Patent Publication Number: US-2023149772-A1

Title: System, method and apparatus for electrically actuated pedal for an exercise or rehabilitation machine

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/813,224, which claims priority to and the benefit of U.S. Prov. Pat. App. No. 62/816,550, filed Mar. 11, 2019, and U.S. Prov. Pat. App. No. 62/816,557, filed on Mar. 11, 2019. All applications are incorporated herein by reference in their entirety. 
    
    
     FIELD 
     The present disclosure relates generally to a pedal and pedal systems for an exercise or rehabilitation machine and, in particular, a pedal that is remotely adjustable during operation. 
     BACKGROUND 
     Improvement is desired in the design of adjustable rehabilitation and exercise devices. Adjustable rehabilitation and exercise devices are desired to customize rehabilitation and exercise to an individual. Some devices include pedals on opposite sides to engage a user. See, e.g., U.S. Pat. No. 10,173,094, titled Adjustable Rehabilitation and Exercise Device, issued to Gomberg, et al., which is hereby incorporated by reference in its entirety. 
     Accordingly, in one aspect, the disclosure provides an adjustable rehabilitation and exercise device having patient engagement members on opposite sides of the device, which are adjustably positionable relative to one another both radially and angularly. 
     SUMMARY 
     This section provides a general summary of the present disclosure and is not a comprehensive disclosure of its full scope or all of its features, aspects and objectives. 
     In accordance with one aspect of the disclosure, a pedal or pedal mechanism is electrically actuatable in response to control signals. The pedal mechanism can be part of equipment for electromechanical exercise or rehabilitation of a user. The pedal mechanism can include a pedal configured to engage an appendage or extremity (e.g., arm or leg) of the user of the equipment and a spindle supporting the pedal and having a spindle axis. A pedal arm assembly supports the spindle and is coupled to a rotational axle of the equipment that is radially offset from the spindle axis to define a range of radial travel of the pedal relative to the rotational axle. The pedal arm assembly can include an electrically actuated coupling assembly to adjust a radial position of the pedal relative to the rotational axle in response to a control signal and to monitor or regulate motion of the user engaged with the pedal. 
     In accordance with an aspect of the disclosure, the pedal arm assembly includes a housing with an elongate aperture through which the spindle extends. 
     In accordance with an aspect of the disclosure, the coupling assembly includes a carriage mounted in the housing and supporting the spindle. 
     In accordance with an aspect of the disclosure, an electric motor is connected to the carriage to linearly move the spindle extending though the elongate aperture. In accordance with an aspect of the disclosure, the elongate aperture is orthogonal to the spindle axis. 
     In accordance with an aspect of the disclosure, the coupling assembly includes a leadscrew that is rotated by the electric motor and is threadingly connected to the carriage. 
     In accordance with an aspect of the disclosure, the carriage includes a throughbore receiving the leadscrew and a threaded nut mounted adjacent to the throughbore for threaded engagement with the leadscrew. 
     In accordance with an aspect of the disclosure, the coupling assembly includes a rail adjacent and parallel to the leadscrew in the housing. The carriage can engage the rail to define linear travel of the carriage and the range of radial travel of the pedal. 
     In accordance with an aspect of the disclosure, the coupling assembly includes a slide pad intermediate the carrier and an interior wall of the housing adjacent the leadscrew. 
     In accordance with an aspect of the disclosure, the coupling assembly is configured to adjust the radial position of the pedal in response to the control signal during pedaling of the pedal. 
     In accordance with an aspect of the disclosure, the coupling assembly is configured to adjust the radial position of the pedal to produce an elliptical pedal path, relative to the rotational axle, during a revolution of the pedal. 
     In accordance with an aspect of the disclosure, the pedal includes a pressure sensor to sense force applied to the pedal and transmit sensed force to a remote or distal receiver. 
     In accordance with an aspect of the disclosure, the pedal includes a pedal bottom to receive the spindle and pivot thereon, pressure sensors, a base plate supported on the pedal bottom and supporting the pressure sensors, and a pedal top above the base plate and operatively engaged with the pressure sensors to transmit force from the user of the pedal to the pressure sensors. 
     In accordance with an aspect of the disclosure, the plurality of pressure sensors includes a toe sensor to sense a first pressure and a heel sensor to sense a second pressure. The first pressure and the second pressure are used by the control system to determine a net force or a true force on the pedal, as will be described herein. 
     In accordance with an aspect of the disclosure, the coupling assembly is configured to translate rotational motion of the electric motor to radial motion of the pedals. 
     In accordance with an aspect of the disclosure, a method can electrically adjust a radial position of a pedal relative to a rotational axle in response to a control signal, regulating rotational motion of the user engaged with the pedal, and sensing rotational position of the pedal. 
     In accordance with an aspect of the disclosure, electrically adjusting the radial position of the pedal includes controlling an electric motor connected to a carriage to linearly move the spindle extending though an elongate aperture of a housing. 
     In accordance with an aspect of the disclosure, electrically adjusting the radial position of the pedal includes mechanically supporting the carriage in the housing on the rail to define linear travel of the carriage and a range of radial travel of the pedal. 
     In accordance with an aspect of the disclosure, electrically adjusting the radial position of the pedal includes rotating a leadscrew driven by the electric motor and connected to the carriage. 
