A massage device for preventing deep vein thrombosis of lower limbs

Abstract

The present application belongs to the technical field of massager, and particularly discloses a massager for preventing lower limb deep vein thrombosis, which comprises a square frame, a bed plate arranged on the square frame, an angle adjusting mechanism arranged below the square frame, a knee bending massage mechanism arranged on the bed plate, and a detachable boosting protection mechanism arranged in the bed plate. The knee bending massage mechanism comprises a thigh U-shaped frame rotatably connected with the bed plate and a calf U-shaped frame rotatably connected with the thigh U-shaped frame. The detachable boosting protection mechanism comprises a second translation assembly arranged in the bed plate, a boosting piece arranged on the translation part of the second translation assembly, and a pushed piece detachably abutting against the front of the boosting piece. The present application synergizes the body position management, massage and lower limb active flexion and extension exercise, and through the boosting protection mechanism, not only can realize the mode switching of full-process assistance, partial boosting and completely autonomous exercise according to the rehabilitation process, but also can ensure the smooth reset of the affected limb when losing force through the built-in loss force safety protection mechanism.

Description

Technical Field

[0001] This invention belongs to the field of massager technology, specifically referring to a massager for preventing deep vein thrombosis in the lower limbs. Background Technology

[0002] Deep vein thrombosis (DVT) of the lower extremities is a common and serious complication in clinical practice, specifically referring to the abnormal clotting of blood in the deep veins of the lower extremities. This condition is highly prevalent in patients after major surgical procedures (especially orthopedic and abdominal surgeries), patients who are bedridden for extended periods, postpartum women, and other individuals whose lower limb mobility is limited for various reasons. DVT not only causes swelling, pain, and functional impairment in the affected limb, but its most fatal risk lies in the fact that if a thrombus breaks off, it can travel through the bloodstream to the lungs, causing a highly fatal pulmonary embolism. Therefore, effective prevention in high-risk groups is of paramount importance in clinical nursing care.

[0003] Currently, clinical physical prevention methods for lower extremity deep vein thrombosis (DVT) mainly fall into two categories. The first category is passive physical intervention, typically represented by massage devices, which apply mechanical compression to the blood vessels externally to promote venous blood return and reduce blood stasis. The second category is active functional exercises, which involve guiding or assisting patients to perform ankle pump exercises, knee flexion and extension, etc., utilizing the voluntary contraction and relaxation of the lower limb muscle groups (especially the gastrocnemius and soleus muscles) to exert the physiological function of the "muscle pump," thereby accelerating deep vein blood flow from within and effectively preventing thrombosis. However, existing DVT prevention programs still face the following technical challenges that urgently need to be addressed: Clinically recognized effective physical prevention measures are diverse, such as elevating the affected limb 15-30 degrees to promote venous return using gravity, using massagers for passive physical compression, and guiding patients to perform active functional exercises to activate the "muscle pump." However, these effective preventive measures are often implemented in isolation or functionally fragmented in current technologies. For example, medical pillows used to elevate the lower limbs only provide single postural support; massagers only provide passive external compression; and devices that assist joint movement mainly focus on restoring joint range of motion. The market lacks devices that integrate and synergistically design several highly effective preventive mechanisms, including limb positioning management, external mechanical compression, and internal active muscle contraction, resulting in an inefficient combination of preventive effects and rehabilitation efficiency.

[0004] Regarding active knee flexion exercises, the recovery of muscle strength in patients is a gradual and dynamic process. In the early stages of rehabilitation, patients have weak muscle strength and require external assistance to complete the movement from knee extension to flexion. As recovery progresses, after the limb is assisted to a certain angle (i.e., after overcoming the resistance of the initial straightening state), patients develop a certain ability to actively exert force. In the later stages of rehabilitation, they can gradually achieve fully independent movement. However, existing assistive devices mostly adopt a "full-range assistance" or "constant force assistance" mode, that is, providing a single assistive force throughout the entire movement trajectory. This deprives patients of the opportunity to perform effective muscle contraction exercises when they are already able to actively exert force, thereby weakening the fundamental effect of preventing thrombosis.

