Wheelchairs, especially medical wheelchairs

Abstract

The present invention relates to a wheelchair comprising a seat (5) and a first wheel (1), and also comprising a second wheel (2) that is higher than the first wheel (1), the first wheel (1) being retractable so that when retracted, it is higher than the second wheel (2).

Description

[Technical Field]

[0001] The present invention relates to the technical field of wheelchairs, preferably more specifically to the technical field of medical wheelchairs. [Background technology]

[0002] According to a first prior art, there exists a wheelchair with a seat on which a person can sit and which is supported by rolling wheels so that the occupant can maneuver on the floor. The occupant may be a person with a permanent or temporary disability, or an immobile patient, for example, in a hospital. When the ground is flat, this is relatively easy to move around. However, when there are obstacles and / or changes in the terrain, such as steps to climb, it can be very difficult for the occupant to overcome this. Not only will the person usually have to be assisted by another walker, but this assistance can require considerable effort from the walker, even if the steps to climb are not very high, especially if the occupant is heavy.

[0003] Of course, a system could be implemented that would assist an occupant to climb steps while remaining quietly seated in a wheelchair, with or without the assistance of a walker. However, while this system may be efficient, it would likely be complex and cumbersome.

[0004] According to a second prior art, for example, disclosed in Patent Document 1, a patient chair with adjustable height for radiographic imaging is known. However, this second prior art is of little use when there are steps to climb and a person is already sitting in the wheelchair.

[0005] Considering the preferred use of medical wheelchairs, the radiology device may have a motorized platform, which allows the (non-disabled, able-bodied) patient to be positioned in a standing position at several different heights, preferably at two different heights. A first examination height, for example 10 cm from the floor, which allows the patient to climb onto the platform but with their feet outside the X-ray field. A second examination height, for example 43 cm from the floor, which allows the X-ray tube to reach down the patient's feet, allowing the patient to undergo a whole body scan (from the soles of the feet to the top of the head).

[0006] Often this platform cannot be removed from the system and represents a physical step of significant height, say a minimum of 10cm, to climb.

[0007] For non-ambulatory patients, imaging is required in a radiolucent wheelchair. Transferring a patient from a personal wheelchair to a radiolucent wheelchair can be difficult depending on the person's weight and disability. This is best done in an open environment with access to both wheelchairs on all sides. Therefore, it is better to perform the transfer outside the acquisition zone of the radiology equipment.

[0008] The radiolucent wheelchair with the patient must then be placed in the acquisition zone of a radiological system, preferably an X-ray system, on a platform to perform the patient image acquisition examination.

[0009] Therefore, the wheelchair should allow the patient to climb this 10 cm step safely and without undue force from the caregiver while seated, and also allow for the patient to dismount from the platform after the examination in the same comfortable manner. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] US Patent Application Publication No. 20160346144 [Patent Document 2] International Publication No. 2021090042 Summary of the Invention [Problem to be solved by the invention]

[0011] The object of the present invention is to at least partially alleviate the above-mentioned drawbacks.

[0012] More specifically, the present invention is directed to a system that is overall rather simple and easy, yet efficient by allowing the occupant to remain quietly in the wheelchair, and that will require little effort from the assisting walker to assist the wheelchair supporting the occupant to successfully climb the steps. The preferred context that the present invention addresses corresponds to situations where the height of the steps to be climbed is known in advance and remains constant, such as for example the height of predetermined steps in a radiology device. [Means for solving the problem]

[0013] Therefore, the present invention proposes to have a second wheel at an appropriate height, i.e., at the height of the steps to be climbed, and the first wheel on the ground is retractable, so that when the second wheel takes over from the first wheel by contacting the steps to be climbed, the first wheel is retracted so that the wheelchair rolls on the steps without the first wheel rolling further on the ground, thereby allowing the wheelchair carrying the occupant to smoothly go from the ground to the higher steps to be climbed, and keeping the seat and the occupant at approximately the same height during the transfer from the first lower height on the ground to the second higher height of the steps to be climbed.

[0014] The first object of the present invention is achieved by a wheelchair comprising a seat and a first wheel, and further comprising a second wheel that is higher than the first wheel, the first wheel being retractable so that when retracted, the first wheel is higher than the second wheel.

[0015] The second wheel is higher than the first wheel relative to the ground on which the wheelchair is placed and can roll. The lowest part of the circumference of the second wheel that can roll on the ground is higher than the lowest part of the circumference of the first wheel, and the first wheel therefore rolls on the ground. Preferably, the axis of rotation of the second wheel is also higher than the axis of rotation of the first wheel.

[0016] The first wheel is retractable so that when retracted, it is higher than the second wheel relative to the ground on which the wheelchair is placed and on which the wheelchair can roll. The lowest part of the circumference of the first wheel that can roll on the ground is higher than the lowest part of the circumference of the second wheel, and the second wheel will therefore roll on the ground. Preferably, the axis of rotation of the first wheel is also higher than the axis of rotation of the second wheel.

[0017] The first object of the present invention is also achieved by a radiation system comprising a wheelchair according to any of the preceding claims and a radiation device comprising a gantry enclosed in a cover, a patient base plate, two radiation sources with mutually orthogonal imaging directions and sliding vertically to perform a vertical scan of a patient standing on said base plate, wherein the gantry cover has an L-shape in top view, and each of the two radiation sources is located outside the L-shaped gantry cover, inside an angular sector of the L, and is enclosed in a vertically sliding cover together with the enclosed radiation source.

[0018] Such a radiation system and device is preferably as claimed and described in US Pat. No. 6,223,999, which is incorporated herein by reference.

[0019] When a radiation device is used by a disabled or non-ambulatory patient, the base plate in the radiation device is the step that the disabled or non-ambulatory patient must climb while seated in a wheelchair. Sitting the disabled or non-ambulatory patient in a wheelchair according to an embodiment of the present invention allows the disabled or non-ambulatory patient to undergo a medical examination in the radiation device with maximum comfort, whereas sitting in a prior art wheelchair would cause discomfort during setup before the medical examination is performed. This is therefore an invaluable advantage of the wheelchair according to the present invention when used in a radiation device having a patient base plate or patient lift platform.

[0020] Some hospitals may not even want to purchase radiation equipment without the wheelchair of the present invention in conjunction with a combined radiation system that presents a patient base plate or lift platform that is not at the same elevation as the rest of the floor. Some hospitals may consider a radiation system that is entirely flawed, which may function perfectly well with walking patients but would cause great discomfort to disabled or non-ambulatory patients.

[0021] According to an embodiment of the invention, the aim is to propose a radiolucent chair for adults and children equipped with a mechanism that makes it possible to place the patient in the chair on a platform that is significantly higher than the floor, for example on a platform with a height of 10 cm.