     In accordance with an aspect of the disclosure, electrically adjusting the radial position of the pedal includes adjusting the radial position of the pedal, during a revolution of the pedal, to produce an elliptical pedal path relative to the rotational axle. 
     In accordance with an aspect of the disclosure, electrically adjusting the radial position of the pedal includes adjusting the radial position of the pedal in response to the control signal during pedaling of the pedal. 
     In accordance with an aspect of the disclosure, regulating rotational motion includes measuring force applied to the pedal and transmitting the measured force to a remote receiver. 
     The above aspects of the disclosure describe a pedal that is actuatable in response to control signals to adjust its position for travel 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of this disclosure and its advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    is a schematic view of an exercise machine with an actuatable pedal in accordance with the present disclosure; 
         FIGS.  2 A- 2 E  are views of the pedal in accordance with the present disclosure; 
         FIGS.  3 A- 3 C  are views of the pedal control assembly in accordance with the present disclosure; 
         FIGS.  4 A- 4 D  are views of the rehabilitation/exercise system in accordance with the present disclosure; 
         FIG.  5    is a flowchart of a method for operating the rehabilitation/exercise system in accordance with the present disclosure; 
         FIG.  6    is a schematic view of a pedal and resulting forces in accordance with the present disclosure; 
         FIG.  7    is a graph showing the points at which the motor can maintain a set resultant force in accordance with the present disclosure; 
         FIG.  8    is a flowchart of a method for operating the rehabilitation/exercise system in accordance with the present disclosure; and 
         FIG.  9    is a flowchart of a method for operating the rehabilitation/exercise system in accordance with the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In general, embodiments of a pedal or pedal system to be engaged by a user to provide exercise or rehabilitation are disclosed. The pedal can be adjusted in its position using control signals. The control signals can be produced according to an application, which in some example embodiments receives position or force signals from the pedal itself. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the present disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail, as they will be readily understood by the skilled artisan in view of the disclosure herein. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
     When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
     Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” “top”, “bottom,” and the like, may be used herein for ease of description to describe one element&#39;s or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated degrees or at other orientations) and the spatially relative descriptions used herein interpreted accordingly. 
     In an aspect, the disclosure provides an adjustable rehabilitation and exercise device having patient engagement members (pedals, handgrips, or the like) on opposite sides of the device, which are adjustably positionable relative to one another radially to provide controlled movement of the members during travel of the engagement members to provide rehabilitation, exercise or both. 
     In an example embodiment, the pedal mechanism or assembly can be part of a rotary rehabilitation apparatus to provide exercise or movement to a user, e.g., moving joints and activating muscles, tendons, and ligaments. The pedal mechanism can assist in tailoring to the user&#39;s needs based upon the user&#39;s physical size, type of injury, and treatment schedule. The pedal mechanism can provide for adjustment of the range of motion of the user&#39;s extremity in a cycling motion by driving an electrical motor in response to control signals. The control signals can be based on a treatment schedule stored in a controller. The control signals can be based at least in part on sensed characteristics of the pedaling action, e.g., in real time use. The pedals can be moved during a revolution to adjust the travel path to alter the travel path of one or more of the user&#39;s limbs from a circular path. The control of the pedal positioning can assist in the rehabilitation of the user by precisely controlling the user&#39;s extension and flexion at the user&#39;s joints. 
       FIGS.  1 - 9   , discussed below, and the various embodiments used to describe the principles of this disclosure are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. 
       FIG.  1    shows a schematic view of a rehabilitation system  100  that includes a pedal system  101  operably engaged with a base  110 , in accordance with the present disclosure. The pedal system  101  includes an engagement member, e.g., a pedal  102 , to engage a user with the rehabilitation system. The pedal  102  is configured for interacting with a patient to be rehabilitated and may be configured for use with lower body extremities such as the feet or legs, or upper body extremities such as the hands or arms, or any other suitable body parts. The pedal  102  is positioned on a spindle  103  that is supported on a pedal arm assembly  104 . The pedal  102  can be pivotably mounted on the spindle  103 . The pedal arm assembly  104  is connected to the axle  105  of the base  110 , which supports and, at times, drives the axle  105 . A controller  112  is electrically connected to the pedal arm assembly  104  to provide a control signal to control operation of the pedal arm assembly  104 . The pedal arm assembly  104  can be coupled to the axle  105  of the rehabilitation or exercise machine with the axle being radially offset from the axis of the spindle  103  to define a range of radial travel of the pedal  102  relative to the axle  105 . As shown in  FIG.  1   , the pedal  102  can be moved from a first position (solid line) to a second position as illustrated by pedal  102 ′ (broken line). The spindle  103  is moved by the pedal arm assembly relative to the fixed axle  105  from the first position (solid line,  103 ) and a second position (broken line,  103 ′). The pedal arm assembly  104  is electrically actuatable by a control signal  117  from the controller  112 . The pedal arm assembly  104  adjusts a radial position of the pedal  102 , e.g., from the solid line position to the broken line position or vice versa, or to any position in between, relative to the axle. In an embodiment with two pedals, one for the left foot and one for the right, each pedal can be individually controlled by the controller  112 . The pedal  102  (solid line) is positioned radially outwardly from the pedal  102 ′ (broken line). The pedal  102  will have a larger travel path than the pedal  102 ′ as they rotate around the axle  105 . The base  110  includes an electric motor  114  for providing a driving force or resistance to the pedal  102  and for providing a simulated flywheel  115 . 
