Stroke patient foot and ankle and lower leg alternating drive rehabilitation device

Abstract

The application discloses a rehabilitation device for alternately driving the ankle and lower leg of a stroke patient. The ankle part of a lying position bearing frame is provided with an ankle shaft alignment beam, left and right rotating screw rods drive the inner and outer ankle positioning sliding seats to move towards each other at equal distances, coaxial supporting holes on the two positioning sliding seats form a device swing axis corresponding to the positions of the inner and outer ankles. A foot swing frame is rotationally supported on the axis, upper and lower traction belts are connected to a double-groove winding drum in opposite winding directions, and the traction load and the foot swing angle are verified through an elastic coupling member and an angle encoder disc. After the foot swing frame returns to the neutral position, a neutral lock tongue drives a neutral permission cam to release the switching block, and then a power switch is switched to a gastrocnemius muscle rolling vehicle. The floating pressing frame of the rolling vehicle supports left and right rollers through an equalizing swing lever, and moves from the distal end to the proximal end of the lower leg; and a controller controls micro swing, return, rolling, return stroke and release according to the alignment, load, angle, position, rolling force and neutral permission signals.

Description

Technical Field

[0001] This invention relates to the technical field of neurorehabilitation assistive devices and lower limb passive movement devices, specifically to an alternating drive device that, in a supine or semi-recumbent position, causes the foot to swing with low amplitude around a device swing axis formed according to the position of the medial and lateral malleoli, and then performs gastrocnemius muscle rolling along the longitudinal direction of the lower leg after the foot returns to a neutral position. Background Technology

[0002] When stroke patients with hemiplegia are resting in bed, undergoing early rehabilitation, or maintaining the same position for extended periods at night, the affected ankle joint may remain in a plantarflexed or inverted position, with insufficient active dorsiflexion and plantarflexion movements, and the calf muscles lack the periodic deformation brought about by ankle pump activity. Clinical assistive devices typically address foot position maintenance, passive ankle joint movement, and external compression of the calf. Common structures include ankle-foot fixation braces, ankle joint trainers with foot pedals as rotating components, stretchers, and airbags or massage rollers that act on the calf.

[0003] Existing pedal-type ankle trainers typically use a pre-fixed axis on the device as the rotation center of the pedals. However, variations exist in the width between the patient's medial and lateral malleoli, the lateral position of the ankle on the bed, and the foot's fixed position. When the device's axis deviates from the actual rotation area of ​​the patient's ankle, changes in the pedal angle may be accompanied by foot movement within the straps, lateral traction of the ankle, or relative slippage of soft tissues. Measuring only the pedal angle or motor torque is insufficient to confirm whether the drive stroke is translated into foot swing angle under appropriate axial conditions.

[0004] Existing calf compression or massage structures typically have independent power sources or independent operating programs. When such structures are installed alongside ankle swing structures, if the two movements are scheduled solely based on a timing program, transmission gaps, drive lag, abnormal shutdowns, or power-on re-energization may cause the calf rolling to start while the foot is still in a dorsiflexion or plantarflexion position, thereby altering the calf support position and the force path of the upper and lower traction bands.

[0005] Therefore, it is necessary to first form the swing axis of the device based on the position of the inner and outer ankles on the same lying load body, and verify the correspondence between the traction load and the swing angle of the foot; after the ankle micro-swing ends, it is also necessary to generate mechanically verifiable power switching conditions from the neutral position of the foot, so that the rolling branch can only obtain power after the foot returns to the neutral position, and disengage from power and release contact when the alignment, traction or rolling state is abnormal. Summary of the Invention

[0006] The purpose of this invention is to provide a rehabilitation device for stroke patients with alternating drive of the foot, ankle, and lower leg, in order to solve the problems of mismatch between the rotating shaft of the fixed device and the position of the patient's ankle, the possibility of simultaneous loading of ankle traction and lower leg rolling, and the inability to confirm that the foot has returned to a neutral position before the power switch by simply relying on the time program.

[0007] To achieve the above objectives, a lower leg support groove is formed along the longitudinal direction of the lower leg in the supine support frame, and an ankle axis alignment beam is transversely arranged at the corresponding position of the ankle. Left and right rotating screws on the ankle axis alignment beam drive the medial and lateral malleolar positioning slides to move equidistantly towards each other. After the two compliant positioning heads are respectively placed against the medial and lateral malleolar sides, the coaxial support holes on the two positioning slides form the swing axis of the device. The two side arms of the foot swing frame are supported by the coaxial support holes, so that the rotation center of the foot swing frame is determined by the position of the positioning slides.

[0008] The foot swing frame consists of a midfoot suspension belt and a forefoot support belt supporting the foot. Upper and lower traction belts extend from the instep and sole sides of the forefoot support belt, respectively, and connect to a double-groove drum in opposite directions. As the double-groove drum rotates, one traction belt tightens while the other releases simultaneously. Elastic connectors are installed along the force paths of the two traction belts. Elastic displacement sensors output deformation, and an angle encoder outputs the foot swing angle. This allows for comparison between the predicted swing angle corresponding to the traction load and drum rotation angle and the actual foot swing angle.

[0009] The neutral positioning notch of the foot swing arm and the neutral locking tongue form a neutral locking state. After the neutral locking tongue enters the neutral positioning notch, it outputs a neutral permission signal, which drives the neutral permission cam to leave the movement path of the shift fork via a linkage. The drive motor selectively connects the ankle swing output gear and the rolling output gear via a power converter; when the foot swing arm is not in the neutral locking state, the neutral permission cam mechanically prevents the sliding clutch sleeve from entering the rolling engagement position.

[0010] The gastrocnemius muscle rolling trolley moves along the longitudinal bottom rail of the lying support frame. The floating pressure frame supports the left and right rollers via compression springs and pressure equalizing swing rods. As the rolling trolley moves from the far end to the near end, the two rollers form moving contact along the back of the lower leg. The pressure frame displacement detector outputs the pressure frame deformation, and the stroke detector outputs the rolling trolley position. The controller controls the drive motor and power converter based on alignment lock, traction deformation, foot swing angle, neutral clearance, pressure frame deformation, and rolling trolley position.

[0011] The equidistant movement of the medial and lateral ankle positioning slides allows the two coaxial support holes to adjust with the ankle width, reducing additional drag caused by the offset of the fixed pivot. The elastic connectors and angle encoders on the two traction belts establish a verifiable relationship between the traction load and the foot swing angle. The neutral locking tongue, neutral permission cam, and sliding clutch sleeve provide the mechanical basis for the engagement of the rolling output. The floating pressure frame and pressure equalizing swing rod allow the two rollers to distribute the contact load according to the change of the lower leg cross-section. The overload release device and manual release handle allow the power and rolling contact to be released even in the event of power failure or abnormal drive. Attached Figure Description

[0012] Figure 1 This is a three-dimensional perspective view of the overall structure of the device of the present invention; Figure 2 A three-dimensional structural diagram of the ankle axis alignment structure and the foot swing frame; Figure 3 A three-dimensional structural diagram of the gastrocnemius muscle rolling assembly; Figure 4 This is a left view of the overall structure of the device of the present invention; Figure 5 This is a front view of the overall structure of the device of the present invention; Figure 6 This is a top view of the overall structure of the device of the present invention; Figure 7 A schematic diagram illustrating the relationship between a power converter and mechanical permitting. Figure 8 This is a block diagram showing the connection between the controller's input signals and output signals. Figure 9 Flowchart for control state switching; Figure 10 This is a schematic diagram illustrating the alternating timing of ankle micro-swing, neutral return, gastrocnemius rolling, and roller return.

