DEVICE FOR THE EXAMINATION OF LIMB JOINTS

Abstract

A device for examining limb joints comprises a support frame to which are attached mechanisms with holders for positioning patient's limbs in the region encompassing patient's hips, thighs and feet, said mechanisms being made of materials that do not interact with magnetic fields. A hip belt (B) is secured to special ports on both sides of the support frame (A) of the device, then a thigh support platform (C) is secured to the support frame on a swingable hinge, and a shank support assembly (D) is secured in the middle part, where on a common adjustment screw guided by a slider and locked in position on the support frame by means of a position nut is located a fixed casing combined with a nut and with two force measurement assemblies. A feet support assembly (E) is secured to the opposite side of the frame. The second variant of the device consists of only the following groups: the support frame (A), the thigh support platform (C) and the shank support assembly (D).

Claims

1. A device for examining limb joints, said device including a support frame to which are attached mechanisms with holders for positioning patient's limbs in the region encompassing patient's hips, thighs and feet, said mechanisms being made of materials that do not interact with magnetic fields, characterized in that a first variant of the device consists of: hip belt (B) which is secured to special ports on both sides of the support frame (A) of the device, then a thigh support platform (C) is secured to the support frame on a swingable hinge, and a shank support assembly (D) is secured in the middle part, where on a common adjustment screw (13) guided by a slider and locked in position on the support frame (1) by means of a position nut (12) is located a fixed casing combined with a nut and with two force measuring assemblies (18), while a feet support assembly (E) is secured to the opposite side of the frame, as well as second variant of the device consists of: the support frame (A) of the device, then a thigh support platform (C) is secured to the support frame on a swingable hinge, and a shank supped assembly (D) is secured in the middle part, where on a common adjustment screw (13) guided by a slider and locked in position on the support frame (1) by means of a position nut (12) is located a fixed casing combined with a nut and with two force measuring assemblies (18).

2. The device according to claim 1 characterized in that the hip belt (B) has two side straps (2) provided with carabiners (3) attached to ports on both sides of the support frame (A), or that the hip belt is not present in the second variant of the device, which comprises groups of devices and mechanisms set up as follows: Asupport frame (in reduced size), Cthigh support platform, Dshank support assembly.

3. The device according to claim 1 characterized in that supports for adjustable pads (15) are secured to the shank support assemblies (D), and adjustable support pads (14) are mounted slidably in the vertical direction on the supports for adjustable pads, the adjustable support pads being adjustable by means of a load adjustment knob (16).

4. The device according to claim 1 characterized in that the fixed casing combined with a nut and with two force measurement assemblies (18) is adjusted in the vertical plane by means of knob (17).

5. The device according to claim 1 characterized in that the thigh support frame (C) is secured rotatably to two lower hinges (4) attached to the support frame (A), while the selected angular position is set by means of angular position locks (5) located near each of the lower hinges (4).

6. The device according to claim 5 characterized in that a thigh pad platform (6) is set on guides combined with the rotating part of the lower hinge (4) and the position of the thigh pad platform (6) is set by means of thigh position locks (7) located on both sides of the platform.

7. The device according to claim 5 characterized in that on the thigh pad platform (6) there are two thigh pads (8) which can be moved towards the sides of the device, and they are locked in position by means of thigh pad locks (10) of each pad.

8. The device according to claim 7 characterized in that each thigh pad (8) has its thigh strap with a protective pad (9).

9. The device according to claim 1 characterized in that the feet support assembly (E) has two blocks (20) for fastening a longitudinal position guide (19) secured to the support frame (A), the said longitudinal position guide having installed on it a feet spacing guide (21) with a spacing adjustment screw (22), a middle connector with an angular position lock (23), a foot holder (24)symmetrically for both limbs, and a feet spacing adjustment crank (26), which can be locked in an initial position in the longitudinal direction by means of an initial position latch (27), or that the feet support assembly is not present in the second variant of the device, which comprises groups of devices and mechanisms set up as follows: Asupport frame (in reduced size), Cthigh support platform, Dshank support assembly.