       FIGS.  2 A,  2 B,  2 C and  2 D  show the pedal  102  in a perspective view, a side view, a rear end view, and a top view, respectively. The pedal  102  includes a pedal bottom cover  201  and a pedal frame  203  on the pedal bottom cover  201 . The pedal frame  203  can be rigid and define a throughbore  205  to receive the spindle  103 . The spindle  103  can be fixed longitudinally in the throughbore  205  while allowing the pedal frame  203  to pivot on the spindle  103 . The spindle  103  extends out of one end of the throughbore  205  and the other end of the throughbore  205  can be covered by a cap  206 . A pedal top  207  is joined on the top of the pedal frame  203  and is configured to receive a foot of a user. The pedal top  207  may include treads to grip a user&#39;s shoe tread or foot directly. The pedal top  207  can include a lip  209  around the periphery with a heel portion being taller than the other parts of the lip. The lip  209  assists in preventing the user&#39;s foot from sliding off the pedal top  207 . The pedal top  207  is moveably mounted to pedal frame  203  to transfer a force applied onto the pedal top  207  to one or more force sensors that are in the pedal  200 . 
       FIG.  2 E  is an exploded view of the pedal  102  to illustrate the structure to sense force applied to the pedal during exercise or rehabilitation. A sensor assembly  215  is mounted within the pedal  102 . The sensor assembly  215  includes base plate  217 , a top plate  218  above the base plate  217 , and one or more force sensors  219  (e.g., a heel sensor located at a heel end of the pedal or a toe sensor located at a toe end of the pedal) between the plates  217 ,  218 . The one or more force sensors  219  sense the force applied to the pedal and output a sensor value that represents force applied to the pedal. The sensor value may go to the controller  112  ( FIG.  1   ). The sensors can output a wireless signal representing the sensed-force or can output a wired signal (e.g., through the spindle  103 ). The base plate  217  is fixed within an upper recess in the pedal frame  203 . One or more force sensors  219  are fixed to the top surface of the base plate  217  or a bottom surface of the top plate  218 . In an example, one force sensor is positioned on base plate  217 . In the illustrated example, the heel sensor is positioned at the heel end of the base plate  217  and the toe sensor is positioned at the toe end of the base plate  217 . When a plurality of sensors is used, the sensor assembly  215  can include processor circuitry and memory operably coupled thereto to perform calculations on sensed-force signals from all of the force sensors  219  and output a calculated force signal from the pedal  102 . The force sensors  219  can be strain gauges, (e.g., foil strain gauge, which changes electrical resistance when it is deformed, and the electrical resistance can be determined by a Wheatstone bridge). The strain gauge can be a piezoresistor, microelectromechanical system (MEMS), variable capacitors, or other sensors that output a signal when a force is applied thereto. The base plate  217  and the top plate  218  move relative to each other such that the force moving at least one of the plates  217 ,  218  is applied to one of the force sensors  219 . In an example embodiment, the plates  217 ,  218  travel less than 2 mm, 1 mm, or 0.5 mm relative to each other and any movement applies a force to the force sensors  219 . In operation, the user will apply a force to the pedal top  207 . This force will cause the pedal  102  to rotate in a travel path defined by the position of the spindle  103  relative to the axle  105 . There can be some resistance, inertial or applied, as described herein. The resistance to pedal rotation must be overcome by the application of force by the user. This force is transmitted through the pedal top  207  to the force sensors  219 , which output a measurement value representing this force. 
       FIGS.  3 A and  3 B  are a side view and an end view of the pedal arm assembly  104 , respectively. The pedal arm assembly  104  includes a housing  301  with an aperture  303  through which the spindle  103  extends. The aperture  303  defines the linear travel of the spindle  103  (and, hence, the pedal  102 ) relative to the fixed axle  105 . A carriage  304  is in the housing  301  aligned with the aperture  303 . The carriage  304  supports the spindle  103  for travel orthogonal to the aperture  303 . An electric motor  305  is fixed at an end of the housing  301  and is fixed by a motor mount  307  to a housing hub  309  of the housing  301 . A slip ring  313  provides an electrical communication path between the electric motor  305  and the controller  112 . 
       FIG.  3 C  is an exploded view of the pedal arm assembly  104 . A shaft coupler  311  connects the drive of the electric motor  305  to a drivescrew  325  mounted inside the housing  301 . The drivescrew  325  is elongate and extends through drivescrew holes  326  positioned near the bottom of the housing  301 . Bearings  327 ,  328  fixed in the drivescrew holes  326  support the drivescrew  325  for rotation. The drivescrew  325  is threaded at least between the bearings  327 ,  328 . The drivescrew  325  can be threaded its entire length. The drivescrew  325  can be rotated in either a clockwise direction or a counterclockwise direction by the electric motor  305 . 