[0005] When patients attempt voluntary or semi-voluntary knee flexion exercises in the later stages of rehabilitation, their muscle endurance is still unstable, making them highly susceptible to sudden loss of control over their lower limbs due to muscle fatigue or sudden weakness. Under current technological conditions, without effective safety protection and stabilization mechanisms, the affected limb may suddenly become unstable and fall due to gravity, easily leading to secondary injuries such as joint sprains and muscle strains. Summary of the Invention

[0006] In response to the above situation, the present invention provides a massager for preventing deep vein thrombosis in the lower extremities. Through an integrated design, it combines body position management, massage and active flexion and extension exercises of the lower extremities. With a push-and-protection mechanism, it can not only switch between full assistance, partial assistance and fully autonomous exercise modes according to the rehabilitation process, but also has a built-in failure safety protection mechanism to ensure that the affected limb is smoothly reset when failure occurs. Thus, while improving the prevention effect, it greatly ensures safety.

[0007] The technical solution adopted by this invention is as follows: This invention proposes a massager for preventing deep vein thrombosis in the lower extremities, including a square frame bracket and a bed board on the square frame bracket, as well as an angle adjustment mechanism located below the square frame bracket, a knee flexion massage mechanism located on the bed board, and a detachable push-assist protection mechanism located inside the bed board. By integrating these three core mechanisms, this invention can synergistically achieve body position management, passive massage, and active exercise, thereby overcoming the shortcomings of the single function of the prior art and providing a comprehensive prevention solution.

[0008] Furthermore, the knee flexion massage mechanism includes a thigh U-shaped frame rotatably connected to the bed board and a calf U-shaped frame rotatably connected to the thigh U-shaped frame. The design of this structure is intended to simulate the thigh and calf parts of the human lower limb, and its rotatable connection point corresponds to the human knee joint, thereby guiding the patient to perform flexion and extension movements that conform to the physiological movement law.

[0009] Furthermore, the detachable booster protection mechanism includes a second translation component disposed within the bed plate, a booster component disposed on the translation part of the second translation component, a pushed component detachably abutting in front of the booster component, a ring disposed on the pushed component, an inner tube fixedly connected to the pushed component, and an outer tube through which the inner tube slides. The space formed between the inner tube and the outer tube is filled with a non-Newtonian fluid, which has a rapidly increasing viscosity when subjected to rapid shear.

[0010] Furthermore, the angle adjustment mechanism is used to drive the bed board to rotate around its rotatable connection with the square frame bracket. The square frame bracket has supports at all four corners of its lower part, and a mounting frame is provided in the middle of the supports. The angle adjustment mechanism includes a first translation component and a connecting rod mounted on the mounting frame. One end of the connecting rod is rotatably connected to the translation part of the first translation component, and the other end is rotatably connected to the lower side of the bed board. The purpose of this angle adjustment mechanism is to conveniently raise the patient's entire lower limb to a specific angle, such as the clinically recommended 15-30 degrees, so as to promote venous blood return by utilizing gravity.

[0011] Furthermore, the knee flexion massage mechanism also includes a ring fixed to the bed board, with the middle part of the thigh U-shaped frame rotatably disposed within the ring, and the middle part of the calf U-shaped frame rotatably disposed within the ring sleeve.

[0012] Furthermore, both the thigh U-shaped frame and the calf U-shaped frame are provided with horizontally arranged support bars, and the support bars of the calf U-shaped frame are provided with electric massage leg pillows.

[0013] Furthermore, the bed board is provided with a placement groove, the detachable push-assist protection mechanism is located in the placement groove, the second translation component is fixed in the placement groove, and the pushed component slides along the translation direction of the second translation component via a guide rod.

[0014] Furthermore, the outer tube is sealed and fitted outside the inner tube, the rear end of the outer tube is fixed to the fixed end of the second translation component, and the end of the inner tube located inside the outer tube has a flow port.