[0022] According to an embodiment of the present invention, a wheelchair is a device that allows for the acquisition of frontal and lateral images of non-ambulatory patients in a functional sitting position. Non-ambulatory patients are patients who cannot walk without the assistance of another person, including wheelchair users and patients who have difficulty remaining stationary while standing without an assistive device. The ability to image these patients will allow them to benefit from low-dose radiographic examinations, 3D modeling and patient-specific parameters, and, if necessary, a spine module for preoperative spine surgery planning, even when the corresponding radiology device exhibits an elevated patient platform. Patients imaged in this wheelchair will have the opportunity to benefit from the complete care pathway offered by radiology devices exhibiting an elevated patient platform.

[0023] Preferred embodiments include one or more of the following features, which can be taken separately or together with the first object of the invention, either in partial or complete combination.

[0024] Preferably, the wheelchair also includes two first front wheels associated with two second front wheels, and two first rear wheels associated with two second rear wheels.

[0025] Thus, a smooth transition from a first low height at ground level to a second high height at step level (the second high height being higher than the first low height) can be performed in stages either at the first front of the wheelchair and the second rear of the wheelchair, or at the first rear of the wheelchair and the second front of the wheelchair.

[0026] Preferably, the wheelchair also includes a first front locking mechanism that fixes the position of the first front wheel when not retracted, and a first rear locking mechanism that fixes the position of the first rear wheel when not retracted.

[0027] Preferably, there is at least a first locking mechanism that fixes the position of at least a portion of the first wheel when not retracted.

[0028] Thus, when the wheelchair is driven at the same height at a given level, the risk is reduced or eliminated that the first wheel will retract when not desired, for example when it comes into contact with a small obstacle or encounters a small change in elevation, thereby causing the wheelchair to lose its balance, which is not only already quite uncomfortable for the occupant, but also creates the risk of the occupant falling to the ground, which is quite dangerous.

[0029] Preferably, the wheelchair also includes a second front locking mechanism for securing the lock of the first front locking mechanism, and a second rear locking mechanism for securing the lock of the first rear locking mechanism.

[0030] Preferably, there is at least a second locking mechanism that secures the first locking mechanism or at least one lock of the first locking mechanism.

[0031] Thanks to this double cascade locking system, it is therefore virtually impossible for even an inattentive walker to accidentally activate the lock on the first retractable wheel.

[0032] Preferably, the wheelchair also includes a third front wheel associated with the two first front wheels and the two second front wheels, and a third rear wheel associated with the two first rear wheels and the two second rear wheels, wherein unlocking of the second front locking mechanism is automatically and mechanically initiated by pressure on the third front wheel exceeding a given threshold corresponding to the load of the wheelchair being on the second front wheel and not on the first front wheel, and this pressure exceeding the given threshold automatically and mechanically activates a lock visual indicator indicating that the second front locking mechanism is unlocked; and unlocking of the second rear locking mechanism is automatically and mechanically initiated by pressure on the third rear wheel exceeding a given threshold corresponding to the load of the wheelchair being on the second rear wheel and not on the first rear wheel, and this pressure exceeding the given threshold automatically and mechanically activates a lock visual indicator indicating that the second rear locking mechanism is unlocked.

[0033] Preferably, there is at least an unlocking of at least one second locking mechanism that is automatically and mechanically actuated by pressure on at least some of the third wheels exceeding a given threshold corresponding to the load of the wheelchair being on at least some of the second wheels but not on all of the first wheels, and this pressure exceeding the given threshold automatically and mechanically activates at least one lock visual indicator that indicates that this second locking mechanism is unlocked.

[0034] Thus, thanks to this particular double cascade locking system, it is no longer practically possible for even a distracted walker to accidentally activate the lock on the first retractable wheel, and this lock can in fact only be activated when there are steps to climb and when the wheelchair is in the immediate vicinity of the steps to climb.

[0035] Preferably, the first front locking mechanism can only be unlocked when the second front locking mechanism is unlocked, and the unlocking of the first front locking mechanism is mechanically driven by manual pressure applied by a user's foot to a first unlocking pedal, and the first rear locking mechanism can only be unlocked when the second rear locking mechanism is unlocked, and the unlocking of the first rear locking mechanism is mechanically driven by manual pressure applied by a user's foot to a second unlocking pedal.

[0036] Preferably, there is at least one unlocking of the at least one first locking mechanism that is only possible when the at least one second locking mechanism is unlocked, and the unlocking of the at least one first locking mechanism is mechanically actuated by manual pressure exerted by a user's foot on at least an unlocking pedal.

[0037] Thanks to this particular double cascade locking system, it is therefore virtually impossible for even a distracted walking aid to accidentally activate the lock on the first retractable wheel, and this lock can in fact only be activated when there are steps to climb and when the wheelchair is in the immediate vicinity of the steps to climb.

[0038] Preferably, the first wheels include a pair of first front wheels and a pair of first rear wheels, the second wheels include a pair of second front wheels and a pair of second rear wheels, the pair of first front wheels being paired with the pair of second front wheels so as to support the load of the wheelchair when the pair of first front wheels is retracted, and the pair of first rear wheels being paired with the pair of second rear wheels so as to support the load of the wheelchair when the pair of first rear wheels is retracted.

[0039] Thus there is a definite pairwise connection between the first and second wheels, so that the second wheels help the first wheels in climbing steps, but only the first wheels with which they are associated.

[0040] Preferably, there are, from the front to the rear of the wheelchair, a pair of first front wheels, a pair of second front wheels, a pair of first rear wheels, and a pair of second rear wheels, and the retraction of the pair of first front wheels is not simultaneous with the retraction of the pair of first rear wheels.

[0041] Thus, a smooth transition from a first low height at ground level to a second high height at step level (the second high height being higher than the first low height) can be performed in stages either at the first front of the wheelchair and the second rear of the wheelchair, or at the first rear of the wheelchair and the second front of the wheelchair.

[0042] Preferably, the axis of rotation of the second wheel is fixed to the structure of the wheelchair so as to remain immobile during retraction of the first wheel.

[0043] The axis of rotation of the second wheel of each pair is offset from the axis of rotation of the first wheel of the pair with which it is coupled by a gap G which depends both on the height H of the stairs to be climbed by the wheelchair and on the difference between the diameter D1 of the first wheel and the diameter D2 of the second wheel.

[0044] The relationship is preferably G=H-(D1-D2) / 2.

[0045] Thus, an improved compromise is achieved between structural simplicity and mechanical efficiency.

[0046] Preferably, the retraction mechanism of the first wheel rotates the first wheel about an axis of rotation offset from the axis of rotation of the first wheel.

[0047] Therefore, the retraction of the first wheel does not interfere with the movement and rolling of the corresponding second wheel.

[0048] Preferably, the retraction mechanism includes a return spring that will return the first wheel to its original non-retracted position when it is no longer retracted, and the first locking mechanism then automatically locks the first wheel in its original non-retracted position.

[0049] Therefore, the safety of the retraction mechanism is improved.

[0050] Preferably, the second wheel is a roller, the roller having a diameter smaller than that of the first wheel, and the circular cross-sectional area of ​​the roller being at most half the circular cross-sectional area of ​​the first wheel.

[0051] This provides an improved compromise between structural simplicity and mechanical efficiency.The rollers may be significantly smaller than the wheels, as they are intended to be used only in specific situations, for example to climb and remain on specific steps, such as those present in radiation equipment.