10. The device according to claim 9 characterized in that the precise position of the feet spacing guide (21) is set by means of a feet load adjustment screw (30) with an adjustment crank (31).

11. The device according to claim 9 characterized in that each foot holder (24) is mounted rotatably in relation to its rotation axis, and its angular position is set by a foot torsion angle position latch (28), whereas the rotation of the foot holder (24) on the feet spacing guides (21) is set by means of the middle connector with an angular position lock (23), and whereas the relative spacing of foot holders (24) is set by the spacing adjustment screw (22).

12. The device according to claim 4 characterized in that it enables measurement of the applied force by means of indicators on the casing (18) or by means of an indicator of the total load applied to the limbs (32).

Description

[0051] The subject of the invention is illustrated by an embodiment shown in drawings, of which FIG. 1 depicts an axonometric view of the device and illustrates a breakdown into functional groups, FIG. 2 depicts the support frame, FIG. 3 depicts the hip belt, FIG. 4 depicts the thigh support platform, FIG. 5 is a rear view of the thigh support platform, FIG. 6 depicts the shank support assembly where the acting force is oriented upwards, FIG. 7 depicts the shank support assembly where the acting force is oriented downwards, FIG. 8 depicts the feet support assembly with the positioning mechanism, FIG. 9 is a rear view of the feet support assembly with the positioning mechanism, FIG. 10 is a side view of the feet support assembly with the positioning mechanism.

[0052] A second variant of the invention is illustrated by an embodiment, where FIG. 11 depicts an axonometric view of the device and illustrates a breakdown into functional groups, FIG. 12 depicts the support frame of reduced size, FIG. 13 depicts the thigh support platform, FIG. 14 is a rear view of the thigh support platform, FIG. 15 depicts the shank support assembly where the acting force is oriented upwards, FIG. 16 depicts the shank support assembly where the acting force is oriented downwards.

[0053] The device comprises groups of devices and mechanisms set up as follows:

[0054] Asupport frame,

[0055] Bhip belt with support frame fastener,

[0056] Cthigh support platform,

[0057] Dshank support assembly,

[0058] Efeet support assembly with positioning mechanism.

[0059] In its second variant the device may consist of only the following groups: A, C and D, without hip belt with support frame fastener (B) and feet support assembly with positioning mechanism (E) (FIG. 11).

[0060] Every group performs specific functions, and the functionality of the entire device is the effect of the operation of its individual components.

[0061] The structure, components and functions of each group are described below.

[0062] Support frame Abasic component of the device. It is placed directly on the bed of the examination apparatus. Special shape elements on the underside of the frame serve for transverse positioning of the frame in the grooves of the bench of the examination apparatus. The support frame is movable along the bed of the examination apparatus to match its position to the patient's position. All the remaining sections of the device are attached to the support frame. It acts as an element which transfers loads between the sections of the device, it is entirely made of materials that do not interact with magnetic fields and at the same time are rigid and lightweight.

[0063] In the second variant of the device the support frame has a reduced size FIG. 12.

[0064] The hip belt B confines the movements of platform C along the guide grooves in the bed of the examination apparatus.

[0065] Forcing the lower limbs to adopt a specific position causes them to act on the support frame A with a force that could move the frame away from the patient. The hip harness counteracts such movement.

[0066] This section consists of: [0067] 1. Hip belt proper [0068] 2. Two side straps [0069] 3. Three carabiner latches

[0070] The installation of the hip belt consists in adapting its length to the patient's dimensions and mounting it on the patient's hips. The belt 1 can be mounted either when the patient is standing prior to positioning the patient on the bench of the apparatus, or when the patient is lying. The patient is then positioned on the bed of the MRI apparatus and the hip belt is fastened with side straps 2 by means of special carabiners 3 locked onto dedicated ports on both sides of platform C.

