Patent Publication Number: US-11039964-B2

Title: Systems and methods for facilitating movement of a patient transport apparatus

Description:
RELATED APPLICATIONS 
     This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/467,499, filed on Mar. 6, 2017, the entire contents and disclosure of which are hereby incorporated herein by reference. 
    
    
     BACKGROUND 
     Patient transport apparatuses such as hospital beds, stretchers, cots, wheelchairs, and chairs are routinely used by operators to move patients from one location to another. A conventional patient transport apparatus comprises a base and a patient support surface upon which the patient is supported. Caster wheels are often coupled to the base to enable transport over floor surfaces. 
     Moving a patient transport apparatus, particularly through healthcare facilities having complicated layouts with narrow corridors, tight elevators, and crowded areas, can be difficult with only caster wheels. In some cases, two operators may be required to move the patient transport apparatus, with one operator pushing on a head end of the patient transport apparatus and the other operator steering and/or pulling a foot end of the patient transport apparatus. 
     Patient transport apparatuses having auxiliary wheel assemblies have been developed to improve maneuverability, reduce demands on operators, and expedite movement of patients. Typically, such auxiliary wheel assemblies comprise one or more auxiliary wheels, which can be selectively raised to a stowed position and lowered to a deployed position. The auxiliary wheels may be power driven in some cases. In the deployed position, the auxiliary wheels are configured to contact a floor surface to roll along the floor surface, but they are generally unable to swivel. Accordingly, lateral movement of the patient transport apparatus is difficult with the auxiliary wheels deployed. As a result, before the patient transport apparatus can be laterally moved, the auxiliary wheels need to be raised back to the stowed position. When the operator wants to again utilize the auxiliary wheels, the auxiliary wheels need to be re-lowered to the deployed position. Constant raising and lowering of the auxiliary wheels between the stowed and deployed positions can be undesirable. 
     A patient transport apparatus designed to overcome one or more of the aforementioned challenges is desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is perspective view of a patient transport apparatus having a wheel assembly in the form of an omni-directional wheel for facilitating movement along a floor surface. 
         FIG. 2  is a schematic illustration of caster wheels and the omni-directional wheel of  FIG. 1 . 
         FIG. 3  is a perspective view of the omni-directional wheel of  FIG. 2  showing the wheel assembly having a base wheel and peripheral wheels. 
         FIG. 4A  is a schematic illustration of the omni-directional wheel of  FIG. 3  showing a motion control device for controlling the motion of the peripheral wheels. 
         FIG. 4B  is a partial view of the motion control device of  FIG. 4A  positioned to control motion of one of the peripheral wheels. 
         FIG. 4C  is a schematic illustration of another motion control device in the form of a brake for controlling the motion of the peripheral wheels. 
         FIG. 4D  is a schematic illustration of another embodiment of the brake for controlling the motion of the peripheral wheels, with the brake disposed in an unbraked mode. 
         FIG. 4E  is a schematic illustration of the brake of  FIG. 4C , with the brake disposed in a braked mode. 
         FIG. 4F  is an enlarged cutaway view of another motion control device for controlling rotation of the peripheral wheels. 
         FIG. 5A  is a schematic illustration of another omni-directional wheel with a brake for controlling the motion of the base wheel and peripheral wheels, with the brake disposed in an unbraked mode. 
         FIG. 5B  is a schematic illustration of the brake of  FIG. 5A , with the brake disposed in a braked mode. 
         FIG. 5C  is a schematic illustration of a support structure of the patient transport apparatus having one or more pedestals and pedals in a stowed position for placing the omni-directional wheel and support wheels into contact with the floor surface. 
         FIG. 5D  is a schematic illustration of the support structure of  FIG. 5C , with the pedestals and pedals in a deployed position for raising the omni-directional wheel and support wheels above the floor surface and preventing movement of the patient transport apparatus along the floor surface. 
         FIG. 6  is a schematic illustration of a deployable omni-directional wheel that can be raised above the floor surface or lowered into contact with the floor surface. 
         FIG. 7A  is a schematic illustration of an operator pushing on a headboard to move the patient transport apparatus of  FIG. 1 . 
         FIG. 7B  is a schematic illustration of the operator pushing on a side rail to move the patient transport apparatus of  FIG. 7A . 
         FIG. 8A  is a schematic illustration of the operator pushing on a headboard to move another embodiment of a patient transport apparatus that has two opposing sides and two omni-directional wheels coupled to those sides. 
         FIG. 8B  is a schematic illustration of the operator pushing on a side rail to move the patient transport apparatus of  FIG. 8A . 
         FIG. 9  is a schematic illustration of yet another embodiment of a patient transport apparatus showing the patient transport apparatus with two omni-directional wheels coupled to two corner portions. 
         FIG. 10  is a schematic illustration of still another embodiment of a patient transport apparatus showing the patient transport apparatus with two omni-directional wheels coupled to two corner portions. 
         FIG. 11  is a schematic illustration of another embodiment of a patient transport apparatus showing the patient transport apparatus having a center portion and two omni-directional wheels rotatably coupled to the center portion about a common axis. 
         FIG. 12  is a schematic illustration of yet another embodiment of a patient transport apparatus showing two omni-directional wheels in a toe-in arrangement. 
         FIG. 13A  is a schematic illustration of the two wheel assemblies of  FIG. 12  showing movement of the patient transport apparatus in a forward direction parallel to the longitudinal axis. 
         FIG. 13B  is a schematic illustration of the two wheel assemblies of  FIG. 12  showing movement of the patient transport apparatus in a direction transverse to the longitudinal axis. 
         FIG. 13C  is a schematic illustration of the two wheel assemblies of  FIG. 12  showing movement of the patient transport apparatus in a lateral direction perpendicular to the longitudinal axis. 
         FIG. 14  is a schematic illustration of another embodiment of a patient transport apparatus having a third omni-directional wheel that has a base rotational axis that is perpendicular to the longitudinal axis. 
         FIG. 15A  is a schematic illustration of the three omni-directional wheels of  FIG. 14  showing movement of the patient transport apparatus in a forward direction parallel to the longitudinal axis. 
         FIG. 15B  is a schematic illustration of the three omni-directional wheels of  FIG. 14  showing movement of the patient transport apparatus in a direction transverse to the longitudinal axis. 
         FIG. 15C  is a schematic illustration of the three omni-directional wheels of  FIG. 14  showing movement of the patient transport apparatus in a lateral direction perpendicular to the longitudinal axis. 
         FIG. 16  is a schematic illustration of another embodiment of a patient transport apparatus showing the patient transport apparatus having a third wheel assembly that has a third base rotational axis that is parallel with the longitudinal axis. 
         FIG. 17  is a schematic illustration of yet another embodiment of a patient transport apparatus showing two omni-directional wheels in a toe-out arrangement. 
         FIG. 18  is a schematic illustration of another embodiment of a patient transport apparatus comprising a third omni-directional wheel having a rotational axis perpendicular to the longitudinal axis of the patient transport apparatus. 
         FIG. 19  is a schematic illustration of another embodiment of a patient transport apparatus comprising a third omni-directional wheel having a rotational axis parallel with the longitudinal axis of the patient transport apparatus. 
         FIG. 20  is a perspective view of another embodiment of a patient transport apparatus having two wheel assemblies in the form of mecanum wheels. 
         FIG. 21  is a schematic illustration of support wheels and the two mecanum wheels of  FIG. 20 . 
         FIG. 22  is a perspective view of one of the mecanum wheels of  FIG. 21  showing the wheel assembly having a base wheel and peripheral wheels. 
         FIG. 23A  is a schematic illustration of the two mecanum wheels of  FIG. 20  showing movement of the patient transport apparatus in a forward direction parallel to the longitudinal axis. 
         FIG. 23B  is a schematic illustration of the two wheel assemblies of  FIG. 23A  showing movement of the patient transport apparatus in a direction transverse to the longitudinal axis. 
         FIG. 23C  is a schematic illustration of the two wheel assemblies of  FIG. 23A  showing movement of the patient transport apparatus in a lateral direction perpendicular to the longitudinal axis. 
         FIG. 24  is a schematic illustration of another embodiment of the patient transport apparatus of  FIG. 23A  having two mecanum wheels coupled to two corners adjacent to the headboard. 
         FIG. 25  is a schematic illustration of yet another embodiment of the patient transport apparatus of  FIG. 23A  having two mecanum wheels coupled to two corners adjacent to the footboard. 
         FIG. 26  is a schematic illustration of still another embodiment of a patient transport apparatus having four mecanum wheels coupled to the four corners of the patient transport apparatus. 
         FIG. 27  is a schematic illustration of yet another embodiment of a patient transport apparatus having four mecanum wheels coupled to the four corners of the patient transport apparatus. 
         FIG. 28  is a schematic illustration of still another embodiment of a patient transport apparatus having four mecanum wheels coupled to the four corners of the patient transport apparatus. 
         FIG. 29  is a schematic illustration of yet another embodiment of a patient transport apparatus having two mecanum wheels coupled to opposing sides of the patient transport apparatus. 
         FIG. 30  is a schematic illustration of still another embodiment of a patient transport apparatus having two mecanum wheels coupled to two diametrically opposite corners of the patient transport apparatus and two support wheels coupled to the other two diametrically opposite corners of the patient transport apparatus. 
         FIG. 31  is a perspective view of another embodiment of a patient transport apparatus having four corners and four omni-directional wheels positioned at its four corners, with the mattress, side rails, headboard, and footboard removed to illustrate that the patient support deck comprises the foot section with a pair of cutouts configured to provide clearance for the pair of non-swiveling omni-directional wheels. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a patient transport apparatus  30  is shown for moving a patient from one location to another. The patient transport apparatus  30  illustrated in  FIG. 1  is a hospital bed. In other embodiments, however, the patient transport apparatus  30  may be a stretcher, cot, wheelchair, chair, or similar apparatus. 