[0052] Preferably, the second wheel is not retractable.

[0053] Thus, when correctly positioned, the second wheel of limited size does not need to be retracted even when the wheelchair is running on the ground outside the radiation device, thereby improving the compromise between structural simplicity and mechanical efficiency.

[0054] Preferably, the wheelchair also includes a base plate supporting the seat, the first wheel being retractable inside this base plate and the second wheel being partly at the level of this base plate and partly below this base plate.

[0055] Thus, the burden and overall volume of the wheelchair is further reduced.

[0056] Preferably, the first wheel is retracted by moving relative to the base plate, and the second wheel remains stationary relative to the base plate during retraction of the first wheel.

[0057] Thus, an improved compromise is achieved between structural simplicity and mechanical efficiency.

[0058] Preferably, the wheelchair further includes: the horizontal axes of rotation of all second wheels are fixed relative to said base plate; the horizontal axes of rotation of all first wheels are movable relative to said base plate during retraction of the first wheels; the horizontal axes of rotation of some first wheels are fixed relative to said base plate except during retraction of the first wheels; and the horizontal axes of rotation of some other first wheels are orientable vertically relative to said base plate except during retraction of the first wheels.

[0059] Therefore, the maneuverability of the wheelchair is further improved.

[0060] Preferably, the wheelchair also includes a lift system disposed between the seat and the base plate for raising and lowering the seat relative to the base plate.

[0061] Thus, the wheelchair is more adaptable to occupants of different sizes.

[0062] Preferably, the seat is radiolucent.

[0063] The wheelchair can therefore be more easily used within the radiation equipment.

[0064] Preferably, this is a wheelchair for non-ambulatory patients to achieve functional sitting position.

[0065] Therefore, the wheelchair can be more easily used in a medical environment.

[0066] Preferably, the difference in height between the first wheel and the second wheel is within a range of 5 cm to 20 cm, or within a range of 8 cm to 12 cm, or approximately 10 cm. More precisely, the difference in height between the lowest part of the outer periphery of the first wheel (the part that touches the ground and rolls on the ground) and the lowest part of the outer periphery of the second wheel (the part that touches the ground and rolls on the ground) is within a range of 5 cm to 20 cm, or within a range of 8 cm to 12 cm, or approximately 10 cm.

[0067] Thus, the overall burden and overall volume of the wheelchair is further reduced, while the height of steps that the wheelchair can easily climb remains significant.

[0068] Preferably, the wheelchair is entirely mechanical and passive, and therefore contains no motors or power sources.

[0069] Thus, the compromise between structural simplicity and mechanical efficiency is further improved.

[0070] Preferably, the wheelchair also includes a brake to prevent the wheelchair from rolling, which is activated by manual pressure applied by the user's foot on a first brake pedal, which preferably automatically and mechanically activates a visual brake indicator to show that the brake is applied, and which is released by manual pressure applied by the user's foot on a second brake pedal.

[0071] Therefore, the safety of the wheelchair is further improved.

[0072] Preferably, the wheelchair further comprises two rods having a length in the range of 50 cm to 150 cm, preferably about 80 cm, which rods can be locked and unlocked in a vertical position and tilted at an angle in the range of 30 degrees to 60 degrees, preferably about 50 degrees, relative to the vertical, and each rod has a handle at its distal end.

[0073] This further improves the ease of use and maneuverability of the wheelchair.

[0074] Preferably, the radiation system also includes a first safety device that stops the vertical scanning when it detects that a part of the patient's body is outside a first predetermined area to avoid a collision between the part of the patient's body and the vertically sliding radiation source cover, and a second safety device that stops the vertical scanning when it detects the presence of an object or person outside the radiation device within a second predetermined area to avoid a collision between the object or person and the vertically sliding radiation source cover.

[0075] Thus, the safety of disabled or non-ambulatory patients who are seated in wheelchairs is further improved.

[0076] Preferably, in a square arrangement having three rows from A to C and three columns from 1 to 3, the top view of the L-shaped gantry cover covers squares C1, C2, C3, B3, A3, the two radiation source covers are respectively positioned in squares B1 and A2, the patient base plate covers square B2, and square A1 remains completely free and empty.

[0077] This further improves the maneuverability of the wheelchair and also provides a better compromise between structural simplicity and mechanical efficiency for the entire radiation system, including both the wheelchair and the radiation device.

[0078] This second object of the present invention is achieved by a mobile patient support device including a base having a top surface, a bottom surface, a front portion, and a rear portion; a seat configured to receive a patient, the seat being secured to the top surface of the base; a first post having a proximal end and a distal end, the proximal end being pivotally attached to the bottom surface of the base; a first wheel secured near the distal end of the first post; and a second wheel secured to the bottom surface of the base rearward of the first wheel, wherein the first post is pivotable between an extended position in which the first wheel is located farther from the bottom surface of the base than the second wheel, and a retracted position in which the first wheel is located closer to the bottom surface of the base than the second wheel.

[0079] Preferred embodiments include one or more of the following features, which can be taken separately or together with this second object of the invention, either in partial or complete combination:

[0080] Preferably, the mobile patient support further includes a first locking mechanism configurable between (1) a locked position in which the first locking mechanism maintains the first strut in an extended position, and (b) an unlocked position in which the first locking mechanism retracts the first strut and moves the first wheel toward the bottom surface of the base.

[0081] Preferably, the mobile patient support further includes a second locking mechanism that is configurable between (1) a first position in which the second locking mechanism maintains the first locking mechanism in its locked position, and (2) a second position in which the first locking mechanism allows transitioning from the locked position to the unlocked position.

[0082] Preferably, the mobile patient support further includes a visual indicator mechanically connected to the second locking mechanism and configured to indicate whether the second locking mechanism is in the first position or the second position.

[0083] Preferably, the second locking mechanism is configured to transition from the first position to the second position when the third wheel is subjected to a sufficient force.

[0084] Preferably, the second locking mechanism further includes a third wheel.

[0085] Preferably, the third wheel is positioned relative to the base such that the distal most edge of the wheel extends further from the bottom surface of the base than the distal most edge of the second wheel.

[0086] Preferably, the first locking mechanism is configured to transition from the locked position to the unlocked position by a user's foot applying pressure to the first locking mechanism.

[0087] Preferably, the first wheel is of a larger diameter than the diameter of the second wheel.

[0088] Preferably, the patient support is configured to be transported onto an elevated platform having a height greater than the vertical distance between the lowest points of the bottom edges of the first and second wheels.

[0089] Preferred embodiments of either the first and second object of the present invention comprise one or more of the features described above, which may be employed separately or together in either partial or complete combination with the first object of the present invention or the second object of the present invention, or with both objects of the present invention when combined partially or completely together.

