Abstract:
A gait training apparatus is provided, and includes a frame, and two robotic limb movement assemblies that are connected to the frame. Each of the limb movement assemblies is adapted to receive a leg of a patient, and comprises a plurality of sections, each of which is provided with devices to move that portion of a patient&#39;s leg that is received therein.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a gait training apparatus for emulating a patient&#39;s normal or physiological gait cycle.  
           [0002]    After an accident, disease or the like leaves a patient with a damaged or otherwise impaired leg, it is necessary to provide rehabilitation to restore mobility to the patient&#39;s leg. Although exercise rehabilitation equipment is, of course, known in a variety of embodiments, the heretofore known equipment relies heavily on a gait therapist to help deliver a desired training gait to a patient, for example while they walk on a treadmill. The patient is supported in a harness, while one or more therapists hold the patient&#39;s legs and move them through the desired motion. In addition to being highly labor intensive, such apparatus make it difficult to maintain repeatability and consistency in the gait motion, especially from one session to the next.  
           [0003]    In an attempt to remedy the foregoing situation, gait trainers have been developed in which a patient&#39;s legs are positioned on footplates that move backward and forward, as well as vertically. Unfortunately, none of the known apparatus allow for emulation of a normal or physiological gate cycle, and at best allow for non-physiological movement.  
           [0004]    It is therefore an object of the present invention to provide a gait training apparatus that allows for true emulation of a patient&#39;s normal or physiological gait cycle.  
         SUMMARY OF THE INVENTION  
         [0005]    The object of the present invention is realized by a gait training apparatus that comprises a frame, and two robotic limb movement assemblies that are connected to the frame, wherein each of the limb movement assemblies is adapted to receive a leg of a patient, and wherein each of the limb movement assemblies comprises a plurality of sections, each of which is provided with means to move that portion of the patient&#39;s leg that is received therein.  
           [0006]    In conjunction with the inventive apparatus, after a patient&#39;s normal gait is analyzed, this data is used to control the robotic limb movement assemblies and hence the gait of the impaired leg.  
           [0007]    Pursuant to further specific embodiments of the present invention, each limb movement assembly can comprise two or more sections, and in particular a thigh movement assembly and a calf movement assembly, as well as optionally a hip movement assembly. Each of the sections of the limb movement assemblies may be operatively connected and controlled in an interrelated manner.  
           [0008]    The various sections of the limb movement assemblies can be provided with actuating means to effect movement of a portion of a patient&#39;s leg received therein. Such actuating means can be computer controlled linear actuators, which can be of a piston/cylinder type. Each of the sections of the limb movement assemblies can also be provided with an adjustable guide rod, such as a telescoping guide rod. Further specific features of the present invention will be described in detail subsequently. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The object and advantages of the present invention will appear more clearly from the following specification in conjunction with the accompanying schematic drawings, in which:  
         [0010]    [0010]FIG. 1 is a pictorial illustration of a preferred embodiment of the unitary device for patient gait training of the present invention.  
         [0011]    [0011]FIG. 2 is an exploded view of the lower limb movement means showing how the various parts are assembled.  
         [0012]    [0012]FIG. 3 is a front section view along the section  3 - 3  of FIG. 1 showing the construction of the lower limb movement means of the present invention.  
         [0013]    [0013]FIG. 3 a  is a detail section view of FIG. 3 showing the connection between height adjuster and the hip actuator assembly.  
         [0014]    [0014]FIG. 3 b  is a detail section view of FIG. 3 showing the connection between the hip assembly and the upper leg movement assembly.  
         [0015]    [0015]FIG. 3 c  is a detail section view of FIG. 3 showing the connection between the thigh assembly and the lower leg movement assembly.  
         [0016]    [0016]FIG. 4 is an exploded view of the height adjuster assembly showing how the parts are assembled.  
         [0017]    [0017]FIG. 5 is an exploded view of the hip assembly showing how the various parts are assembled.  
         [0018]    [0018]FIG. 6 is an exploded view of the thigh assembly showing how the various parts are assembled.  
         [0019]    [0019]FIG. 7 is an exploded view of the calf assembly showing how the various parts are assembled.  
         [0020]    [0020]FIG. 8 is a pictorial illustration of a typical treadmill use of a preferred embodiment of the present invention, showing the device in use by a patient using a treadmill.  