     A support structure  32  provides support for the patient during movement of the patient transport apparatus  30 . The support structure  32  illustrated in  FIG. 1  comprises a base  34  and an intermediate frame  36 . The intermediate frame  36  is spaced above the base  34 . The support structure  32  also comprises a patient support deck  38  disposed on the intermediate frame  36 . The patient support deck  38  comprises several sections, some of which articulate (e.g., pivot) relative to the intermediate frame  36 , such as a head section, a seat section, a thigh section, and a foot section. The patient support deck  38  provides a patient support surface  42  upon which the patient is supported. The patient support surface  42  is supported by the base  34 . 
     A mattress  40  is disposed on the patient support deck  38 . The mattress  40  comprises a direct patient support surface  43  upon which the patient is supported. The base  34 , intermediate frame  36 , patient support deck  38 , and patient support surfaces  42 ,  43  each have a head end and a foot end corresponding to the designated placement of the patient&#39;s head and feet on the patient transport apparatus  30 . The construction of the support structure  32  may take on any known or conventional design, and is not limited to that specifically set forth above. 
     Side rails  44 ,  46 ,  48 ,  50  are coupled to the intermediate frame  36  on corresponding left and right sides  47 ,  49  of the patient transport apparatus  30 . A first side rail  44  is positioned at a right head end of the intermediate frame  36  on the right side  49  of the patient transport apparatus  30 . A second side rail  46  is positioned at a right foot end of the intermediate frame  36  on the right side  49  of the patient transport apparatus  30 . A third side rail  48  is positioned at a left head end of the intermediate frame  36  on the left side  47  of the patient transport apparatus  30 . A fourth side rail  50  is positioned at a left foot end of the intermediate frame  36  on the left side  47  of the patient transport apparatus  30 . If the patient transport apparatus  30  is a stretcher or a cot, there may be fewer side rails. The side rails  44 ,  46 ,  48 ,  50  are movable between a raised position in which they block ingress and egress into and out of the patient transport apparatus  30  and a lowered position in which they are not an obstacle to such ingress and egress. In some configurations, the side rails  44 ,  46 ,  48 ,  50  are movable to one or more intermediate positions between the raised and lowered positions. In still other configurations, the patient transport apparatus  30  may not include any side rails. 
     The patient transport apparatus  30  has a longitudinal axis L and head and foot ends  51 ,  53 . A headboard  52  and a footboard  54  are coupled to the intermediate frame  36  at the head and foot ends  51 ,  53 . In other embodiments, when the headboard  52  and footboard  54  are included, the headboard  52  and footboard  54  may be coupled to other locations on the patient transport apparatus  30 , such as the base  34 . In still other embodiments, the patient transport apparatus  30  does not include the headboard  52  or the footboard  54 . 
     Manual steering interfaces  56 , such as grips or handles  58 , are shown integrated into the footboard  54  and side rails  44 ,  46 ,  48 ,  50  to steer and/or facilitate movement of the patient transport apparatus  30  over the floor surfaces. Additional manual steering interfaces  56  may be integrated into the headboard  52  and/or other components of the patient transport apparatus  30 . The manual steering interfaces  56  are graspable by the operator to manipulate the patient transport apparatus  30  for movement. 
     Other forms of the manual steering interface  56  are also contemplated. The manual steering interface may comprise one or more handles  58  coupled to the intermediate frame  36 . The manual steering interface  56  may simply be a surface  60  on the patient transport apparatus  30  spaced apart from the patient support surfaces  42 ,  43  and upon which the operator logically applies force to cause movement of the patient transport apparatus  30  in one or more directions, also referred to as a push location. This may comprise one or more surfaces  60  on the intermediate frame  36  or base  34 . This could also comprise one or more surfaces  60  on or adjacent to the headboard  52 , footboard  54 , and/or side rails  44 ,  46 ,  48 ,  50 . In other embodiments, the manual steering interface may comprise separate handles for each hand of the operator. For example, the manual steering interface may comprise two handles. 
     Support wheels  98  are coupled to the base  34  to support the base  34  on a floor surface such as a hospital floor. The support wheels  98  allow the patient transport apparatus  30  to move in any direction along the floor surface by swiveling to assume a trailing orientation relative to a desired direction of movement. In the embodiment shown in  FIGS. 1 and 2 , the support wheels  98  comprise four swivel wheels, such as caster wheels, each arranged in corner portions  66  of the base  34 . The support wheels  98  are able to rotate and swivel about swivel axes S during transport. Each of the support wheels  98  forms part of a caster assembly. Each caster assembly is mounted to the base  34 . It should be understood that various configurations of the caster assemblies are contemplated. In some embodiments, the support wheels  98  are not caster wheels and/or may be non-steerable, steerable, non-powered, powered, or combinations thereof. Additional support wheels  98  are also contemplated. The support wheels  98  may comprise spherical caster wheels as shown that are configured to swivel about a swivel axis S and roll along the floor surface in any direction. In the illustrated embodiment, each spherical caster wheel comprises a post mounted to the base  34  and positioned along the swivel axis S for swiveling the spherical caster wheel about the swivel axis S. The post may be spaced apart from a center of the spherical caster wheel and be mounted to an edge of the spherical caster wheel. However, in other embodiments, the post may be mounted to a center of the spherical caster wheel or a portion of the spherical caster wheel, between the edge and the center, e.g. a portion that is one-third the distance from the center to the edge of the spherical caster wheel. Still in other embodiments, the support wheel is a spherical wheel that is not configured as a caster mounted to the base for swiveling about a swivel axis. It is contemplated that the support wheels may comprise other types of wheels. Any number or type of suitable support wheels are contemplated. 
     Referring to  FIG. 2 , the patient transport apparatus  30  comprises one or more additional wheel assemblies  62  arranged in any suitable configuration. The additional wheel assembly  62  shown is coupled to the support structure  32  to facilitate movement of the patient transport apparatus  30  along the floor surface. One embodiment of the patient transport apparatus  30  may comprise one wheel assembly  62 , which is attached to a center portion  64  of the base  34  and positioned radially inward from the corner portions  66  of the base  34 . In other embodiments, the wheel assembly  62  may be offset or spaced from the center portion toward the left side  47 , the right side  49 , the head end  51 , the foot end  53 , and/or any combination of the same. In the illustrated embodiment, the center portion  64  of the base  34  comprises a cross member  68  extending across the width of the base  34  with the wheel assembly  62  coupled to the cross member  68 . The wheel assembly  62  is capable of rolling along the floor surface in more than one direction. The wheel assembly  62  shown in  FIG. 2  comprises an omni-directional wheel  70 . In other embodiments, the wheel assembly  62  comprises a mecanum wheel or other type of wheel capable of rolling along the floor surface in more than one direction. The patient transport apparatus  30  can include any number of wheel assemblies  62  (as exemplified in  FIGS. 8A-26 ). 
     Referring to  FIG. 3 , the omni-directional wheel  70  comprises a base wheel  76  that has an outer periphery  78 . The base wheel  76  is coupled to the cross member  68  to rotate about a base rotational axis R 1 , which is perpendicular to the longitudinal axis L of the patient transport apparatus  30 . In the embodiment shown, the base wheel  76  is rotatably coupled to a fork  77 , which is in turn fixed to the cross member  68 . The base wheel  76 , in the embodiment shown, does not swivel relative to the cross member  68 , and the base wheel  76  is rotatable within a plane that remains fixed relative to the base  34 . Thus, the base wheel  76  rotates about the base rotational axis R 1  with movement of the patient transport apparatus  30  in longitudinal directions parallel with the longitudinal axis L. It is contemplated that the base wheel  76  can be attached to other portions of the base  34  in any suitable orientation for enabling movement of the patient transport apparatus  30  in any direction. 
     In the version shown in  FIG. 3 , the base wheel  76  comprises two base wheel portions  76   a ,  76   b  spaced from one another on a wheel shaft  79 . The wheel shaft  79  is rotatably journaled in the fork  77  via bearings B or similar devices. The base wheel portions  76   a ,  76   b  are fixed to the wheel shaft  79  to rotate together with the wheel shaft  79 . In other embodiments, the base wheel  76  rotates about a wheel shaft fixed to the fork  77 . In other embodiments, only a single wheel portion or additional wheel portions are present. 
     The omni-directional wheel  70  further comprises peripheral wheels  80  (also referred to as rollers) rotatably coupled to the base wheel  76  adjacent the outer periphery  78 . The peripheral wheels  80  are rotatably coupled to the base wheel  76  to rotate about peripheral rotational axes R 2 , which are perpendicularly oriented relative to the base rotational axis R 1 . The peripheral wheels  80  collectively are disposed radially outwardly from the outer periphery  78  of the base wheel  76  so that the peripheral wheels  80  contact the floor surface, while the base wheel  76  remains spaced from the floor surface. Thus, the peripheral wheels  80  collectively rotate with the base wheel  76  about the base rotational axis R 1  with movement of the patient transport apparatus  30  in the longitudinal directions, but one or more of the peripheral wheels  80  rotate about the peripheral rotational axes R 2  with movement of the patient transport apparatus  30  in directions transverse to the longitudinal axis L. The omni-directional wheel  70  shown in  FIG. 3  comprises ten peripheral wheels  80  rotatably coupled to the outer periphery  78  of the base wheel  76  (a set of five peripheral wheels  80  on each base wheel portion  76   a ,  76   b ). Of course, it is contemplated that the omni-directional wheel  70  can have any number or type of peripheral wheels  80  coupled to any portion of the periphery  78  of the base wheel  76  in any orientation for moving the patient transport apparatus  30  in various directions. 