[0090] Further features and advantages of the present invention will become apparent from the following description of embodiments of the invention, given as non-limiting examples, with reference to the accompanying drawings listed below. [Brief explanation of the drawings]

[0091] [Figure 1] 1 shows a perspective view of an example of a wheelchair according to an embodiment of the present invention. [Figure 2] 1 shows a side view of an example of a wheelchair according to an embodiment of the present invention. [Figure 3] 1 shows a side view of an example of a wheelchair underbody in accordance with an embodiment of the present invention. [Figure 4] 1 shows a perspective view of an example of a lower portion of a wheelchair according to an embodiment of the present invention. [Figure 5] 1 shows a side view of an example lower portion of a wheelchair according to an embodiment of the present invention during the first stage of climbing steps. [Figure 6] 1 shows a side view of an example lower part of a wheelchair according to an embodiment of the present invention during a second stage of climbing steps. [Figure 7] 1 shows a side view of an example of a lower part of a wheelchair according to an embodiment of the present invention during the third stage of climbing steps. [Figure 8]10 shows a side view of an example lower part of a wheelchair according to an embodiment of the present invention in a fourth stage of climbing steps. [Figure 9] 1 shows a side view of an example of a wheelchair according to an embodiment of the present invention after climbing a step. [Figure 10] 1 shows a perspective view of an example wheelchair lower part showing part of the locking system according to an embodiment of the present invention. [Figure 11] 1 shows a top view of an example wheelchair lower part showing part of the locking system according to an embodiment of the present invention. [Figure 12] 1 shows a perspective view of an example wheelchair lower part showing part of the locking system according to an embodiment of the present invention. [Figure 13] 1 shows a perspective view of an example of a wheelchair framework according to an embodiment of the present invention; [Figure 14] 1 shows a side view of an example wheelchair framework according to an embodiment of the present invention after climbing a step. [Figure 15] 1 shows a perspective view of an example of a wheelchair framework on the ground according to an embodiment of the present invention; [Figure 16] 1 shows a perspective view of an example of a wheelchair framework, partially on a step, according to an embodiment of the present invention; FIG. [Figure 17] 1 shows a perspective view of an example of a wheelchair framework, fully on a step, according to an embodiment of the present invention; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0092] In all figures, In the horizontal plane, a longitudinal direction X corresponds to the fore-and-aft direction of the wheelchair; In the horizontal plane, the transverse direction Y is perpendicular to the longitudinal direction X. a vertical direction Z that is perpendicular to both the longitudinal direction X and the lateral direction Y and perpendicular to the horizontal plane; There is.

[0093] In all figures, the second wheel 2 is referred to interchangeably as second wheel 2 or as roller 2 .

[0094] FIG. 1 shows a perspective view of an example of a wheelchair according to an embodiment of the present invention.

[0095] The wheelchair includes a seat 5, which is supported by a lifting system 50 that can move the seat 5 vertically and maintain the seat 5 at different heights. The lifting system 50 is supported by a substantially horizontal base plate 3. A first set of wheels 1, including two front wheels 11 and two rear wheels 12, is mounted below the base plate 3.

[0096] The lifting system 50 is disposed between the seat 5 and the base plate 3 and raises and lowers the seat 5 relative to the base plate 3. The seat 5 is X-ray transparent. This wheelchair is designed for non-ambulatory patients to achieve a functional sitting position. This wheelchair is completely mechanical and passive, and therefore does not include a motor or a power source.

[0097] Two vertical rods 51, each with a handle 52 at its free end, extend upward from the horizontal base plate 3. Each handle 52 includes an actuator for pivoting the rod 51 about a horizontal axis Y. The two rods 51 have a length in the range of 50 cm to 150 cm, preferably about 80 cm, can be locked or unlocked in a vertical position, and can be tilted at an angle in the range of 30 to 60 degrees, preferably about 50 degrees, relative to the vertical, and have a handle 52 at their respective distal ends.

[0098] FIG. 2 shows a side view of an example of a wheelchair according to an embodiment of the present invention.

[0099] In addition to the seat 5 and the first wheel 1, the wheelchair also includes a second wheel 2 that is higher than the first wheel 1. The first wheel 1 is retractable so that when retracted, it is higher than the second wheel 2. The wheelchair actually includes two first front wheels 11 associated with two second front wheels 21 and two first rear wheels 12 associated with two second rear wheels 22.

[0100] FIG. 3 shows a side view of an example of a lower portion of a wheelchair according to an embodiment of the present invention.

[0101] The wheelchair also includes a first front locking mechanism 13 that fixes the position of the first front wheel 11 when not retracted, and a first rear locking mechanism 14 that fixes the position of the first rear wheel 12 when not retracted.

[0102] The second wheel 2 is a roller 2, which has a diameter smaller than that of the first wheel 1 and a circular cross-sectional area that is at most half that of the first wheel 1. The circular cross-sectional area of ​​the first wheel 1 is the circular surface of the first wheel 1 that can be seen in plane XZ, which is the plane of FIG. 3. The circular cross-sectional area of ​​the roller 2 is the circular surface of the roller 2 that can be seen in plane XZ, which is the plane of FIG. 3. The roller 2 is not retractable, and its rotation axis is fixed and immovable relative to the base plate 3. The height difference h between the first wheel 1 and the second wheel 2 is in the range of 5 cm to 20 cm, or in the range of 8 cm to 12 cm, or about 10 cm.

[0103] Small wheels 31, 32 each have a diameter that is much smaller than, and less than half the diameter of, their associated rollers 21, 22. Small wheels 31, 32 are associated with rollers 21, 22, respectively, such that when the wheelchair is loaded on rollers 21, 22, respectively, the wheelchair also presses against small wheels 31, 32, respectively, to activate the unlocking of the second locking mechanism, and visual indicators 33, 34 are mechanically actuated by small wheels 31, 32, respectively, to protrude from upper surface 30 of base plate 3, while when the wheelchair is loaded on first wheel 1, these visual indicators 33, 34, respectively, are mechanically retracted into base plate 3.

[0104] FIG. 4 shows a perspective view of an example of a lower portion of a wheelchair according to an embodiment of the present invention.

[0105] The wheelchair also includes a brake to prevent the wheelchair from rolling, which is activated by manual pressure applied by the user's foot on a first brake pedal, which preferably automatically and mechanically activates a brake visual indicator 90 indicating that the brake is engaged, and which is released by manual pressure applied by the user's foot on a second brake pedal. The brake visual indicator 90 is mechanically activated by the user's foot pressing on the first brake pedal, and protrudes from the upper surface 30 of the base plate 3. The brake visual indicator 90 is mechanically activated by the user's foot pressing on the second brake pedal, and retracts into the base plate 3. The lift system 50 is mechanically activated by the user's foot pressing on the lift pedal 53.

[0106] The base plate 3 also includes a first unlocking pedal 36 and a second unlocking pedal 35. The manner in which these first unlocking pedal 36 and second unlocking pedal 35 function will be explained below with reference to the following figures.

[0107] FIG. 5 shows a side view of an example lower portion of a wheelchair according to an embodiment of the present invention during the first stage of climbing steps.