[0015] Furthermore, a protective plate is provided at the opening of the placement slot, and the ring sleeve slides through the protective plate.

[0016] Furthermore, the lower end of the bracket is equipped with casters, allowing the entire device to be moved easily.

[0017] The beneficial effects achieved by the present invention using the above structure are as follows: (1) This invention integrates three recognized effective preventive measures—limb position management, passive massage, and active functional exercise—through integrated collaborative design, overcoming the shortcomings of existing technologies where each preventive measure is functionally isolated and implemented in isolation. By driving the bed board to rise through the angle adjustment mechanism, the overall posture of the lower limbs can be adjusted to promote venous return using gravity. At the same time, the electric massage leg pillow set on the U-shaped frame of the calf can provide continuous passive mechanical pressure to the calf muscle group. Meanwhile, the knee flexion massage mechanism guides the patient to perform active flexion and extension exercises. The three work together on the same device to achieve the optimal combination of preventive effects and significantly improve rehabilitation efficiency.

[0018] (2) This invention realizes the stepless adjustment of rehabilitation exercise mode from full assistance to complete autonomy, and solves the technical problem that existing auxiliary devices deprive patients of the opportunity to exert force due to the "constant force" or "full assistance" mode. Its core lies in the design that can be separated from the push protection mechanism. By controlling the second translation component, the push component on it can achieve two states with the pushed component: "full push" and "partial push followed by separation". This allows the treatment plan to be accurately matched to the patient's entire process from weak muscle strength to gradual recovery, ensuring that the patient can perform effective active muscle contraction when he / she has the ability, thereby truly activating the physiological function of the "muscle pump" and fundamentally improving the effect of thrombosis prevention.

[0019] (3) The present invention incorporates a sophisticated safety protection mechanism for loss of strength, which completely solves the safety hazard of secondary injury caused by unstable muscle strength and sudden loss of strength during patients’ autonomous or semi-autonomous exercise. This protection function is achieved by non-Newtonian fluid filling the space between the inner and outer tubes. During patients’ autonomous exercise, if the lower limbs suddenly lose control and fall rapidly, it will drive the inner tube to move at high speed, causing the non-Newtonian fluid to generate an extremely high shear rate and thicken and harden instantly when passing through the flow port, thereby forming a huge damping force, so that the affected limb can be reset smoothly and slowly. This passive safety design does not require additional control, responds quickly, and greatly ensures the safety of patients during the rehabilitation process. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of a massager for preventing deep vein thrombosis in the lower extremities, as proposed in this invention.

[0021] Figure 2 This is a schematic diagram of the initial state of a massager for preventing deep vein thrombosis in the lower extremities proposed in this invention.

[0022] Figure 3 This is a schematic diagram of the body position adjustment state of a massager for preventing deep vein thrombosis in the lower extremities proposed in this invention.

[0023] Figure 4This is a schematic diagram of the structure of a massager for preventing deep vein thrombosis in the lower limbs during knee flexion exercises, as proposed in this invention.

[0024] Figure 5 This is an exploded structural diagram showing the positional relationship between the bed board and the square frame bracket of a massager for preventing deep vein thrombosis in the lower extremities, as proposed in this invention.

[0025] Figure 6 This is a schematic diagram illustrating the positional relationship between the calf U-shaped frame and the thigh U-shaped frame of a massager for preventing deep vein thrombosis in the lower limbs, as proposed in this invention.

[0026] Figure 7 This is a schematic diagram of a detachable push-support mechanism for a massager for preventing deep vein thrombosis in the lower extremities, as proposed in this invention.

[0027] Figure 8 for Figure 7 Enlarged view of section A in the middle.

[0028] Figure 9 This is a schematic diagram of the structural relationship between the inner and outer tubes of a massager for preventing deep vein thrombosis in the lower extremities, as proposed in this invention.

