating emissions on the anatomical part A only at the moment when the tracing unit 3 informs the system that the part A is again in the positions Ps.
• the tracing unit 3 comprises inertial sensors 6 for detecting translation and rotation, for example triaxial accelerometers and gyroscopes, also combined with magnetic-field sensors, which enable reconstruction and representation of the kinematics of the anatomical part A during its movement.
• inertial sensors 6 for detecting translation and rotation for example triaxial accelerometers and gyroscopes, also combined with magnetic-field sensors, which enable reconstruction and representation of the kinematics of the anatomical part A during its movement.
• the sensors 6 are arranged so as to not get in the way of the radiation, for example, behind the detector 2.
• the inertial sensors 6 are sensors of the "human motion tracker" type MTx 3DOF produced by the company Xsens.
• the movement of the part A can be detected by using viewing systems 9 with high acquisition rate and luminous and/or reflecting markers 10.
• the viewing systems 9 can be fixed with respect to the source 1 or fixed on an independent support 13, whereas the markers 10 must be visible and are associated to the anatomical part A, for example fixed thereto or fixed with respect to the detector 2, or in the vicinity thereof, in such a way as to enable the unit 3 to trace the position of the anatomical portion of interest.
• the viewing system 9 can be a digital system "Optotrak Certus" produced by the company Northern Digital Inc.
• the unit 4 for movement of the source 1 comprises a robotized arm 14, and the radiation detector 2 is a detector that can be worn, which can be applied to said anatomical part, preferably via a band 9 transparent to the radiation emitted by the source 1.
• Figure 2 shows an embodiment of the apparatus in which the unit 4 for movement of the source 1 once again comprises a robotized arm 14, and the radiation detector is a detector 8 fixed with respect to the movement said source 1 , constituting therewith a "C"-shaped structure 16 capable of receiving the anatomical part A between the point of emission of the radiation and the detector 8.
• the sensors 6/10 may be fixed with respect to the source 1 that follows the displacements of the part A.
• the robotized arm 14 comprises a triaxial translation device, preferably with six degrees of freedom, possibly provided with zero- gravity function and/or a linear-guide pantograph in order to facilitate manual movement of the source 1 , in particular if it is of a heavy type, by the operator for initialization or offset of the system, maintaining accuracy and precision in the displacement.
• the apparatus can moreover comprise a mobile support for resting the subject thereon, preferably a treadmill 18 to enable the subject to carry out said cycles of movements.
• the robotized arm with six degrees of freedom can be set on a mobile carriage 19, which in effect increases the degrees of freedom along the three axes X, Y, Z and enables an easy adaptability of the system to treadmills already existing in clinics.
• the diagram of Figure 4 represents the operating scheme of an apparatus of the type described, where the tracing unit receives from the sensors 6/10 signals associated to the movement of the part A and then transmits to the movement unit 4, and via this to the computer 7, the data regarding the positions assumed by the part A during movement.
• the computer 7 After the computer 7 has been programmed on the basis of the positions selected and of the possible other conditions under examination, it in turn governs start of the mobile support 18, and then displacement of the arm 14 and activation of the source 1 to be able to acquire the radiological images of interest at the moment when the part A assumes the positions selected.
• the detector 2/8 has acquired the radiological images, these are finally transmitted to the processor 7, for example in a wired way or wireless way with an antenna 21, and possibly displayed on the screen 20.
• the method comprises a first step of initialization of the system with acquisition of data regarding the kinetics of said anatomical part A, which is performed during a first movement or cycle of movements for acquiring the kinematics of the movement of the patient and the paths followed by the anatomical portions of interest.
• the method envisages one or more displacements of the source 1 in said positions Ps and a step of irradiation of the anatomical part A only in said positions assumed during the movements or subsequent cycles of movements.
• the first step of acquisition is preferably preceded by an initialization, step in which the operator enters possible data on the subject S through a managing computer, associates the detector 2/8 to the anatomical portion of interest, and positions the subject on the mobile support 18.
• the operator sets the parameters of the support (speed and slope in the case of a treadmill) on the basis of the kinematic action of interest (walking, trotting, cantering, galloping, etc., in the case of a horse) and sets the subject with the limb of interest loaded.