[0108] There is a step, which is a platform 6, resting on a floor surface 100. The platform 6 is an elevation platform whose upper surface 60 can be raised and lowered to different heights so that different parts of the patient's body can be imaged. A wheelchair partially climbs onto the platform 6 with its upper surface 60. The rear rollers 22 press against the upper surface 60 of the platform 6, thereby bearing the rear weight of the wheelchair, until the first rear wheel 12 is above the floor surface 100 and no longer contacts the floor surface 100, thereby no longer bearing the rear weight of the wheelchair. After the wheelchair weight presses against the third small rear wheel 32, unlocking the rear locking mechanism 14 of the rear wheels 12, the rear small wheel 32 also presses against the upper surface 60 of the platform 6, thereby mechanically protruding the rear visual indicator 34 above the upper surface 30 of the base plate 3.

[0109] FIG. 6 shows a side view of an example lower portion of a wheelchair according to an embodiment of the present invention during the second stage of climbing steps.

[0110] The wheelchair has partially climbed onto this platform 6 with its upper surface 60. The rollers 22 press against the upper surface 60 of the platform 6, thereby bearing the rear load of the wheelchair, and continue to roll on the upper surface 60 of the platform 6, so that the first rear wheel 12, which abuts against the platform 6, is mechanically actuated simply by the pressure of the platform 6 against the first rear wheel 12 and pivots together with its rear base 16 about the rear retraction axis 18 so as to be retracted into the base plate 3. At the end of this second stage, the front load of the wheelchair is still resting on the first front wheel 11.

[0111] FIG. 7 shows a side view of an example lower part of a wheelchair according to an embodiment of the present invention during the third stage of climbing steps.

[0112] The wheelchair is partially mounted on this platform 6 which has an upper surface 60. The front rollers 21 press against the upper surface 60 of the platform 6, thereby bearing the front load of the wheelchair, and the first front wheel 11 is above the floor surface 100 and no longer in contact with this floor surface 100, and therefore no longer bears the front load of the wheelchair. After the front locking mechanism 13 of the front wheels 11 is unlocked by the load of the wheelchair pressing against the third small front wheels 31, these small front wheels 31 also press against the upper surface 60 of the platform 6, thereby mechanically protruding the front visual indicator 33 above the upper surface 30 of the base plate 3.

[0113] FIG. 8 shows a side view of an example lower part of a wheelchair according to an embodiment of the present invention during the fourth stage of climbing steps.

[0114] The wheelchair is partially mounted on this platform 6 with its upper surface 60. The front rollers 21 press against the upper surface 60 of the platform 6, thereby bearing the front load of the wheelchair, and continue to roll on the upper surface 60 of the platform 6, so that the first front wheel 11, which abuts against the platform 6, is mechanically actuated simply by the pressure of the platform 6 on the first front wheel 11 and pivots together with its front base 15 about the front retraction axis 17 so as to be retracted into the base plate 3. At the end of this fourth stage, the entire load of the wheelchair, i.e. the front load of the wheelchair and the rear load of the wheelchair, is no longer borne by either of the first wheels 1, i.e. the first front wheel 11 or the first rear wheel 12, but is borne by both the rollers 2, i.e. the front roller 21 and the rear roller 22.

[0115] The first wheels 1 include a pair of first front wheels 11 and a pair of first rear wheels 12. The second wheels 2, which are rollers 2, include a pair of second front wheels 21 and a pair of second rear wheels 22. The pair of first front wheels 11 are paired with the pair of second front wheels 21 so as to support the front load of the wheelchair when the pair of first front wheels 11 are retracted into the base plate 3. The pair of first rear wheels 12 are paired with the pair of second rear wheels 22 so as to support the rear load of the wheelchair when the pair of first rear wheels 12 are retracted into the base plate 3.

[0116] From the front to the rear of the wheelchair, there are a pair of first front wheels 11, a pair of second front wheels 21, a pair of first rear wheels 12, and a pair of second rear wheels 22, so the retraction of the pair of first front wheels 11 is not simultaneous with the retraction of the pair of first rear wheels 12.

[0117] The axis of rotation of the second wheel 2 is fixed to the structural base plate 3 of the wheelchair so as to remain stationary during retraction of the first wheel 1. The retraction mechanism of the first wheel 1 rotates the first wheel 1 about an axis of rotation 18 for the first rear wheel 12 or about an axis of rotation 17 for the first front wheel 11, which are offset from the axis of rotation of the first wheel 1.

[0118] The retraction mechanism includes a return spring (not shown) which will return the first wheel 1 to its original non-retracted position when it is no longer retracted into the base plate 3, a first rear locking mechanism 14 for the first rear wheel 12 and a first front locking mechanism 13 for the first front wheel 11, which in turn automatically locks the first wheel 1 in its original non-retracted position.

[0119] A base plate 3 supports the seat 5, and a first wheel 1 is retractable inside the base plate 3, more precisely inside the housing of the base plate 3, while a second wheel 2 is partially at the height of the base plate 3 and partially below the base plate 3. The first wheel 1 is retracted by moving relative to the base plate 3, while the second wheel 2 remains stationary relative to the base plate 3 during retraction of the first wheel 1. The wheelchair base plate 3 also includes horizontal rotation axes of all second wheels 2 that are fixed relative to the base plate 3 and horizontal rotation axes of all first wheels 1 that are movable relative to the base plate 3 during retraction of the first wheels 1. Except during retraction of the first rear wheel 12, the horizontal rotation axis of the first rear wheel 12 is fixed relative to the base plate 3. Except during retraction of the first front wheel 11, the horizontal rotation axis of the first front wheel 11 is oriented vertically relative to the base plate 3.

[0120] FIG. 9 shows a side view of an example wheelchair according to an embodiment of the present invention after climbing a step.

[0121] The entire wheelchair is positioned on the upper surface 60 of the raised platform 6. The wheelchair is fully loaded on the secondary wheels 2, i.e. on both the front rollers 21 and the rear rollers 22, while all primary wheels 1, i.e. both the first front wheel 11 and the first rear wheel 12, are retracted into the base plate 3 and therefore do not support the load of the wheelchair any more. The base plate 3 effectively abuts a vertical wall 7 of the radiography apparatus, against which the seat 5 rests for stability, so that images can be taken with as little movement of the seat 5 relative to the radiography apparatus as possible.

[0122] FIG. 10 shows a perspective view of an example wheelchair underbody showing part of the locking system according to an embodiment of the present invention.

[0123] FIG. 11 shows a top view of an example wheelchair lower part showing part of the locking system according to an embodiment of the present invention.

[0124] The wheelchair also includes a second front locking mechanism that secures the lock of the first front locking mechanism, a second rear locking mechanism that secures the lock of the first rear locking mechanism, and both the second front locking mechanism and the second rear locking mechanism are similar to each other.

[0125] Here, the second rear locking mechanism 14 is shown, which secures the lock of the first rear locking mechanism 4. A locking pin 49 is integrated into the base plate 3, which can block or release the rotating disc 40, which, depending on its rotational position, pushes or pulls two rods 41 and 42 to block or release safety pins 43 and 44, respectively, and thus block or release the first rear wheel 12, respectively.

