CT imaging device

Abstract

The present invention relates in particular to the structure of a dental and medical cone beam computed tomography (CBCT) imaging device. The basic configuration of the device includes a substantially vertically extending frame portion (11) that supports the X-ray imaging means (14, 15) of the device via a horizontally extending support structure (12). The device includes a patient support structure (18) that extends substantially parallel to and is essentially the same length as the substantially vertically extending frame portion (11).

Description

[Technical Field]

[0001] The present invention relates to computed tomography imaging devices. In particular, features of devices according to the present invention are applicable for use in the context of dental and medical cone-beam computed tomography (CBCT) imaging devices. [Background technology]

[0002] Computed tomography (CT) is a type of X-ray imaging in which the volume to be imaged is irradiated from different directions and the desired two- or three-dimensional image can be reconstructed from the image information thus obtained.

[0003] Conventional CT machines are large and heavy, and they are typically floor-mounted. The patient is typically positioned for imaging within the machine's examination opening on a horizontally extending, laterally movable examination platform.

[0004] For example, since the development of cone-beam computed tomography (CBCT) technology, which uses slower rotation speeds of the imaging means, devices that weigh less than conventional CT devices have been developed. Some CBCT devices are, for example, configured to be mobile rather than floor-mounted. Other designs include a vertically extending frame and a horizontally extending support for the imaging means. Such a support may, for example, comprise a ring-shaped gantry or a so-called C-arm, and such devices may be designed, for example, with a view to the need for cranial imaging. It is known that the rotation of the imaging means is arranged around a (virtual) vertical axis of rotation, and in this context, supports have been developed specifically designed to help keep the patient's head still while standing during exposure. Summary of the Invention

[0005] The object of the present invention and its preferred embodiments is a CT device, in particular a CBCT device, that is applicable for general use and allows imaging of various parts of the anatomy. The characteristic features of the present invention are defined in claim 1. [Brief explanation of the drawings]

[0006] The present invention will now be described in more detail with reference to preferred embodiments thereof and the accompanying drawings. [Figure 1] 1 is a schematic side view illustrating certain components of one exemplary embodiment of an apparatus according to the present invention. [Figure 2a] 2 shows structural details applicable for use in the context of the vertically extending frame of the device of FIG. 1; [Figure 2b] 2 shows structural details applicable for use in the context of the vertically extending frame of the device of FIG. 1; [Figure 3a] Some details of patient support configurations applicable for use in an apparatus such as that shown in FIG. 1 are given by way of example. [Figure 3b] 2 shows an example cross section of a patient support configuration applicable for use in an apparatus such as that shown in FIG. 1; [Figure 4] 1 is a schematic side view illustrating certain components of another exemplary embodiment of an apparatus according to the present invention. [Figure 5] FIG. 5 is a schematic side view of the apparatus of FIG. 4 showing certain components of the configuration driven into an inclined position. [Figure 6] 10 is a schematic side view illustrating certain components of yet another exemplary embodiment of an apparatus according to the present invention. [Figure 7] 1 is a block diagram illustrating examples of components that a control system of an apparatus according to the present invention may be configured to control. DETAILED DESCRIPTION OF THE INVENTION

[0007] Figure 1 shows a schematic side view of certain components of one example embodiment of an apparatus according to the invention. The dental or medical CT imaging apparatus of Figure 1 comprises a substantially vertically extending frame portion 11 having an upper end and a lower end. Extending essentially horizontally from this substantially vertically extending frame portion 11 is a support arrangement 12 that supports an X-ray source 14 and an image detector 15, which are not themselves visible in Figure 1. The X-ray source 14 and the image detector 15, which together form the X-ray imaging means 14, 15, may be mounted on the support arrangement 12 essentially opposite each other, but in embodiments may be arranged so that their mutual positions are adjustable.

[0008] 1 further illustrates patient support 18, a structure that is mechanically connected to and extends substantially parallel to substantially vertically extending frame portion 11. In the embodiment of FIG. 1, patient support 18 is essentially the same length as substantially vertically extending frame portion 11.

[0009] According to one embodiment, for example, the length of the substantially vertically extending frame portion 11 is approximately 240 cm.

[0010] According to one embodiment, for example, the length of the substantially vertically extending frame portion 11 is between 220 cm and 260 cm.

[0011] According to one embodiment, for example, the length of patient support 18 is 80-90% of the length of substantially vertically extending frame portion 11 .

[0012] According to one embodiment, for example, patient support 18 has a longer dimension in a first direction and a shorter dimension in a second direction that is orthogonal to the first direction.

