A Device for Determining a Position of a Metal Object in or at a Patient Body

Abstract

The invention is directed to a device (100) for determining a position of a metal object (200) in or at a patient body (300), the device (100) comprising: a sensor unit (102) configured to be moved along a pre-determined trajectory (104), wherein the sensor unit (102) is configured for generating a magnetic field (106) during a movement of the sensor unit (102) along the trajectory (104), wherein the sensor unit (102) is configured for receiving a response signal induced by the generated magnetic field (106), wherein the sensor unit (102) is configured for detecting a change of the response signal induced by the generated magnetic field (106) during said movement due to a change (110) of a distance between the sensor unit (102) and the metal object (200) in or at the patient body (300), and wherein in the sensor unit (102) is configured for determining the position of the metal object (200) based on the detected change (110) of the response signal during said movement.

Claims

1. A device for determining a position of a metal object in or at a patient body, the device comprising: a sensor unit configured to be moved along a pre-determined trajectory, wherein the sensor unit is configured for generating a magnetic field during a movement of the sensor unit along the trajectory, receiving a response signal induced by the generated magnetic field, detecting a change of the response signal induced by the generated magnetic field during said movement due to a change of a distance between the sensor unit and the metal object in or at the patient body and determining the position of the metal object based on the detected change of the response signal during said movement and a camera, wherein the camera is configured for generating an image of the patient body, identifying a contour of the patient body based on the generated image, and wherein the device is configured for adapting the trajectory based on the identified contour of the patient body.

2. The device according to claim 1, wherein the change of the response signal is dependent from the trajectory.

3. (canceled)

4. The device according to claim 1, wherein the device comprises an optical indicator, e.g. a laser beam, and wherein the optical indicator is configured for illuminating the position of the metal object based on the determined position of the metal object.

5. The device according to claim 1, wherein the sensor unit is located inside of a wall element, a chair and/or an examination table.

6. The device according to claim 1, wherein the sensor unit comprises a first sub-sensor unit which moves along the trajectory, wherein the sensor unit comprises a second sub-sensor unit and a third sub-sensor unit, which both are located at a fixed position, and wherein the device is configured for determining the position of the metal object based on the detected change of the distance during a movement of the first sub-sensor unit along the pre-determined trajectory and the fixed positions of the second sub-sensor unit and the third sub-sensor unit.

7. The device according to claim 1, wherein the sensor unit comprises a plurality of sub-sensor units, wherein each sub-sensor unit of the plurality of sub-sensor units is movable arranged inside a wall, wherein the device is configured for calculating a shift for each of the sub-sensor units for relocating each of the sub-sensor units of the plurality of sub-sensor units based on a pattern, and wherein the device is configured for moving each sub-sensor unit of the plurality of sub-sensor units based on the calculated shift.

8. The device according to claim 7, wherein the device is configured for adapting the pattern based on a received probability value, describing where to find metal objects in or at the patient body.

9. The device according to claim 8, wherein the device is configured for changing a sensitivity of each of the sub-sensor units of the plurality of sub-sensor units based on the pattern and the probability.

10. The device according to claim 3, wherein the device is configured for adapting the pattern based on the identified contour of the patient body.

11. The device according to claim 6, wherein each sub-sensor unit comprises a generating element and a detecting element wherein each of the generating elements is configured for generating a continuously alternating magnetic field at a pre-determined frequency, wherein each of the generating elements is paired with one detecting element, wherein each of the generating elements operates at a different pre-determined frequency, and wherein each of the detecting elements is configured for filtering out frequencies that do not include the frequency of the paired generating element.

12. The device according to claim 6, wherein each of the sub-sensor units each comprises a generating element and a detecting element, wherein each of the generating elements is configured for generating electro-magnetic pulses in a predefined sequence, wherein each predefined sequence is configured such that no pulse overlaps in time with another pulse from another generating element, wherein each predefined sequence comprises for each pulse a buffer, and wherein each buffer is configured for allowing a measurement of a response of the metal object to the generated pulse, wherein each of the detecting elements is configured for measuring the response of the metal object to the generated pulse.