[0013] Explanation of reference numerals in the attached figures 1. Horizontal support frame; 11. Longitudinal bottom rail; 12. Lower leg support; 13. Bed frame connecting seat; 14. Anti-slip support feet; 2. Ankle axis alignment beam; 21. Left and right turning screw; 22. Medial malleolus positioning slide; 23. Lateral malleolus positioning slide; 24. Compliant positioning head; 25. Coaxial support hole; 26. Alignment locking sleeve; 27. Center scale; 28. Alignment locking detection piece; 3. Foot swing frame; 31. Lateral support arm; 32. Forefoot support strap; 33. Midfoot suspension strap; 34. Heel pressure relief window; 35. Angle encoder disc; 36. Neutral positioning notch; 37. Neutral locking tongue. 38. Inward-turning flexible limiting plate; 39. Outward-turning flexible limiting plate; 4. Pull-pull traction transmission mechanism; 41. Upper traction belt; 42. Lower traction belt; 43. Reversing guide wheel; 44. Double-groove drum; 45. Elastic connecting piece; 46. Elastic displacement detection piece; 47. Traction transmission shaft; 48. Compensating wheel; 5. Gastrocnemius muscle rolling cart; 51. Traveling slide; 52. Longitudinal transmission component; 53. Floating pressure frame; 54. Left roller; 55. Right roller; 56. Pressure equalizing swing rod; 57. Compression spring; 58. Pressure frame displacement detection piece; 59. Proximal reversing component; 510 5. Remote reset component; 6. Travel detection component; 7. Power converter; 8. Drive motor; 9. Common input shaft; 10. Sliding clutch sleeve; 11. Ankle swing output gear; 12. Rolled output gear; 13. Switching fork; 24. Neutral permission cam; 35. Travel switching lug; 46. Overload release device; 57. Controller; 68. Display indicator; 79. Manual release handle; 80. Storage unit; 10. Flexible bushing; 11. Directional positioning tongue; 12. Bushing position switch; 13. Alignment locking signal; 14. Medial ankle positioning slide position; 15. R, position of the lateral ankle positioning slide; qC, lateral coordinate of the fixed center seat; Ec, alignment deviation; δt, traction deformation of the current tightening traction belt; kt, equivalent stiffness of the calibrated spring; Ft, traction force; α, foot swing angle; Δφd, signed angle change of the double-groove drum; rd, effective winding radius of the double-groove drum; Rf, equivalent arm of the forefoot bearing; αp, predicted swing angle; Eα, angular position residual; y, position of the rolling carriage; δr, deformation of the pressure frame; kr, equivalent stiffness of the rolling support; Fr, rolling force; Gr, gradient of rolling force change; N, neutral clearance signal. Detailed Implementation

[0014] like Figure 1As shown, this device is used when the patient is in a supine, semi-recumbent, or bedside early rehabilitation state to perform low-amplitude passive traction on the affected ankle. After the ankle movement ends and the foot returns to a neutral position, mechanical rolling along the longitudinal direction of the lower leg is applied to the gastrocnemius muscle area. The supine support frame 1 constitutes the common load-bearing body of all the actuators. The supine support frame 1 can be placed on the bed surface and connected to the bed frame or bedside fixed beam through the bed frame connecting seat 13. The bottom of the supine support frame 1 is equipped with anti-slip feet 14, and the longitudinal bottom rail 11 is set on both sides or below the lower leg support groove 12. The gastrocnemius muscle rolling cart 5 moves along the longitudinal bottom rail 11 between the distal and proximal positions of the lower leg. The lower leg support groove 12 supports the posterior side of the lower leg and has a shallow arc-shaped cross-section. The groove surface is covered with a removable flexible bushing 8 to separate the skin from the rigid support.

[0015] The lower leg support 12 is laterally fixed to the ankle axis alignment beam 2 at one end near the ankle. The medial malleolus positioning slide 22 and the lateral malleolus positioning slide 23 are slidably disposed on both sides of the ankle axis alignment beam 2. The left and right helical screw 21 passes through the two positioning slides, with a left-hand threaded section on one side and a right-hand threaded section on the other side, the two threaded sections being symmetrical about the fixed center seat. When the left and right helical screw 21 is rotated, the medial malleolus positioning slide 22 and the lateral malleolus positioning slide 23 move closer to or further away from the fixed center seat in opposite directions and with equal nominal displacement, causing the two coaxial support holes 25 to change position according to the width of the ankle, and keeping the midpoint of the two holes near the longitudinal center plane of the lying support frame 1.

[0016] In one embodiment, the left and right rotating lead screw 21 is driven by an outer handwheel, with a torque limiting knob positioned between the handwheel and the lead screw. After the caregiver places the patient's lower leg in the lower leg support 12, they first position the medial and lateral malleoli roughly on either side of the ankle axis alignment beam 2, then rotate the handwheel to bring the two compliant positioning heads 24 close to the medial and lateral malleoli, respectively. The compliant positioning heads 24 are not rigid cusps, but are connected to corresponding positioning slides via universal pressure seats. The universal pressure seats allow the compliant positioning heads 24 to deflect around two small angles, enabling the contact surfaces of the positioning heads to conform to the local contours near the medial and lateral malleoli. The contact surfaces of the compliant positioning heads 24 may be padded, the function of which is to determine the position of the device's swing axis and limit lateral ankle movement, rather than continuously applying high pressure to bony prominences.

[0017] After the two compliant positioning heads 24 are aligned, the left and right rotating screws 21 are fixed by the alignment locking sleeve 26. The alignment locking sleeve 26 can be a tightening sleeve fitted on the handwheel shaft, or an eccentric locking component that clamps the left and right rotating screws 21. The alignment locking detection component 28 is set on the closed path of the alignment locking sleeve 26, and outputs the alignment locking signal A after the alignment locking sleeve 26 reaches the locked position. The center scale 27 is arranged along the ankle axis alignment beam 2 and is used to read the position qL of the medial malleolus positioning slide and the position qR of the lateral malleolus positioning slide. The center scale 27 can be mechanically graduated and manually confirmed, or it can use a magnetic grating, optical grating, or resistive displacement reading component to output the two slide positions to the controller 7. When reading with electrical signals, the controller 7 can calculate the deviation of the midpoint of the center of the two positioning slides relative to the fixed center seat to avoid one positioning slide being blocked by foreign objects and not moving according to the equidistant relationship.

[0018] The alignment deviation Ec can be calculated using the following formula: Ec = |(qL + qR) / 2 - qC| In the formula, qL represents the position of the medial malleolus positioning slide 22 on the lateral coordinate, in millimeters; qR represents the position of the lateral malleolus positioning slide 23 on the same lateral coordinate, in millimeters; qC represents the coordinate of the fixed center seat of the ankle axis alignment beam 2, in millimeters; and Ec represents the alignment deviation of the midpoint of the two slides relative to the fixed center seat, in millimeters. This formula is used to verify the symmetrical movement of the left and right rotating screw 21 and the locking result of the alignment locking sleeve 26, but is not used to evaluate the patient's ankle anatomy. The controller 7 is allowed to enter the subsequent neutral verification state only when Ec does not exceed the upper limit obtained from the device calibration and the alignment locking signal A is valid. If only the alignment locking sleeve 26 is closed and Ec exceeds the limit, the display prompt 71 outputs the device prompt "Please check the positioning slide or clear the obstruction".

[0019] The lower part or inner side of the medial malleolus positioning slide 22 and the lateral malleolus positioning slide 23 respectively form coaxial support holes 25. Bearings, low-friction bushings, or removable bushings can be installed in the two coaxial support holes 25. The center line connecting the two coaxial support holes 25 constitutes the swing axis of the device. This axis is determined by the positions of the two positioning slides relative to the patient's medial and lateral malleoli, rather than by a single-sided hinge fixed to the supine support frame 1. The two lateral arms 31 of the foot swing frame 3 are respectively inserted into or rotatably connected to the coaxial support holes 25, allowing the foot swing frame 3 to rotate with low amplitude in the dorsiflexion and plantarflexion directions around the swing axis of the device. For different left and right affected sides, the foot swing frame 3 can be mirror-mounted, or the medial malleolus positioning slide 22 and the lateral malleolus positioning slide 23 can be symmetrically structured to maintain the correspondence between the swing axis of the device and the position of the patient's ankle.

[0020] like Figure 2As shown, the two lateral support arms 31 of the foot swing frame 3 extend forward from the swing axis of the device, forming a heel pressure relief window 34 at the corresponding position of the heel. The heel pressure relief window 34 is surrounded by arc-shaped load-bearing edges located on both sides of the heel, ensuring that the center of the heel avoids the rigid base plate. The midfoot suspension strap 33 spans the two lateral support arms 31 and supports the midfoot area; the forefoot support strap 32 is located at the front of the foot swing frame 3 and supports the forefoot area behind the metatarsal heads. The forefoot support strap 32 moves along the longitudinal adjustment groove on the lateral support arms 31 and is fixed by a length locking member, allowing the equivalent force arm Rf of the forefoot support strap 32 relative to the swing axis of the device to be adjusted according to the foot length specification.

[0021] The foot support frame 3 has an inversion flexible restraint plate 38 and an eversion flexible restraint plate 39 on its inner and outer sides, respectively. These two flexible restraint plates can be formed from elastic plates, webbing, or soft wings, and their height is below the upper edge of the dorsum of the foot, not serving as a rigid clamping structure. When the patient's foot has an inversion tendency, the inversion flexible restraint plate 38 first contacts the inner side of the foot and provides increasing lateral restraint; the eversion flexible restraint plate 39 restricts eversion deviation in the same way. Since the main load-bearing capacity of the foot is borne by the midfoot suspension belt 33 and the forefoot support belt 32, the flexible restraint plates are only used to keep the foot within the force plane of the upper and lower traction belts, reducing deviation of the foot from the predetermined path during counter-traction.