         [0021]    [0021]FIG. 9 is a side detail view showing the patient&#39;s leg attached to the lower limb movement means. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0022]    [0022]FIG. 1 shows a preferred embodiment of the unitary device  21  for gait training of the present invention. The unitary device  21  includes a support frame or means  22 , and two powered lower limb movement means  23 . The lower limb movement means  23  are secured to the support means  22  via bolts  70  that are attached to two swing-arm elements  31  and linear actuator  32 . Provision for attachment of a patient harness to the support means  22  (in a well-known manner) is provided by eyebolts  69  and securing nut means  69   a  (see also FIG. 8).  
         [0023]    [0023]FIG. 2 is an exploded view showing the construction of one of the lower limb movement means  23 . The lower limb movement means  23  is comprised of a height adjuster assembly  24 , a hip movement assembly  25 , a thigh movement assembly  27 , and a calf movement assembly  29 . The height adjuster assembly  24  is attached to the hip movement assembly  25  via a bearing mounted through holes in support plate elements  57  and  58 . In addition, a bolt  41  and a nut  41   a  attach the linear actuator  56  to the support plate elements  58 . The bearing comprises an axle  33 , two anti-friction (ball) bearing elements  34 , a bearing holder  35 , spacers  36  and  37 , an end plate  38 , a lock washer  39 , and an axle nut  40 . Assembled bearing components are best seen in section as shown in FIGS. 3 and 3 a . The hip movement assembly  25  is attached to the thigh movement assembly  27  via a bolt  42  protruding through the upper end of the linear actuator  49  and through the hip movement assembly  25 . In addition, holes in the support plates  48  and various parts of the hip movement assembly are fitted with a bearing allowing rotation between the hip movement assembly  25  and the thigh movement assembly  27 . The bearing is comprised of an axle  43 , two anti-friction bearings  34 , a bearing holder  35 , spacers  44 ,  45 , and  46 , an end plate  38 , a washer  39 , and an axle nut  40 . Assembled hip movement assembly  25  and thigh movement assembly  27  are best shown in FIG. 3 b . In a similar manner, the thigh movement assembly  27  is attached to the calf movement assembly  29  via a bolt  41  inserted through the hole in the upper end of the linear actuator  67  and support plates  47 . In addition, the thigh movement assembly  27  is attached to the calf movement assembly  29  via a bearing inserted in holes in the support plates  68  and  47 . The bearing is comprised of an axle  33 , two anti-friction (ball) bearing elements  34 , a bearing holder  35 , spacers  36  and  37 , an end plate  38 , a lock washer  39 , and an axle nut  40 . Bearing  75  is best shown assembled in FIG. 3 c.    
         [0024]    [0024]FIG. 4 is an exploded view showing the construction of the height adjuster assembly  24 . As shown, on the lower end of the assembly, two linear actuators  59  and a guide rod  60  are constrained by support plate elements  58  in conjunction with threaded fasteners  41  and securing nuts  41   a . On the upper end of the assembly, the linear actuator  59  and the guide rod  60  are constrained by support plate elements  62 . A spacer element  63  serves to maintain appropriate distance between the support plate elements  62 . Two brackets  61  are attached to the support plate elements  62  using threaded fasteners  41  and  41   a . The swing-arm elements  31  are attached to the brackets  61  with bolts  72  in such a manner as to allow rotation of the swing-arm elements  31  about the bolts  72 . Linear actuator  32  is attached to the lower bracket  61  using bolt  72 . Preferably, the support plates  62  and brackets  61  are constructed of sheet metal, either steel or aluminum. The linear actuators  59  are of any commonly available commercial type (hydraulic, pneumatic, or electrical) suitable for the load and movement requirements of the height adjuster assembly  24 .  
         [0025]    [0025]FIG. 5 is an exploded view showing the assembly of the various components of the hip movement assembly  25 . As shown, on the upper end of the assembly, a linear actuator  55  and a guide rod  54  are constrained by two support plate elements  57  and threaded fasteners  41  and securing nuts  41   a . The attachment of the linear actuator  55  to the support plates  57  is in a manner that allows free rotation of the linear actuator about the fastener  41 . On the lower end of the assembly, two sets of support plates  52  and spacer  53  along with threaded fasteners  42  and securing nuts  42   a  constrain the guide rod  54  and the linear actuators  55  and  56 , as shown. The linear actuators  55  and  56  are attached in such a way as to allow free rotation about the fasteners  42 . Preferably, the support plate elements  57  and  52  are made of sheet metal, either steel or aluminum. The guide rod  54  comprises two concentric tubing elements arranged to limit motion to that along their shared primary axis, for example in a telescoping manner.  