     Referring to  FIGS. 4A-4E , the omni-directional wheel  70  further comprises one or more motion control devices  82  configured to selectively control rotation of one or more of the peripheral wheels  80  about their respective peripheral rotational axes R 2  independent of rotation of the base wheel  76  about the base rotational axis R 1 . By controlling rotation of the one or more peripheral wheels  80  independently from controlling rotation of the base wheel  76 , the omni-directional wheel  70  is capable of controlling movement in various, desirable ways. For instance, if the peripheral wheels  80  are inhibited from rotating about their peripheral rotational axes R 2  when they contact the floor surface, but the base wheel  76  is still allowed to rotate about the base rotational axis R 1 , then the omni-directional wheel  70  acts to reduce dog-tracking of the patient transport apparatus  30  when moving down long hallways, which would otherwise occur if the peripheral wheels  80  were able to freely rotate about their peripheral rotational axes R 2 . Similarly, the omni-directional wheel  70  would provide better, more stable movement of the patient transport apparatus  30  around corners, since the peripheral wheels  80  are inhibited from rolling about their peripheral rotational axes R 2  under the inertia of the patient transport apparatus  30  moving around the corners. Similarly, one or more of the peripheral wheels  80  can be actively driven about their peripheral rotational axes R 2  independent of driving the base wheel  76 . For instance, if the operator desires to move the patient transport apparatus  30  down a long hallway, the base wheel  76  may be driven, without driving the peripheral wheels  80 . Conversely, if the operator desires to move the patient transport apparatus  30  laterally, one or more of the peripheral wheels  80  may be driven, without driving the base wheel  76 . 
     In the embodiment shown in  FIG. 4A , the motion control device  82  comprises a motor  84  and a control wheel  86  actuated by the motor  84 . The control wheel  86  is rotatably coupled to a control wheel fork  81 . As best shown in  FIG. 4B , an actuator  83  extends between the control wheel fork  81  and the fork  77  on which the base wheel  76  is rotatably coupled. The actuator  83  is configured to selectively move the control wheel fork  81  and the control wheel  86  to urge the control wheel  86  against the peripheral wheel  80 . The control wheel  86  may be used as a brake to inhibit rotation of the peripheral wheel  80  or as a drive wheel to actively rotate the peripheral wheel  80  about its peripheral rotational axis R 2 , by virtue of frictional engagement between the control wheel  86  and the peripheral wheel  80 . In this embodiment, the actuator  83  may comprise a linear actuator with a housing fixed to the fork  77  and a rod linearly movable relative to the housing. The rod extends from the housing to the control wheel fork  81 . The actuator  83  can be any suitable mechanism for selectively moving the control wheel  86  into engagement with one of the peripheral wheels  80 . In this arrangement, the control wheel  86  is configured to engage the peripheral wheel  80  that is in contact with the floor surface as shown. In embodiments where the omni-directional wheel  70  comprises two or more base wheel portions  76   a ,  76   b , like that shown in  FIG. 3 , a similar motion control device  82  may be arranged on an opposite side of the fork  77 . In further embodiments, separate motion control devices  82  may be provided for each of the peripheral wheels  80 . In still further embodiments, the control wheels  86  may be in constant frictional contact with their associated peripheral wheels  80  such that the actuator  83  is unnecessary. 
     Referring to  FIG. 4C , in another embodiment, the motion control device  82  comprises a brake  85  for selectively inhibiting rotation of at least one of the peripheral wheels  80 . While the embodiment of the motion control device illustrated in  FIGS. 4A and 4B  comprises one brake for controlling the motion of any one of the peripheral wheels  80 , the motion control device  82  illustrated in  FIG. 4C  may comprise a plurality of dedicated brakes for controlling the motion of a respective one of the peripheral wheels  80 . More specifically, while the motion control device illustrated in  FIGS. 4A and 4B  comprises the control wheel  86  operably coupled to the fork  77  to inhibit the rotation of or actively rotate any one of the peripheral wheels  80  positioned immediately beneath the control wheel  86 , the motion control device  82  illustrated in  FIG. 4C  may comprise a plurality of brakes  85  coupled to the base wheel  76  adjacent to a respective one of the peripheral wheels  80 . However, it is contemplated that other embodiments of the brakes may be coupled to any portion of the wheel assembly and may be used to control the motion of any of the peripheral wheels  80 . 
     In the illustrated embodiment, each brake  85  may comprise a brake actuator  87  to move a friction surface, or other suitable braking device, to engage the peripheral wheel  80 . The brake actuator  87  may be any mechanism suitable to move the friction surface or other suitable braking device to inhibit rotation of the peripheral wheel  80  about the peripheral rotational axis R 2 . The brake actuator  87  may comprise a linear actuator, solenoid, or other suitable actuator. Drum brakes or other suitable brakes are also contemplated. The brake  85  may be configured to selectively inhibit rotation of only one peripheral wheel  80 , when for example the peripheral wheel contacts the floor surface, or to selectively impede rotation of all the peripheral wheels  80  at the same time. It is contemplated that the omni-directional wheel  70  may comprise any number of suitable brakes mounted to any portion of the wheel assembly for selectively inhibiting rotation of the peripheral wheels  80 . In some cases, the brakes  85  only need to slightly inhibit rotation of the peripheral wheels  80  about their peripheral rotational axes R 2 , such as when employing the omni-directional wheels  70  to transport the patient down a long hallway. In this case, some rotation of the peripheral wheels  80  about their respective peripheral rotational axes R 2  is tolerable so long as they are at least partially impeded from freely rotating. 
     The omni-directional wheel  70  may also comprise a base brake  88  for selectively impeding rotation of the base wheel  76 . The base brake  88  may comprise a brake actuator  89  mounted to the fork  77  or any other suitable part of the patient transport apparatus  30  to move a friction surface, or other suitable braking device, to engage the wheel shaft  79  of the base wheel  76 . However, drum brakes or other suitable brakes are contemplated. The omni-directional wheel  70  may comprise any suitable brake for selectively inhibiting rotation of the base wheel  76 . 
     The brakes  85  for the peripheral wheels  80  and the base brake  88  for the base wheel  76  are actuated independently and/or in conjunction with one another to control the motion of the patient transport apparatus  30  along the floor surface or to selectively hold the patient transport apparatus  30  in a fixed location on the floor surface. As one example, the brakes  85  may be actuated to prevent rotation of the peripheral wheels  80  about their respective peripheral rotational axes R 2 , and the base brake  88  may not be actuated so as to permit rotation of the base wheel  76  about the base rotational axis R 1  such that the patient transport apparatus  30  is constrained in a manner that facilitates moving down long hallways or around corners as previously described. As another example, the base brake  88  may be actuated to prevent rotation of the base wheel  76  about the base rotational axis R 1 , and the brakes  85  may not be actuated so as to permit free rotation of the peripheral wheels  80  such that the patient transport apparatus  30  is constrained from moving purely longitudinally, but is able to move transversely to the longitudinal axis L, such as in a lateral direction perpendicular to the longitudinal axis L. In still other examples, the brakes  85  and the base brake  88  are selectively actuated to constrain/permit movement of the patient transport apparatus  30  in various directions along the floor surface other than the longitudinal and lateral directions. 
     Still referring to  FIG. 4C , the omni-directional wheel  70  may comprise a base wheel drive  90  for controlling rotation of the base wheel  76 . In this embodiment, the base wheel drive  90  comprises a drive device, which is operably coupled to the base wheel  76  to control rotation of the base wheel  76 . The drive device may comprise a drive motor  94  for rotating the wheel shaft  79  about the base rotational axis R 1 . The drive motor  94  may be mounted to the fork  77  or any other suitable part of the patient transport apparatus  30 . The drive motor  94  may comprise a drive shaft to directly drive the wheel shaft  79  or may comprise one or more drive shafts, drive gears, and/or transmissions to drive the base wheel  76 . The base wheel drive  90  can have other suitable configurations or be omitted from the omni-directional wheel  70 , such that the omni-directional wheel  70  is non-driven. 
     Referring to  FIGS. 4D and 4E , in another embodiment, the motion control device  82  comprises a drum brake  91  movable between an unbraked mode ( FIG. 4D ) for permitting the rotation of all the peripheral wheels  80  at the same time and a braked mode ( FIG. 4E ) for inhibiting the rotation of all the peripheral wheels  80  at the same time. The drum brake  91  comprises two brake linings  92  attached to two brake shoes  93  that are pivotally attached to the base wheel  76 . A brake actuator (e.g., motor) is coupled to a cam  95  to rotate the cam  95  and urge the brake linings  92  against all of the peripheral wheels  80  simultaneously to inhibit rotation of the same. 
     Referring to  FIG. 4F , in another embodiment, the motion control device  82  may comprise a gear train  95  configured to drive one or more peripheral wheels  80  independent of the rotation of the base wheel. The gear train  95  comprises a crown gear  97 , which is rotatably coupled to the base wheel  76  for rotating independent of the rotation of the base wheel  76 . The crown gear  97  is engaged with pinion gears  99 , which are in turn engaged with bevel gears  101  fixedly attached to the peripheral wheels  80 . A control gear  103  is carried by the base wheel  76  to independently rotate relative to the base wheel  76  during operation, and drive the peripheral wheels  80  independent of the rotation of the base wheel  76 . A motor  104  selectively rotates the control gear  103  to rotate the crown gear  97 . An actuator  105  is coupled to the base wheel  76  for selectively moving the control gear  103  in/out of meshing engagement with radially inward teeth of the crown gear  97 . When engaged, the control gear  103  may act as a brake to inhibit motion of the crown gear  97  relative to the base wheel  76  or may be actively driven to rotate the crown gear  97  relative to the base wheel  76 . When not engaged, the crown gear  97  is able to freely rotate relative to the base wheel  76  thereby allowing free rotation of the peripheral wheel  80  in contact with the floor surface. Other embodiments of the bevel gear train  95  may comprise a clutch selectively coupling the control gear  103  to the crown gear  97 . The wheel assembly  62  may comprise a housing  106  that defines an internal cavity  108  with the motion control device  82  being disposed within the internal cavity  108 . Other suitable motion control devices, base wheel drives, or combinations of the same are contemplated. 