[0126] When the locking pin 49 is raised (see FIG. 10), it blocks the rotation of the rotating disc 40, thereby keeping the rods 41 and 42 immobile, and the rods 41 and 42 each continue to press the safety pins 43 and 44 into the rear base 16 to keep the first rear wheel 12 blocked.

[0127] When the locking pin 49 is lowered (see Figure 11), it releases the rotation of the rotating disc 40, thereby pulling the rods 41 and 42 respectively, which in turn pull the safety pins 43 and 44 respectively out of the two rear bases 16, thereby releasing the rear bases 16, which then allow the first rear wheel 12 to be retracted by rotation of both the first rear wheel 12 and its rear base 16 about their axis 18 once the rollers 22 have taken up the load of the wheelchair.

[0128] When the locking pin 49 is lowered, the rotating disc 40 is rotated by a cable 48 that is pulled by the pressure exerted by the user's foot on the pedal 36 (see FIG. 4). The pulled cable can be angled by rotating around a pulley 47.

[0129] The unlocking of the second rear locking mechanism 14 is automatically and mechanically triggered by pressure on the third rear wheel 32 exceeding a given threshold value corresponding to the wheelchair load being on the second rear wheel 22 but not on the first rear wheel 12. This pressure exceeding the given threshold automatically and mechanically activates a lock visual indicator 34, which indicates that the second rear locking mechanism 14 is unlocked. The unlocking of the first rear locking mechanism 4 is only possible when the second rear locking mechanism 14 is unlocked, and the unlocking of the first rear locking mechanism 4 is mechanically triggered by manual pressure applied by the user's foot on a first unlock pedal 36 (see FIG. 4 ).

[0130] Similarly, although not shown in Figure 11, unlocking of the second front locking mechanism is automatically and mechanically triggered by pressure on the third front wheel 31 exceeding a given threshold value corresponding to the wheelchair load being on the second front wheel 21 but not on the first front wheel 11. This pressure exceeding the given threshold automatically and mechanically activates a lock visual indicator 33, which indicates that the second front locking mechanism 13 is unlocked. Unlocking of the first front locking mechanism is only possible when the second front locking mechanism 13 is unlocked, and unlocking of the first front locking mechanism is mechanically triggered by manual pressure applied by the user's foot on the second unlock pedal 35 (see Figure 4).

[0131] The first locking mechanisms 14 and 13 on both the rear and front operate in the same way. When the roller 2 is not on the platform 6, the third small wheels 31 and 32 are not on the platform 6 and are in a lowered position. These automatically place the locking pin 49 in the up position, which prevents the wheel retraction mechanism from moving. When the roller 2 and the third small wheels 31 and 32 are on the platform 6, they are pushed up. This pulls the locking pin 49 down, which allows the wheel retraction mechanism to move freely. The transmission between the third small rear wheel 32 and the locking pin 49 is performed by rotation of a horizontal bar about the axis of rotation indicated by the rotation arrow on Figure 10.

[0132] Both the rear and front wheel retraction mechanisms function similarly. Activating a foot pedal, either rear wheel retraction mechanism pedal 36 or front wheel retraction mechanism pedal 35, pulls cable 48, which rotates rotating disc 40. Connecting rods 41 and 42 withdraw two safety pins 43 and 44 from their housings, freeing first wheel 1 for retraction. Rotation of rotating disc 40 is only possible if second locking mechanism 14 is first unlocked by translating locking pin 49 downward.

[0133] FIG. 12 shows a perspective view of an example wheelchair underbody showing part of the locking system according to an embodiment of the present invention.

[0134] The rod 42 can push the safety pin 44 into the hole 64 in the first rear base 16 and can also pull the safety pin 44 out of the hole 64 in the first rear base 16 .

[0135] FIG. 13 shows a perspective view of an example of a wheelchair framework according to an embodiment of the present invention.

[0136] The wheelchair is on the floor surface and is ready to roll on the floor surface with its first wheels 1, i.e. both its first front wheel 11 and its first rear wheel 12. The wheelchair is loaded on the first wheels 11 and 12 and not on the second wheels 21 and 22. The first wheels 11 and 12 are in an operating position, i.e. an extended position, and are blocked in this extended position so that they can receive the load of the wheelchair.

[0137] FIG. 14 shows a side view of an example wheelchair framework according to an embodiment of the present invention after climbing a step.

[0138] The wheelchair is on the upper surface 60 of the platform 6 and is either blocked in this position to allow an X-ray image to be taken, or is ready to roll on the upper surface 60 of the platform 6 with its second wheels 2, i.e. with both its second front wheel 21 and its second rear wheel 22, after such an X-ray image has been taken. The wheelchair is loaded on the second wheels 21 and 22 rather than the first wheels 11 and 12. The first wheels 11 and 12 are in a retracted position within their housings in the base plate 3 (which has here been removed to better show the inside of the base plate 3), and the load of the wheelchair is taken by the second wheels 21 and 22.

[0139] FIG. 15 shows a perspective view of an example of a wheelchair framework on the ground according to an embodiment of the present invention.

[0140] A dummy 8 representing a patient sits in a wheelchair seat 5, and the wheelchair rolls on a floor surface 100 and enters the X-ray radiation device so that both front and side images of the dummy 8 can be taken simultaneously.

[0141] FIG. 16 shows a perspective view, partially on a step, of an example of a wheelchair framework according to an embodiment of the present invention.

[0142] The dummy 8 is still seated in the wheelchair seat 5, the wheelchair is rolling partly on the floor surface 100 on the first front wheel 11 and partly on the upper surface 60 of the platform 6 on the second rear wheel 22, the first rear wheel 12 is retracted into the housing of the base plate 3 (the housing of the base plate 3 has now been removed), and the wheelchair is in the X-ray radiation device so that both front and side images of the dummy 8 can be taken simultaneously.

[0143] FIG. 17 shows a perspective view of an example wheelchair framework, fully on the step, according to one embodiment of the present invention.

[0144] The dummy 8 is still seated in the wheelchair seat 5, the wheelchair is rolling on the upper surface 60 of the platform 6 on both the second front wheel 21 and the second rear wheel 22, the first front wheel 11 and the first rear wheel 12 are retracted into their housings in the base plate 3 (this housing in the base plate 3 has now been removed), and the wheelchair is in the X-ray radiological diagnostic device and is correctly positioned on the platform 6 in a specific position that allows front and side images of this dummy 8 to be taken.

[0145] Next, the overall flow will be explained in relation to FIGS.

[0146] The plate base 3 of the wheelchair, preferably a medical wheelchair, includes the following features: four first wheels 11 and 12, each equipped with an individual brake; a first wheel retraction mechanism for retracting the first wheels 11 and 12 of the chair when placing the wheelchair on the top 60 of the platform 6 of the X-ray imaging device; A safety locking mechanism that locks the wheelchair in position once it is placed on top 60 of lifting platform 6, as shown in Figure 17.