     A rail  330  is fixed in the housing  321  above the drivescrew  325 . The rail  330  is elongate and defines a travel path of the spindle  103 . The rail  330  includes a top guide edge  331  at the top of the rail and a bottom guide edge  332  at the bottom of the rail. 
     The carriage  304  includes a top member  336  configured to mechanically engage the rail  330  to guide the carriage  304  along the longitudinal length of the rail  330 . The carriage  304  includes a bottom member  337  to engage the drivescrew  325  to provide the motive force to move the carriage in the housing  321 . The top member  336  is fixed to the bottom member  337 . In an example embodiment, the top member  336  and bottom member  337  are formed from a unitary block of a rigid material (e.g., a metal or rigid polymer). A plurality of upper bearing blocks  341  fixed to the top member  336  is slidably engaged on the top guide edge  331 . A plurality of lower bearing blocks  342  fixed to the top member  336 , below the upper bearing blocks  341 , is slidably engaged on the bottom guide edge  332 . The bottom member  337  includes a throughbore  348  to receive the drivescrew  325 . In an example embodiment, the throughbore  348  is threaded to engage threads of the drivescrew  325 . In the illustrated example, a carriage coupling  339  is fixed to the bottom member  337  at the throughbore  348 . The carriage coupling  339  is internally threaded to mate with the external threads of the drivescrew  325 . In operation, the electric motor  305  turns the drivescrew  325 , and the carriage  304  through the carriage coupling  339  translates the rotational motion of the drivescrew to linear movement of the carriage  304  on the rail  330 . 
     The carriage  304  includes a spindle engagement  345  to fix the spindle  103  thereto. The spindle engagement  345  can include a threaded recess to receive a threaded carriage end of the spindle  103 . 
     A cover plate  322  is provided on the housing  321  to cover the recesses  323  receiving the internal components. The cover plate  322  includes the aperture  303  through which the spindle extends. The aperture  303  and the spindle engagement  345  are aligned to allow the spindle  103  to travel on the carriage  304  in the aperture  303 . 
     A slide plate  350  is provided on the bottom member  337 . The slide plate  350  slidably engages the housing (e.g., laterally adjacent the drivescrew  325 ) to assist in preventing rotation of the carriage  304  in the housing. 
       FIGS.  4 A,  4 B, and  4 C  are a perspective view, a side view and a rear view, respectively, of an exercise or rehabilitation electromechanical system  400  that uses the pedal and pedal arm assembly ( 102 ,  104 ) described herein.  FIG.  4 D  is an exploded view of the exercise or rehabilitation electromechanical device  400 . The electromechanical system  400  includes one or more pedals that couple to one or more radially-adjustable couplings. The electromechanical system  400  includes a left pedal  102 A that couples to a left radially-adjustable coupling assembly  104  via a spindle  103  through a shroud  401 . The radially-adjustable coupling  124  and shroud  401  can be disposed in a circular opening of a left outer cover  403  and the pedal arm assembly  104  can be secured to a drive sub-assembly  405 . The drive sub-assembly  405  may include the electric motor  114  that is operably coupled to the controller  112 . The drive sub-assembly  405  may include one or more braking mechanisms, such as disc brakes, which enable instantaneously locking the electric motor  114  or stopping the electric motor  114  over a period of time. The electric motor  114  may be any suitable electric motor (e.g., a crystallite electric motor). The electric motor  114  may drive the axle  105  directly. In the illustrated example, the motor connects to a central pulley  407  that is fixed to the axle  105 . The central pulley  407  can be connected to the drive axle of the electric motor  114  by a belt or chain or can be directly connected to the electric motor  114 . The central pulley  407  can be a lightweight polymer wheel having apertures therein to save weight. The central pulley  407  is lightweight such that it does not provide any significant inertial energy that resists movement of the pedals  102  in use. The drive sub-assembly  405  can be secured to a frame sub-assembly  409 , which includes a main support spine and legs extending outwardly therefrom. One set of legs may include wheels to move the system. A top support sub-assembly  411  may be secured on top of the drive sub-assembly  405  to essentially enclose the electric motor  114  and the central pulley  407 . A right pedal  102 B couples to a right radially-adjustable coupling  401 B via a right pedal arm assembly  104  disposed within a cavity of the right radially-adjustable coupling  401 B. The right pedal  102 B is supported in the same manner as the left pedal  102 A, but on the other side and 180 degrees out of phase with the left pedal  102 A. An internal volume may be defined when the left outer cover  403 A and the right outer cover  403 B are secured together around the frame sub-assembly  409 . The left outer cover  403 A and the right outer cover  403 B may also make up the frame of the system  400  when secured together. The drive sub-assembly  405 , top support sub-assembly  411 , and pedal arm assemblies  104  may be disposed within the internal volume upon assembly. A storage compartment  420  may be secured to the frame sub-assembly  409  to enclose the drive sub-assembly  405  and top support sub-assembly  411 . 
     Further, a computing device arm assembly  421  may be secured to the frame and a computing device mount assembly  422  may be secured to an end of the computing device arm assembly  421 . A computing device  423  (e.g., controller  112 ) may be attached or detached from the computing device mount assembly  421  as desired during operation of the system  400 . 