[0071] The lengths of side straps 2 can still be adjusted at this stage to take up possible slack. This facilitates positioning of the limbs on the platform at a later stage.

[0072] When diagnostic tasks are completed, it just suffices to unfasten the hip belt 1 to free the patient.

[0073] The thigh support platform C is the first of the sections designed to precisely position the patient's lower limbs.

[0074] This section consists of: [0075] 4. Lower hinge [0076] 5. Angular position lock [0077] 6. Thigh pad platform [0078] 7. Thigh platform position lock [0079] 8. Thigh pad [0080] 9. Thigh strap with protective pad [0081] 10. Thigh pad position lock

[0082] The fixed parts of the two lower hinges 4 are secured to the support frame of the device. The moving parts of the mechanism enabling adjustment of the angular position of the thigh support are arranged coaxially in these components. The angle between the base of the device and the thighs is fixed by locking the angular position lock 5 in one of the several available positions. This angle can be changed stepwise from 0 to ca. 45. The set angle depends on the purpose of the examination. The thigh pad platform 6 moves along guides of the moving part of the lower hinge 4. Upon setting the platform in the desired position it must be secured in that position by means of thigh platform position locks 7 on both sides of the device. The thigh pads 8 are designed to support the patient's thighs and arrange them in a selected position. The spacing between the pads on the platform can be adjusted by moving the pads closer to or away from each other to adapt that spacing to patient's anthropological features, patient's dimensions and to the purpose of the examination. Upon setting the desired position, the pads can be secured by means of thigh pad position lock 10, separately for the left and the right pad. Locks 10 are located at the back of the thigh pad platform 6. Upon setting all parameters of the position of patient's limbs within the thigh section, the thighs can be secured. This is done by fastening the patient's thighs to the previously arranged section by means of thigh straps 8 which are attached to the thigh pads 9. The fastening is effected by tightening the thigh straps 9 with protective pads to restrict the free movement of patient's limbs during the setting of subsequent sections of the device and throughout the examination.

[0083] Upon completing the examination the thigh straps 9 must be unfastened before the patient can leave the bench of the device. When the angle between the thighs and the base of the device is set to higher values, the structural components of the thigh supporting section may make leaving the bench by the patient difficult. In such case it is advisable to release both angular position locks 10 so that the thigh section falls to neutral position.

[0084] The shank support assembly D may take on one of two possible configurations, depending on the purpose of the examination. This section has two independent shank supports mounted on one common adjustment screw.

[0085] The shank support assembly consists of: [0086] 11. Guide slider [0087] 12. Position nut [0088] 13. Adjustment screw [0089] 14. Support pad, adjustablesymmetrically for both limbs [0090] 15. Adjustable pad supportsymmetrically for both limbs [0091] 16. Load adjustment knobsymmetrically for both limbs [0092] 17. Central adjustment turning handle (crank) [0093] 18. Casing combined with a nut and with two force measurement assembliessymmetrically for both limbs

[0094] In the second version of the device the shank support assembly consists of: [0095] 11. Guide slider [0096] 12. Position nut [0097] 13. Adjustment screw [0098] 14. Support pad, adjustablesymmetrically for both limbs [0099] 17. Central adjustment turning handle (crank) [0100] 18. Casing combined with a nut and with two force measuring assembliessymmetrically for both limbs [0101] 32. Indicator of the total load applied to both limbs

[0102] The shank support assembly may be installed on the platform at any time. It is installed by inserting the guide slider 11 into a special socket at the end of a special guide on the support frame of the platform. It is desirable that the force applied by the assembly to the limb acts along the intended direction, which is coincident with the axis of the shank support assembly. When comparative examinations of the structures of both limbs are conducted, both shanks should be supported in a similar manner.

[0103] Upon installing the shank support assembly D onto the support frame A and upon selecting its position on the guide, the assembly should be secured in position by tightening the position nut 12. The installation position of the assembly can be readjusted at any stage of using the device by loosening the position nut 12, repositioning the assembly and retightening the nut.