[0147] In the initial position, the first wheels 11 and 12 are locked in a vertical position by the first wheel locking mechanism. In this initial position, the patient (or a dummy 8 acting as the patient here) can be transferred from the personal wheelchair to the medical wheelchair according to the embodiment of the present invention, which can be easily performed since the transfer is performed outside the enclosed space inside the cabin of the radiation device. Then, as can be seen on Fig. 15, the medical wheelchair, with the dummy 8 (or patient) sitting in the seat 5 of the medical wheelchair, can be moved from the transfer zone to near the platform 6.

[0148] The medical wheelchair is pushed towards the platform 6 until the rear rollers 22 come into contact with the top 60 of the platform 6. The load is transferred from the first rear wheel 12 to the rear rollers 22, but as the first rear wheel 12 is a few millimeters lower than the top 60 of the platform 6, this requires some force to ensure that they can support the load of the medical wheelchair. The medical wheelchair is pushed until the first rear wheel 12 comes into contact with the side 61 created by the step of the platform 6 (see Figure 16). A visual indicator (34 for the rear roller 22) shows that the first rear wheel 12 is in the correct position. A safety mechanism unlocks the retraction system of the first rear wheel 12.

[0149] The operator actuates the pedal 36 (see FIG. 4), which unlocks the retraction of the first rear wheel 12. This is possible because the first rear wheel locking mechanism 4 has been previously unlocked by the second rear locking mechanism 14. The first rear wheel 12 and its support 16, i.e., its rear base 16, can now rotate about its retraction axis 18 (see FIG. 6).

[0150] The medical wheelchair is pushed further towards the platform 6 until the front rollers 21 come into contact with the top 60 of the platform 6. The weight of the wheelchair is transferred from the first front wheel 11 to the front rollers 21, but as the first front wheel 11 is a few millimetres lower than the top 60 of the platform 6, this requires some force to ensure that they can support the load of the medical wheelchair. The medical wheelchair is pushed until the first front wheel 11 comes into contact with the side 61 created by the step of the platform 6 (see Figure 16).

[0151] A visual indicator (33 for the front roller 21) shows that the first front wheel 11 is in the correct position. A safety mechanism unlocks the retraction system of the first front wheel 11.

[0152] The operator activates the pedal 35 (see Figure 4), which unlocks the retraction of the first front wheel 11. This is possible because the first front wheel locking mechanism was previously unlocked. The first front wheel 11 and its support 15 can now rotate around its retraction axis 17 (see Figure 8).

[0153] In Figure 17, the medical wheelchair is now in the scanning position. An X-ray acquisition is carried out using the radiology equipment. After the X-ray acquisition is finished, the medical wheelchair is lowered from the platform 6. The first wheels 1 are equipped with return springs which ensure that as soon as they leave the platform 6, first the first front wheels 11 and secondly the first rear wheels 12 are successively placed in a vertical position. Once in the vertical position, these first wheels 1 are automatically locked in the vertical position.

[0154] Although the present invention has been described with reference to preferred embodiments, many variations are possible within the scope of the invention. [Explanation of symbols]

[0155] 1. First Wheel 2 Second Wheel 3 Base Plate 4 First rear locking mechanism 5 seats 6. Platform 7 Vertical Wall 8 Dummy 11 First front wheel 12 First rear wheel 13 Second front locking mechanism 14 Second rear locking mechanism 15 Front base 16 Rear base 17 Front retraction shaft 18 Rear retractable shaft 21 Second front wheel 22 Second rear wheel 30 Top side 31 Front small wheel 32 Rear small wheel 33 Front visual indicator 34 Rear visual indicator 35 Second unlocking pedal 36 First unlocking pedal 40 rpm disc 41 and 42 Rods 43 and 44 Safety Pins 47 Pulley 48 Cable 49 Lock pin 50 Lifting System 51 Rod 52 Handle 53 Lift pedal 60 Top surface, top 61 Side 64 holes 90 Brake visual indicator 100 floor

Claims

1. Seats (5), A first wheel (1); Including, A second wheel (2) higher than the first wheel (1). further comprising The wheelchair wherein the first wheel (1) is retractable so that when retracted, it is higher than the second wheel (2).

2. two first front wheels (11) associated with two second front wheels (21); two first rear wheels (12) associated with two second rear wheels (22); The wheelchair of claim 1 further comprising:

3. a first front locking mechanism for fixing the position of the first front wheel (11) when not retracted; a first rear locking mechanism (4) for fixing the position of the first rear wheel (12) when not retracted; The wheelchair of claim 2 further comprising:

4. a second front locking mechanism (13) for fixing the lock of the first front locking mechanism; a second rear locking mechanism (14) for fixing the lock of the first rear locking mechanism (4); The wheelchair of claim 3 further comprising:

5. a third front wheel (31) associated with the two first front wheels (11) and the two second front wheels (21); a third rear wheel (32) associated with the two first rear wheels (12) and the two second rear wheels (22); further comprising the unlocking of the second front locking mechanism (13) is automatically and mechanically triggered by the pressure on the third front wheel (31) exceeding a given threshold value corresponding to the load of the wheelchair being applied to the second front wheel (21) but not to the first front wheel (11); said pressure exceeding a given threshold automatically and mechanically activates a lock visual indicator that indicates said second front locking mechanism (13) is unlocked; the unlocking of the second rear locking mechanism (14) is automatically and mechanically triggered by the pressure on the third rear wheel (32) exceeding a given threshold value corresponding to the load of the wheelchair being applied to the second rear wheel (22) but not to the first rear wheel (12); 5. The wheelchair of claim 4, wherein the pressure exceeding a given threshold automatically and mechanically activates a lock visual indicator that indicates that the second rear locking mechanism (14) is unlocked.

6. the first front locking mechanism can only be unlocked when the second front locking mechanism (13) is unlocked; unlocking of said first front locking mechanism is mechanically actuated by manual pressure applied by a user's foot to a first unlocking pedal (35); the first rear locking mechanism (4) can only be unlocked when the second rear locking mechanism (14) is unlocked; 6. Wheelchair according to claim 4 or 5, wherein unlocking of the first rear locking mechanism (4) is mechanically actuated by manual pressure exerted by the user's foot on a second unlocking pedal (36).

7. The first wheel (1) is A pair of first front wheels (11) and a pair of first rear wheels (12) Including, The second wheel (2) is A pair of second front wheels (21) and a pair of second rear wheels (22) Including, The pair of first front wheels (11) are paired with the pair of second front wheels (21) so as to support the load of the wheelchair when the pair of first front wheels (11) are retracted; 7. The wheelchair of claim 1, wherein the pair of first rear wheels (12) is paired with the pair of second rear wheels (22) so as to support the load of the wheelchair when the pair of first rear wheels (12) is retracted.

8. From the front to the rear of the wheelchair, the pair of first front wheels (11); the pair of second front wheels (21); the pair of first rear wheels (12); the pair of second rear wheels (22); There are 8. Wheelchair according to claim 7, wherein the retraction of the first pair of front wheels (11) is not simultaneous with the retraction of the first pair of rear wheels (12).

9. 9. Wheelchair according to claim 8, wherein the axis of rotation of the second wheel (2) is fixed to the structure of the wheelchair so as to remain immobile during retraction of the first wheel (1).