       FIG.  5    is a flowchart of a method  500  for controlling the pedal position. At  501 , a pedal position is loaded into the controller  112  or memory  113 . The pedal position can be entered via a user interface through an I/O on the base  110 . The user interface can present a treatment plan (e.g., for rehabilitation or exercise) for a user according to certain embodiments of this disclosure. The user interface can be at the base or at a remote device in communication with the base. The treatment plan can be set by a user (e.g., a physician, nurse, physical therapist, patient, or any other suitable user). The pedal position can be part of an individualized treatment plan taking into account the condition of the user (e.g., recovery after a surgery, knee surgery, joint replacement, a muscle conditions or any other suitable condition). 
     At  502 , the radial position of a pedal relative to the axle is electrically adjusted in response to a control signal output by the controller  112  to control the electric motor  305  to position the carriage  304 , and hence the pedal  102 , through the spindle  103 . In an example embodiment, the electric motor  305  is connected to the carriage  304  through a linkage (e.g., the drivescrew  325  to linearly move the spindle  103 ). In an example embodiment, the radial position of the pedal is adjusted, during a revolution of the pedal, to produce an elliptical pedal path relative to the axle. The radial position of the pedal can be adjusted in response to the control signal during a user pedaling the pedal. 
     At  503 , the rotational motion of the user engaged with the pedal is controlled. The controller can control the position of the pedal  103  in real time according to the treatment plan. The position of a right pedal can be different than that of the left pedal. The pedal can also change position during the use. The pedal can also sense the force a user is applying to the pedal. A force value can be sent from the pedal to the controller, which can be remote from the pedal. 
     At  504 , the rotational position of the pedal is sensed. The rotational position of the pedal can provide information regarding the use, e.g., to control radial position of the pedal, the rotational motion (e.g., speed, velocity, acceleration, etc.) and the like. 
       FIG.  6    is a schematic view  600  of a pedal  103  and resultant force vectors. The pedal  103  will experience greater applied force from the foot  601  (represented by the shoe) in the first quadrant and the second quadrant (i.e., when driving the pedal down). There will be the less applied force in the third quadrant and fourth quadrants. When pedaling a bicycle with forward motion and inertial energy, or a stationary bike with a heavy flywheel, e.g., greater than twenty pounds, the user experiences inertial force that affects the feel experienced by the user. In an example embodiment, the drive components (e.g., the electric motor, the pulley, the pedal connector assembly, and the pedals) all have a mass of less than 10 kilograms. The inertial force can be felt when there is a reduced applied force, e.g., when both pedals are not applying a force. A heavily weighted flywheel will continue the force felt by the user (e.g., greater than 15 kg, greater than 20 kg, or more). However, an example embodiment of the present disclosure does not have a heavy flywheel. In this case, the electric motor must be controlled to simulate a flywheel and the inertia of the flywheel, which can be felt by a user, such that the electric motor controls a resistance to travel of the pedals. If the electric motor did not provide increased force to the pedal, then the pedal would slow a greater amount. If the electric motor did not provide a resistance to the force applied by the user to the pedal, the user could not apply a sufficient force to the pedal. Thus, the control system simulates the flywheel by controlling the electric motor to drive the pulley when the one or more pedals are not rotating within a desired range. Controlling the electric motor  114  to simulate a flywheel can assist in keeping the user compliant with the treatment plan on the rehabilitation system  100 . 
       FIG.  7    shows a graph  700  of pedaling forces from pedaling and a simulated flywheel from the electric motor  114 . The applied force at the right pedal  701  peaks at time t 1  essentially between quadrant  1  and  2 . The quadrants are defined relative to the right pedal. The applied force at the left pedal  702  peaks at time t 2  in quadrant  4 . The sum of the applied forces of both the right pedal and the left pedal is shown at  703 . At  705 , there is shown the desired steady force that a user experiences with a flywheel. The desired level of force can be changed according to the rehabilitation regimen prescribed to the user, which can be stored in memory and used by a controller. In the illustrated example of  FIG.  7   , the force is set at about 500N. It is desired, in some embodiments of the present disclosure, to simulate a flywheel by driving the electric motor  114  when the sum of forces  703  fall below the desired level of force  705 . At time t 3 , the electric motor  114  must drive the pedals to accelerate the pedals so that the force at the pedals is at the desired level of force  705 . The same occurs at time t 4 . The force applied by the electric motor  114  is schematically shown at  707 ,  708 . At times t 3 , t 4 , the pedals are not receiving enough force from the user and the rotational speed will drop. The electric motor  114  applies an acceleration to keep the force essentially the same, i.e., by Newton&#39;s second law, F=m*a. In the present system  100 , the mass is quite low so that the system is portable. Accordingly, the change in acceleration will have an effect on the force perceived by the user at the pedals as the mass of the drive components in the present rehabilitation system is low. At times t 1  and t 2 , the force at the pedals is at its highest and is above the desired level of force  705 . Here, the electric motor  114  will drop the force at the pedals. While there will be some variation from the desired level of force due to the forces applied to the pedals at different quadrants and positions of the pedals in the travel path, the force can be held in a range around the set value at  705 . 