[0022] The counter-traction transmission mechanism 4 is located on the outside, below, or between the lateral support arms 31 of the foot swing frame 3. The upper traction belt 41 extends from the instep side of the forefoot support belt 32 and is connected to the double-groove drum 44 via a guide pulley 43 located above the foot swing frame 3; the lower traction belt 42 extends from the sole side of the forefoot support belt 32 and is connected to the double-groove drum 44 via another guide pulley 43 located below the foot swing frame 3. The double-groove drum 44 has an upper groove and a lower groove, the spiral directions of the two grooves are opposite and the effective winding radius is the same. The upper traction belt 41 and the lower traction belt 42 are fixed to two grooves respectively. When the double groove drum 44 rotates in the first direction, the upper traction belt 41 shortens while the lower traction belt 42 lengthens simultaneously. The forefoot support belt 32 is pulled in the direction of the instep, and the foot swing frame 3 swings slightly in the dorsiflexion direction around the swing axis of the device. When the double groove drum 44 rotates in the second direction, the lower traction belt 42 shortens while the upper traction belt 41 lengthens simultaneously, and the foot swing frame 3 swings slightly in the plantarflexion direction.

[0023] The upper and lower traction straps are designed with opposing tensions, concentrating the driving force on the forefoot support strap 32 and preventing a single traction strap from relying on gravity or foot rebound for repositioning during each change of direction. To prevent the released traction strap from becoming completely slack, a compensating pulley 48 is positioned on the common tension path of the two traction straps. Supported by a tension spring, the compensating pulley 48 absorbs a small difference in strap length when the double-groove drum 44 changes direction, ensuring that the traction strap not under main tension maintains a low pretension. The stroke of the compensating pulley 48 can be mechanically limited to prevent the traction strap from detaching from the reversing guide pulley 43. The traction strap can be made of low-elongation webbing, covered steel wire rope, or medical high-strength fiber strap, with the portion in contact with the patient's foot separated by the forefoot support strap 32.

[0024] In one embodiment, identical elastic couplings 45 are connected in series along the force paths of the upper traction belt 41 and the lower traction belt 42. Each elastic coupling 45 has a guide sleeve, a calibration spring, and a measuring slider. When the corresponding traction belt is under force, the measuring slider moves along the guide sleeve and compresses the calibration spring, and the elastic displacement detection plate 46 reads the displacement of the measuring slider. During backbend micro-swing, the controller 7 selects the deformation corresponding to the upper traction belt 41; during plantar flexion micro-swing, the controller 7 selects the deformation corresponding to the lower traction belt 42, and records the currently selected deformation as δt. The controller 7 calculates the traction force Ft based on the equivalent stiffness kt of the current elastic coupling. Ft = kt · δt In the formula, Ft is the traction force corresponding to the current tightening of the traction belt, in N; kt is the equivalent stiffness of the corresponding calibrated spring within its effective stroke, in N / mm; δt is the traction deformation measured by the corresponding elastic displacement sensor 46, in millimeters. The two elastic couplings are calibrated using a standard tension gauge during the manufacturing stage, and their respective stiffness parameters are written into the controller 7. This relationship is used to limit the traction load on the forefoot support strap 32 and to identify situations where the traction belt is jammed by a foreign object, the foot swing frame 3 is obstructed from rotation, and the traction path is abnormal. The controller 7 does not rely on Ft to generate muscle tone levels or other diagnostic conclusions.

[0025] Angle encoder 35 is positioned at the point where the lateral support arm 31 rotates relative to the coaxial support hole 25, outputting the foot swing angle α with the position corresponding to the neutral positioning notch 36 as zero. The encoder of the drive motor 61 or the angle detection element on the traction drive shaft 47 outputs the signed angle change Δφd of the double-groove drum 44 relative to the neutral position. Based on the effective winding radius rd, the angle change Δφd, and the equivalent force arm Rf of the forefoot support 32, the predicted swing angle αp corresponding to the change in traction belt length can be obtained. αp = (rd · Δφd / Rf) · 180 / π In the formula, αp is the predicted swing angle in degrees; rd is the effective winding radius of the double-groove drum 44 in millimeters; Δφd is the signed angular change of the double-groove drum 44 relative to the neutral position in radians, with opposite signs for dorsiflexion and plantarflexion; Rf is the equivalent distance from the swing axis of the device to the main force point of the forefoot support 32 in millimeters; π is pi. Rf is determined by the locking position of the forefoot support 32. This formula is used to verify the amount of tape released from the drum and the rotation of the foot swing frame 3, and is not used to evaluate the human ankle joint movement function.

[0026] An angular position residual Eα is formed between the actual foot swing angle α output by the angle encoder disk 35 and the predicted swing angle αp: Eα = |α - αp| In the formula, Eα is in degrees. When the traction belt slips in the groove, the forefoot support 32 is not locked, the foot swing frame 3 is compressed by the bedding, or the rotation of the coaxial support hole 25 is obstructed, the rotation angle of the double-groove drum 44 may not be converted into the corresponding foot swing angle, and Eα increases accordingly. The controller 7 requires Eα to continuously exceed the residual upper limit for a preset number of samplings before entering the abnormal processing stage to eliminate fluctuations in a single sampling. After entering the abnormal processing stage, the controller 7 stops the traction in the current direction; when Ft is within the allowable return range, the drive motor 61 runs in reverse at a low speed, reducing the traction force and bringing the foot swing frame 3 closer to the neutral position.

[0027] The foot swing arm 3 has a neutral positioning notch 36 in the neutral position. The neutral positioning notch 36 can be formed on the positioning ring on the outer periphery of the angle encoder disk 35, or it can be formed on the arc-shaped positioning plate of the lateral support arm 31. The neutral locking tongue 37 is biased toward the neutral positioning notch 36 by a spring. When the foot swing arm 3 approaches the neutral swing angle, the neutral locking tongue 37 slides along the positioning plate and enters the neutral positioning notch 36. After the neutral locking tongue 37 enters the notch, it restricts the foot swing arm 3 from continuing to move freely beyond the neutral position, and triggers the neutral permission switch to output a neutral permission signal N to the controller 7. The neutral locking tongue 37 also drives the neutral permission cam 67 through a linkage, constituting the mechanical permission condition of the power converter 6.

[0028] like Figure 3As shown, the walking slide 51 of the gastrocnemius rolling machine 5 is slidably connected to the longitudinal bottom rail 11. The longitudinal bottom rail 11 can be set on both sides of the calf support groove 12, allowing the walking slide 51 to cross the calf support groove 12, or it can be set below the calf support groove 12 and drive the floating pressure frame 53 through the side arm. The longitudinal transmission component 52 can be a synchronous belt, chain, rack, or lead screw. In this embodiment, a low-speed synchronous belt is preferably used in conjunction with two end pulleys. The rolling output gear 65 drives the synchronous belt to move through a reduction mechanism, and the walking slide 51 is fixedly connected to the synchronous belt. The stroke detection component 511 is arranged along the longitudinal bottom rail 11, outputting the rolling machine position y in millimeters. The distal reset position corresponds to the position close to the ankle but avoiding the Achilles tendon attachment area, and the proximal reversal position corresponds to the device setting position below the proximal end of the gastrocnemius muscle belly.

[0029] A floating pressure frame 53 spans above the lower leg support groove 12, and its two sides are slidably connected to the traveling slide 51 via vertical guide rods. A compression spring 57 is sleeved on the vertical guide rods, allowing the floating pressure frame 53 to float up and down relative to the traveling slide 51. The left roller 54 and the right roller 55 are rotatably connected to the two ends of the pressure equalizing swing rod 56, and the middle part of the pressure equalizing swing rod 56 is hinged to the floating pressure frame 53. The pressure equalizing swing rod 56 allows the two rollers to swing at a small angle when the left and right heights of the lower leg cross-section are not completely consistent, so that both rollers contact the rear or rear outer area of ​​the lower leg together, reducing the situation where one roller contacts first and then bears the entire load.