[0013] According to one embodiment, for example, patient support 18 is radiolucent for at least a major portion thereof and in at least a first direction.

[0014] According to one embodiment, for example, the radiolucent portion of patient support 18 is essentially the same length as substantially vertically extending frame portion 11 .

[0015] According to one embodiment, for example, patient support 18 includes a section that is not radiolucent at at least one of its ends in a first direction.

[0016] According to one embodiment, for example, the length of the radiolucent portion of patient support 18 in the first direction is 80-90% of the length of the substantially vertically extending frame portion 11.

[0017] According to one embodiment, for example, the support arrangement 12 supporting the X-ray imaging means 14, 15 is a circular gantry having a central axis 13. The gantry may partially surround or completely house the X-ray imaging means 14, 15.

[0018] According to one embodiment not directly visible in Fig. 1, for example, the device comprises a drive mechanism 16 arranged to drive the X-ray imaging means 14, 15 about an axis of rotation, which may coincide with the central axis 13 of the support arrangement 12 in the form of a gantry, which may be a physical axis, as in the case of Fig. 1, or a virtual axis of rotation.

[0019] According to one embodiment, for example, the central axis 13 of the gantry coincides with the center / axis of rotation of the X-ray imaging means 14, 15 as they are driven along a curved path.

[0020] According to one embodiment, the axis of rotation is an instantaneous (virtual) axis of rotation, and the location of the instantaneous axis of rotation relative to the central axis 13 can be arranged to be changed.

[0021] According to one embodiment, the source 14 and / or image detector 15 components are arranged so that they are laterally movable from a location exactly opposite the other component.

[0022] According to one embodiment, the structure 12 supporting the X-ray imaging means 14, 15 comprises a gantry having a central axis, and the structure of the apparatus allows for the X-ray source 14 to be moved laterally between a position where the central ray it generates coincides with the central axis of the gantry and a position where the central ray it generates does not coincide with the central axis of the gantry, and for the image detector 15 to be moved laterally between a position where a vector normal to the detector surface at the center of the image detector 15 coincides with the central axis of the gantry and a position where a vector normal to the detector surface at the center of the image detector 15 does not coincide with the central axis of the gantry. Lateral movement of the X-ray imaging means 14, 15 may include moving the X-ray imaging means 14, 15 to a position where they face each other, while the central ray generated by the X-ray source 14 does not coincide with the central axis of the gantry and while the vector normal to the detector surface at the center of the image detector 15 does not coincide with the central axis of the gantry.

[0023] According to another embodiment, another drive mechanism 17 is arranged on the apparatus to enable the support structure 12 to move back and forth in a direction substantially parallel to the extension of the substantially vertically extending frame portion 11. According to one embodiment, the drive mechanism 17 may be configured to move the support structure 12 along or alongside the substantially vertically extending frame portion 11.

[0024] In the example according to Fig. 2a, the drive mechanism 17 of the support structure 12 discussed above comprises a motor 110 and a gear 111 arranged to rotate a pulley 112. In the configuration shown as one embodiment in Fig. 2a, the motor 110 and the pulley 112 are located near the lower end of the substantially vertically extending frame part 11, while another pulley 112' is located near the upper end of the substantially vertically extending frame part 11, around which a corresponding functional component such as a belt 113 or a chain runs. This mechanism is then operatively connected to the support structure 12 to drive it along the substantially vertically extending frame part 11, such that a groove 114 is arranged in the substantially vertically extending frame part 11 and a protrusion 121 is arranged on the support structure 12 so as to slide along the groove 114, as shown by way of example in Fig. 2b. In one embodiment, to minimize friction, roller-type linear guideways are used, where the motion is rolling rather than sliding.

[0025] According to one embodiment not shown in any of the figures, for example, the drive mechanism for driving the support structure 12 comprises a motor located on the support structure 12 itself.

[0026] Regardless of the details of the configuration of the drive mechanism 17 for driving the support structure 12, in one preferred embodiment the configuration of the apparatus allows the support structure 12 to be driven over essentially the entire length between the upper and lower ends of the substantially vertically extending frame portion 11.

[0027] According to yet another embodiment, as shown in FIG. 1, the apparatus includes connection arrangements 19, 20 connecting the patient support 18 to the substantially vertically extending frame portion 11.

[0028] According to another embodiment, an example of which is shown in FIG. 3 a, the apparatus comprises connection arrangements 19 , 20 that mechanically connect a patient support 18 to a substantially vertically extending frame portion 11 .