       FIGS. 5A and 5B  illustrate another embodiment of an omni-directional wheel  170  with only a single wheel portion  176 . In this embodiment, a brake  120  acts to engage the omni-directional wheel  170  in a manner that inhibits rotation of a base wheel  176  about the base rotational axis R 1  and inhibits rotation of peripheral wheels  180  about the peripheral rotational axes R 2  at the same time. The brake  120  moves between an unbraked mode ( FIG. 5A ) for permitting the rotation of all the peripheral wheels  180  about the peripheral rotational axes R 2  and a braked mode ( FIG. 5B ) for inhibiting the rotation of all the peripheral wheels  180  about the peripheral rotational axes R 2  at the same time. In this embodiment, the omni-directional wheel  170  is rotatably coupled to a fixed shaft  124  by a bearing  126 . The fixed shaft  124  is in turn fixedly attached to the fork  77 . The fixed shaft  124  comprises a splined portion  128  having splines. 
     The brake  120  comprises a disc  130  having a splined opening  132  that receives the splined portion  128  of the fixed shaft  124  such that their corresponding splines engage in a mating relationship that enables the disc  130  to slide laterally along the splined portion  128  without being able to rotate about the splined portion  128 . The disc  130  slides toward the omni-directional wheel  170  to engage the omni-directional wheel  170  in the braked mode and slides away from the omni-directional wheel  170  to be disengaged from the omni-directional wheel  170  in the unbraked mode. 
     The disc  130  comprises a periphery and a plurality of frictional contact surfaces  134  positioned about the periphery for contacting the peripheral wheels  180  and inhibiting movement of the same. The disc  130  and the contact surfaces  134  may be integral portions of a one-piece rubber body. However, separate discs and/or contact surfaces and/or other suitable materials are contemplated. An actuator assembly  136  is coupled to the fork  77  and configured to move the disc  130  between its positions associated with the braked mode and the unbraked mode. The actuator assembly  136  may comprise an actuator  138  having a movable rod fixed to a disc carrier  140  that holds the disc  130 . The disc carrier  140  is fixed to the disc  130  and comprises guide rods  141  arranged to slide within openings in the fork  77  upon operation of the actuator  138 . The actuator  138  may comprise a linear actuator or other suitable type of actuator. The brake  120  may comprise a biasing member  142  arranged between the fork  77  and the disc carrier  140  for normally moving the disc  130  to its position associated with the unbraked mode. 
     In the braked mode, owing to the frictional engagement of the frictional contact surfaces  134  with the peripheral wheels  180  and the splined portion  128  generally impeding rotation of the disc  130  about the base rotational axis R 1 , not only are the peripheral wheels  180  inhibited from rotating about their peripheral rotational axes R 2 , but the base wheel  176  is also inhibited from rotation about the base rotational axis R 1 . 
     Referring to  FIGS. 5C and 5D , in another embodiment, the support structure  32  may comprise a brake  144  and/or a pedal  146  for actuating the brake  144 . The brake  144  may merely engage the floor surface in a frictional manner that inhibits movement of the patient transport apparatus  30  and/or the brake  144  may lift one or more support wheels  98  and/or the omni-directional wheel  70  above the floor surface. As shown in  FIG. 5D , floor brakes may be employed to inhibit movement of the omni-directional wheel  70  along the floor surface. The floor brakes may comprise deployable pedestals  148  that are actuated by the pedal  146  to be raised above the floor surface during transport ( FIG. 5C ) and actuated by the pedal  146  to be lowered into contact with the floor surface during braking ( FIG. 5D ). 
     Referring to  FIG. 6 , in some embodiments, the omni-directional wheel  70  may be deployable from a stowed position  150  above the floor surface to a deployed position  152  in contact with the floor surface. A support arm  154  can be pivotally coupled to the support structure  32 , and the omni-directional wheel  70  can be rotatably coupled to an end of the support arm  154 . An actuator  156 , such as a linear actuator, can be coupled to the omni-directional wheel  70  and/or the support arm  154  for moving the omni-directional wheel  70  between the stowed position  150  and the deployed position  152 . 
     Referring to  FIGS. 7A and 7B , a control system is provided to control operation of the wheel assembly  62 , and specifically the one or more motion control devices  82 , the base brake  88 , and the base wheel drive  90 , and any other powered devices that may be located on the patient transport apparatus  30 . In particular, the control system is electrically coupled to the actuators and motors of the motion control devices  82 , the base brake  88 , and the base wheel drive  90  recited herein for controlling the same. The actuators described herein may comprise electric actuators, hydraulic actuators, pneumatic actuators, combinations thereof, or any other suitable types of actuators for performing the functions described. The motors described herein may comprise electric motors, brushed motors, brushless motors, stepper motors, servo motors, combinations thereof, or any other suitable types of motors for performing the functions described. 
     The control system comprises a controller  102  having one or more microprocessors for processing instructions or for processing algorithms stored in memory to control operation of the motion control devices  82 , base brake  88 , base wheel drive  90 , and other powered devices. Additionally or alternatively, the controller  102  may comprise one or more microcontrollers, field programmable gate arrays, systems on a chip, discrete circuitry, and/or other suitable hardware, software, or firmware that is capable of carrying out the functions described herein. The memory may further store one or more look-up tables that define control parameters of the motion control devices  82 , base brake  88 , base wheel drive  90 , and other powered devices. The controller  102  may be carried on-board the patient transport apparatus  30 , or may be remotely located. In one embodiment, the controller  102  is mounted to the base  34 . The controller  102  may comprise one or more sub-controllers configured to control all motion control devices  82 , base brake  88 , base wheel drive  90 , and the other powered devices or one or more sub-controllers for each of the motion control devices  82 , base brake  88 , base wheel drive  90 , and the other powered devices. Power to the motion control devices  82 , base brake  88 , base wheel drive  90 , or other powered devices and/or the controller  102  may be provided by a power storage system, such as a battery system. 
     The controller  102  is coupled to the motion control devices  82 , base brake  88 , and base wheel drive  90  in a manner that allows the controller  102  to control them. The controller  102  may electrically communicate with the motion control devices  82 , base brake  88 , and/or base wheel drive  90  via wired or wireless connections. The controller  102  generates and transmits control signals to the motion control devices  82 , base brake  88 , and/or base wheel drive  90 , or components thereof, to perform one of more desired movements or functions. The controller  102  may monitor an actual state of the motion control devices  82 , base brake  88 , and/or base wheel drive  90 , and determine desired states to which the motion control devices  82 , base brake  88 , and/or base wheel drive  90  should be placed, based on one or more input signals that the controller  102  receives from one or more input devices. The state of the motion control devices  82 , base brake  88 , and/or base wheel drive  90  may be a position, a relative position, a speed, a force, a load, a current, an energization status (e.g., on/off), or any other parameter of the motion control devices  82 , base brake  88 , and/or base wheel drive  90 . The input devices used to control operation of the motion control devices  82 , base brake  88 , and/or base wheel drive  90  comprises operator input devices  100  and/or a sensing system in communication with (e.g., coupled to) the controller  102 . 
     In one embodiment, the operator input devices  100  used to control operation of the motion control devices  82 , base brake  88 , and/or base wheel drive  90  comprise operator input devices  100  activated by caregivers or other users, which transmit corresponding input signals to the controller  102 . The controller  102  controls operation of the motion control devices  82 , base brake  88 , and/or base wheel drive  90  based on the input signals. In one embodiment, the operator input devices  100  are located on one or more control panels. It is to be appreciated that control panels could be coupled to one or more of the headboard  52 , the footboard  54 , the intermediate frame  36 , the patient support deck  38 , any combination of the side rails  44 ,  46 ,  48 ,  50 , or any other suitable location. 
     The operator input devices  100  receive commands or selections from an operator that is indicative of a desired motion of the patient transport apparatus  30 . The controller  102  may receive an input signal from the operator input device  100  based on the operator&#39;s inputted command or selection for actuating the motion control devices  82  to control rotation of the peripheral wheels  80  independently of the rotation of the base wheel  76 . The controller  102  may also be used for actuating the base brake  88  or the base wheel drive  90  to control rotation of the base wheel  76  based on the input signal received from the operator input device  100 . The operator input device  100  may comprise a touch screen having touch-selectable buttons that can be selected by the operator to place the patient transport apparatus  30  in a desired mobility configuration and indicate which direction the operator intends to move the patient transport apparatus  30 , i.e., the direction of desired movement of the patient transport apparatus  30 . This could be as simple as the touch screen having touch-selectable buttons corresponding to each of the longitudinal and lateral directions of the bed, namely forward, backward, left, and right (as observed when at the operator input device  100  on the headboard  52 ). The operator input devices  100  may also comprise sensors that communicate with the controller  102  to determine the desired motion of the patient transport apparatus  30 , as described in U.S. Patent Application Publication No. 2016/0089283 to DeLuca et al., hereby incorporated by reference. 
     The operator input device  100  may have user input selections available to the operator such as “brake,” “free,” “free forward/rearward,” “free left/right,” “drive forward,” “drive rearward,” “drive left,” “drive right,” “increase speed,” “decrease speed,” other suitable selections, or any combination thereof. For instance, the “brake” selection places the motion control devices  82  and the base brake  88  in the braked mode, and the “free” selection places the motion control devices and the base brake  88  in the unbraked mode. 
     Referring to  FIG. 7A , the “free forward/rearward” selection inhibits rotation of one or more of the peripheral wheels  80  about the corresponding peripheral rotational axis R 2  associated with moving the patient transport apparatus  30  in the left/right direction and permits the base wheel  76  to rotate about the base rotational axis R 1 . In the embodiments shown, the operator can input or select the “free forward/rearward” selection using the operator input device  100 . The operator input device  100  can generate an input signal based on the “free forward/rearward” selection and transmit the input signal to the controller  102 . The controller  102  places the motion control devices  82  in the braked mode in response to the input signal, so as to inhibit rotation of the associated peripheral wheels  80  and inhibit corresponding movement of the patient transport apparatus  30  in the left/right direction. The controller  102  also places the base brake  88  in the unbraked mode to permit the base wheel  76  to freely rotate, such that the operator can engage the manual steering interface  56  to move the patient transport apparatus  30  in the forward/rearward directions parallel with the longitudinal axis L, including around corners. 