[0030] The axes of the left roller 54 and the right roller 55 can be arranged laterally relative to the calf, or they can be tilted at opposite small angles. The oppositely tilted rollers create a slight tendency to converge towards the center as the traveling slide 51 moves proximally, causing the contact area to move forward with the rolling trolley, rather than repeatedly kneading in a fixed position. The outer layer of the rollers can be covered with an elastomer, with a smooth surface and no sharp protrusions. A flexible bushing 8 is located between the calf skin and the rollers. The bushing surface is made of a low-friction fabric, allowing the rollers to roll outside the bushing and transmit the compression to the calf without directly dragging the skin.

[0031] The pressure frame displacement detection element 58 is installed between the floating pressure frame 53 and the traveling slide 51 to output the pressure frame deformation δr. The equivalent stiffness of the compression spring 57 is kr, and the rolling force Fr can be calculated by the following formula: Fr = kr · δr In the formula, Fr is the equivalent rolling force transmitted by the floating pressure frame 53 through the left and right rollers, in N; kr is the equivalent stiffness of the compression springs 57 on both sides and the equalizing rocker arm 56 under the current structure, in N / mm; δr is the compression amount of the floating pressure frame measured by the pressure frame displacement detection element 58, in millimeters. The controller 7 provides the allowable rolling force range according to the equipment specifications and usage settings. If Fr is lower than the lower contact limit, it indicates that the rollers may not be in contact with the flexible bushing 8 or the floating pressure frame 53 may not be lowered; if Fr exceeds the upper rolling force limit, the controller 7 stops driving and controls the walking slide 51 to return to the preset distance in the opposite direction. The rolling force is only used for equipment load control and is not used as a basis for judging the condition of blood vessels, muscles, or pain level.

[0032] To identify when the rolling mill encounters folded bushings, sheet wrinkles, or transmission jamming during its movement, controller 7 calculates the rolling pressure gradient Gr when the absolute value of the displacement between two adjacent valid position samples is not less than the minimum calculated distance Δymin. Gr = |Fr(i) - Fr(i-1)| / |y(i) - y(i-1)| In the formula, Fr(i) and Fr(i-1) are the rolling pressure corresponding to adjacent effective positions, in N; y(i) and y(i-1) are the corresponding rolling position, in millimeters; Gr is in N / mm.

[0033] When |y(i)-y(i-1)| is less than Δymin, the current data is not used to update Gr to avoid amplification errors caused by the denominator approaching zero. When the rolling carriage travels a distance of Δymin and Fr suddenly increases, Gr exceeds the upper limit of the gradient change obtained by the standard calf model calibration. The controller 7 stops advancing towards the proximal end and causes the walking slide 51 to reverse. The display prompt 71 prompts the inspection of the flexible bushing 8 and the longitudinal transmission path.

[0034] like Figure 7 As shown, the power switch 6 enables a drive motor 61 to supply power to the counter-traction transmission mechanism 4 and the gastrocnemius rolling mill 5 at different stages. The drive motor 61 is connected to the common input shaft 62 via an overload release device 69. An axially movable sliding clutch sleeve 63 is provided on the common input shaft 62. The ankle swing output gear 64 and the rolling output gear 65 are respectively loosely or rotatably supported at different positions on the common input shaft 62. When the sliding clutch sleeve 63 moves to the ankle swing engagement position, it engages with the ankle swing output gear 64; when it moves to the rolling engagement position, it engages with the rolling output gear 65; and when it is in the intermediate position, it is in the disengaged position. The switching fork 66 is connected to the sliding clutch sleeve 63 and can be driven by a small switching actuator or by a cam and spring on the common input shaft.

[0035] The neutral permission cam 67 is located on the movement path of the switching fork 66. When the neutral locking tongue 37 has not entered the neutral positioning notch 36, the neutral permission cam 67 remains in the blocking position, and the switching fork 66 can only move the sliding clutch sleeve 63 from the ankle engagement position to the disengaged position at most, and cannot continue to enter the rolling engagement position. After the neutral locking tongue 37 enters the neutral positioning notch 36, it rotates the neutral permission cam 67 through the linkage, causing the blocking surface to leave the path of the switching fork 66. Only after the controller 7 receives the neutral permission signal N can it drive the switching actuator to make the sliding clutch sleeve 63 enter the rolling engagement position. Even if the controller 7 or the program mistakenly issues a switching command, as long as the foot swing arm 3 is not in the neutral locking state, the neutral permission cam 67 will still mechanically prevent the rolling output engagement.

[0036] The proximal reversing element 59 is located at the proximal end of the longitudinal bottom rail 11. When the traveling slide 51 reaches the proximal set position, the proximal reversing element 59 triggers the limit switch and pushes the limit switching protrusion 68, causing the sliding clutch sleeve 63 to first enter the disengaged position. The controller 7 then changes the direction of the drive motor 61, causing the sliding clutch sleeve 63 to re-engage the rolling output gear 65, and the traveling slide 51 returns from the proximal end to the distal end. The distal reset element 510 is located at the distal end of the longitudinal bottom rail 11. When the traveling slide 51 returns to the distal end and the Fr of the floating pressure frame 53 drops to the return allowable value, the distal reset element 510 releases the restriction on the switching fork 66, and the sliding clutch sleeve 63 can return to the ankle swing engagement position. Thus, the ankle micro-swing, neutral return, rolling forward, and rolling return are not only sequenced by a time program, but also form a mechanical state chain by the neutral locking tongue, the proximal reversing element, and the distal reset element.

[0037] An overload release device 69 is disposed between the drive motor 61 and the common input shaft 62. The overload release device 69 can be composed of end face teeth pressed by a preloaded spring, ball bearing grooves, or a friction disc. When the torque required by the common input shaft 62 exceeds the mechanical disengagement threshold, the meshing end faces slide apart, preventing the drive motor 61 from continuing to transmit high torque to the foot swing frame 3 or the gastrocnemius roller 5. The disengagement threshold of the overload release device 69 is higher than the maximum normal operating torque but lower than the torque that might damage the traction belt or roller, and is determined by bench testing. The controller 7 can identify overload disengagement by sudden changes in drive motor current and a decrease in output shaft speed, and enters a pause release state.

[0038] The manual release handle 72 is located on the outside of the supine support frame 1, allowing caregivers to pull it directly in case of power failure, controller malfunction, or when the patient needs to remove the device immediately. The manual release handle 72 acts simultaneously on the switching fork 66, the neutral locking tongue 37, and the floating pressure frame 53 via a cable or linkage. Pulling the handle causes the sliding clutch sleeve 63 to disengage, the neutral locking tongue 37 to retract from the neutral positioning notch 36, and the floating pressure frame 53 to be lifted, causing the left and right rollers to disengage from the flexible bushing 8. Because this release path does not rely on the drive motor 61 and controller 7 for power, the device can release foot traction and lower leg rolling contact when the electrical system is unavailable.

[0039] The flexible bushing 8 is detachably connected to the calf support groove 12. A directional positioning tongue 81 is provided at the distal end of the flexible bushing 8, and the calf support groove 12 forms a positioning socket only in a predetermined direction. A bushing positioning switch 82 is located within the positioning socket; the bushing positioning switch 82 is triggered only after the directional positioning tongue 81 is inserted into the correct position. If the flexible bushing 8 is installed in reverse, not fully unfolded, or not inserted, the controller 7 will not allow the sliding clutch sleeve 63 to enter the rolling engagement position. The flexible bushing 8 forms a continuous low-friction surface in the walking area of ​​the left and right rollers and forms clearance openings near the ankle alignment beam 2 and the positioning slide to prevent the bushing from obstructing the compliant positioning head 24 or affecting the coaxial support hole 25.

[0040] like Figure 8 As shown, the input signals of controller 7 include alignment lock signal A, medial malleolus positioning slide position qL, lateral malleolus positioning slide position qR, foot swing angle α, elastic deformation of the two traction belts, double-groove drum rotation angle change Δφd, rolling carriage position y, pressure frame deformation δr, neutral clearance signal N, proximal reversal signal, distal reset signal, bushing positioning signal, overload disengagement signal, and manual emergency stop signal. Controller 7 selects δt from the two elastic deformations based on the current traction direction. The output of controller 7 is connected to the start / stop and steering control terminals of drive motor 61, the switching actuator of switching fork 66, the electrically controlled release of neutral locking tongue 37, the reset of overload disengagement device 69, and the display prompt 71.

[0041] The controller 7 collects qL, qR, α, δt, Δφd, y, and δr at a fixed sampling period Ts, which can be selected from 20 milliseconds to 100 milliseconds. In one embodiment, Ts is 50 milliseconds. An n-point moving average is used for continuous variables, and the filtered value is calculated as Xavg(k) = (1 / n)·ΣX(kj), where X is the variable to be processed, j ranges from 0 to n-1, and n is determined by sensor noise and mechanical response time. Continuous effective counting is used to de-jitter the position lock signal A, neutral clearance signal N, near-end commutation signal, far-end reset signal, and bushing position signal. The controller 7 only confirms that the corresponding mechanical state has been established after the signal has been continuously valid for the confirmation time td.