13. A method for determining a position of a metal object in or at a patient body, the method comprising the steps of: generating a magnetic field during a movement of a sensor unit along a trajectory, receiving a response signal induced by the generated magnetic field, detecting a change of the response signal induced by the generated magnetic field during said movement due to a change of a distance between the sensor unit and the metal object in or at the patient body, and determining the position of the metal object based on the detected change of the response signal during said movement generating an image of the patent body, identifying a contour of the patient body based on the generated image, and adapting the trajectory based on the identified contour of the patient body.

14. A method for autonomous imaging, the method comprising the steps: detecting a metal object with a device according to claim 1, acquiring at least one image with a medical imaging apparatus.

15. A computer program stored on a non-transitory computer readable medium, such that when executed instructs a processor unit to perform the step of the method according to claim 13.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0067] FIG. 1 shows a device according to an embodiment of the present invention.

[0068] FIG. 2 shows a device according to an embodiment of the invention.

[0069] FIG. 3 shows a device according to an embodiment of the invention.

[0070] FIG. 4 shows a device according to an embodiment of the invention.

[0071] FIG. 5 shows a device according to an embodiment of the invention.

[0072] FIG. 6 shows a flowchart illustrating the steps of a method according to an embodiment of the invention.

[0073] FIG. 7 shows a flowchart illustrating the steps of a method according to an embodiment of the invention.

[0074] FIG. 8 shows a flowchart illustrating the steps of a method according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0075] FIG. 1 shows a device 100 for determining a position of a metal object 200 in or at a patient body 300. The device 100 comprises a sensor unit 102 configured to be moved along a predetermined trajectory 104. Furthermore, the sensor unit 102 is configured for generating a magnetic field 106 during a movement of the sensor unit 102 along a trajectory 104. In addition, the sensor unit 102 is configured for receiving a response signal induced by the generated magnetic field 106. Furthermore, the sensor unit is configured for detecting a change of the response signal induced by the generated magnetic field 106 during said movement due to a change 110 of a distance between the sensor unit 102 and a metal object 200 in the or at the patient body. Moreover, the sensor unit 102 is configured for determining the position of the metal object 200 based on the detected change 110 of the response signal during said movement.

[0076] The advantage of this aspect may be that with the help of the sensor unit 102 and the device 100, a presence and a position of a metal object 200 can be detected. This is beneficial for MRI and X-ray examinations where the presence of a metal object 200 is critical, since the metal object 200 may be pulled towards the magnetic field 106 or generates artefacts in the resulting medical image. In addition, the labor can be reduced for preparing a patient for a medical imaging procedure, since the device 100 may enable the patient to remove the metal object 200 by himself, since the device 100 may indicate the position of the metal object 200.

[0077] The device 100 comprises a sensor unit 102. The sensor unit is in this example located at the first position 102′ and at a second position 102″. The sensor unit 102 moves along the predetermined trajectory 104. The sensor unit 102 generates at the first position 102′ a magnetic field 106. Furthermore, the sensor unit 102 generates at the second position 102″ a second magnetic field 107. The first magnetic field and the second magnetic field 107 both extend up to the metal object 200. A first distance 110 is located between the sensor unit 102 and the first position 102′ and the metal object 200. In addition, there is a second distance 112 between the sensor unit 102 at the second position 102″ and the metal object 200. The difference between the first distance 110 and the second distance 112 can be indicated as the change 108 of the distance between the first position 102′ and the second position 102″ of the sensor unit 102. Based on the detected change 108, the location of the metal object 200 located in or at a patient body 300 can be calculated.

[0078] FIG. 2 shows a device 100 which comprises a camera 114. The camera 114 is configured for generating an image of the patient body 300. Furthermore, the camera 114 is configured for identifying a contour 302 of the patient body 300. Moreover, the device 100 is configured for adapting the trajectory 104 based on the identified contour 302 of the patient body 300. Furthermore, the device 100 is configured for adapting the trajectory 104 based on the generated image of the camera 114. Moreover, the device 100 comprises an optical indicator 116, e.g. a laser beam. The optical indicator 116 can be, for example, a device for generating an optical indicator so that a laser beam points towards the metal object 200. Therefore, the optical indicator 116 is configured for illuminating the position of the metal object 200 based on the determined position of the metal object 200.