10. 10. The wheelchair according to any one of claims 1 to 9, wherein the retraction mechanism of the first wheel (1) rotates the first wheel (1) about an axis of rotation (17, 18) offset from the axis of rotation of the first wheel (1).

11. said retraction mechanism includes a return spring which will return said first wheel (1) to its original unretracted position when no further retraction occurs; Wheelchair according to any one of claims 1 to 10, wherein the first locking mechanism then automatically locks the first wheel (1) in its original non-retracted position.

12. 12. The wheelchair according to any one of claims 1 to 11, wherein the second wheel (2) is a roller (2), the roller (2) having a diameter smaller than the diameter of the first wheel (1), and the circular cross-sectional area of ​​the roller (2) is at most half the circular cross-sectional area of ​​the first wheel (1).

13. Wheelchair according to any one of claims 1 to 12, wherein the second wheel (2) is not retractable.

14. A base plate (3) supporting the seat (5) further comprising The first wheel (1) is retractable inside the base plate (3), Wheelchair according to any one of claims 1 to 13, wherein the second wheel (2) is partly at the level of the base plate (3) and partly below the base plate (3).

15. The first wheel (1) is retracted by moving relative to the base plate (3), Wheelchair according to claim 14, wherein the second wheel (2) remains immobile relative to the base plate (3) during retraction of the first wheel (1).

16. the horizontal rotation axes of all the second wheels (2) are fixed relative to the base plate (3); the horizontal rotation axes of all first wheels (1) are movable relative to said base plate (3) during retraction of the first wheels (1); the horizontal rotation axes of the first wheels (12) are fixed relative to said base plate (3) except during retraction of the first wheels (1); the horizontal rotation axes of several other first wheels (11) can be oriented vertically relative to said base plate (3), except during retraction of the first wheel (1); 16. The wheelchair of claim 14 or 15, further comprising:

17. Located between the seat (5) and the base plate (3), The seat (5) is raised and lowered relative to the base plate (3). Wheelchair according to any one of claims 14 to 16, further comprising a lifting system (50).

18. Wheelchair according to any one of the preceding claims, wherein the seat (5) is radiolucent.

19. 19. A wheelchair according to any one of claims 1 to 18, for a non-ambulatory patient to assume a functional sitting position.

20. Wheelchair according to any one of claims 1 to 19, wherein the height difference between the first wheel (1) and the second wheel (2) is in the range of 5 cm to 20 cm, or in the range of 8 cm to 12 cm, or about 10 cm.

21. It is entirely mechanical and passive, and therefore The motor also The power supply, 21. A wheelchair according to any one of claims 1 to 20, which does not include a seatbelt.

22. A brake to prevent the wheelchair from rolling further comprising the brake is actuated by manual pressure applied by a user's foot to a first brake pedal; This preferably results in automatic mechanical activation of a visual brake indicator that indicates that the brake is being applied; 22. A wheelchair as claimed in any one of the preceding claims, wherein the brake is released by manual pressure applied by the user's foot on a second brake pedal.

23. Two rods (51), a length in the range of 50 cm to 150 cm, preferably about 80 cm; Can be locked in a vertical position can be unlocked and tilted at an angle between 30 and 60 degrees relative to the vertical, preferably about 50 degrees; each having a handle (52) at its distal end; 23. Wheelchair according to any one of claims 1 to 22, further comprising two rods (51).

24. A wheelchair according to any one of claims 1 to 23; A gantry enclosed within a cover, a patient base plate or platform (6); two radiation sources with mutually orthogonal imaging directions, sliding vertically to perform a vertical scan of a patient standing on said base plate or platform (6); a radiation device including: Including, The gantry cover has an L-shaped top view; Each of the two radiation sources comprises: the outside of the L-shaped gantry cover; Inside the angular sector of the L placed in A radiation system enclosed within a vertically sliding cover with the radiation source enclosed therein.

25. a first safety device that stops the vertical scanning when detecting that a part of the patient's body is outside a first predetermined area to avoid a collision between the part of the patient's body and the vertically sliding radiation source cover; a second safety device that stops the vertical scanning when detecting the presence of an object or person outside the radiation device within a second predetermined area to avoid a collision between the object or person and the vertically sliding radiation source cover; 25. The radiation system of claim 24, further comprising:

26. In a square array with three rows A to C and three columns 1 to 3, The top view of the L-shaped gantry cover covers squares C1, C2, C3, B3, and A3; the two radiation source covers are disposed within squares B1 and A2, respectively; The patient base plate or platform (6) covers square B2; 26. A radiation system according to claim 25, wherein the square A1 remains completely free and empty.

27. a base (3) having a top surface, a bottom surface, a front portion, and a rear portion; a seat (5) configured to receive a patient, the seat (5) being fixed to the top surface (30) of the base (3); a first post having a proximal end and a distal end, the proximal end pivotally attached to the bottom surface of the base (3); a first wheel (1) fixed to the first strut near the distal end; a second wheel (2) fixed to the bottom surface of the base (3) at a position rearward of the first wheel (1); Including, the first support column is pivotable between an extended position in which the first wheel (1) is positioned farther from the bottom surface of the base (3) portion than the second wheel (2), and a retracted position in which the first wheel (1) is positioned closer to the bottom surface of the base (3) portion than the second wheel (2).

28. 28. The mobile patient support device of claim 27, further comprising a first locking mechanism configurable between (i) a locked position in which the first locking mechanism maintains the first strut in the extended position, and (b) an unlocked position in which the first locking mechanism retracts the first strut and moves the first wheel toward the bottom surface of the base.

29. 29. The mobile patient support device of claim 28, further comprising a second locking mechanism, the second locking mechanism being configurable between (1) a first position in which the second locking mechanism maintains the first locking mechanism in its locked position, and (2) a second position in which the first locking mechanism allows the first locking mechanism to transition from the locked position to the unlocked position.

30. 30. The mobile patient support device of claim 29, further comprising a visual indicator mechanically connected to the second locking mechanism and configured to indicate whether the second locking mechanism is in the first position or the second position.

31. 31. The mobile patient support device of claim 29 or 30, wherein the second locking mechanism further comprises a third wheel.

32. 32. The mobile patient support device of claim 31 , wherein the third wheel is positioned relative to the base such that a distal-most edge of the wheel extends further from the bottom surface of the base than a distal-most edge of the second wheel.

33. 33. The mobile patient support device of any one of claims 29-32, wherein the second locking mechanism is configured to transition from the first position to the second position when the third wheel is subjected to a sufficient force.

34. 34. The mobile patient support device of any one of claims 28-33, wherein the first locking mechanism is configured to transition from the locked position to the unlocked position by a user's foot applying pressure to the first locking mechanism.

35. 35. The mobile patient support device of any one of claims 27 to 34, wherein the first wheel is of a larger diameter than the diameter of the second wheel.

36. 36. The mobile patient support device of any one of claims 27 to 35, wherein the patient support is configured to be transported onto an elevated platform having a height that is greater than the vertical distance between the lowest points of the bottom edges of the first and second wheels.

Images