[0042] Controller 7 generates the ankle micro-swing permission variable Gm and the gastrocnemius rolling permission variable Gp, respectively. The ankle micro-swing permission condition is: Gm=1 when A=1, Ec≤Ec,max, the manual emergency stop signal is invalid, the walking slide 51 is in the distal reset position, the floating pressure frame 53 is in the raised or low-load position and the sliding clutch sleeve 63 is in the ankle swing engagement position; otherwise, Gm=0.

[0043] The conditions for permissible gastrocnemius rolling are: Gp=1, when A=1, Ec≤Ec,max, bushing positioning signal is valid, manual emergency stop signal is invalid, neutral permission signal N is valid, |α-α0| does not exceed the upper limit of neutral angle difference and neutral permission cam 67 has released mechanical obstruction; otherwise, Gp=0. Ec,max is the upper limit of alignment deviation, and α0 is the neutral reference angle recorded in this usage. Controller 7 does not perform ankle traction when Gm=0, and does not allow the sliding clutch sleeve 63 to enter the rolling engagement position when Gp=0.

[0044] like Figure 9 As shown, the state machine of controller 7 includes initialization state S1, ankle alignment state S2, neutral verification state S3, ankle micro-swing state S4, neutral return state S5, gastrocnemius rolling state S6, rolling cart return state S7, and pause release state S8. In initialization state S1, the sliding clutch sleeve 63 is in the disengaged position, the drive motor 61 is stopped, the floating pressure frame 53 is in the raised or low-load position, and controller 7 reads the zero points of each sensor and checks the manual emergency stop signal. If the sensor zero point exceeds the allowable range of the equipment, the display prompt 71 outputs the corresponding component check prompt, and the device remains in the initialization state.

[0045] In ankle alignment state S2, the caregiver rotates the screw 21 left and right to bring the two compliant positioning heads 24 against the inner and outer ankle sides and closes the alignment lock sleeve 26. The controller 7 reads A, qL, and qR and calculates Ec. When A is valid and Ec does not exceed Ec,max, the controller 7 records the current alignment position as the mechanical alignment parameter used this time. If one positioning slide does not move, the center scale reading changes asymmetrically, or the alignment lock sleeve 26 is not closed, the controller 7 is not allowed to enter the neutral verification state. The caregiver can loosen the alignment lock sleeve 26 to readjust without removing the foot swing frame 3.

[0046] In neutral verification state S3, controller 7 keeps the sliding clutch sleeve 63 in the disengaged position. The nurse places the foot on the midfoot suspension 33 and the forefoot support 32, adjusting the longitudinal position of the forefoot support 32 and the tension of the midfoot suspension 33. The foot swing frame 3 can rotate with low resistance in a powerless state. The nurse moves the foot swing frame 3 close to a comfortable neutral position, the neutral locking tongue 37 enters the neutral positioning notch 36, controller 7 reads N and α, and records this position as the neutral reference angle α0. The neutral reference angle is determined by the device structure and the current swing frame position, and is not required to be fixed at an absolute 90 degrees for all patients. After recording α0, the position of the forefoot support 32 and the Rf value are simultaneously written into the current operating parameters.

[0047] Before entering the ankle micro-swing state S4, the controller 7 keeps the floating pressure frame 53 raised, confirms that the gastrocnemius roller 5 is in the distal reset position, and controls the sliding clutch sleeve 63 to enter the ankle swing engagement position. The first run uses a low-speed trial swing. The controller 7 simultaneously reads the current traction belt deformation δt, the change in the double-groove drum rotation angle Δφd, and the foot swing angle α, calculating Ft, αp, and Eα. Only after Ft and Eα are within the allowable range for the trial swing does the controller 7 increase the micro-swing amplitude to the set value. The set value is determined by the equipment specifications and the gear selected by the medical staff, and is not automatically generated by the controller 7 based on disease classification.

[0048] In the ankle micro-swing state S4, the ankle can first complete several reciprocating movements in the dorsiflexion and plantarflexion directions, or it can return to the neutral position after each unidirectional micro-swing. Regardless of the operating mode, before each directional reversal, the controller 7 first reduces the speed of the drive motor 61 and checks whether Ft decreases as the double-groove drum 44 rotates. If the double-groove drum 44 rotates but Ft does not decrease, it indicates that the traction belt may be stuck; if Ft decreases but α does not approach α0, it indicates that the foot swing frame 3 may be obstructed by external forces. At this time, the controller 7 enters the pause release state instead of continuing to execute the reversal.

[0049] After completing the set ankle micro-swing motion, the controller 7 enters the neutral return state S5. The drive motor 61 drives the double-groove drum 44 at a return speed lower than the actual micro-swing speed, causing the foot swing frame 3 to gradually approach α0. The neutral locking tongue 37 slides along the positioning plate. When the foot swing frame 3 enters the neutral allowable zone, the neutral locking tongue 37 enters the neutral positioning notch 36 and outputs N. After receiving N, the controller 7 stops the drive motor 61 and causes the sliding clutch sleeve 63 to first enter the disengaged position. Only when N remains valid and |α-α0| does not exceed the upper limit of the neutral angle difference will the neutral permission cam 67 be in the unblocked position, allowing the switching fork 66 to continue pushing the sliding clutch sleeve 63 into the rolling engagement position.

[0050] At the start of the gastrocnemius rolling state S6, the foot swing frame 3 is held in a neutral position by the neutral locking tongue 37, the upper and lower traction belts are under low pretension, and the power of the drive motor 61 is transmitted to the longitudinal transmission component 52 through the rolling output gear 65. The controller 7 first pushes the walking slide 51 a short distance towards the proximal end at a low speed, reads δr and calculates Fr. If Fr is lower than the contact lower limit, the controller 7 stops and prompts to lower the floating pressure frame 53 or check the flexible bushing 8; if Fr is within the allowable range, the walking slide 51 continues to move from the distal end to the proximal end. The rolling carriage position y is used to limit the starting and ending points of the rolling, and the controller 7 does not allow the walking slide 51 to cross the preset proximal boundary.

[0051] During the rolling motion, the left and right rollers 54 and 55 roll longitudinally along the lower leg with the floating pressure frame 53. The pressure equalizing swing arm 56 automatically swings according to the changes in the lower leg's cross-section, and the compression spring 57 absorbs local height changes. The controller 7 continuously calculates Fr and Gr. When Fr changes slowly and is within the allowable range, the rolling cart maintains the set speed; when Fr approaches the upper limit, the controller 7 reduces the walking speed; if Fr or Gr exceeds the upper limit, the controller 7 immediately stops and reverses, causing the floating pressure frame 53 to release some of the compression. This speed adjustment is based solely on mechanical load and does not automatically generate treatment intensity according to the patient's disease stage.

[0052] After the traveling slide 51 reaches the proximal reversing member 59, the controller 7 enters the return state S7 of the rolling carriage. The proximal reversing member 59 first disengages the sliding clutch sleeve 63. After the controller 7 confirms that the speed of the drive motor 61 has dropped to zero, it changes direction and then re-engages the rolling output gear 65. During the return stroke, the floating pressure frame 53 can maintain a low rolling force or be slightly raised by the lifting mechanism, so that the left and right rollers 54 and 55 return to the far end with a small contact load. After the traveling slide 51 reaches the far-end reset member 510, the sliding clutch sleeve 63 disengages again. The controller 7 checks y and Fr to confirm that the rolling carriage has returned to a position where the next cycle can begin.

[0053] Figure 10 An alternating cycle is shown. Both ankle dorsiflexion and plantarflexion micro-oscillations are completed by the ankle swing output branch, entering the neutral return phase after the set action is completed. The power converter 6 only allows the rolling output engagement after the neutral locking tongue 37 enters the neutral positioning notch 36 and the foot swing angle α enters the neutral allowable zone. After the gastrocnemius rolling forward and rolling carriage return are completed, the distal reset member 510 returns the sliding clutch sleeve 63 to the disengaged position and restores the mechanical permission of the ankle swing output. The two output gears will not engage with the common input shaft 62 simultaneously.