     Similar to the “free forward/rearward” selection, the “drive forward” and “drive rearward” selections inhibit rotation of the peripheral wheels  80  associated with moving the patient transport apparatus  30  in the left/right direction and permit the base wheel  76  to rotate for moving the patient transport apparatus  30  in the forward/rearward direction. The operator input device  100  can generate an input signal based on the “drive forward” or “drive rearward” selection and transmit the input signal to the controller  102 . The controller  102  places the motion control device  82  in the braked mode in response to the input signal, so as to inhibit rotation of the peripheral wheels  80  and prevent corresponding movement in the left/right direction. The controller  102  also places the base brake  88  in the unbraked mode to permit the base wheel  76  to freely rotate so as to move the patient transport apparatus  30  in the forward/rearward directions parallel with the longitudinal axis L. In contrast to the “free forward/rearward” selection, the “drive forward” and “drive rearward” selections further actuate the base wheel drive  90  to rotate the base wheel  76  to drive the patient transport apparatus  30  in the corresponding forward or rearward directions. More specifically, in the embodiments shown, the controller  102  further actuates the base wheel drive  90  to rotate the base wheel  76  for moving the patient transport apparatus  30  in a forward direction parallel with the longitudinal axis L with the footboard  54  leading, when the controller  102  receives the input signal based on the “drive forward” selection. Similarly, the controller  102  further actuates the base wheel drive  90  to rotate the base wheel  76  for moving the patient transport apparatus  30  in the rearward direction parallel with the longitudinal axis L with the headboard  52  leading when the input signal is based on the “drive rearward” selection. 
     Referring to  FIG. 7B , the “free left/right” selection inhibits rotation of the base wheel  76  about the base rotational axis R 1 , yet permits the peripheral wheels  80  to rotate about their peripheral rotational axes R 2  for moving the patient transport apparatus  30  in the left/right direction transverse to the longitudinal axis. In the embodiments shown, the operator can select the “free left/right” selection on the operator input device  100 . The operator input device  100  can generate an input signal based on the “free left/right” selection and transmit the input signal to the controller  102 . The controller  102  places the base brake  88  in the braked mode in response to the input signal, so as to inhibit rotation of the base wheel  76 . The controller  102  also places the motion control device  82  in the unbraked mode to permit the peripheral wheels  80  to freely rotate about their peripheral rotational axes R 2  (while braked about the base rotational axis R 1  along with the base wheel  76 ), such that the operator can engage the manual steering interface  56  to move the patient transport apparatus  30  in the left/right directions transverse to the longitudinal axis L, such as laterally relative to the longitudinal axis L. 
     Similar to the “free left/right” selection, the “drive left” and “drive right” selections inhibit rotation of the base wheel  76  about the base rotational axis R 1 , yet permits the peripheral wheels  80  to rotate about their peripheral rotational axis R 2  for moving the patient transport apparatus  30  in the left/right direction transverse to the longitudinal axis L. In the embodiments shown, the operator can input or select the “drive left” selection or the “drive right” selection on the operator input device  100  and transmit a corresponding input signal to the controller  102 . The controller  102  places the base brake  88  in the braked mode in response to the input signal, so as to inhibit rotation of the base wheel  76 . Additionally, the controller  102  actuates the motion control device  82  to actively drive and rotate one or more of the peripheral wheels  80 , such as the peripheral wheel  80  in contact with the floor surface, to move the patient transport apparatus  30  in the corresponding left or right directions. More specifically, the controller  102  further actuates the motion control device  82  to rotate the peripheral wheel  80  for moving the patient transport apparatus  30  in a left direction perpendicular to the longitudinal axis L, when the controller  102  receives the input signal based on the “drive left” selection. Similarly, the controller  102  further actuates the motion control device  82  to rotate the peripheral wheel  80  for moving the patient transport apparatus  30  in a right direction perpendicular to the longitudinal axis L when the input signal is based on the “drive right” selection. 
     The “increase speed” or “decrease speed” selections can generate input signals transmitted from the operator input device  100  to the controller  102 , which in turn actuates the base wheel drive  90  and/or the motion control device  82  to adjust the speed of the patient transport apparatus  30  based on the input signals. As but one example, the “increase speed” and “decrease speed” selections can be inputted into the operator input device  100  to incrementally increase or decrease the speed of the patient transport apparatus  30  in the forward direction, rearward direction, left direction, or right direction, or combinations thereof, if a corresponding one or more of the “drive forward,” “drive rearward,” “drive left,” or “drive right” selections are inputted in conjunction therewith. In other embodiments, the controller  102  may actuate the base wheel drive  90  and/or the motion control device  82  to adjust the speed of the patient transport apparatus  30  based on current direction without active input from the operator input device  82 . It is contemplated that the operator input device  100  and the controller  102  can be configured to control the speed and direction of the patient transport apparatus  30  in various other suitable configurations. 
       FIGS. 8A-19  illustrate multiple embodiments of the patient transport apparatus having one or more omni-directional wheels arranged in various configurations and coupled to various portions of the support structure of the patient transport apparatus. 
     Referring to  FIGS. 8A and 8B , another embodiment of the patient transport apparatus  430  is similar to the patient transport apparatus  30  of  FIGS. 7A and 7B , and it comprises similar components identified by the same reference numbers increased by  400 . However, while the patient transport apparatus  30  of  FIGS. 7A and 7B  has a single omni-directional wheel  70  coupled to a cross member  68 , the patient transport apparatus  430  has two omni-directional wheels  470 ,  472  rotatably coupled to opposing sides  504 ,  506  of the base  434  about two base rotational axes R 1  that are collinear with one another and perpendicular to the longitudinal axis L of the patient transport apparatus  430 . Put another way, the two omni-directional wheels  470 ,  472  are rotatably coupled to opposing sides  504 ,  506  of the base  434  about a common base rotational axis R 1 . 
     Each omni-directional wheel  470 ,  472  is similar to the omni-directional wheel  70  of  FIGS. 7A and 7B , which has a base wheel  76  and peripheral wheels  80  coupled to the outer periphery  78  of the base wheel  76 . In particular, the first and second omni-directional wheels  470 ,  472  include base wheels  476   a ,  476   b  having outer peripheries  478   a ,  478   b . The base wheels  476   a ,  476   b  are rotatably coupled to the support structure  432  about a common rotational axis R 1  that is perpendicular to the longitudinal axis L of the patient transport apparatus  430 . The omni-directional wheels  470 ,  472  comprise peripheral wheels  480   a ,  480   b  disposed about the outer peripheries  478   a ,  478   b  to rotate about peripheral rotational axes R 2 . In addition, the omni-directional wheels  470 ,  472  comprise motion control devices  482   a ,  482   b  configured to selectively control rotation of the corresponding peripheral wheels  480   a ,  480   b  independent of the rotation of the base wheels  476   a ,  476   b , as previously described. 
     In  FIG. 8A , the operator can input a “drive forward” selection into the operator input device  500 , which generates an input signal and transmits the same to the controller  502 . The controller  502  may then actuate the two omni-directional wheels  470 ,  472  for moving the patient transport apparatus  430  in the forward direction in the same manner that the controller  102  of  FIG. 7A  actuates the single omni-directional wheel  70  for moving the patient transport apparatus  30  in the forward direction along, for example, a long hallway. In particular, the “drive forward” selection can be inputted into the operator input device  500  to generate and transmit signals to the controller  502 , which in turn places the motion control devices  482   a ,  482   b  in the braked mode to inhibit rotation of the peripheral wheels  480   a ,  480   b  and prevent corresponding movement of the patient transport apparatus  430  in the left/right directions. In addition, the controller  502  places the base brakes  488   a ,  488   b  in the unbraked mode to permit the base wheels  476   a ,  476   b  to freely rotate and permit movement of the patient transport apparatus  430  in the forward direction. The “drive forward” selection can also generate a signal transmitted from the operator input device  500  to the controller  502 , which in turn actuates the base wheel drives  490   a ,  490   b  for rotating the base wheels  476   a ,  476   b  in a direction that moves the patient transport apparatus  430  in the forward direction with the footboard  454  leading. The operator can grasp the manual steering interface  456  to apply a torque to steer the patient transport apparatus  430  and/or direct movement of the patient transport apparatus  430 . It is contemplated that the controller  502  may actuate the two omni-directional wheels  470 ,  472  to move the patient transport apparatus  430  in the opposite direction in the same manner that the controller  102  of  FIG. 7A  actuates the single omni-directional wheel  70  to move the patient transport apparatus  30  in the rearward direction in the “drive rearward” configuration. 
     In  FIG. 8B , the operator can input a “drive right” selection into the operator input device  500 , which generates an input signal and transmits the same to the controller  502 . The controller  502  may in turn actuate the two omni-directional wheels  470 ,  472  to move the patient transport apparatus  430  in the right direction in the same manner that the controller  102  of  FIG. 7B  actuates the single omni-directional wheel  70  to move the patient transport apparatus  30  in the right direction when, for example, the patient transport apparatus  430  is being parked in a hospital room or shifted to the side in an elevator. In particular, the “drive right” selection can generate signals transmitted from the operator input device  500  to the controller  502 , which in turn actuates the brakes  488   a ,  488   b  to inhibit rotation of the base wheel  476   a ,  476   b  and prevent corresponding movement of the patient transport apparatus  430  in the forward/rearward directions. The controller  502  also places the motion control devices  482   a ,  482   b  in the unbraked mode to permit the peripheral wheels  480  to freely rotate and permit movement of the patient transport apparatus  430  in the left/right directions. The “drive right” selection also generates a signal transmitted from the operator input device  500  to the controller  502 , which in turn actuates the motion control devices  482   a ,  482   b  to rotate the peripheral wheels  480   a ,  480   b  in a direction that moves the patient transport apparatus  430  in the right direction. The operator can grasp the manual steering interface  456  to facilitate steering the patient transport apparatus  430  when the direction in which the patient transport apparatus  430  was originally pointed has been inadvertently changed. It is contemplated that the controller  502  may actuate the two omni-directional wheels  470 ,  472  to move the patient transport apparatus  430  in the opposite direction in the same manner that the controller  102  actuates the single omni-directional wheel  70  to move the patient transport apparatus  30  toward the left in the “drive left” configuration. Other mobility configurations in any direction and associated inputs are also contemplated. 