[0029] Figure 10 for Figure 9 Enlarged view of section B.

[0030] Among them, 1. Square frame bracket, 11. Bracket, 12. Mounting bracket, 13. Casters, 2. Bed board, 21. Placement slot, 22. Protective plate, 3. Angle adjustment mechanism, 31. First translation component, 32. Linkage rod, 4. Knee flexion massage mechanism, 41. Thigh U-shaped frame, 42. Lower leg U-shaped frame, 43. Ring hoop, 44. Electric massage leg pillow, 45. Support bar, 5. Detachable push-support protection mechanism, 51. Second translation component, 52. Pushing component, 53. Pushed component, 54. Ring sleeve, 55. Inner tube, 56. Outer tube, 57. Flow port.

[0031] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown, the present invention proposes a massager for preventing deep vein thrombosis in the lower extremities, including a square frame bracket 1 as a basic support, and a bed board 2 disposed on the square frame bracket 1.

[0035] To achieve positional management of the entire lower limb, the device is equipped with an angle adjustment mechanism 3. Specifically, each of the four lower corners of the square frame bracket 1 is provided with a bracket 11, and the lower end of the bracket 11 is provided with a caster wheel 13 to facilitate the movement and deployment of the device. The middle of each bracket 11 is connected to a mounting frame 12. The angle adjustment mechanism 3 is located on the mounting frame 12 and includes a first translation component 31 and a connecting rod 32. The first translation component 31 (e.g., a ball screw slide driven by a servo motor) is fixedly installed on the mounting frame 12, and its translation direction is parallel to the length direction of the patient's body. One end of the bed board 2 (near the patient's buttocks) is rotatably connected to the edge of the square frame bracket 1. One end of the connecting rod 32 is rotatably connected to the translation part of the first translation component 31, and the other end is rotatably connected to the lower side of the bed board 2. Through this structure, the translational movement of the first translation component 31 can drive the connecting rod 32, thereby lifting or lowering the bed board 2, causing it to rotate around the rotatable connection, thereby achieving precise adjustment of the overall elevation angle of the patient's lower limb.

[0036] To facilitate knee flexion exercises and massage of the lower limbs, a knee flexion massage mechanism 4 is provided on the bed board 2. This mechanism includes a thigh U-shaped frame 41 and a calf U-shaped frame 42. A ring hoop 43 is fixed on the bed board 2, and its position corresponds to the center of rotation of the hip joint when the patient performs knee flexion exercises. The middle part of the thigh U-shaped frame 41 is rotatably located within the ring hoop 43. The ends of the two corresponding edge vertical rods of the thigh U-shaped frame 41 and the calf U-shaped frame 42 are rotatably connected to each other to simulate the human knee joint. In order to provide effective support for the lower limbs, several support bars 45 are arranged in a horizontal array on both the thigh U-shaped frame 41 and the calf U-shaped frame 42. In particular, an electric massage leg pillow 44 is provided on the support bar 45 of the calf U-shaped frame 42. The leg pillow has a built-in vibration or air pressure massage unit, which can provide continuous passive massage to the patient's calf muscles throughout the exercise.

[0037] The core of this invention lies in the detachable push-assist protection mechanism 5 located inside the bed board 2. The bed board 2 has a placement groove 21, where the components of the detachable push-assist protection mechanism 5 are housed. A protective plate 22 is provided at the opening of the placement groove 21 to ensure the flatness and safety of the bed board 2 surface, leaving only the necessary movement channel. The mechanism includes a second translation component 51, whose structure is similar to that of the first translation component 31. It is fixed to the bottom of the placement groove 21, and the translation direction is also parallel to the body length direction. A pusher 52 is provided on the translation part of the second translation component 51. The mechanism also includes a pushed component 53, which slides along the same path as the translation direction of the second translation component 51 via a guide rod, and can be detachably abutted against the front of the pusher 52 (i.e., the side near the ring 43). A ring 54 is fixedly connected to the upper side of the pushed component 53. The ring 54 slides through the opening of the protective plate 22 and is rotatably connected to the middle of the lower leg U-shaped frame 42.