[0054] The conditions for entering the pause release state S8 include interruption of the alignment lock signal A, Ec exceeding the limit, Ft exceeding the limit, continuous Eα exceeding the limit, Fr exceeding the limit, Gr exceeding the limit, the rolling carriage position y not following the drive command, abnormal loss of the neutral permission signal N, failure of the bushing positioning signal, activation of the overload release device 69, and a manual emergency stop signal. Upon entering S8, the controller 7 first stops the drive motor 61 and moves the sliding clutch sleeve 63 into the disengaged position. If the abnormality occurs in the ankle micro-swing state and the traction force is still within the release range, the controller 7 can briefly reverse the low-speed drive of the double-groove drum 44 to lower Ft and bring the foot swing frame 3 closer to neutral; if the abnormality type does not allow automatic return, the caregiver pulls the manual release handle 72 to release the traction.

[0055] If an abnormality occurs during the calf rolling process, the controller 7 first disengages the sliding clutch sleeve 63, and then determines whether to allow the walking slide 51 to reverse based on Fr and y. If Fr is only slightly exceeded and the longitudinal transmission component 52 is not jammed, the controller 7 can reverse a short distance; if the overload disconnector 69 has already activated or the position does not follow, the controller 7 will not re-engage the power, but will instead prompt the nursing staff to lift the floating pressure frame 53 and check the rolling path. The display prompts 71 are limited to equipment statuses such as "alignment lock not closed", "abnormal traction load", "foot swing frame not following", "rolling contact too high", "rolling cart not returned to position", and "shield not in place".

[0056] The device parameters are structurally calibrated at the factory. The pitch of the left and right lead screws 21 and the symmetry of the two positioning slides can be checked with standard gauge blocks; the coaxiality of the coaxial support hole 25 can be measured by inspecting the mandrel; the angle encoder 35 reading at the neutral positioning notch 36 of the foot swing frame 3 is set to zero or reference position. Each locking position of the forefoot support strap 32 corresponds to an Rf value. During manufacturing, the distance from the device's swing axis to the main force point of the forefoot support strap 32 can be measured with measuring tools and recorded in the position table. In this way, the controller 7 does not need to estimate Rf based on the patient's disease state during use.

[0057] The kt of the series elastic coupling 45 is calibrated using a standard tension table. During calibration, the traction belt is fixed, and the output of the elastic displacement detection plate 46 is recorded at different tension points to obtain the force-displacement curve within the effective stroke. If the calibrated spring is approximately linear within the effective range, Ft=kt·δt can be used; if there is repeatable nonlinearity, a segmented calibration table can be stored in the controller 7, but the correspondence between the elastic deformation and the traction force as described in the claims is still generated by the specific elastic coupling. The rd of the double-groove drum 44 is determined by the groove size and remains approximately constant within the range of the actual winding of one layer of the traction belt.

[0058] The compression spring 57's kr is calibrated using a standard compression table. After the left and right rollers 54 and 55 and the equalizing rocker arm 56 are assembled, a standard arc-shaped model is used to replace the lower leg. Different compression amounts are applied to the floating pressure frame 53, and the output of the pressure frame displacement detection device 58 is recorded. This yields the correspondence between Fr and δr. Different lower leg circumference specifications can use equalizing rocker arms 56 of different lengths and compression springs 57 of different stiffnesses. Each specification corresponds to a set of kr, rolling allowable range, and longitudinal stroke boundaries. The specification parameters are stored in the controller 7 or a detachable specification identification device.

[0059] In use, the nurse first places the supine support frame 1 on the bed surface and fixes the bed connecting seat 13, so that the longitudinal bottom rail 11 is roughly parallel to the patient's lower leg. Then, the gastrocnemius muscle roller 5 is placed in the distal reset position and the floating pressure frame 53 is raised. The cleaned flexible sleeve 8 is inserted into the lower leg support slot 12 according to the directional positioning tongue 81. After the patient's lower leg is placed in the lower leg support slot 12, the nurse adjusts the medial malleolus positioning slide 22 and the lateral malleolus positioning slide 23 so that the compliant positioning head 24 gently abuts against the sides of the medial and lateral malleoli, respectively, and then closes the alignment lock sleeve 26. After the controller 7 confirms A and Ec, it enters the neutral verification.

[0060] The patient's foot is then placed in the foot swing frame 3, with the heel positioned above the heel pressure relief window 34. The midfoot is supported by the midfoot suspension belt 33, and the forefoot by the forefoot support belt 32. When adjusting the position of the forefoot support belt 32, it should be positioned within the stable force-bearing area of ​​the forefoot, without acting on the toes. The inversion flexible restraint plate 38 and the eversion flexible restraint plate 39 only need to maintain light contact with the lateral edge of the foot. The nursing staff rotates the foot swing frame 3 to the neutral position without power. After the neutral locking tongue 37 enters the neutral positioning notch 36, the controller 7 records α0 and Rf. Only after the trial swing confirmation is completed does the device enter formal alternation operation.

[0061] In one parameter example, the unilateral micro-oscillation amplitude of the foot swing frame 3 relative to the neutral reference angle α0 is 3 to 8 degrees, and the angular velocity is 0.5 to 3 degrees per second; the forward speed of the gastrocnemius roller 5 is 2 to 15 millimeters per second. The upper limit of traction is jointly determined by the rated load of the traction belt, the calibration range of the elastic connector 45, and the load-bearing structure of the forefoot support belt 32, while the upper limit of rolling is jointly determined by the specifications of the compression spring 57, the roller contact width, and the effective stroke of the floating pressure frame 53. The above parameters are used to illustrate the correspondence between structural quantities, detection quantities, and control quantities, and do not constitute a treatment prescription uniformly applicable to all patients.

[0062] In another embodiment, the upper traction belt 41 and the lower traction belt 42 can be connected to two coaxial drums respectively. The two drums are synchronized by a counter-gear, so that when one traction belt tightens, the other traction belt is released. This structure still retains the counter-traction relationship, the series elastic coupling 45, and the verification relationship of the angle encoder 35. The double-groove drum 44 can also be driven by a worm gear reducer to improve the self-holding capability after stopping, but an overload release device 69 and a manual release handle 72 are still required to prevent the self-locking transmission from being unable to disengage when the power is off.

[0063] In alternative implementations, the compliant positioning head 24 can be a spherical pressure head, a swingable pad, or an arc-shaped positioning block with an elastic layer. The alignment locking sleeve 26 can lock the left and right turn screws 21, or it can lock the two positioning slides separately. If the two positioning slides are locked separately, the center scale 27 and Ec verification are still used to confirm that the midpoint of the two positioning slides has not deviated from the fixed center seat. Regardless of the positioning head used, the two coaxial support holes 25 should move with the corresponding positioning slides so that the support axis of the foot swing frame 3 is formed by the position of the positioning slides.

[0064] In a further embodiment, the heel pressure relief window 34 can be fitted with a detachable heel suspension strap. The heel suspension strap is installed only when the patient's heel requires auxiliary support; its two ends are connected to the arc-shaped support edges of the foot swing frame 3, forming a flexible suspension below the center of the heel. The heel suspension strap does not serve as a source of ankle axis alignment signals, nor does it participate in dynamic switching authorization. This allows for selection of suspension or light support based on the condition of the heel skin, without altering the core structure of medial and lateral malleolar alignment, superior and inferior traction, and neutral mechanical authorization.

[0065] In another embodiment, the gastrocnemius rolling machine 5 can be equipped with a single wide roller and two guide rollers on both sides. The wide roller is connected to the floating pressure frame 53 via ball joints to adapt to the lateral curvature of the calf. The preferred left and right double roller structure has a pressure equalizing swing rod 56, which facilitates respectively conforming to the two rear sides of the calf while retaining a middle avoidance area. The hardness, diameter, and axial length of the outer layer of the roller can be adjusted according to the device specifications, but the rolling force Fr is still obtained by the deformation of the floating pressure frame 53 relative to the traveling slide 51, and the rolling machine position y is still obtained by the stroke detection element 511 on the longitudinal bottom rail 11.

[0066] The power converter 6 can also use electromagnetic gear clutches to connect the ankle swing output gear 64 and the rolling output gear 65 respectively. However, a mechanical isolation baffle driven by the neutral locking tongue 37 is still provided between the two clutches, so that the rolling clutch cannot be closed when the neutral locking tongue 37 has not entered the neutral positioning notch 36. Compared with simply setting the two electromagnetic clutches to be mutually exclusive in the software, the mechanical isolation baffle retains the physical constraint that the rolling output can only be engaged after the foot returns to the neutral position.