       FIG. 9  illustrates another embodiment of a patient transport apparatus  630 , which is similar to the patient transport apparatus  430  of  FIG. 8A , and it comprises similar components identified by the same reference numbers increased by  200 . However, while the patient transport apparatus  430  of  FIG. 8A  comprises two omni-directional wheels  470 ,  472  rotatably coupled to the base  434  between the head and foot ends, on opposing left and right sides  504 ,  506  of the same, the patient transport apparatus  630  comprises two omni-directional wheels  670 ,  672  coupled to the corner portions  666  of the base  634  adjacent to the headboard  652 . More specifically, the two omni-directional wheels  670 ,  672  include two base wheels  676   a ,  676   b  rotatably coupled to the corner portions  666  about two base rotational axes R 1  that are collinear with one another and perpendicular to the longitudinal axis L of the patient transport apparatus  630 . Put another way, the two omni-directional wheels  670 ,  672  are rotatably coupled to the corner portions  666  of the base  634  about a common rotational axis. It is contemplated that the patient transport apparatus  630  may operate in the same manner as the patient transport apparatus  430  illustrated in  FIGS. 8A and 8B . 
       FIG. 10  illustrates still another embodiment of a patient transport apparatus  830 , which is similar to the patient transport apparatus  430  of  FIG. 8A  and comprises similar components identified by the same reference numbers increased by  400 . However, while the patient transport apparatus  430  of  FIG. 8A  comprises two omni-directional wheels  470 ,  472  rotatably coupled to the base  434  between the head and foot ends, on opposing left and right sides  504 ,  506  of the same, the patient transport apparatus  830  comprises two omni-directional wheels  870 ,  872  coupled to corner portions  866  of the base  834  adjacent to the footboard  854 . In particular, the two omni-directional wheels  870 ,  872  include two base wheels  876   a ,  876   b  rotatably coupled to the two corner portions  866  about two base rotational axes R 1  that are collinear with one another and perpendicular to the longitudinal axis L of the patient transport apparatus  830 . Put another way, the two omni-directional wheels  870 ,  872  are rotatably coupled to the corner portions  866  of the base  834  about a common rotational axis. It is contemplated that the patient transport apparatus  830  may operate in the same manner as the patient transport apparatus  430  illustrated in  FIGS. 8A and 8B . 
       FIG. 11  illustrates yet another embodiment of a patient transport apparatus  1030 , which is similar to the patient transport apparatus  430  of  FIG. 8A  and comprises similar components identified by the same reference numbers increased by  600 . However, while the patient transport apparatus  430  of  FIG. 8A  comprises two omni-directional wheels  470 ,  472  rotatably coupled to the base  434  between the head and foot ends on opposing left and right sides  504 ,  506  of the same, the patient transport apparatus  1030  comprises two omni-directional wheels  1070 ,  1072  having two base wheels  1076   a ,  1076   b  spaced inwardly from the opposing left and right sides  1104 ,  1106  of the base  1034 . The base wheels  1076   a ,  1076   b  may be rotatably coupled to the cross member  1068  about two base rotational axes R 1  that are collinear with one another and perpendicular to the longitudinal axis L of the patient transport apparatus  830 . Put another way, the two omni-directional wheels  1070 ,  1072  are rotatably coupled to the cross member  1068  of the base  1034  about a common rotational axis. It is contemplated that the patient transport apparatus  1030  may operate in the same manner as the patient transport apparatus  430  illustrated in  FIGS. 8A and 8B . 
       FIG. 12  illustrates yet another embodiment of a patient transport apparatus  1230 , which is similar to the patient transport apparatus  30  of  FIG. 7A  and comprises similar components identified by the same reference numbers increased by  1200 . However, while the patient transport apparatus  30  of  FIG. 7A  comprises the single omni-directional wheel  70  coupled to the cross member  68  of the base  34 , the patient transport apparatus  1230  has two omni-directional wheels  1270 ,  1272  with two base wheels  1276   a ,  1276   b  arranged in a toe-in configuration toward the footboard  1254 . In particular, the two base wheels  1276   a ,  1276   b  are rotatably coupled to a cross member  1268  about two base rotational axes R 1   a , R 1   b  that are transverse to the longitudinal axis L of the patient transport apparatus  1230 , by a common acute angle α in opposite directions from the axis L. Put another way, the two base rotational axes R 1   a , R 1   b  converge toward the head end  1251  of the support structure  1232  and intersect one another at a common point along the longitudinal axis L. In the illustrated embodiment, the base wheels  1276   a ,  1276   b  are rotatably coupled to the cross member  1268  about two base rotational axes R 1   a , R 1   b  that are transverse to the longitudinal axis L by 45 degrees and −45 degrees, respectively. Other common angles or distinct angles are contemplated. As but one example, one of the first and second omni-directional wheels may have a base rotational axis perpendicular to the longitudinal axis and be configured as the driving wheel, and the other of the first and second omni-directional wheels may have a base rotational axis that is parallel with the longitudinal axis and be configured as the steering wheel whereby activing driving of the steering wheel causes left/right motion to steer while the driving wheel causes forward/rearward motion. The driving wheel and/or the steering wheel can be manually controlled by an operator using an operator input, or can be automatically controlled. 
       FIGS. 13A-13C  illustrate rotation of the two omni-directional wheels  1270 ,  1272  of  FIG. 12  for moving the patient transport apparatus  1230  in a forward direction parallel with the longitudinal axis L, a direction transverse to the longitudinal axis L, and a lateral direction perpendicular to the longitudinal axis L. The omni-directional wheels  1270 ,  1272  have base wheel drives  1290   a ,  1290   b  and motion control elements  1282   a ,  1282   b , such that each one of the omni-directional wheels  1270 ,  1272  can be selectively configured as a driving wheel and/or a steering wheel. In  FIG. 13A , the controller  1302  may be configured to actuate the base wheel drives  1290   a ,  1290   b  to rotate the base wheels  1276   a ,  1276   b  in a forward trajectory relative to the footboard  1254  such that the patient transport apparatus  1230  moves in a forward longitudinal direction that is parallel with the longitudinal axis L of the patient transport apparatus  30  (as indicated by the motion arrow). The controller  1302  may be configured to actuate the motion control elements  1282   a ,  1282   b  to rotate the peripheral wheels  1280   a ,  1280   b  in a forward trajectory relative to the footboard  1254  and compensate for the radially inward travel associated with the rotation of the corresponding base wheels  1276   a ,  1276   b . Of course, it is contemplated that the controller  1302  may be configured to actuate the motion control elements  1282   a ,  1282   b  to inhibit rotation of the peripheral wheels  1280   a ,  1280   b , allow partial rotation of the same, or the peripheral wheels  1280   a ,  1280   b  may freely rotate and merely act as followers. 
       FIG. 13B  illustrates the controller  1302  being configured to actuate one of the base wheel drives  1290   a ,  1290   b  to rotate the base wheel  1276   a  in the forward trajectory relative to the footboard  1254 , while not actively driving rotation of the other base wheel  1276   b , permitting free rotation of the base wheel  1276   b , actively driving the other base wheel  1276   b  at a slower rotational speed, or while inhibiting rotation of the other base wheel  1276   b  (e.g., via the base brake  1288   a  or  1288   b ) such that the patient transport apparatus  1230  moves in a direction that is transverse to the longitudinal axis L of the support structure  1232  (as indicated by the motion arrow). Furthermore, the controller  1302  may be configured to actuate the motion control element  1282   b  to rotate the peripheral wheels  1280   b  in the direction transverse to the longitudinal axis L and/or actuate the motion control element  1282   a  to brake, lock or otherwise inhibit rotation of the peripheral wheels  1280   a . In other embodiments, the controller may move the base wheel  1276   b  to a retracted position such that the base wheel  1276   b  is spaced above the floor surface as exemplified in  FIG. 6 . Of course, it is contemplated that the controller  1302  may be configured to actuate any of the motion control elements  1282   a ,  1282   b  to control rotation of the peripheral wheels  1280   a ,  1280   b  in any direction and in any manner. 
       FIG. 13C  shows the controller  1302  being configured to actuate the base wheel drives  1290   a ,  1290   b  to rotate the base wheel  1276   a  in the forward trajectory relative to the footboard  1254  and rotate the other base wheel  1276   b  in a rearward trajectory relative to the footboard  1254  such that the patient transport apparatus  1230  moves in a lateral direction that is perpendicular to the longitudinal axis L of the patient transport apparatus  1230 . The controller  1302  may be configured to actuate the motion control elements  1282   a  to rotate the peripheral wheels  1280   a  in a rearward trajectory relative to the headboard  1252  and actuate the motion control elements  1282   b  to rotate the peripheral wheels  1280   b  in a forward trajectory relative to the footboard  1254 , such that the peripheral wheels  1280   a ,  1280   b  can move the patient transport apparatus  1230  in the lateral direction that is perpendicular to the longitudinal axis L and compensate for the forward and rearward movement associated with rotation of the base wheels  1276   a ,  1276   b . Of course, it is contemplated that controller  1302  may be configured to actuate the motion control elements  1282   a ,  1282   b  to inhibit rotation of the peripheral wheels  1280   a ,  1280   b  in a rearward trajectory toward the headboard  1252 , allow only partial rotation of the peripheral wheels  1280   a ,  1280   b , or the peripheral wheels  1280   a ,  1280   b  may freely rotate and merely act as followers. 