[0038] To provide safety protection during patient self-exercise, an inner tube 55 is fixedly connected to the front of the pushed member 53 (i.e., the direction close to the ring 43). At the same time, an outer tube 56 is sealed and fitted over the outside of the inner tube 55. The rear end of the outer tube 56 (the end away from the pushed member 53) is sealed and fixed to the fixed end of the second translation component 51. A closed space is formed between the inner tube 55 and the outer tube 56, which is filled with non-Newtonian fluid. A flow port 57 is opened at the end of the inner tube 55 located inside the outer tube 56.

[0039] The specific work process is as follows: Preparation and positioning: First, move the device to one end of the foot of the hospital bed using the casters 13. Adjust the height of the bed board 2 using the telescopic structure (such as telescopic sleeve or lifting mechanism) that can be additionally set on the bracket 11, so that it is flush with the bed surface. After the device is securely connected to the hospital bed, guide the patient to move until the buttocks are at the junction of the device and the hospital bed, that is, roughly aligned with the rotation center of the hoop 43. In the initial state, the thigh U-shaped frame 41 and the calf U-shaped frame 42 are close to parallel and attached to the bed board 2. The patient places the thigh on the support bar 45 of the thigh U-shaped frame 41, and the calf is comfortably placed on the electric massage leg pillow 44 of the calf U-shaped frame 42.

[0040] Posture adjustment: In order to utilize gravity to promote venous return, the angle adjustment mechanism 3 can be activated, and the control system drives the servo motor on the first translation component 31 to move its translation part away from the patient's buttocks. The translation part lifts the bed board 2 through the connecting rod 32, causing it to rotate upward around the front rotating connection point by a preset angle (e.g., 15-30 degrees), thereby raising the patient's entire lower limb.

[0041] Full-process assisted knee flexion exercise mode: When the patient is in the early stage of rehabilitation and has weak muscle strength and cannot complete the movement independently, the bed board 2 is in the flat position. The servo motor of the second translation component 51 is activated. Its translation part drives the pusher 52 to move forward (towards the ring 43). The pusher 52 pushes the pushed part 53. Since the pushed part 53 is connected to the lower leg U-shaped frame 42 through the ring 54, this movement will drive the lower leg U-shaped frame 42 to rotate around its rotation connection point with the thigh U-shaped frame 41 and move towards the thigh U-shaped frame 41, thereby assisting the patient to complete the knee flexion movement. After reaching the predetermined angle, the second translation component 51 moves in the opposite direction. Under the action of the lower limb's own weight, the pushed part 53 is pressed against the pusher 52 and returns to its original position smoothly and slowly. Throughout the process, the electric massage leg pillow 44 continues to work to massage the lower leg.

[0042] Partially assisted or autonomous exercise mode: As the patient's muscle strength recovers, this mode can be switched to. The second translation component 51 can be set to only assist a short initial stroke and then stop after overcoming the static friction and initial motion resistance of the equipment, or to not assist at all. In this case, the patient needs to rely on their own muscle strength to actively drive the lower leg U-shaped frame 42 and the thigh U-shaped frame 41 to perform knee flexion and extension movements. The pushed component 53 will separate from the assist component 52, and the pushed component 53 and other components will move independently of the assist component 52. This allows the patient to perform effective muscle contraction exercises and activate the "muscle pump" effect.