[0067] The device can be configured for a low-power standby mode. When the foot swing arm 3 is locked by the neutral locking tongue 37 and the gastrocnemius roller 5 is in the distal reset position, the controller 7 reduces the sampling frequency of non-critical analog quantities, but continues to monitor the A, N, manual emergency stop signals, and the overload disengagement device 69 status. Upon any change in critical status, the controller 7 resumes normal sampling and maintains the disengaged sliding clutch sleeve 63. The low-power mode does not cancel the mechanical neutral permission and manual release path.

[0068] Storage unit 73 can record the alignment position qL, qR, Ec, front foot bearing position, micro-swing peak value α, traction peak value Ft, number of times the angular residual exceeds the limit, rolling pressure peak value Fr, number of times the rolling carriage travels back and forth, number of times it disengages due to overload, and number of times it is manually released for each operation. This record is used for equipment maintenance and operation process verification. For example, if Eα exceeds the limit multiple times while Ft is low, check whether the traction belt is slipping or whether the front foot bearing is locked; if Gr suddenly increases multiple times, check whether the flexible bushing 8 is wrinkled or whether the longitudinal bottom rail 11 needs cleaning. Storage unit 73 does not need to store disease diagnosis information.

[0069] To verify the manufacturing consistency of the device, bench tests can be conducted using an ankle model and a lower leg model. The ankle model has adjustable inner and outer ankle widths and a known axis of rotation. By adjusting the left and right lead screws 21 respectively, it is checked whether the device's swing axis formed by the coaxial support hole 25 corresponds to the model's axis of rotation. The double-groove drum 44 is driven to output different rotation angles, and the αp and α of the angle encoder disk 35 are compared to confirm that Eα is within the design range. A known resistance is applied in the traction path, and it is checked whether the drive motor 61 stops and returns to its original position after Ft exceeds the limit. The lower leg model has different cross-sectional heights and configurable local protrusions, which are used to check the fit of the equalizing pendulum 56, Fr calculation, Gr anomaly identification, and reverse return action.

[0070] The reliability of the power engagement can be verified through repeated cyclic tests. In the test, the foot swing arm 3 is intentionally kept in a dorsiflexion or plantarflexion position, and a rolling engagement command is sent to the engagement actuator. It is observed whether the neutral permission cam 67 prevents the sliding clutch sleeve 63 from entering the rolling engagement position. Then, the foot swing arm 3 is returned to the neutral positioning notch 36, and it is checked whether the neutral locking tongue 37, N, and engagement shift fork 66 operate in sequence. Engaging the ankle swing output can also be attempted before the rolling carriage returns to the distal end to verify whether the distal reset element 510 maintains mechanical obstruction. The above tests are used to confirm that the mechanical permission chain functions independently of software timing parameters.

[0071] The controller 7 of this device only processes displacement, angle, elastic deformation, position, and switch status signals generated by the device structure, and outputs drive motor start / stop, direction, power switching, stop, retraction, and equipment status prompts. Alignment deviation Ec, traction force Ft, angular residual Eα, rolling force Fr, and rolling force change gradient Gr are all used for equipment operation control and are not used to determine deep vein thrombosis, muscle tone level, nerve recovery degree, or other disease states.

[0072] Thus, the ankle alignment beam 2 first forms a swing axis that adjusts with the position of the medial and lateral ankles through two coaxial support holes 25; the counter-traction transmission mechanism 4 drives the foot swing frame 3 on this axis, and the elastic connector 45 and the angle encoder 35 verify the traction load and angular response; after the foot swing frame 3 returns to the neutral position, the neutral locking tongue 37 and the neutral permission cam 67 allow the shared drive motor 61 to switch to the gastrocnemius rolling machine 5; the floating pressure frame 53 and the pressure equalizing swing rod 56 cause the left and right rollers to move longitudinally along the lower leg and limit the rolling pressure. The above alignment state, load state and neutral state constitute the mechanical or signal prerequisites for subsequent actions in sequence.

Claims

1. A rehabilitation device for stroke patients with alternating actuation of the ankle and lower leg, characterized in that, A supine support frame has a calf support groove formed along the longitudinal direction of the patient's lower leg, and an ankle axis alignment beam is laterally fixed at the corresponding position of the ankle in the calf support groove; The ankle axis alignment beam is slidably connected to the medial malleolus positioning slide and the lateral malleolus positioning slide on both sides. The medial malleolus positioning slide and the lateral malleolus positioning slide are threaded together to a left-hand and right-hand screw with oppositely helical threaded sections, so that the compliant positioning heads on the two positioning slides move towards each other at equal distances. The medial malleolus positioning slide and the lateral malleolus positioning slide respectively form coaxial support holes. After the two compliant positioning heads are respectively attached to the patient's medial malleolus and lateral malleolus and locked by the alignment lock sleeve, the center line of the two coaxial support holes forms the swing axis of the device. The alignment lock detection element outputs the alignment lock signal A when the alignment lock sleeve is in the locked position. The foot swing frame has lateral arms on both sides that are rotatably supported by two coaxial support holes. The foot swing frame supports the patient's foot through a midfoot suspension strap and a forefoot support strap, enabling the foot swing frame to perform low-amplitude micro-swings in the dorsiflexion and plantarflexion directions around the swing axis of the device. The traction transmission mechanism has an upper traction belt and a lower traction belt that extend from the instep and sole sides of the forefoot support, respectively. These belts are connected to a double-groove drum via a guide wheel in opposite directions, causing the double-groove drum to tighten one traction belt and simultaneously release the other as it rotates. Elastic couplings are connected in series along the force paths of the upper and lower traction belts. The deformation of each elastic coupling is output by a corresponding elastic displacement sensor. The rotation position of the foot swing frame is output as the foot swing angle α by an angle encoder. A neutral positioning notch is formed on the rotating side of the foot swing frame, and a centering point is elastically offset towards this notch on the horizontal support frame. The neutral locking tongue triggers a neutral permission detection contact and outputs a neutral permission signal N when it enters the neutral positioning notch, simultaneously driving the neutral permission cam away from the movement path of the switching fork. A power switch has a common input shaft driven by a drive motor. A sliding clutch sleeve on the common input shaft can axially switch between the ankle swing output gear, the disengaged position, and the rolling output gear. The ankle swing output gear is connected to the double-groove drum drive. When the neutral locking tongue does not enter the neutral positioning notch, the neutral permission cam restricts the switching fork between the ankle swing engagement position and the disengaged position, preventing the sliding clutch sleeve from entering the rolling engagement position. The gastrocnemius muscle rolling machine has a traveling slide slidably connected to the longitudinal bottom rail of the supine support frame. A floating pressure frame is provided on the traveling slide, spanning above the calf support groove. The floating pressure frame supports the left and right rollers through a compression spring and a pressure equalizing swing rod. The traveling slide is driven by a longitudinal transmission component connected to the rolling output gear to move along the distal to proximal end of the calf. The stroke detection device outputs the rolling machine position y, and the pressure frame displacement detection device outputs the pressure frame deformation δr of the floating pressure frame relative to the traveling slide. The controller is connected to the alignment locking detection element, the elastic displacement detection piece, the angle encoder disk, the stroke detection element, the neutral permission detection contact, the pressure frame displacement detection element, the drive motor, and the power converter. When the alignment locking signal A is valid, the sliding clutch sleeve is in the ankle swing engagement position, the traction force corresponding to the deformation of the elastic connector does not exceed the traction upper limit, and the angular residual between the foot swing angle α and the predicted swing angle corresponding to the double-groove drum rotation angle does not exceed the residual upper limit, the controller controls the drive motor to rotate forward and backward to enable the foot swing frame to complete low-amplitude dorsiflexion micro-swing and low-amplitude plantarflexion micro-swing. The controller controls the foot swing frame to return to neutral position. After the angle range, the neutral permission signal N is valid, and the neutral permission cam releases the mechanical obstruction of the shift fork, the sliding clutch sleeve is controlled to enter the rolling engagement position from the disengaged position, and the gastrocnemius rolling trolley is controlled to move from the distal end to the proximal end and then return to the distal end; when any of the following abnormalities occur, such as the alignment lock signal A fails, the traction force exceeds the traction limit, the angle position residual continuously exceeds the residual limit, the rolling force corresponding to the pressure frame deformation δr exceeds the rolling limit, the rolling trolley position y does not change with the drive command, or the neutral permission signal N is abnormally lost, the drive motor is controlled to stop and the sliding clutch sleeve enters the disengaged position.