       FIG.  8    is a method  800  of electromechanical rehabilitation using a simulated flywheel. At  801 , a pedal force value is received from the pedal sensor to indicate the force being applied to the pedal by the user when pressing on the pedal. The pedal force can be sensed using a single sensor at each pedal. In an example embodiment, the pedal force value can be a statistically or mathematically computed value from a plurality of pedal sensors. The pedal force value, or total force, can be computed from a toe end force received as a toe signal from a toe sensor at the toe end of the pedal and a heel end force received as a heel signal from a heel sensor at a heel end of the pedal. The pedal force value can be the sum of the toe end force and the heel end force. The pedal force value can be received at the controller  112  or the computing device  423 . The pedal force value can be transmitted over a physical connection, e.g., through the slip rings and over wires connected to the controller. The pedal force value can be wirelessly sent over a near field communication (e.g., using Bluetooth™ standard) from the sensor in the pedal to a remote receiver in base  110  or computing device  423 . 
     As noted, power transmission to the motor on the pedal arm may be conducted via slip rings. Other embodiments can include a wireless power transmission system that can use transformer coils (such as thin pairs of them) on the main unit and the pedal arm. DC voltage can be wirelessly passed to the pedal arm to charge onboard battery pack(s). The controller can split the charge to left and right controllers for the respective pedal arms. The motor control of the pedal arms can be controlled by the onboard controller. Embodiments of the transformer coils can be similar or identical to retail mobile phone wireless chargers. 
     Another aspect of the assembly can include limit switches. Some versions comprise microswitches, such as one at each end of the carriage travel. The state of the limit switches can be interpreted by the controller to detect when the carriage/spindle assembly is at either end of travel. The limit switches are optional. 
     At  802 , the pedal rotational position is received, e.g., at the controller  112  or computing device  423 . The rotational position of the pedal can be used to compute the rotational velocity or rotational speed of the pedals. Any change in velocity can indicate a change in acceleration. 
     At  803 , motor control signals are output. The one or more control signals output to the electric motor  114  can cause the electric motor  114  to control rotational inertia at the pedals based at least upon the pedal force value, a set pedal resistance value, and a pedal velocity. The pedal velocity can be computed from the position of the pedal over time. The pedal resistance value can be set in during programming an exercise regimen or a rehabilitation regimen, e.g., through an I/O in the base  110  from a remote server and stored in the memory  113 . In an example embodiment, if the pedal velocity is being maintained and the pedal force value is within a set range (which can be stored in the memory), a maintain-drive control signal is sent to the electric motor  114 . The maintain-drive control signal operates the electric motor  114  to stay at a same mechanical drive output to the pedals, which will maintain a feel at the pedals that is the same, i.e., the inertia remains the same. In an example embodiment, if the pedal velocity is being maintained and the pedal force value is less than a prior pedal force value at a prior pedal revolution (e.g., the pedal velocity is maintained with less force than the previous pedal revolution in the same pedal position but during the immediately prior revolution), the maintain-drive control signal is sent. 
     In some embodiments, if the pedal velocity is less than a prior pedal velocity during a prior pedal revolution and the pedal force value is less than a prior pedal force value at the prior pedal revolution, an increase-motor-drive control signal can be sent to the electric motor  114 . The increase-motor-drive control signal will cause the electric motor to rotate faster, i.e., accelerate, to increase the perceived inertial force at the pedals. 
     If the pedal force value is greater than the pedal force value during a prior pedal revolution or if the pedal velocity is greater than a prior pedal velocity during the prior pedal revolution, a decrease-motor-drive control signal can be sent to the electric motor. This will slow the electric motor and reduce the force at the pedals. The decrease-motor-drive control signal can be sent when the pedal velocity is more than a prior pedal velocity during a prior pedal revolution. The decrease-motor-drive control signal can be sent when the pedal force value is more than a pedal force value during a prior pedal revolution. 
     The control signals can cause the electric motor to control simulated rotational inertia applied to the pedals through an intermediate drive wheel connected to a drive axle to the pedals. This will simulate an inertial force perceived at the pedals by the user, where the inertial force would be provided by a flywheel in a traditional stationary exercise machine. This is useful in the present rehabilitation system as the electric motor  114  and any intermediate drive linkage between the electric motor  114  and the pedals (e.g., an intermediate drive wheel or pulley) is essentially free from or without adding inertial energy to the pedals. 
       FIG.  9    is a method  900  for simulating a flywheel and controlling the force at the pedal as perceived by the user. At  901 , the pedal position is determined. The pedal position can be determined by sensors on the pedals or by measuring the position of the spindle or axle. The position of the axle can be determined by reading the indicia on the axle as it turns. The pedals are fixed to the axle through the pedal arm assembly, and the radial position of the pedals is known as it is set by the control arm assembly. At  902 , the rotational velocity of the pedals is determined. At  903 , the pedaling phase is determined. The pedaling phase can be a phase in a rehabilitation regimen. For example, a phase can be an active phase with the user pedaling with force or a coasting phase where the user is pedaling slowly without applying much force to the pedals. 
     The method  900  then has three different ways it can produce electric motor control signals to control the operation of the electric motor driving the pedals. At  905 , if the pedaling phase is not in a coasting phase and the sensed-force value is in a set range, a signal is sent to the electric motor to maintain a current drive of the electric motor at a present drive state to simulate a desired inertia on the one or more pedals. The force value can be set in memory of the device, e.g., as part of the rehabilitation regimen for the user. The force can be set as a value with a +/−buffer to establish a range. For example, when beginning a rehabilitation regimen, the force can be low for the first few pedaling events and increase thereafter. The force can be measured at the pedal using the devices and methods described herein. 