[0043] Loss of strength safety protection: During self-exercise, if the patient suddenly loses strength due to muscle fatigue or spasm, the lower limbs will fall rapidly (extend) under the action of gravity. At this time, the pushed component 53 will drive the inner tube 55 to generate a high-speed relative motion with respect to the outer tube 56. According to the characteristics of non-Newtonian fluid (shear-thickening fluid), when the shear rate of the fluid increases sharply when it passes through the flow port 57, its viscosity will soar instantly, and the fluid will become as hard as a semi-solid, thereby generating a huge damping force, effectively preventing the rapid movement of the inner tube 55, so that the lower limbs can slowly and smoothly return to their original position, avoiding secondary injuries such as joint sprains or muscle strains caused by sudden loss of control. During the extension and reduction process, the inner tube 55 extends out of the outer tube 56, and the combined internal volume of the two increases. The non-Newtonian fluid can be replenished through the replenishment tank connected to the inner tube 55 (the structure is similar to the oil reservoir in the hydraulic buffer in the prior art), ensuring that the system is always full of liquid.

[0044] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0045] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

[0046] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A massager for preventing deep vein thrombosis in the lower extremities, comprising a square frame bracket (1) and a bed board (2) disposed on the square frame bracket (1), characterized in that: It also includes an angle adjustment mechanism (3) located below the square frame bracket (1), a knee flexion massage mechanism (4) located on the bed board (2), and a detachable push-protection mechanism (5) located inside the bed board (2). The angle adjustment mechanism (3) is used to drive the bed board (2) to rotate around its rotational connection with the square frame bracket (1); The knee flexion massage mechanism (4) includes a thigh U-shaped frame (41) rotatably connected to the bed board (2) and a calf U-shaped frame (42) rotatably connected to the thigh U-shaped frame (41). The detachable booster protection mechanism (5) includes a second translation component (51) disposed in the bed board (2), a booster (52) disposed on the translation part of the second translation component (51), a pushed component (53) detachably abutting in front of the booster (52), a ring (54) disposed on the pushed component (53), an inner tube (55) fixedly connected to the pushed component (53), and an outer tube (56) through which the inner tube (55) slides. The space formed between the inner tube (55) and the outer tube (56) is filled with non-Newtonian fluid.

2. A massager for preventing deep vein thrombosis in the lower extremities according to claim 1, characterized in that: The square bracket (1) is provided with brackets (11) at the four corners of the lower part, and the bracket (11) is provided with a mounting frame (12) in the middle. The angle adjustment mechanism (3) includes a first translation component (31) and a connecting rod (32) on the mounting frame (12). One end of the connecting rod (32) is rotatably connected to the translation part of the first translation component (31), and the other end is rotatably connected to the lower side of the bed board (2).

3. A massager for preventing deep vein thrombosis in the lower extremities according to claim 2, characterized in that: The knee flexion massage mechanism (4) also includes a ring hoop (43) fixed on the bed board (2), the middle part of the thigh U-shaped frame (41) is rotatably located in the ring hoop (43), and the middle part of the calf U-shaped frame (42) is rotatably located in the ring sleeve (54).

4. A massager for preventing deep vein thrombosis of the lower extremities according to claim 3, characterized in that: Both the thigh U-shaped frame (41) and the calf U-shaped frame (42) are provided with horizontally arranged support bars (45), and the support bars (45) of the calf U-shaped frame (42) are provided with electric massage leg pillows (44).

5. A massager for preventing deep vein thrombosis of the lower extremities according to claim 4, characterized in that: The bed board (2) has a placement groove (21), the detachable push protection mechanism (5) is located in the placement groove (21), the second translation component (51) is fixed in the placement groove (21), and the pushed component (53) slides along the translation direction of the second translation component (51) via a guide rod.

6. A massager for preventing deep vein thrombosis of the lower extremities according to claim 5, characterized in that: The outer tube (56) is sealed on the outside of the inner tube (55). The rear end of the outer tube (56) is fixed to the fixed end of the second translation component (51). The end of the inner tube (55) located inside the outer tube (56) has a flow port (57).

7. A massager for preventing deep vein thrombosis of the lower extremities according to claim 6, characterized in that: The opening of the placement slot (21) is provided with a protective plate (22), and the ring (54) slides through the protective plate (22).

8. A massager for preventing deep vein thrombosis of the lower extremities according to claim 7, characterized in that: The lower end of the bracket (11) is provided with casters (13).

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