[0029] The connection arrangements 19, 20 may include patient support adjustment mechanisms 19', 20' configured to allow the patient support 18 to be displaced closer and farther from the substantially vertically extending frame portion 11.

[0030] According to another embodiment, the drive mechanisms 19", 20" are disposed in operative connection with the patient support adjustment mechanisms 19', 20'.

[0031] According to another aspect, patient support adjustment mechanisms 19', 20' may include a first adjustment mechanism 19' disposed substantially at an upper end of substantially vertically extending frame portion 11 together with drive mechanism 19" included in drive mechanism 19", 20", and a second adjustment mechanism 20' disposed substantially at a lower end of substantially vertically extending frame portion 11 together with drive mechanism 20" included in drive mechanism 19", 20".

[0032] According to one embodiment, for example, the patient support adjustment mechanisms 19', 20' are disposed in functional association with a control system of the apparatus, the control system being configured to control the drive mechanisms 19", 20" of the adjustment mechanisms 19', 20'.

[0033] According to one aspect, for example, the control system is configured to control the first connection arrangement 19, 20, which includes a first adjustment mechanism 19' disposed substantially at the upper end of the substantially vertically extending frame portion 11 together with a drive mechanism 19" and a second adjustment mechanism 20' disposed substantially at the lower end of the substantially vertically extending frame portion 11 together with a drive mechanism 20", to maintain the same distance between the substantially vertically extending frame portion 11 and the patient support 18 at the upper and lower ends of the first substantially vertically extending frame portion 11 when adjusting the distance between the two.

[0034] According to another embodiment, the distance between the end of the substantially vertically extending frame portion 11 and the patient support 18 can be adjusted differently. According to one embodiment, the first and second adjustment mechanisms 19', 20' are arranged to be independently controlled.

[0035] According to one embodiment, as shown in FIG. 3b, considering the first orientation of the patient support configuration 18 discussed above, its cross section for its major portion is curved to better support the patient against the concave surface of the patient support configuration 18.

[0036] According to another embodiment, as shown in FIG. 3b, at the cross-sectional edges 181 of the patient support arrangement 18, the cross-sectional shape curves in opposite directions.

[0037] According to another embodiment, as further shown in Figure 3b, a retaining structure 182 is positioned near the edge 181 of the above-discussed cross section of the patient support configuration 18, opposite the concave surface of its main portion. The retaining structure 182 may be, for example, an elongated handle or attachment structure used to receive a strap designed to extend on or over the concave surface of the patient support configuration 18 to provide additional support to the patient and help maintain stillness during imaging exposures.

[0038] According to one embodiment, the apparatus, in addition to what may be referred to as the first substantially vertically extending frame portion 11 discussed above, further comprises a second substantially vertically extending frame portion 21 mechanically connected to the first substantially vertically extending frame portion 11 of essentially the same length as the first substantially vertically extending frame portion 11. Figure 4 shows an example of such a configuration as a schematic side view.

[0039] According to one aspect, and referring to FIG. 4 , an articulating connection arrangement 22 is disposed near the upper ends of the first substantially vertically extending frame portion 11, 12, which mechanically connects the first substantially vertically extending frame portion 11 and the second substantially vertically extending frame portion 21 and enables tilting of the first substantially vertically extending frame portion 11 relative to the second substantially vertically extending frame portion 21 about a horizontal tilt axis.

[0040] According to another embodiment, a mounting structure 23, not directly visible in Figure 4, is arranged on a side of the second substantially vertically extending frame portion 21 in connection with the articulating connection arrangement 22. The mounting structure 23 may be arranged movably along or alongside the second substantially vertically extending frame portion 21.

[0041] According to another aspect, a locking mechanism 24 configured to enable connection and separation of the first substantially vertically extending frame portion 11 and the second substantially vertically extending frame portion 21 is disposed, for example, near the lower end of the second substantially vertically extending frame portion 21.

[0042] When the second substantially vertically extending frame portion 21 is stably attached and the locking mechanism 24 does not connect the first substantially vertically extending frame portion 11 and the second substantially vertically extending frame portion 21, the lower end of the first substantially vertically extending frame portion 11 is free to move horizontally, and the articulated connection 22 between the frame portions 11, 21 allows the first substantially vertically extending frame portion 11 to rotate about a horizontal tilt axis near the upper end of the first substantially vertically extending frame portion 11, while the movably arranged mounting structure 23 allows the upper end of the first substantially vertically extending frame portion 11 to be lowered and raised.