     At  907 , if the pedaling phase is in the coasting phase and the rotational velocity has not decreased, decrease the current drive of the electric motor and maintain a decreasing inertia on the one or more pedals. This should simulate inertia at the pedals, e.g., simulate a flywheel when the system is slowing gradually. The electric motor will continue to apply a force to the pedals, but the force decreases with each revolution of the pedals or over time to simulate the flywheel producing the inertial force. 
     At  909 , if the pedaling phase is not in the coasting phase and the rotational velocity has decreased, increase drive of the electric motor to maintain a desired rotational velocity. That is, the electric motor will accelerate the pedals to maintain the force at the pedals as perceived by the user. The increase in the drive by the electric motor can be maintained for a time period or a number of revolutions of the pedals. In an example embodiment, the electric motor  114  increases the drive for ⅛, ¼, or ⅜ of a revolution of the pedal. 
     The controller as described herein can output motor control signals that control the force output by the electric motor to the pedals. The controller is configured to increase drive of the electric motor to increase the rotational velocity of the one or more pedals when the one or more pedals are at or below a minimum sensed-force threshold, and to decrease drive to reduce the rotational velocity of the one or more pedals when the one or more pedals are at a maximum sensed-force threshold. The minimum sensed-force threshold and the maximum sensed-force threshold are the forces sensed at the pedals. The values of the minimum and the maximum can be set in the program for an individual&#39;s rehabilitation schedule on the rehabilitation system. The program should limit the range of motion of the user by adjusting the radial position of the pedals and control the amount of force that the user can apply to the pedals. For the force to be at any given value, the amount of force applied to the pedals requires that pedals resist the force being applied. That is, if the pedal will free spin above a maximum force, then the user cannot apply more than that force to the pedal. The electric motor can also resist the rotational movement of the pedals by refusing to turn until the minimum force is applied to the pedals. The controller, through output of control signals to the electric motor, simulates a flywheel by controlling operation of the electric motor to drive the pulley (or axle wheel) when the one or more pedals are not rotating in a desired range of either force or rotational velocity. 
     The force value in the controller can be the sum of forces to maintain a level of drive at the one or more pedals below a peak of the sum of forces and above a valley of the sum of forces. That is, the sum of forces is derived from the forces at both the pedals, one of which can be engaged by a user&#39;s good leg and the other by the user&#39;s leg in need of exercise or rehabilitation. 
     The foregoing description of the embodiments describes some embodiments with regard to exercise system or a rehabilitation system or both. These phrases are used for convenience of description. The phrases exercise system or rehabilitation system as used herein include any device that is driven by or causes motion of a person or animal, typically to provide travel of body parts. The exercise system can include devices that cause travel of an extremity or appendage, i.e., a leg, an arm, a hand, or a foot. Other embodiments of exercise systems or rehabilitation systems can be designed for range of motion of joints. 
     The foregoing description describes a pedal, which is engaged by a user&#39;s foot to impart force to the pedal and rotate the pedals along a travel path defined by the position of the pedal relative to the rotational axis of the device. The description relating to a pedal herein can also be applied to handgrips such that a user can grip the handgrips and the device can operate in the same manner as described herein. In an example embodiment, the term pedal can include a handgrip. 
     The rehabilitation and exercise device, as described herein, may take the form as depicted of a traditional exercise/rehabilitation device which is non-portable and remains in a fixed location, such as a rehabilitation clinic or medical practice. In another example embodiment, the rehabilitation and exercise device may be configured to be a smaller, lighter and more portable unit so that it is able to be easily transported to different locations at which rehabilitation or treatment is to be provided, such as a plurality of patients&#39; homes, alternative care facilities or the like. 
     Consistent with the above disclosure, the examples of systems and method enumerated in the following clauses are specifically contemplated and are intended as a non-limiting set of examples. 
     1. A pedal assembly for equipment for electromechanical exercise or rehabilitation of a user, comprising:
         a pedal configured to be engaged by the user;   a spindle mounted to the pedal and having a spindle axis; and   a pedal arm assembly mounted to the spindle for support thereof, the pedal arm assembly is configured to be coupled to a rotational axle of the equipment, the rotational axis is radially offset from the spindle axis to define a range of radial travel of the pedal relative to the rotational axle, the pedal arm assembly comprising a coupling assembly that is electrically actuated to selectively adjust a radial position of the pedal relative to the rotational axle in response to a control signal.       

     2. The pedal assembly of any of these examples, wherein the pedal arm assembly comprises a housing with an elongate aperture through which the spindle extends; wherein the coupling assembly comprises a carriage mounted in the housing to support the spindle, and an electric motor coupled to the carriage to linearly move the spindle relative to the housing. 
     3. The pedal assembly of any of these examples, wherein the elongate aperture is orthogonal to the spindle axis. 
     4. The pedal assembly of any of these examples, wherein the coupling assembly comprises a leadscrew configured to be rotated by the electric motor and threadingly coupled to the carriage. 