[0079] FIG. 3 shows a device 100 which is embodied as a wall element 400. Inside the wall element 400, the sensor unit 102 is located. The sensor unit comprises a first sub-sensor unit 120 which moves along the trajectory 104. In addition, the sensor unit 102 comprises a second sub-sensor unit 122 and a third sub-sensor unit 124. The second sub-sensor unit 122 and the third sub-sensor unit 124 are both located at a fixed position. For example, the second sub-sensor unit 122 and the third sub-sensor unit 124 can detect whether a metal object 200 is present or not. In case a metal object 200 is present, the first sub-sensor unit starts moving and the location of the metal object 200 is determined.

[0080] FIG. 4 shows a device 100 which is embodied as a wall 402. The device comprises a sensor unit 102 which comprises a plurality of sub-sensor units 130. An exemplary sub-sensor unit 132 of the plurality of sub-sensor units 130 comprises a generating element 136 and a detecting element 138, wherein the generating element 136 is configured for generating a continuously alternating magnetic field at a predefined frequency. Furthermore, the detecting element 138 is configured for detecting a continuously alternating magnetic field.

[0081] FIG. 5 shows a device 100 which is embodied as a wall 402. The device 100 comprises a plurality of sub-sensor units 130. An exemplary sub-sensor unit 132 of the plurality of sub-sensor units 130 each comprises a generating element 136′ and a detecting element 138′, wherein each of the generating elements 136′ is configured for generating electromagnetic pulses in a predefined sequence. Said detecting elements 138′ are configured for measuring the response of the metal object to the generated pulse.

[0082] FIG. 6 shows a flowchart of the method 700 which illustrates the steps of generating S1 a magnetic field 106 during a movement of a sensor unit 102 along a trajectory 104. Furthermore, the method 700 comprises the step of receiving S2 a response signal induced by the generated magnetic field 106. In addition, the method 700 comprises the step of detecting S3 a change 108 of the response signal induced by the generated magnetic field during said movement due to a change 108 of a distance between the sensor unit 102 and the metal object 200 in or at the patient body 300. Moreover, the method comprises the step of determining S4 the position of the metal object 200 based on the detected change 108 of the response signal during said movement.

[0083] FIG. 7 shows a further method 710 which comprises the steps of generating S1 a magnetic field, receiving S2 a response signal, detecting S3 a change of the response signal, and determining a position of the metal object 200. The further method 710 further comprises the steps of removing S5 the metal object 200 based on the determined position and/or repeating S6 the steps of the method as described before and hereinafter in order to assure that no metal object 200 is located in or at the patient body.

[0084] FIG. 8 shows a method 800 for autonomous imaging. The method 800 comprises the step of detecting S10 a metal object 200 with the device 100 as described before and hereinafter. In addition the method 800 comprises the step of acquiring S11 at least one image with a medical imaging apparatus.

[0085] The reference symbols used in the Figures are listed in a summary form in the list of reference symbols. In principle, identical parts are provided with the same reference symbol in the Figures.

[0086] Where a definite or indefinite article is used when referring to a singular noun, e.g. “a”, “an” or “the”, this includes a plurality of that noun unless something else is specifically stated. It is to be understood that the term used are interchangeable and under appropriate circumstances, the embodiments of the invention described herein are capable of operating in other sequences than described or illustrated herein.

LIST OF REFERENCE SIGNS:

[0087] 100 device [0088] 102 sensor unit [0089] 102′ sensor unit at a first position [0090] 102″ sensor unit at a second position [0091] 104 predetermined trajectory [0092] 106 magnetic field at the first position [0093] 107 magnetic field at the second position [0094] 108 change [0095] 110 first distance [0096] 112 second distance [0097] 114 camera [0098] 116 optical indicator [0099] 120 first sub-sensor unit [0100] 122 second sub-sensor unit [0101] 124 third sub-sensor unit [0102] 130 sub-sensor unit [0103] 134 pattern [0104] 136 generating elements [0105] 136′ generating elements [0106] 138 detecting elements [0107] 138′ detecting elements [0108] 200 metal object [0109] 300 patient body [0110] 302 contour [0111] 400 wall element [0112] 402 wall [0113] 700 method [0114] 710 further method [0115] 800 method for autonomous imaging [0116] S1 generating a magnetic field [0117] S2 receiving a response signal [0118] S3 detecting a change of the response signal [0119] S4 determining the position of the metal object [0120] S5 removing the metal object [0121] S5 repeating the method [0122] S10 detecting a metal object [0123] S11 acquiring at least one image