2. The alternating drive device for ankle axis alignment micro-oscillation and gastrocnemius muscle rolling in stroke hemiplegic patients according to claim 1, characterized in that, The middle part of the left and right helical screws is rotatably supported on the fixed center seat of the ankle axis alignment beam. The medial malleolus positioning slide and the lateral malleolus positioning slide are respectively threaded to the left-hand threaded section and the right-hand threaded section on both sides of the left and right helical screws. The two compliant positioning heads are respectively connected to the corresponding positioning slides through universal pressure seats, so that the compliant positioning heads can deflect with the local bony contour after they are close to the medial and lateral malleolus sides. The ankle axis alignment beam is provided with a center scale for reading the lateral positions qL and qR of the two positioning slides. qL and qR are signed positions relative to the same lateral coordinate origin. The controller calculates the alignment deviation Ec according to Ec=|(qL+qR) / 2-qC|, where qC is the lateral coordinate of the fixed center seat. The controller forms the ankle swing allowable condition only when the alignment locking signal A is valid and the alignment deviation Ec does not exceed the preset alignment upper limit.

3. The ankle axis alignment micro-oscillation and gastrocnemius muscle rolling alternating drive device for stroke hemiplegic patients according to claim 1, characterized in that, The rear of the foot swing frame forms a heel pressure relief window below the swing axis of the device. The heel pressure relief window is surrounded by arc-shaped load-bearing edges on both sides of the heel. The two ends of the midfoot suspension strap are respectively connected to the two side support arms. The forefoot support strap is slidably connected to the foot swing frame along the length of the foot and is fixed by a length locking member, so that the midfoot and forefoot form a suspension path that crosses the heel pressure relief window. The inner and outer sides of the foot swing frame are respectively provided with inward flexible limiting plates and outward flexible limiting plates. The inward flexible limiting plates and the outward flexible limiting plates restrict the foot from deviating from the traction plane where the upper and lower traction straps are located without pressing against the center of the heel.

4. The alternating drive device for ankle axis alignment micro-oscillation and gastrocnemius muscle rolling in stroke hemiplegic patients according to claim 1, characterized in that, The double-groove drum forms an upper and lower groove with opposite spiral directions and the same effective winding radius. The upper traction belt and the lower traction belt are fixed to the upper groove and the lower groove, respectively. Two guide wheels are respectively set on the instep-side traction path and the sole-side traction path of the forefoot support belt. The release sides of the upper and lower traction belts pass through a compensating wheel supported by a tension spring. When the double-groove drum changes its rotation direction, the release side traction belt is pre-tensioned by the compensating wheel and kept in the guide groove of the corresponding guide wheel.

5. The alternating drive device for ankle axis alignment micro-oscillation and gastrocnemius muscle rolling in stroke hemiplegic patients according to claim 1, characterized in that, Each elastic connector has a guide sleeve, a calibration spring set in the guide sleeve, and a measuring slider that moves with the compression of the calibration spring. The corresponding elastic displacement detection piece is set along the moving direction of the measuring slider. The controller selects the traction deformation δt and the corresponding calibration spring stiffness kt according to the currently tightened traction belt, and calculates the traction force Ft according to Ft=kt·δt. The controller calculates the predicted swing angle αp according to αp=(rd·Δφd / Rf)·180 / π based on the signed angle change Δφd of the double groove drum relative to the neutral position, the effective winding radius rd of the double groove drum, and the equivalent force arm Rf of the front foot bearing relative to the swing axis of the device. Then, it forms the angular position residual Eα according to Eα=|α-αp|. When the traction force Ft exceeds the traction limit or the angular position residual Eα continuously exceeds the residual limit to reach the preset sampling number, the controller controls the drive motor to stop the current direction movement, and controls the drive motor to run in reverse at low speed when the traction force is within the allowable return range, until the neutral locking tongue enters the neutral positioning notch.

6. The alternating drive device for ankle axis alignment micro-oscillation and gastrocnemius muscle rolling in stroke hemiplegic patients according to claim 1, characterized in that, The two sides of the floating pressure frame are slidably connected to the traveling slide via vertical guide rods, and two compression springs are respectively sleeved on the vertical guide rods; the left roller and the right roller are rotatably connected to the two ends of the pressure equalizing swing rod, and the middle part of the pressure equalizing swing rod is hinged to the floating pressure frame, so that the two rollers can float in opposite directions according to the height difference of the lower leg cross section; the pressure frame displacement detection device is set between the floating pressure frame and the traveling slide; the controller calculates the rolling force Fr according to Fr=kr·δr, where kr is the equivalent stiffness formed by the compression spring and the pressure equalizing swing rod; when the rolling force Fr is within the allowable rolling force range, the controller moves the traveling slide from the far end to the near end; when the rolling force Fr exceeds the upper limit of the rolling force, the controller stops the traveling slide and makes it retreat a preset distance in the opposite direction.

7. The alternating drive device for ankle axis alignment micro-oscillation and gastrocnemius muscle rolling in stroke hemiplegic patients according to claim 1, characterized in that, The switching fork is connected to the sliding clutch sleeve and moves along the axial direction of the common input shaft between the ankle engagement position, the disengagement position, and the rolling engagement position; the neutral permission cam is connected to the neutral locking tongue through a connecting rod, and restricts the switching fork between the ankle engagement position and the disengagement position when the neutral locking tongue has not entered the neutral positioning notch; a proximal reversing member is provided at the proximal end of the longitudinal bottom rail, and when the traveling slide reaches the proximal end, the proximal reversing member pushes the travel switching protrusion to make the sliding clutch sleeve enter the disengagement position first; a distal reset member is provided at the distal end of the longitudinal bottom rail, and after the traveling slide returns to the distal end, the distal reset member releases the mechanical obstruction in the ankle engagement direction, so that the ankle micro-swing, neutral locking, rolling forward, rolling return, and ankle reset form a mechanical permission chain in sequence.

8. The alternating drive device for ankle axis alignment micro-oscillation and gastrocnemius muscle rolling in stroke hemiplegic patients according to claim 1, characterized in that, A flexible bushing is detachably connected inside the calf support groove. The flexible bushing forms a continuous low-friction rolling surface in the walking area of ​​the left and right rollers, and a directional positioning tongue is provided at one end near the ankle. The calf support groove forms a positioning socket only on the side corresponding to the directional positioning tongue. A bushing positioning switch is provided in the positioning socket. Only after the directional positioning tongue is inserted into the positioning socket and the bushing positioning switch is triggered will the controller allow the sliding clutch sleeve to enter the rolling engagement position.

9. The alternating drive device for ankle axis alignment micro-oscillation and gastrocnemius muscle rolling in stroke hemiplegic patients according to claim 1, characterized in that, An overload release device is provided between the common input shaft and the drive motor. The overload release device has an engagement end face pressed by a pre-tensioned spring, and separates the common input shaft from the drive motor when the input torque exceeds the mechanical disengagement threshold. A manual release handle is provided on the outside of the horizontal support frame. The manual release handle is connected to the switching fork, the neutral locking tongue, and the floating pressure frame respectively through a cable. When the manual release handle is pulled, the sliding clutch sleeve enters the disengagement position in sequence, the neutral locking tongue exits the neutral positioning notch, and the floating pressure frame is lifted, so as to release the foot traction and lower leg rolling contact in the event of power failure or abnormal drive.

10. The alternating drive device for ankle axis alignment micro-oscillation and gastrocnemius muscle rolling in stroke hemiplegic patients according to claim 1, characterized in that, The controller has four states: initialization, ankle alignment, neutral verification, ankle micro-swing, neutral return, gastrocnemius rolling, rolling cart return, and pause / release. In the initialization state, the controller disengages the sliding clutch and reads the initial values ​​of each sensor. In the ankle alignment state, it confirms the alignment lock signal A and alignment deviation Ec. In the neutral verification state, it confirms the neutral permission signal N and the foot swing angle α. In the ankle micro-swing state, it controls the forward and reverse rotation of the double-groove drum based on the traction force Ft and the angle residual Eα. In the neutral return state, it controls the foot swing frame to enter the middle position at low speed. The controller establishes a positioning notch and, in the gastrocnemius rolling state, controls the traveling slide to move towards the near end based on the rolling pressure Fr and the rolling carriage position y. In the rolling carriage return state, it controls the traveling slide to return to the far end. When any of the following abnormalities occur in any operating state: alignment lock failure, traction force exceeding the limit, continuous angular position residual exceeding the limit, rolling pressure exceeding the limit, rolling carriage position not following, abnormal loss of neutral permission signal, bushing position signal failure, or manual emergency stop signal, the controller enters a pause release state, controls the drive motor to stop, disengages the sliding clutch sleeve, and outputs a device status prompt corresponding to the source of the abnormality through the display prompt.

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