[0104] This should be followed by mounting the components that will come into contact with the limbs. The casing combined with a nut and with two force measuring assemblies 18 is mounted onto the adjustment screw 13. The force measuring assemblies enable measurement of the force applied to the support pads 14, separately for each limb.

[0105] Then, by turning the crank 17, the shank support pads 15 should be moved into an initial position matching the position of the patient's leg. The force measurement assemblies 18 will not always indicate identical values. The device allows the limb support to be adjusted so that loads on both legs are identical. Turning the load adjustment knob 16 clockwise moves the adjustable pad 14 away from the adjustable pad support 15 increasing thereby the force applied to the limb, the value of that force being determinable by means of the force measurement assembly 18.

[0106] In the second variant of the device the force applied is measured jointly for both limbs by means of indicator 32, whereas the design of the combined casing 18 causes symmetrical distribution of the load between both limbs. Therefore the force applied to one limb constitutes half of the value displayed by indicator 32.

[0107] In the second version of the device the desired load on both limbs is applied by turning the crank 17 while observing the indicator 32.

[0108] Applying a force of defined value and direction of action to a limb improves the visibility of potential damages in that limb's locomotor system. The device described herein, as a whole, enables to fulfil such functions. In the case of comparative examinations between two limbs, it is important that the manner of applying force, its direction and value are as close as possible for both limbs.

[0109] The last section E, the feet support assembly, is designed to lock patient's feet in a defined position.

[0110] That section comprises: [0111] 19. Longitudinal position guide [0112] 20. Guide fastening block [0113] 21. Feet spacing guide [0114] 22. Spacing adjustment screw [0115] 23. Middle connector with an angular position lock [0116] 24. Foot holdersymmetrically for both limbs [0117] 25. Foot fastening strap with protective padsymmetrically for both limbs [0118] 26. Feet spacing adjustment crank [0119] 27. Initial position lock [0120] 28. Foot torsion angle position latch [0121] 29. Feet reaction force measurement support [0122] 30. Feet load adjustment screw [0123] 31. Adjustment crank

[0124] The positioning of the assembly starts with the setting of its longitudinal position. The optimal position should be adapted to the features of the patient while moving the entire section along the longitudinal position guide 19. The longitudinal position guide 19 is secured in two guide fastening blocks 20 on both ends of the guide, said blocks constituting at the same time position limiters for the entire assembly. The next entire section is locked by means of initial position lock 27. Depending on the settings of the previous sections, the angle between the base plane and the feet supporting surfaces should be determined. The device enables setting this angle stepwise from 90 to 45. Such settings correspond to natural arrangement of feet ranging from the position in which the legs are straightened to the angle of 90 in the knee. The angle position is secured by means of the middle connector with an angular position lock 23. The feet section enables setting the spacing between feet to adapt the arrangement of patient's limbs on the platform to the type of examination. The required distance between patient's feet is adjusted by means of the removable feet spacing adjustment crank 26. Clockwise turning of the crank symmetrically increases the spacing, anticlockwise turning decreases the spacing.

[0125] The device also enables setting the torsion angle of the entire foot on the platform. That angle can be adjusted separately for each foot. Releasing the foot torsion angle position latch 28 enables turning the foot holder 24 by up to 45 in both outward and inward directions. The angle is adjusted in a stepwise manner and upon setting the desired position the foot holder 24 is locked in that position by releasing the foot torsion angle position latch again.

[0126] In order to prevent changes in the position of patient's feet during load adjustment and during the examination, the fastening straps with protective pad 25 should be fastened.

[0127] If an initial load is to be applied during the examination, the load is applied to the limbs in the longitudinal direction up to the required value by means of the adjustment crank 31 operating the feet load adjustment screw 30. The combined feet reaction force measurement support 29 enables determining the value of the force applied.