[0043] Figure 5 shows the apparatus according to Figure 4 at a stage where the upper end of the first substantially vertically extending frame portion 11 has moved downward and the lower end of the first substantially vertically extending frame portion 11 has moved horizontally on the surface. The apparatus may be configured to allow the upper end of the first substantially vertically extending frame portion 11 to be lowered all the way to the vicinity of the lower end of the second substantially vertically extending frame portion 21.

[0044] According to yet another aspect, not directly visible in Figures 4 and 5, a drive mechanism 27 is disposed along or alongside the second substantially vertically extending frame portion 21 in operative connection with the second substantially vertically extending frame portion 21 for driving the mounting structure 23. When in mechanical connection with the first substantially vertically extending frame portion 11, adjacent its upper end, the drive mechanism 27 can move the upper end of the first substantially vertically extending frame portion 11.

[0045] The drive mechanism 27 for driving the mounting structure 23 may be configured similarly to the drive mechanism 17 for driving the support arrangement 12 for the imaging means 14,15.

[0046] According to one embodiment, the drive mechanism 27 that drives the mounting structure 23 comprises a chain drive.

[0047] According to yet another aspect, locking mechanism 24 includes a displacement mechanism 25, not directly visible in FIGS. 4 and 5, that moves the lower end of first substantially vertically extending frame portion 11 a fixed distance away from second substantially vertically extending frame portion 21 when locking mechanism 24 separates first substantially vertically extending frame portion 11 and second substantially vertically extending frame portion 21.

[0048] According to one embodiment not shown in detail in the figures, for example, the locking mechanism 24 comprises a motorized arrangement having mating components on the sides of the powered structure and on the first substantially vertically extending frame portion 11, respectively.

[0049] The locking mechanism 24 may further include a guide arrangement configured to guide the lower end of the first substantially vertically extending frame portion 11 straight on the locking mechanism 24 when the lower end of the first substantially vertically extending frame portion 11 is moving towards the locking mechanism 24.

[0050] According to yet another embodiment, and as shown by way of example in FIGS. 4 and 5, the first substantially vertically extending frame portion 11 includes at least one wheel or roller 26 near its lower end.

[0051] According to an alternative embodiment, instead of wheels or rollers, a structure designed to slide on a surface may be arranged at the lower end of the first substantially vertically extending frame portion 11 .

[0052] According to one embodiment, for example as shown in Figure 6, the support arrangement 12 for the imaging means 15, 16 in the form of a gantry does not essentially completely surround the imaging means 14, 15, but serves mainly or solely as a support structure for holding the imaging means 14, 15 and as a structure arranged on the gantry for driving the imaging means 14, 15 about an axis. This kind of solution makes it possible to realize a gantry that reduces weight and provides better access to the volume between the imaging means 14, 15, and also physically allows to take into account areas that may have a clear line of sight into that volume.

[0053] FIG. 7 illustrates, as a block diagram, example components of a control system applicable for use in a device according to the present disclosure. In various embodiments, not all of these features are necessarily present in the control system of the device. The control system depicted in FIG. 7 is primarily configured to enable control of the operation of the X-ray source and the image detector. Components controlling the operation of the X-ray source and the image detector may include components physically located at the X-ray source and the image detector and / or elsewhere in the device. The control system of FIG. 7 also controls various drive mechanisms of the device, such as those that move the support structure, the support structure itself, and the imaging means supported by the adjustment mechanism of the patient support. In the case of embodiments including both first and second substantially vertically extending frame portions, the control system may also control the drive mechanisms of the mounting structures, for example, as discussed above. Additionally, in the case of a device including an electrically actuated locking mechanism for connecting and separating the first and second substantially vertically extending frame portions, the control system may also control the drive mechanisms of the locking mechanism. Overall, the control system may be arranged to control all or any portion of the operations discussed above.

Claims

1. A dental or medical CT imaging device, a first vertically extending frame portion 11 with an upper end and a lower end; a support arrangement 12 extending horizontally from said first vertically extending frame portion 11; an X-ray source 14 and an image detector 15 mounted on said support structure 12 and collectively forming X-ray imaging means 14, 15; a first drive mechanism 16 arranged to drive said X-ray imaging means 14, 15 about an axis of rotation 13; a second drive mechanism 17 arranged to move said support arrangement 12 in a direction parallel to the extension of said first vertically extending frame portion 11; - a patient support 18; a first connection arrangement (19, 20) that mechanically connects the patient support (18) to the first vertically extending frame portion (11); a control system, the first connection arrangement (19, 20) comprising a patient support adjustment mechanism (19′, 20′) configured to enable the patient support (18) to be displaced toward and away from the first vertically extending frame portion (11); The device is characterized in that the patient support (18) is mechanically connected to the first vertically extending frame portion (11) and has a structure extending parallel to the first vertically extending frame portion (11), and the length of the patient support (18) is at least 80% of the length of the first vertically extending frame portion (11).