       FIG. 14  illustrates another embodiment of a patient transport apparatus  1430  that is similar to the patient transport apparatus  1230  of  FIGS. 12-13C , and it comprises the same components identified by reference numbers increased by  200 . However, while the patient transport apparatus  1200  of  FIGS. 12-13C  comprises two omni-directional wheels  1270 ,  1272 , the patient transport apparatus  1430  comprises three omni-directional wheels  1470 ,  1472 ,  1474 . Omni-directional wheels  1470 ,  1472  are substantially similar to the omni-directional wheels  1270 ,  1272  of  FIGS. 12-13C . The third omni-directional wheel  1474  may be configured as the driving wheel, and the first and second omni-directional wheels  1470 ,  1472  may be configured as the steering wheels, for moving the patient transport apparatus in desired directions. More specifically, the first and second omni-directional wheels  1470 ,  1472  may be used to provide directional control (e.g., steering, slew, lateral control) based on their respective rates of rotation compared to one other and the third omni-directional wheel  1474 . The base wheel drive  1490   c  (e.g., including the motor), for the third omni-directional wheel  1474  can be larger and more powerful than the base wheel drives  1490   a ,  1490   b  (e.g., including the motors), for the first and second omni-directional wheels  1470 , 1472 . It is contemplated that the base wheel drives for the three omni-directional wheels  1470 ,  1472 ,  1474  can have the same size and/or power. As but one example, the third omni-directional wheel  1474  being configured as the driving wheel can be particularly useful for moving the patient along lengthy corridors having an incline. 
     The third omni-directional wheel  1474  comprises a third base wheel  1476   c  having a third outer periphery  1478   c  and rotatably coupled to the support structure  1432  about a third base rotational axis R 1   c . The third omni-directional wheel  1474  comprises peripheral wheels  1480   c  disposed about the third outer periphery  1478   c  to rotate about peripheral rotational axes R 2 . The third omni-directional wheel  1474  comprises one or more third motion control devices  1482   c  configured to selectively control rotation of the peripheral wheels  1480   c  independent of the rotation of the third base wheel  1476   c  about the third base rotational axis R 1   c , in the same manner as previously described. The third base rotational axis R 1   c  is perpendicular to the longitudinal axis L. Other third wheel assemblies are contemplated. 
       FIGS. 15A-15C  show rotation of the omni-directional wheels  1470 ,  1472 ,  1474  for moving the patient transport apparatus  1430  in a corresponding one of a forward direction parallel with the longitudinal axis L, a direction transverse to the longitudinal axis L, and a lateral direction perpendicular to the longitudinal axis L. These configurations are similar to the configurations shown in  FIGS. 13A-13C . However, the patient transport apparatus  1430  comprises the third omni-directional wheel  1474  that can rotate and perform as the auxiliary drive wheel to facilitate moving the apparatus in the forward direction ( FIG. 15A ) and the direction transverse to the longitudinal axis L ( FIG. 15B ). When the operator intends to move the patient transport apparatus  1430  in the lateral direction, the controller  1502  can actuate a base brake  1488   c  of the third base wheel  1476   c  and actuate the motion control device  1482   c  to rotate one of the third peripheral wheels  1480   c . Of course, other mobility configurations are contemplated. As but one example, in other embodiments, the controller  1502  may actuate the base wheel drive  1490   c  to rotate the base wheel  1476   c  in a forward trajectory relative to the footboard  1454  or a rearward trajectory relative to the footboard  1454 . Still, in other embodiments, the controller  1502  may actuate the motion control device  1482   c  to rotate one of the third peripheral wheels  1480   c  toward the left side  1506  or the right side  1504  of the patient transport apparatus  1430  for lateral movement. The controller  1502  may actuate the base wheel drive  1490   c  to rotate the base wheel  1476   c  in a manner that assists with moving the patient transport apparatus  1430  in the intended direction or the controller  1502  may actuate the base wheel drive  1490   c  to rotate the base wheel  1476   c  in a manner that opposes the intended direction of movement of the patient transport apparatus  1430 , thereby operating as a speed control mechanism to slow movement of the patient transport apparatus  1430 . Similarly, the controller  1502  may actuate the motion control device  1482   c  to rotate one of the third peripheral wheels  1480   c  in a manner that assists with moving the patient transport apparatus  1430  in the intended direction or the controller  1502  may actuate the motion control device  1482   c  to rotate one of the third peripheral wheels  1480   c  in a manner that opposes the intended direction of movement of the patient transport apparatus  1430 , thereby operating as a speed control mechanism to slow movement of the patient transport apparatus  1430 . 
       FIG. 16  illustrates another embodiment of a patient transport apparatus  1630  that is similar to the patient transport apparatus  1430  illustrated in  FIGS. 14-15C , and it comprises the same components identified by reference numbers increased by  200 . However, while the third base wheel  1476   c  of  FIGS. 14-15C  is rotatably coupled to the support structure  1432  about a third base rotational axis R 1   c  that is perpendicular to the longitudinal axis L, the third base wheel  1676   c  is rotatably coupled to the support structure  1432  about a third base rotational axis R 1   c  that is parallel with the longitudinal axis L. In this embodiment, the third omni-directional wheel  1674  may be configured as the steering wheel. Each one of the first and second omni-directional wheels  1670 ,  1672  may be configured as a primary longitudinal driving wheel and/or an auxiliary steering wheel for moving the patient transport apparatus in desired directions. Other driving and/or steering wheel configurations are contemplated. 
       FIGS. 17-19  show other embodiments of patient transport apparatuses  1830 ,  2030 ,  2230  that are similar to the patient transport apparatuses  1230 ,  1430 ,  1630  illustrated in  FIGS. 12, 14, and 16  and include similar components identified by numbers increased by  600 . However, while  FIGS. 12, 14, and 16  show each patient transport apparatus  1230 ,  1430 ,  1630  having two forward wheel assemblies in a toe-in configuration toward the footboard  1254 ,  1454 ,  1654 , each patient transport apparatus  1830 ,  2030 ,  2230  of  FIGS. 17-19  comprises two forward wheel assemblies in a toe-out configuration relative to the footboard  1854 ,  2054 ,  2254 . 
     More specifically, the base wheels  1276   a ,  1276   b  of  FIG. 12  are rotatably coupled to the support structure  1232  about two base rotational axes that converge toward the head end portion  1251  of the support structure  1232 . In contrast to the base wheels  1276   a ,  1276   b  of  FIG. 12 , the base wheels  1876   a ,  1876   b  of  FIG. 17  are rotatably coupled to the support structure  1832  about two base rotational axes R 1   a , R 1   b  that converge toward the foot end portion  1853  of the support structure  1832 . 
     Similarly, while the base wheels  1476   a ,  1476   b  of  FIG. 14  are rotatably coupled to the support structure  1432  about two base rotational axes R 1   a , R 1   b  that converge toward the head end portion  1451  of the support structure  1432 , the base wheels  2076   a ,  2076   b  of  FIG. 18  are rotatably coupled to the support structure  2032  about two base rotational axes R 1   a , R 1   b  that converge toward the foot end portion  2053  of the support structure  2032 . 
     Moreover, while the base wheels  1676   a ,  1676   b  of  FIG. 16  are rotatably coupled to the support structure  1632  about two base rotational axes R 1   a , R 1   b  that converge toward the head end portion  1651  of the support structure  1632 , the base wheels  2276   a ,  2276   b  of  FIG. 19  are rotatably coupled to the support structure  2232  about two base rotational axes R 1   a , R 1   b  that converge toward the foot end portion  2253  of the support structure  2232 . 
     Referring to  FIGS. 20 and 21 , still another embodiment of a patient transport apparatus  2430  is illustrated. The patient transport apparatus  2430  is similar to the patient transport apparatus  30  of  FIG. 1  and comprises components identified by the same numbers increased by  2400 . However, while patient transport apparatus  30  of  FIG. 1  comprises a single omni-directional wheel  70  coupled to the cross member  68  of the base  34 , the patient transport apparatus  2430  comprises two mecanum wheels  2470 ,  2472  coupled to opposing sides  2504 ,  2506  of the base  2434 . Furthermore, while  FIG. 22  illustrates the mecanum wheel  2470  and its arrangement of components, the mecanum wheels  2470 ,  2472  are similar to one another. In the illustrated embodiment, the mecanum wheels  2470 ,  2472  include base wheels  2476   a ,  2476   b  having outer peripheries  2478   a ,  2478   b  rotatably coupled to the support structure  2432  about base rotational axes that are collinear with one another such that the base wheels  2476  are rotatably coupled to the support structure  2432  about a common rotational axis that is perpendicular to the longitudinal axis L. In addition, the base wheel drives  2490   a ,  2490   b  include drive axles (not shown), which are perpendicular to the longitudinal axis L and coupled to a respective one of base wheels  2476   a ,  2476   b . The mecanum wheels  2470 ,  2472  respectively comprise left and right handed peripheral wheels  2480   a ,  2480   b  positioned about the outer peripheries  2478   a ,  2478   b  to freely rotate about peripheral rotational axes. In this embodiment, the rotation of the peripheral wheels  2480   a ,  2480  are not driven or inhibited by any motion control element or other drive. However, the direction of rotation of the base wheels  2476   a ,  2476   b  and the position of the peripheral wheels  2480   a ,  2480   b  relative to the wheelbase diagonal are exemplified in the description for  FIGS. 23A-30 . Other embodiments of the patient transport apparatus having two or more mecanum wheels positioned in any configuration are contemplated. 