     5. The pedal assembly of any of these examples, wherein the carriage comprises a throughbore that receives the leadscrew and a threaded nut mounted adjacent to the throughbore, such that the threaded nut threadingly engages the leadscrew. 
     6. The pedal assembly of any of these examples, wherein the coupling assembly comprises a rail adjacent and parallel to the leadscrew, the rail and the leadscrew are in the housing, and the carriage engages the rail for linear travel along the rail in the range of radial travel of the pedal. 
     7. The pedal assembly of any of these examples, wherein the coupling assembly comprises a slide pad between the carriage and an interior wall of the housing, and the slide pad is adjacent to the leadscrew. 
     8. The pedal assembly of any of these examples wherein, during operation, the coupling assembly is configured to adjust the radial position of the pedal in response to the control signal. 
     9. The pedal assembly of any of these examples, wherein the coupling assembly is configured to adjust the radial position of the pedal to produce an elliptical pedal path, relative to the rotational axle, during a revolution of the pedal. 
     10. The pedal assembly of any of these examples, wherein the pedal comprises a pressure sensor to sense a force applied to the pedal, and transmit the sensed force to a distal receiver. 
     11. The pedal assembly of any of these examples, wherein the pedal comprises a pedal bottom to receive and pivot about the spindle, the pressure sensor comprises a plurality of pressure sensors, a base plate on the pedal bottom to support the plurality of pressure sensors, and a pedal top positioned above the base plate and operatively engaged with the plurality of pressure sensors to transit force from the user of the pedal to the plurality of pressure sensors. 
     12. The pedal assembly of any of these examples, wherein the plurality of pressure sensors comprises a toe sensor to sense a first pressure and a heel sensor to sense a second pressure, and the first pressure and the second pressure are used by the control system to determine a net force on the pedal. 
     13. The pedal assembly of any of these examples, wherein the transmitted sensed force signal is used by a controller to adjust at least one of rotation of the pedals or the radial position of the pedals. 
     14. The pedal assembly of any of these examples, wherein the coupling assembly is configured to translate rotational motion of the electric motor into radial motion of the pedals. 
     15. A method for electromechanical exercise or rehabilitation, comprising:
         electrically adjusting a radial position of a pedal relative to a rotational axle in response to a control signal;   regulating rotational motion of an appendage of a user engaged with the pedal;   sensing a rotational position of the pedal for use in further electrically adjusting the radial position of the pedal; and   further electrically adjusting the radial position of the pedal in response to another control signal.       

     16. The method of any of these examples, wherein electrically adjusting the radial position of the pedal comprises controlling an electric motor coupled to a carriage to linearly move a spindle in a housing. 
     17. The method of any of these examples, wherein electrically adjusting the radial position of the pedal comprises mechanically supporting the carriage on a rail of the housing for linear travel of the carriage over a range of radial travel of the pedal. 
     18. The method of any of these examples, wherein electrically adjusting the radial position of the pedal comprises rotating a leadscrew with the electric motor to linearly move the carriage. 
     19. The method of any of these examples, wherein electrically adjusting the radial position of the pedal comprises, during a revolution of the pedal, adjusting the radial position of the pedal to produce an elliptical pedal path relative to the rotational axle. 
     20. The method of any of these examples, wherein electrically adjusting the radial position of the pedal occurs while the pedal is rotating about the rotational axle, and regulating rotational motion comprises sensing a force applied to the pedal and transmitting the sensed force to a remote receiver. 
     The structures connected to the pedals have a low mass and, hence, a low inertial energy potential. The motor, e.g., through a wheel connected to the axle, can provide the resistive force at the pedals and the inertial force once the pedals are turning. 
     The foregoing description of the embodiments describes some embodiments with regard to an exercise system or a rehabilitation system or both. These phrases are used for convenience of description. The phrases exercise system or rehabilitation system as used herein include any device that is driven by or causes motion of a person or animal, typically to provide travel of body parts. The exercise system can include devices that cause travel of an appendage, i.e., a leg, an arm, a hand, or a foot. Other exercise systems or rehabilitation systems can be designed for a range of motion of joints. 
     The foregoing description describes a pedal, which is engaged by a user&#39;s foot to impart force to the pedal and rotate the pedals along a travel path defined by the position of the pedal relative to the rotational axis of the device. The description relating to a pedal herein can also be applied to handgrips such that a user can grip the handgrips and the device can operate in the same manner as described herein. In an example embodiment, the term pedal can include a handgrip. 
     The rehabilitation and exercise device, as described herein, may take the form as depicted of a traditional exercise/rehabilitation device which is more or less non-portable and remains in a fixed location, such as a rehabilitation clinic or medical practice. In another example embodiment, the rehabilitation and exercise device may be configured to be a smaller, lighter and more portable unit so that it is able to be easily transported to different locations at which rehabilitation or treatment is to be provided, such as a plurality of patient&#39;s homes, alternative care facilities or the like. In other embodiments, this equipment can be used in other unrelated applications, such as other types of pedal-powered vehicles (e.g., bicycles, etc.), a hand-powered winch, etc. 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements, assemblies/subassemblies, or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. The benefits, advantages, solutions to problems, and any feature(s) that can cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, sacrosanct or an essential feature of any or all the claims.