2. 2. The device according to claim 1, wherein the length of said first vertically extending frame portion is between 220 cm and 260 cm.

3. 3. Apparatus according to claim 1 or 2, characterized in that the length of the patient support (18) is 80-90% of the length of the first vertically extending frame portion (11).

4. 4. The apparatus of claim 1, wherein the patient support has a longer dimension in a first direction and a shorter dimension in a second direction orthogonal to the first direction.

5. 5. The apparatus of claim 4, wherein the patient support is radiolucent at least in part in the first direction.

6. 6. The apparatus of claim 5, wherein the portion of the patient support that is radiolucent is at least 80% or more of the length of the first vertically extending frame portion.

7. 7. Apparatus according to claim 5 or 6, characterized in that the patient support (18) comprises a non-radiopaque section at at least one of its ends in the first direction.

8. 8. The apparatus of claim 7, wherein the length of the radiolucent portion of the patient support in the first direction is 80-90% of the length of the first vertically extending frame portion.

9. the apparatus comprising a third drive mechanism (19", 20") disposed in operative connection with the patient support adjustment mechanism (19', 20'); the patient support adjustment mechanism (19', 20') comprises a first adjustment mechanism (19') disposed at the upper end of the first vertically extending frame portion (11) together with a drive mechanism (19") included in the third drive mechanism (19", 20"), and a second adjustment mechanism (20') disposed at the lower end of the first vertically extending frame portion (11) together with a drive mechanism (20") included in the third drive mechanism (19", 20"); 2. The apparatus of claim 1, wherein the control system is configured to control the third drive mechanism (19"), (20") arranged in operative connection with the patient support adjustment mechanism (19', 20').

10. 10. The device of claim 9, wherein the control system is configured to control the first connection arrangement (19, 20), comprising the first adjustment mechanism (19′) having a drive mechanism (19″) disposed at the upper end of the first vertically extending frame portion (11) and the second adjustment mechanism (20′) having a drive mechanism (20″) disposed at the lower end of the first vertically extending frame portion (11), to maintain the same distance between the first vertically extending frame portion (11) and the patient support (18) at the upper end and the lower end of the first vertically extending frame portion (11) when adjusting the distance between the first vertically extending frame portion (11) and the patient support (18).

11. Apparatus according to any one of the preceding claims, characterized in that the second drive mechanism (17) is arranged to move the support arrangement (12) along the first vertically extending frame portion (11).

12. Apparatus according to any one of the preceding claims, wherein the apparatus comprises a second vertically extending frame portion (21) mechanically connected to the first vertically extending frame portion (11).

13. 13. The device according to claim 12, characterized in that an articulating connection arrangement 22 is arranged near the upper end of the first vertically extending frame portion 11, which mechanically connects the first vertically extending frame portion 11 and the second vertically extending frame portion 21 and enables the first vertically extending frame portion 11 to be tilted about a horizontal tilt axis relative to the second vertically extending frame portion 21.

14. a mounting structure 23 disposed on a side of the second vertically extending frame portion 21, connected to the articulation arrangement 22; 14. The apparatus of claim 13, wherein the mounting structure (23) is movably disposed along the second vertically extending frame portion (21).

15. 15. The apparatus of claim 14, further comprising a fourth drive mechanism (27) operatively connected to the second vertically extending frame portion (21) and configured to drive the mounting structure (23) along the second vertically extending frame portion (21).

16. 16. The device according to any one of claims 12 to 15, characterized in that a locking mechanism 24 is arranged at the lower end of the second vertically extending frame portion 21, the locking mechanism being configured to enable connection and separation of the first vertically extending frame portion 11 and the second vertically extending frame portion 21.

17. the locking mechanism 24 comprises a displacement mechanism 25 configured to push the lower end of the first vertically extending frame portion 11 a fixed distance away from the second vertically extending frame portion 21 when the locking mechanism separates the first vertically extending frame portion 11 and the second vertically extending frame portion 21; and / or 17. Apparatus according to claim 16, characterized in that the first vertically extending frame portion 11 is provided at its lower end with at least one wheel or roller 26 or structure designed to slide on a surface.

Images