       FIGS. 23A-23C  illustrate rotation of the mecanum wheels  2470 ,  2472  for moving the patient transport apparatus  2430  in a forward direction parallel with the longitudinal axis L, a direction transverse to the longitudinal axis L, and a lateral direction perpendicular to the longitudinal axis L. In  FIG. 23A , the controller  2502  is configured to actuate the base wheel drives  2490   a ,  2490   b  to rotate the base wheels  2476   a ,  2476   b  in a forward trajectory toward the footboard  2454  such that the patient transport apparatus  2430  moves in a forward direction that is parallel with said longitudinal axis L of the patient transport apparatus  2430 . Moving the base wheels  2476   a ,  2476   b  in the same direction either forward or rearward relative to the footboard  2454  causes forward or rearward movement of the patient transport apparatus  2430 .  FIG. 23B  illustrates the controller  2502  being configured to actuate the base wheel drives  2490   a ,  2490   b  to rotate the base wheel  2476   b  in the forward trajectory toward the footboard  2454  and inhibit rotation of the other base wheel  2476   a  such that the patient transport apparatus  2430  moves in a direction that is transverse to the longitudinal axis L of the support structure  2432 . Rotating the base wheel  2476   b  on the left side  2506  in a forward trajectory relative to the footboard  2454  while not actively rotating, rotating at a slower rotational speed, or inhibiting rotation of the base wheel  2476   a , causes diagonal movement of the patient transport apparatus  2430  in a forward-left diagonal direction along the rolling direction of the freely rotating peripheral wheels  2480   b . It is contemplated that rotating the base wheel  2476   a  on the right side  2506  in a forward trajectory relative to the footboard  2454  while not actively rotating, more slowly rotating, or inhibiting rotation of the base wheel  2476   b , causes diagonal movement of the patient transport apparatus  2430  in a forward-right diagonal direction along the rolling direction of the freely rotating peripheral wheels  2480   a .  FIG. 23C  shows the controller  2502  being configured to actuate the base wheel drives  2490   a ,  2490   b  to rotate the base wheel  2476   a  in the forward trajectory toward the footboard  2454  and rotate the other base wheel  2476   b  in a rearward trajectory toward the headboard  2452  such that the patient transport apparatus  2430  moves in a lateral direction that is perpendicular to the longitudinal axis L of the patient transport apparatus  2430  and toward the left side  2506  of the patient transport apparatus  2430 . It is contemplated that the controller  2502  may actuate the base wheel drives  2490   a ,  2490   b  to rotate the base wheel  2476   b  in the forward trajectory toward the footboard  2454  and rotate the other base wheel  2476   a  in a rearward trajectory toward the headboard  2452  such that the patient transport apparatus  2430  moves in a lateral direction that is perpendicular to the longitudinal axis L of the patient transport apparatus  2430  and toward the right side  2504  of the patient transport apparatus  2430 . 
     Referring to  FIG. 24 , another embodiment of a patient transport apparatus  2630  is similar to the patient transport apparatus  2430  of  FIGS. 23A-23C , and it comprises similar components identified by the same reference numbers increased by  200 . However, while the patient transport apparatus  2430  of  FIGS. 23A-23C  comprises two mecanum wheels  2470 ,  2472  coupled to opposing sides  2504 ,  2506 , the patient transport apparatus  2630  comprises two mecanum wheels  2670 ,  2672  coupled to the corners  2666  adjacent to the headboard  2652 . The mecanum wheels  2670 ,  2672  may include left and right handed peripheral wheels  2680   a ,  2680   b  positioned about the outer peripheries  2678   a ,  2678   b  to freely rotate about peripheral rotational axes. 
     Referring to  FIG. 25 , yet another embodiment of a patient transport apparatus  2830  is similar to the patient transport apparatus  2430  of  FIGS. 23A-23C , and it comprises similar components identified by the same reference numbers increased by  400 . However, while the patient transport apparatus  2430  of  FIGS. 23A-23C  comprises two mecanum wheels  2470 ,  2472  coupled to opposing sides  2504 ,  2506 , the patient transport apparatus  2830  of  FIG. 25  comprises two mecanum wheels  2870 ,  2872  coupled to the corners  2866  adjacent to the footboard  2854 . The mecanum wheels  2870 ,  2872  may include left and right handed peripheral wheels  2880   a ,  2880   b  positioned about the outer peripheries  2878   a ,  2878   b  to freely rotate about peripheral rotational axes. 
     Referring to  FIG. 26 , still another embodiment of a patient transport apparatus  3030  is similar to the patient transport apparatus  2630  of  FIG. 24 , and it comprises similar components identified by the same reference numbers increased by  400 . However, while the patient transport apparatus  2630  of  FIG. 24  comprises two support wheels  2698  coupled to the corners  2866  adjacent to the footboard  2854 , the patient transport apparatus  3030  comprises two mecanum wheels  3070   a ,  3072   a  coupled to the corners  3066  adjacent to the footboard  3054 . Furthermore, while the mecanum wheels  3070   b ,  3072   b  coupled to the corners  3066  adjacent to the headboard  3052  comprise a respective one of right and left handed peripheral wheels  3080   b , the mecanum wheels  3070   a ,  3072   a  coupled to the corners  3066  adjacent to the footboard  3054  comprise an opposite configuration with a respective one of left and right handed peripheral wheels  3080   a , in such a way that each peripheral wheel of the four mecanum wheels  3070   a ,  3072   a ,  3070   b ,  3072   b  applies force at generally right angles relative to corresponding wheelbase diagonals (not shown). This wheel configuration can improve the stability of the patient transport apparatus  3030  and improve its maneuverability in any direction at any speed and direction of rotation for each wheel  3070   a ,  3072   a ,  3070   b ,  3072   b . Other mecanum wheel configurations including other configurations of the peripheral wheels are contemplated. 
     Other embodiments of the mecanum wheels and/or omni-directional wheels coupled to any portion of the patient transport apparatus in any suitable arrangement are contemplated. As but one example,  FIG. 27  illustrates one embodiment of a patient transport apparatus  3230  that is similar to the patient transport apparatus  3030  of  FIG. 26 , and it comprises similar components identified by the same reference numbers increased by  200 , except that the peripheral wheels  3280   a ,  3280   b  on the right side are oriented in the same direction and the peripheral wheels  3280   a ,  3280   b  on the left side are oriented in the same direction, yet opposite to those on the right side. 
     As a further example,  FIG. 28  is a schematic illustration of still another embodiment of a patient transport apparatus  3430 . The patient transport apparatus  3430  is similar to the patient transport apparatus  3230  of  FIG. 27 , and it comprises similar components identified by the same reference numbers increased by  200 , except that the orientations of the peripheral wheels  3480   a ,  3480   b  are reversed compared to  FIG. 27 . 
     As still another example,  FIG. 29  is a schematic illustration of yet another embodiment of a patient transport apparatus  3630 . The patient transport apparatus  3630  is similar to the patient transport apparatus  2430  of  FIG. 23A , and it comprises similar components identified by the same reference numbers increased by  1200 . The patient transport apparatus  3630  of  FIG. 29  comprises two mecanum wheels  3670 ,  3672  coupled to opposing sides  3704 ,  3706  of the patient transport apparatus  3630  and having peripheral wheels  3680   a ,  3680   b  positioned in a reverse orientation relative to those shown in  FIG. 23A . 
       FIG. 30  is a schematic illustration of still another embodiment of a patient transport apparatus  3830 . The patient transport apparatus  3830  is similar to the patient transport apparatus  2430  of  FIG. 23A , and it comprises similar components identified by the same reference numbers increased by  1400 . While the patient transport apparatus  2430  of  FIG. 23A  comprises two mecanum wheels  2470 ,  2472  coupled to opposing left and right sides  2472 ,  2470  of the patient transport apparatus  2430 , the patient transport apparatus  3830  of  FIG. 30  comprises two mecanum wheels  3870 ,  3872  coupled to two diametrically opposite corners  3866  of the patient transport apparatus  3830 . 
     Referring to  FIG. 31 , another embodiment of a patient transport apparatus  3830  is shown and it comprises similar components as  FIGS. 7A and 7B . However, the patient transport apparatus  3830  of  FIG. 31  has four omni-directional wheels  3870   a ,  3872   a ,  3870   b ,  3872   b  rotatably coupled to the four corners of the patient transport apparatus  3830  about four base rotational axes R 1  that are perpendicular to the longitudinal axis L of the patient transport apparatus  3830 . Furthermore, the patient transport apparatus  3830  comprises a patient support deck  3838  including a foot section  3839  with cutouts  3841 ,  3843  for providing clearance for the base  3834  when the foot section  3839  pivots toward the floor surface from its position shown in  FIG. 31 . Because these omni-directional wheels  3870   a ,  3872   a  do not swivel, the cutouts  3841 ,  3843  are sized to accommodate the base  3834 , but do not need to be sized larger to accommodate sweeping paths associated with swiveling wheels. 
     Other configurations of mecanum wheels, omni-directional wheels, support wheels, and combinations thereof, are contemplated. In certain embodiments, all of the omni-directional wheels employed on the patient transport apparatus are configured to be actively driven, only a portion are configured to be actively driven, or all are zero velocity wheels that freely rotate and are not driven by a motor. Additionally, in some embodiment employing mecanum wheels, all of the mecanum wheels are configured to be actively driven, only a portion are configured to be actively driven, or all are zero velocity wheels that freely rotate and are not driven by a motor. Still other configurations can employ any combination of mecanum wheels, omni-directional wheels, and/or support wheels. 
     It will be further appreciated that the terms “include,” “includes,” and “including” have the same meaning as the terms “comprise,” “comprises,” and “comprising.” 
     Several embodiments have been discussed in the foregoing description. However, the embodiments discussed herein are not intended to be exhaustive or limit the invention to any particular form. The terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations are possible in light of the above teachings and the invention may be practiced otherwise than as specifically described.