• the operator moves the source 1 until he finds the correct distance and position from the subject, for example with the use of a distance-metre.
• the operator starts the mobile support and consequently the subject S walks causing movement of the anatomical part under examination and possibly of the detector if this fixed with respect thereto.
• the tracing system 3 carries out a first kinematic analysis of the movement and makes it available to the operator, for example by displaying it on a screen 20.
• the operator then analyses the sequence and evaluates the kinematic steps and the corresponding positions Ps in which he desires to acquire the x-ray images ( Figure 8), and then sets the image-acquisition sequence and parameters corresponding to said selected positions.
• the unit 4 starts to move the source 1 , for example an x-ray generator, in the discrete positions Ps of interest keeping the distance between the source and the detector constant. This is possible thanks to the information coming from the unit 4.
• the source 1 emits radiation according to the acquisition sequence set, and the detector 2/8 sends to a processor the radiological images acquired corresponding to the positions Ps for recording and subsequent processing.
• the operator views the radiological images acquired by the system, which are preferably presented on a monitor 20, and then makes measurements and diagnostic evaluations.
• the unit for movement of the radiation source 1 is a linear-guide system 40, comprising a first servo linear axis A1 with horizontal guide 41 and a second servo linear axis A2 with vertical guide 42.
• the combination of the two servo linear axes enables creation of a robotized system of movement of the x-ray source.
• the displacement of the source occurs preferably via linear and/or circular interpolation or via "point-by-point" displacements, possibly with the capacity to get the source 1 to perform small automated angular displacements about the axes A1 and/or A2.
• Figure 15 is a schematic illustration of the tests conducted for measuring the angle of acceptance of the sensor 2 as the angle of incidence of the radiation emitted by the source 1 varies. From these tests, it has emerged that the angle of acceptance can range between 80° and 100° (90° ⁇ 10°).
• the system 40 is housed within a shell 43 mounted on a support 46 and is height-adjustable by means of a lengthenable connection 47.
• the shell 43 and the support 46 can moreover be manoeuvred by means of handles 44 for displacing on wheels 45 that can be blocked.
• the shell 43 moreover houses a viewing system 9 with high acquisition rate, of the type described previously, which forms part of the unit 3 for tracing the movements of the anatomical part A being examined, in combination with luminous and/or reflecting markers 10 associated to the anatomical part A, for example fixed thereto or fixed with respect to a detector that can be worn 49, or in the vicinity thereof, in such a way as to enable the unit 3 to trace the position of the anatomical portion of interest.
• a viewing system 9 with high acquisition rate of the type described previously, which forms part of the unit 3 for tracing the movements of the anatomical part A being examined, in combination with luminous and/or reflecting markers 10 associated to the anatomical part A, for example fixed thereto or fixed with respect to a detector that can be worn 49, or in the vicinity thereof, in such a way as to enable the unit 3 to trace the position of the anatomical portion of interest.
• the senor 49 is a sensor sensitive to x rays of the "flat panel" technology type.
• this technology enables use of just three base elements, namely,
• the geometry of the coupling between the sensor and the radiogenic source may be variable, as likewise the characteristics of the radiogenic source, in order to be able to carry out at least two different types of test:
• the patient/animal is made to climb on the treadmill 18, and the speed and possibly the slope of the treadmill are set, the latter being started for example with a control terminal 48 managed by the operator.
• the operator acquires, via the tracing system 3, the path T followed by the joint A under examination.
• Step 3 The operator observes the path T and identifies points of interest, for example P1- P5, in which to acquire the radiographic image, on the basis, for example of a diagnostic hypothesis on the pathological condition that affects the part A.
• the operator starts the treadmill 18 again, and the system 4/40 for movement of the source 1 displaces the source 1 in the points of interest P1-P5 already set. During the successive cycles of movement of the part A, just in the points PIPS one or more radiological images IR1-IR5 are acquired.

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Citations (6)

• 2010
  • 2010-12-03 IT IT000238A patent/ITFI20100238A1/it unknown
• 2011
  • 2011-11-29 WO PCT/IB2011/002952 patent/WO2012073109A1/en active Application Filing

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