         [0026]    [0026]FIG. 6 is an exploded view showing the construction of the thigh or upper leg movement assembly  27 . On the upper end of the assembly, a linear actuator  50  and guide rod  51  are held by support plates  48  and threaded fasteners  41  and  41   a . On the lower end of the assembly, linear actuators  49  and  50  and the guide rod  51  are held by support plate elements  47  and threaded fasteners  41  and  41   a . Upper leg holder  28  is attached to support plate elements  47  by way of threaded fasteners  41  and  41   a.    
         [0027]    [0027]FIG. 7 is an exploded view showing the construction of the calf or lower leg movement assembly  29 . On the upper end of the assembly, a linear actuator  65  and guide rod  66  are constrained by support plate elements  68  by means of threaded fasteners  41  and  41   a . On the lower end of the assembly, linear actuators  65  and  67  and the guide rod  66  are held by support plate elements  64  and threaded fasteners  41  and  41   a . Ankle holder  30  is attached through holes in the lower portion of the support plate elements  64  and is retained by a cotter pin  76 .  
         [0028]    [0028]FIG. 8 shows the primary manner of use of the preferred embodiment of the present invention. The patient  80  is attached to the robotic leg movement means through ankle cuffs  30 , knee cuffs  28 , and thigh pads  26 . The patient&#39;s weight is supported in part by a harness means  81  (in a well known manner) attached to support means  22  through rope  82  and eyebolts  23 . Provision is made through use of a pulley system or other similar implement attached to rope  82  (not shown), in well-known manners, to vary the amount of the patient&#39;s weight supported by the device. Adjustment of width of the leg movement means  23  to accommodate various patient physical dimensions is accomplished through controlled motion of linear actuators  32 .  
         [0029]    [0029]FIG. 9 is a side view of the patient&#39;s leg attached to the lower limb movement means  23 . Adjustment of overall height of the lower limb movement means  23  is accomplished through simultaneous adjustment of linear actuators  59  in such a way as to allow proper contact of the patient&#39;s feet with the treadmill  83  (as shown in FIG. 8). Appropriate movement of the linear actuator  65 , in conjunction with the guide rod  66 , allows adjustment of the distance between support plates  64  and  68 , thereby adjusting the lower limb movement means  23  to fit the patient&#39;s calf. Similarly, activation of the linear actuator  50  in combination with the guide rod  51  allows adjustment of the lower limb movement means  23  to correspond to the patient&#39;s upper leg length. In a like manner, the linear actuator  55 , in conjunction with the guide rod  54 , provides adjustment for the precise contact point of the hip holder  26 . Walking motion of the patient,  80 , is attained through motion of linear actuators  67 ,  49 , and  56 . Linear actuators  65 ,  50 ,  55 , and  59  are held stationary during walking motion, being used only for adjustment. Movement of the patient&#39;s calf is controlled by movement of the linear actuator  67 , which causes the ankle cuff  30 , the support plates  64 , the guide rod  66 , and the support plates  68  to rotate as a unit about the bearing  75 , thereby raising or lowering the calf. In a similar manner, motion of the patient&#39;s thigh is brought about by motion of the linear actuator  49 , which causes the knee holder  28 , the support plates  47  and  48 , the linear actuator  50 , and the guide rod  51  to rotate as a unit about the bearing  74 , thereby raising or lowering the patient&#39;s thigh (and calf if the linear actuator  67  is stationary). Motion of the patient&#39;s hip is carried out through motion of the linear actuator  56 . Such motion causes the guide rod  54 , the support plates  57  and  52 , the hip holder  26 , and the linear actuator  55  to rotate as a unit about the bearing  73 , thereby moving the patient&#39;s hip in a motion describing an arc. Coordination of the walking motion of the patient  80  is to be carried out by a computer control system. Such control system forms no part of the present invention.  
         [0030]    The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims.