Abstract:
The invention uses specialized wheel sets to navigate over various surfaces. The invention has a primary drive wheel with two outrigger wheels to provide stability. In the basic motorized configuration of the apparatus, the user provides certain hand movements of the control mechanism, which in turn produces control signal(s). Incorporated into the invention is a power lifting mechanism, which aids the user to be elevated from a seated position to a standing position without any assistance. A built-in seat is incorporated within the invention. The built-in seat is a fold down type that is adjustable in height. 
     In the virtual mode, various user motion signals are relayed, by wireless means, to an embedded computer module, within the apparatus. This embedded computer provides control signals to operate the invention. 
     For ease of transport and erection, retractable/deployable units are incorporated into the design of the invention.

Description:
The present application claims priority under 35 U.S.C. § 119(e) of Provisional Application No. 60/366,187 and 60/388,602, filed Mar. 21, 2002 and Jun. 12, 2002, respectively, the disclosures of which are included herein, in full, by reference. 

   BACKGROUND OF THE INVENTION 
   Technical Field 
   The present invention is directed to a walker apparatus adapted for operation in a basic powered and virtual mode of operation for assisting individuals that are handicapped with their mobility. This is accomplished by assisting the individual from a seated position, and operates as a powered unit, provides a seat for resting, storage of medical items and other objects and provides dual independent control. As regards the invention, a “virtual walker” is defined as a sensor driven, computer controlled, motorized walker. The sensors are located on a shoe-like device that is part of the overall apparatus which provides various force measurements which are associated with the gait of the user that are applied to the user&#39;s lower limbs during walking, turning and/or running sequences. These measurements are processed by the shoe-like device and relayed by a wireless link to the walker portion of the apparatus. 
   The electronics of the walker apparatus includes a microprocessor, which analyzes the gait parameters to correct any deficiencies in the user&#39;s gait and provide control guidance parameters to the mechanized portion of the walker portion of the apparatus in the virtual mode. 
   BRIEF DESCRIPTION OF THE PRIOR ART 
   Individuals with diverse disabilities ambulate with the use present day walkers that flood the marketplace. Most commercial walkers have not changed over the years from a basic design. The main objective of this invention is to provide mobility to certain handicapped individuals who are not adequately served by present day walkers. The invention will allow these individuals to move freely in many environments. 
   Thus, the goal of this invention is to develop a new and revolutionary walker to provide maximum mobility for certain handicapped individuals. The invention provides handicapped individuals the freedom to maneuver in most environments under conditions and operating capability not presenting and not provided by, commercial walker designs. The invention provides for an easily collapsible, stable walker for use by handicapped individuals with different types and degree of ambulatory conditions. These conditions can range from fracture, orthopedic surgery (such as joint replacement, spinal cord injuries, amputation, stroke, arthritic, and the effects of multiple sclerosis) to name a few. 
   One of the unique features of the invention is the ability to lift individuals from a seated position to a standing position from which the individual, then, may maneuver the walker as needed. The walker apparatus also has power steering incorporated into its design. 
   In the virtual mode of operation of the walker apparatus, steering and speed control is provided by gait parameters generated by the walker apparatus. Handicapped individuals who have both a single upper and lower functioning limb as the result of amputation, stroke, fracture, and or other abnormality can operate the walker apparatus with modest or no difficulty. 
   Senior citizens have a high mortality rate after sustaining a fracture from a fall, for example. Generally, those individuals do not expire from the broken bone but from complications, for example, pneumonia, cardiac problems, and others, as may result from immobility of the body. The invention in the walker apparatus will provide the needed exercise and stimulation of muscles and bones to alleviate these complications. 
   The walker portion of the invention is designed with a built-in adjustable seat to provide rest to the user and has compartments for storage of medical items such as oxygen and storage areas for other items such as groceries, gifts, books, and other necessary resorted to and relied upon by individuals. 
   DESCRIPTION OF THE PRIOR ART 
   The Walker Apparatus 
   Prior walker apparatus developed to assist handicapped individuals is well known. One typical patent to Hickman, U.S. Pat. No. 3,872,945. Several deficiencies are immediately noted when comparing Hickman to the present invention, namely the following: 1) a very high center of gravity which makes it highly unstable; 2) no storage space available for medical items such as oxygen bottles, tanks; and the like; and 3) not readily collapsible for ease of transport. 
   The patent to Perkins, U.S. Pat. No. 4,280,578, also is deficient in many respects including the following: 1) the difficulty or lack of achievability under practical conditions for the user to maintain a straight course of travel; 2) the center of gravity leading to instability; and 3) no storage space available for items of any type. 
   Another patent of the prior art issued to Weir et al, U.S. Pat. No. 4,456,086, suffers from several difficulties and deficiencies, including: 1) not readily collapsible; 2) a high center of gravity, as previously discussed; 3) the likelihood of high risk of injury to the user because the user is constrained by shoulder straps and knee clamps; 4) the apparatus is extremely cumbersome and not easily transportable; 5) the use of the apparatus is for riding not walking; and 6) the apparatus fails to assist the user to the seated location. 
   The patent by Mennesson, U.S. Pat. No. 4,463,817, also has a number of deficiencies when a comparison is made with the walker apparatus of the invention, as follows: 1) the user likely would require assistance in getting into the device; 2) the device is not fully collapsible; and 3) it is believed that patients with artificial limbs would have a difficult time operating this device. 
   The Houston et al, U.S. Pat. No. 4,802,542, are seen to present the following problems and deficiencies: 1) the apparatus has a very high center of gravity; 2) in many cases the requirement presents itself that someone must assist the user into the seat; 3) the user rides rather than walks; and 4) the apparatus is not easily collapsible. 
   Another prior art-type device is illustrated by Rodenborn, U.S. Pat. No. 5,168,947. The patent displays the following deficiencies: 1) the apparatus has a very high center of gravity; 2) the apparatus is not readily collapsible; and 3) the user likely would find it difficult to get onto the platform without assistance. 
   The apparatus described by Reed, U.S. Pat. No. 5,224,562, also has several deficiencies: 1) the apparatus has a high center of gravity; 2) the apparatus fails to include a seat arrangement; 3) the apparent provides no apparent arrangement for storage; and 4) a power lifting device to aid user in an upright position. 
   Finally, the patent to Lathrop, U.S. Pat. No. 5,524,720, includes the following deficiencies: 1) the apparatus is not readily collapsible; 2) the apparatus provides no assist to the user to get into an upright position; 3) the apparatus is extremely heavy (about 200 pounds); 4) the user of the apparatus rides rather than walks; and 5) it is believed that the upper portion of the device is not supported properly and a structural failure could develop in this area. 
   The Virtual Mode Operation of the Invention 
   Prior gait parameter acquisition systems as a footwear apparatus were developed to assist in gait analysis studies on individuals. 
   Prior inventions directed to this expertise include the patent to Confer, U.S. Pat. No. 4,745,930, that is seen to present the following deficiencies: 1) no force measurements acquired; 2) no internal data processor; 3) bulky wiring and 4) the inability to determine lateral motion. 
   In the patent to Cavanagh, U.S. Pat. No. 4,771,394, the following deficiencies are noted: 1) no force measurements acquired; 2) no internal data processor; 3) bulky wiring to external processor; 4) the device is not wireless and 5) the device is unable to determine lateral motion. 
   In the patent to Schmidt et al., U.S. Pat. No. 5,408,873, related to the determination of compressive forces on the foot, the following deficiencies are noted: 1) a very small contact surface to obtain force measurements; 2) the device does not measure force components in the heel area; 3) the device does not determine lateral force components; 4) the device includes no internal processor; and 5) the device includes bulky wiring to external processor. 
   In patents to Fyfe, U.S. Pat. Nos. 5,955,667 and 6,301,964B1, the apparatus fails to provide determination of heal strike forces in three dimensions, and includes the following deficiencies: 1) only heel force measurements are acquired; 2) no internal processor; and 3) bulky wiring to external processor. 
   U.S. Pat. Nos. 4,239,974 to Swander et al., 4,402,524 to D′Antonio et al., and 6,259,372B1 to Taranowski et al., to disclose aspects of discussion relating to the provision for self generated power for an apparatus. 
   SUMMARY OF THE INVENTION 
   This invention provides the necessary improvements to overcome the deficiencies noted in the prior art. 
   To this end, the walker portion of the invention has the following features: 
   1. engageable drive 
   2. internal lifting mechanism 
   3. power steering 
   4. adjustable holding rail 
   5. adjustable stability configuration 
   6. adjustable and retractable seat 
   7. extremely lightweight, and easily portable 
   8. operate as a powered wheelchair, with storage capability 
   9. forward/reverse motion capability 
   “Kinematics” is defined as the science of motion. In human and animal movement, it is the study of the positions, angles, velocities and accelerations of body joints and segments. In humans, “gait” is described as the heel-strike, mid-stance and toe-off. An important phase of gait analysis is amount of up-down and sideways motion that an individual generates during walking or running activities. By being able to measure precise force components in the heel-strike along with the mid-stance and toe-off segment of a given gait sequence one can then perform analysis on that given individual and ascertain any abnormality in the gait. 
   The shoe-like portion of the invention has the following features: 
   1. three axis accelerometers in medial and lateral heel area 
   2. three axis accelerometers in medial and lateral sole area 
   3. piezo-electric generator in sole and heel 
   4. energy storage device, such as an internal battery source 
   5. extremely lightweight 
   6. wireless data link 
   7. error correction for data transfer 
   The invention uses specialized wheel sets to negotiate over various surfaces. The invention has a primary drive wheel with two outrigger wheels to provide stability. 
   In the basic motorized configuration of the apparatus, the user provides certain hand movements of the control mechanism, which in turn produces a power assist control signal(s). 
   In the basic powered version the user will determine speed of the walker by sending the appropriate control signal to the drive unit. The motorized unit consists primarily of a drive motor, gear reduction unit and coupling mechanism. 
   The drive wheel requires some sort of tread design in order to maneuver properly in different types of terrain like standard automobile tires. Specialized tread designs are used for specific terrain or a generalized tread design that will be effective over most terrain. 
   The power lifting mechanism is incorporated into the invention and aids the handicapped individual to be elevated from a seated position to one of standing position without any assistance. 
   Steering is accomplished by control signals generated by the user to drive a reversible DC motor that rotates the forward drive wheel unit to the desired alignment direction. 
   A built-in seat is incorporated within the invention to provide a resting platform should the user require it during the use of the invention. The built-in seat is a fold down type that is adjustable in its height. 
   A built-in power source such as a lithium battery or some other power source (such as fuel cell(s), storage capacitor(s), etc.) will provide the power required for the control module. A sealed battery unit such as an AGM (Absorption Glass Mat) battery will provide the power source for the motorized units and power lifting mechanism. The purpose of the sealed AGM battery is to provide maximum power, deep discharge capability, rechargeablity, operate in extreme temperature ranges and to provide the greatest safety to the handicapped individual. 
   The shoe-like portion of the invention uses new technologies to create a new method to monitor and evaluate various gait parameters. Specifically these are in the areas of power development and management, embedded processing system, miniaturized sensors, error correction and miniature wireless communication links. 
   In the shoe-like portion of the invention, various parameters are obtained, processed and relayed to the walker portion by wireless means that relate to various gait measurements such as force, velocity and acceleration in the three-dimensional planes [pitch, roll and yaw] of each lower extremity for either animals or humans. 
   Miniature piezo-electric sensors obtain the force measurements in the both the sole and heel areas of each of the lower extremities. Acceleration is acquired by three-dimensional accelerometers located in the lateral and medial portions of the sole and heel areas. 
   The sensor data is processed in the embedded processor where the processor&#39;s programs can be altered to meet the desired objectives and where various gait parameters are determined such as acceleration, velocity, stride lengths, direction of movement and force vectors of each lower extremity at predetermined intervals. The processed data can be stored in the embedded processor memory. 
   This processed data is transmitted to a remote location. The transmission can either be by Infrared (IR) or Radio Frequency (RF) methods. The transmission method is determined by a given application. In some cases RF emissions can not be tolerated because of safety or interference potentials. In other conditions the local environment will interrupt IR transmission modes. The wireless link data is protected from corruption by error correction techniques. 
   Power is provided by internal batteries that are augmented by self contained piezo-electric power generators with storage of the generated power in storage devices such as capacitors. The capacitors in turn recharge the internal battery. 
   The clinicians who prescribe the use this invention will determine what parameters that are to be processed and/or where the desired output parameters are to be relayed. 
   The overall walker is designed for ease of use, transport and storage. In designing mobility to the walker, overall effectiveness and safety have not been compromised. For ease of transport and usage, the apparatus has multiple retractable components, which can be deployable with minimum effort and with safety checking circuits to ensure proper erection prior to its use. 
   The mobility of the walker is determined and measured by the ability of the walker&#39;s freedom of movement (percentage of the terrain over which the walker is mobile) and its average speed or travel time over any given terrain. 
   A walker&#39;s weight plus the handicapped individual&#39;s weight upon the walker and tracked footprint (the area of track which impacts any given surface) determine the resultant surface pressure that the walker imparts on any given surface. The surface strength, coupled with the walker&#39;s will determine the walker&#39;s mobility effectiveness and is defined as the walker&#39;s mobility index (WMI). The higher the WMI, the less mobile the walker becomes. 
   As a general rule of thumb, a lower WMI not only equates to better surface mobility but also indicates better performance on inclines, in non-stable surface (such as sand, snow, etc.), over obstacles/gaps crossings and when traversing vegetation. 
   From a mobility perspective, powered walkers offer the best solution for a versatile walker that is required to operate over diverse surfaces, including extremely rough surfaces, because tracks inherently provide a greater surface area than self-propelled wheels, resulting in a lower WMI. 
   A walker&#39;s mobility will be impacted by its traction ability over various surfaces (e.g., dry/wet soil, sand, snow, ice, carpets, rugs, etc.) and its ability to maneuver over obstacles, cross-gaps, etc. 
   The invention incorporates a very low WMI and uses weight reduction techniques such as using carbon composites or other similar materials to accomplish better mobility. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects and advantages of the present invention will become apparent from the following detailed description of the preferred embodiment thereof taken in conjunction with the accompanying drawings, wherein: 
       FIG. 1A  is a side view of the invention in the operational engaged mode configuration; 
       FIG. 1B  is the opposite side view of the invention in the operational engaged mode configuration; 
       FIG. 1C  is the plan view of the invention in the operational engaged mode configuration; 
       FIG. 1D  is the end view of the invention in the operational engaged mode with the seat-engaged configuration; 
       FIG. 1E  is partial side view of the  FIG. 1D ; 
       FIG. 1F  is a side view of the walker apparatus in collapsed configuration; 
       FIGS. 2A and 2B  are views of the power drive mechanism of the walker apparatus illustrating an engaged and disengaged mode configuration; 
       FIGS. 3A-3D  are views in section of the form of locking configuration of several structural components of the walker apparatus in the operational mode configuration; 
       FIGS. 3E-3N  are views illustrating further forms of locking configurations of structural components of the walker apparatus in the operational mode configuration; 
       FIGS. 4A-4B  are views of the operative controls of a right and left control module; 
       FIGS. 5A-5F  are views in section of several drive mechanisms for actuating alternately a pair of spaced cut-off switches; 
       FIGS. 6A-6B  are block diagram for the basic powered version and virtual mode version of the electronics configuration; 
       FIGS. 6C-6K  are schematic diagrams of various operative mode configurations and power supplies; 
       FIGS. 7A-7F  are views of the left foot and right foot covering illustrating the location of critical units; 
     FIGS.  8 A and  8 B- 14 A and  14 B are block diagram of the left and right foot electronics packages including several sub-system configurations; and 
       FIG. 15  is the block diagram for the remote processing sub-system configuration; 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The Walker Apparatus 
   the walker apparatus of the invention is illustrated in the main figure groupings of  FIGS. 1-3  and  5 , including the various individual figures “A”. “B”, “C”, and so forth, within each main figure grouping. As described generally, the walker apparatus may be operated in a basic powered and virtual mode when in a fully assembled, operating condition, illustrated in  FIGS. 1A and 1B . The structure of the walker apparatus also is capable of being collapsed from the fully assembled, operating condition when readied for transport, storage, or any one of a myriad of other reasons. The action of collapsing the walker apparatus of the invention may be carried out with relative ease through movement and interaction of individual components pivotally, or by “embedding” parts, more particularly telescoping a part in a manner that its movement is within an adjacent part or alongside the part, or by other well-known actions and capabilities. As previously discussed, a feature of the invention is the capability of conversion of the walker apparatus from a condition of assembly to one of disassembly, and in return to initial condition. This aspect of the invention will be discussed in greater detail as the full description of the walker apparatus unfolds. Another aspect of the invention, also previously discussed, is the built-in capability of prevention of the walker apparatus functioning in the assembled condition unless and until all of the structural components are properly positioned, for example, in a fully extended or fully pivoted operative disposition of use when returned from the collapsed position. 
     FIGS. 1A-1C  comprising two elevation views and a plan view illustrate the walker apparatus of the invention by their schematic presentation of the various structural elements that make up frame F. The discussion within the written description in many instances identifies the structural elements as right-side and left-side structural elements. Typically, the identifying nomenclature, “right-side,” will refer to the structural elements in  FIG. 1A , when viewing the walker apparatus from the front. Thus, the identifying nomenclature, “left-side”, will refer to the structural elements in  FIG. 1B , also when viewing the walker apparatus from the front. However, if the structural elements of the walker apparatus are viewed from the rear the identifying nomenclature will reverse, as may be appreciated, in connection with the description and a consideration of operation, for example, of the apparatus for operating the lifting assembly B 2  seen in  FIG. 1C , but principally as seen in  FIG. 1F . 
   Frame F may be considered to provide generally a base B, a lifting bar handle  19  of lifting bar assembly B 1 , and intermediate mounting structure B 2  carried by the Base B for supporting the lifting bar assembly B 1  over base B. 
   Referring specifically to  FIGS. 1A and 1B , base B includes a leg support unit (B R ) including segments  7 ,  8  and  9 , together with leg support unit (B L ) that includes leg segments  27 ,  28 , and  29  (base B and leg support units B R  and B L  are considered to be the same). Each leg segment of the leg support units (B R ) and (B L ), and for that matter other component parts of the walker apparatus to be described as the description continues, have structural specification characteristics of length, width, and cross-section, for example, permitting the components to meet conditions of operation requiring strength and other characteristics of performance under various and differing operating conditions. These features and others, such as capabilities of materials, manufacture, and construction for the most part are considered to be within the knowledge of those skilled in the art. Therefore, unless it is important for a full and complete understanding of the invention and its important aspects, the description will not launch into any specific discussion of any individual component. The discussion, however, as it unfolds will address with a degree of specificity features of the structure regarding the capability of conversion of the walker apparatus from, and in return to, an operative mode of operation. 
   Leg segments  7 - 9  of the leg support unit A (B R ) and leg segments  27 - 29  of leg support unit (B L ) of the walker apparatus, and the other structural components to be described, are connected together in a manner to accommodate any one or more of several required actions when it I required to collapse the structure of the walker apparatus from the operative condition of frame F as seen in  FIGS. 1A-1C . This requirement generally follows a desire, for example, to store or transport the walker apparatus from one location to another. Following a period of storage or movement of the walker during transport it will be necessary to return the structures to their assembled, operative state of operation of  FIGS. 1A-1C . This operation may be carried out with relative ease reversing the operation therefore concluded. 
     FIGS. 3B and 3I  illustrate the connection of segments of the leg support unit (B R ) including leg segments  8  and  9 , and leg segments  7  and  8 , respectively. 
     FIG. 3B  is a cross-section of the mating end portions of the leg segments  8  and  9  together with mating sleeve  83  that surrounds the segments. The mating sleeve  83  is attached to segment  9  in a manner permitting movement of segment  8  relative to the attached components. The mating sleeve  83  may be attached to the segment  9  by an adhesive compound or the equivalent and coupled by a quick-release locking mechanism unit  128  into the right-side main lift bar section. The micro-switch  82  is engaged (closed) under the condition that the quick-release locking mechanism unit  128  is properly and remains properly installed. Another switch is responsive to the positioning of leg segment  9 , as the leg segment  9  locates to the fully extended position relative to the segment  8 . 
   Further specifies to amplify upon the discussion above and the discussion below regarding  FIG. 3D , referring leg segment  8  and  9 , and leg segments  28  and  29 , will be brought out during the discussion directed to  FIGS. 5E and 5F  as the description unfolds. 
     FIG. 3I  is a side elevation view of the mating end portions of leg segments  7  and  8  together with mating sleeve unit  146 . Leg segments  7  and  8  are attached by the mating sleeve unit  146 . Leg segments  7  and  8  are attached by the mating sleeve unit  146  and held in place by locking fastener  65  cooperatively located within the mating sleeve unit  146 . 
     FIGS. 3D and 3J  illustrate the connection of leg segments of the leg support unit (B) including leg segments  28  and  29 , and leg segments  27  and  28 , respectively. 
     FIG. 3D  is a cross-section of the mating end portions of the leg segments  28  and  29  together with a mating sleeve  87  that surrounds leg segments  28  and  29 . The mating sleeve  87  is attached to leg segment  29  in a manner permitting movement of leg segment  28  relative to the attached components. The mating sleeve  87  may be attached to leg segment  29  by an adhesive compound or the equivalent and coupled by a quick release locking mechanism unit  130  into the left-side main lift bar section. A micro-switch  86  is engaged (closed) under conditions that the quick release mechanism  130  is properly and remains properly installed. Another switch is response to the positioning of leg segment  29 , as the leg segment locates to the fully extended position relative to leg segment  28 . 
     FIG. 3J  is a side elevation view of the mating end portions of leg segment  27  and  28  together with a mating sleeve unit  147 . Leg segments  27  and  28  are attached by the mating sleeve unit  147  and held in place by a locking fastener  66  cooperatively located within the mating sleeve unit  147 . 
   A drive mechanism  20  provides a mounting for one end of each leg support unit (B R ) and (B L ) at a front location of the walker apparatus, and a pair of outrigger wheel assemblies  18  and  38  provides a mounting at the opposite end of each leg support unit B R  and B L , at a rear location of the walker apparatus. The leg support units B R  and B L  come together at the front location within the region of drive mechanism  20  and may be connected to a housing of the drive mechanism using any one of various types of mounting configurations providing a secure, strong, and stable support for the walker apparatus. 
   The outrigger wheel assembly  18  is mounted on leg segment  9  of the leg support unit (B R ) within the vicinity of its end furthest removed from the front location. Similarly, the outrigger wheel assembly  38  is mounted on leg segment  29  of leg support unit (B L ) within the vicinity of its end furthest removed from the front location. Again, any of the various types of mounting configurations providing a secure, strong, and stable support for the outrigger wheel assemblies  18  and  38  on a respective leg segment of the leg support units (B R ) and (B L ) may be used. 
   The leg support units (B R ) and (B L ) each diverge along their rearward extension so that wheel assemblies  18  and  38  together the drive mechanism  20  define a three-point support of the base B on a surface. The angle of divergence is acute, and may be in the range, for example, of from approximately 20° to 40° as determined by operating requirements. Typically, a three-point support will permit ease of movement of the walker apparatus both in the basic powered and virtual mode of operation and appropriate, internal structural strength and stability characteristics required for safety in operation of apparatus of the type described. 
   The intermediate mounting structure B 2  of Frame F ( FIGS. 1A-1C ) includes three cooperating triangular frameworks, each substantially equilateral in outline. The frameworks may be seen in  FIGS. 1A-1C . One framework comprises incline main strut  2 , leg support unit (B R ), and a frame member  1 . Another framework comprises incline main strut  22 , leg support unit (B L ), and frame member  1 . Yet another framework comprises frame member  1  and the incline main struts  2  and  22 . The frameworks also introduce substantial support capability required by movable apparatus, such as the walker apparatus of the present invention. 
   The intermediate structure B 2  of frame F is mounted on Base B in a manner that is now addressed. 
   The framework illustrated in  FIG. 1A , formed partially by incline main strut  2  and frame member  1 , is mounted on leg support unit (B R ) between drive mechanism  20  and the point of connection of segments  7  and  8 . 
   Frame member  1  illustrated in  FIGS. 1A-1C  is a planer, generally rectangular, planar construction. The frame member  1  extends in one direction (horizontal) between leg support units (B R ) and (B L ), throughout a distance equal to the angle of divergence of the leg support units, and the spaced location of the connection of leg segments  7  and  8  relative to the drive mechanism  20 . The frame member  1  also extends from a location within the leg support units (B R ) and (B L ) vertically to the region of an axis through the pivot locations  65  and  66 . The mating sleeve unit  146  is of a length to extend into the confronting edge surface of frame member  1  throughout a distance considered satisfactory. The locking fastener  65  secures the parts in their mounted position. 
   The lower end of the main incline strut  2  is connected to drive mechanism  20 . As discussed, the drive mechanism  20  may be supported within a housing including a neck portion. The main incline strut  2  extends toward the neck portion and a location substantially along its vertical axis, on the right side. A mating bearing sleeve  160  is received through the main strut  2  into the neck. A pivot fastener  161  secures the components. 
   The other end of main incline strut  2  and frame member  1  are connected together completing the framework. To this end, a mating bearing sleeve unit  148  is received through main strut  2  and into the confronting edge surface of frame member  1 . A pivot fastener  67  completes the connection and secures the components. 
   The framework illustrated in  FIG. 1B , formed partially by incline main strut  22  and frame member  1 , is mounted on leg support unit (B L ) between drive mechanism  20  and the point of connection of segments  27  and  28 . The mounting particulars are similar to those described regarding the mounting of the framework of  FIG. 1A . 
   The opposed, confronting edge of frame member  1  is disposed within the region of the pivot connection of leg segments  27  and  28  of leg support unit (B L ) and the mating sleeve unit  147  is extended into the surface along the edge of frame member  1  uniting the frame member and leg segments  27  and  28 . The locking fastener  66  secures the parts in their mounted position. 
   The lower end of the main incline strut  22  is connected to drive mechanism  20 . To this end, the main incline strut  22  extends toward the neck portion and a location substantially along its vertical axis, on the opposite side of the mounting location of main incline strut  2 . A mating bearing sleeve  162  is received through the incline main strut  22  into the neck. A pivot fastener  163  secures the components. 
   Finally, the other end of the main incline strut  22  and frame member  1  are connected together completing the framework. To this end, a mating bearing sleeve unit  149  extends through main incline strut  22  into the confronting edge surface of frame member  1 . A pivot fastener  68  completes the connection and secures the components. 
   A brace unit  5  extends between frame member  1  and the main incline strut  2  of the framework within the right-side of the intermediate support structure B 2 . The brace unit  5  is located in a disposition somewhat closer to the apex than the base of the framework. It is believed that this choice of location better enhances the structural support capability provided by the framework and, in turn, by the intermediate support structure B 2  in support of the lifting bar assembly B 1 . 
   The brace  5  is located to the inside of the main incline strut  2  and along the edge of the side of frame member  1 . A mating bearing sleeve unit  142  is received through one end of the brace and into the frame member  1 . A pivot fastener  63  is received by the mating bearing sleeve and secures the structures together. Similarly, a mating bearing sleeve unit  144  is received through both the brace  5 , within the region of the other end, and main incline strut  2 . A locking fastener  50  is received into the mating bearing sleeve to secure the structures. 
   A similar brace unit  25  extends between frame member  1  and the main incline strut  22  of the left-side framework, in the orientation discussed above. A mating bearing sleeve  145  is received through both the brace  25  and main incline strut  22 . A locking fastener  105  is received into the mating bearing sleeve to secure the structures. A mating bearing sleeve unit  143  is also received through the brace  25  and into the frame member  1 . A pivot fastener  64  is received by the mating bearing sleeve unit  143  and secures the parts together. 
   The brace unit  25  is disposed in same general orientation of the brace unit  5 . As such, the brace unit  25  also extends between the main incline strut  22  and the frame member  1  somewhat closer to the apex of the framework for the reasons previously stated. 
   The lifting bar assembly B 41  is best seen in  FIG. 1C  includes a U-shaped lifting bar member having a right-side leg, a left-side leg and a lifting bar handle  19 . The right-side leg (also illustrated in  FIG. 1A ) includes a lifting bar section  3  and a lifting bar extension  4 , while the left-side leg (also illustrated in  FIG. 1B ) includes lifting bar section  23  and a lifting bar extension  24 . The lifting bar handle  19  that connects lifting bar extension sections  4  and  24  at an end functions as a lifting bar handle.  FIG. 1C  illustrates the lifting bar assembly in the lifting mode of operation with both the right-side lifting bar section  23  and lifting bar extension section  24 , and left-side lifting bar section  3  and lifting bar extension section  4  in their fully extended configuration.  FIG. 1C  also illustrates the leg segment units B R  and B L  including leg segments  7 - 9  (now on the left-side) and leg segments  27 - 29  (now on the right-side) in their fully extended configuration, also. In addition,  FIG. 1C  illustrates generally the location of control units  21  and  39 , perhaps better illustrated in  FIGS. 4A and 4B , respectively. Thus, the control unit  21  comprises the left control unit and control unit  39  comprises the right control unit. 
   Lifting bar section  3  and lifting bar extension section  4  of the right-side leg of lifting bar member are connected together using the same structural concepts as applied in connecting leg segments  8  and  9  of the right-side leg support unit. 
     FIG. 3A  is a cross-section of the mating end lengths of the lifting bar section  3  and lifting bar extension section  4  together with a mating sleeve  81  that surrounds both the lifting bar section  3  and lifting bar extension section  4 . The mating sleeve  81  is attached to the lifting bar extension section  4  in a manner permitting movement of lifting bar section  3  relative to the attached components. The mating sleeve  81  is attached to lifting bar extension section  4  by an adhesive compound or the equivalent and coupled by a quick-release locking mechanism unit  127  into the right-side lifting bar section  3 . A micro-switch  80  is engaged (closed) and remains engaged under conditions that the quick-release locking mechanism unit  127  is properly installed. Another switch is responsive to the positioning of lifting bar extension, as the lifting bar extension  4  locates to the fully extended position relative to lifting bar section  3 . 
   Lifting bar section  23  and lifting bar extension section  24  of the left-side leg of lifting bar member, also connected together, are connected according to the structural concepts employed in connecting the sections of the right-side leg of the lifting bar assembly. 
     FIG. 3C  is a cross-section of the mating end lengths of the lifting bar section  23  and lifting bar extension section  24  together with a mating sleeve  85  that surrounds the lifting bar section  23  and lifting bar extension section  24 . The mating sleeve  85  is attached to the lifting bar extension  24  in a manner permitting movement of lifting bar section  23  relative to the attached components. The mating sleeve  85  is attached to lifting bar extension section  24  by an adhesive compound or the equivalent and coupled by a quick-release locking mechanism unit  129  into the left-side lifting bar section  23 . A micro-switch  84  is engaged (closed) and remains engaged under conditions that the quick-release locking mechanism unit  129  is properly installed. Another switch is responsive to the positioning of the lifting bar extension section  24  as the lifting bar extension section moves to and locates in the fully extended position relative to lifting bar section  23 . 
   The lifting bar assembly B 1  extends from and is secured to frame F at the pivot locations  67  and  68 , also serving as pivot mounting locations for the right-side and left-side frameworks illustrated in  FIGS. 1A and 1B , respectively. To this end, the mating bearing sleeve unit  148  received through main incline strut  2  is also received through lifting bar section  3  before extending into the confronting side surface of frame member  1 . The pivot fastener  67  retains the structures in place. In a similar manner, the mating bearing sleeve unit  149  received through lifting bar section  23  before extending into the confronting side surface of frame member  1 . The pivot fastener  68  retains the structures in place. 
   A linkage arm  6  extends between a bolt/nut assembly unit  88  of a lifting bar drive mechanism  45  and an anchor assembly  17 . The anchor assembly  17  is supported by lifting bar section  3  within the region of its ends near the location of connection of lifting bar section  3  and lift bar extension section  4 . The anchor assembly  17 , for example, may include a pair of confronting plates and the linkage arm  6  may be received between the plates. A pivot pin (not shown) also received through the plates will secure the linkage arm for movement following movement of the bolt/nut assembly unit  88 , as will be discussed. The bolt/nut assembly  88  may be connected to the linkage arm  6  by any means that may be convenient and applicable for the movements to be obtained. 
   The lifting bar drive mechanism  45 , referring now to  FIG. 5A , includes a sleeve assembly  69  having a pair of spaced legs extending from a web having an elongated length. The web may be secured to the rear surface, on the “left-side”, as seen in  FIG. 1A , of frame member  1  in any convenient manner. The spaced legs of the sleeve define a channel, and a lip extending along each leg serves to retain the bolt/nut assembly unit  88  within the channel permitting only movement in one linear direction of the other. 
   With reference to  FIG. 5A , the lifting bar drive mechanism  45  includes a motor  77 , a gear box  78 , a screw drive unit  79 , and a screw holder switch unit  89 . The screw drive unit  79  is coupled to the gear box  78  and supported by the screw holder switch unit  89  for during the bolt nut assembly unit  88  in one or the other of the opposite directions as determined by motor  77  operation. 
   A cutoff switch  134  is located within the sleeve assembly  69  in position for engagement by bolt/nut assembly unit  88  when it reaches its maximum point of travel in one direction. Therefore, when bolt/nut assembly unit  88  completes the path of travel in that direction it contacts and activates the cutoff switch  134 . Similarly, when bolt/nut assembly unit  88  reaches its maximum point of travel in the other direction it contacts and activates screw holder/switch unit  89 . 
   A linkage arm  26  extends between a bolt/nut assembly unit  99  of a lifting bar drive mechanism  46  and an anchor assembly  37 . The connection of components and the manner of their movement and interaction duplicates that of the structures just described. Thus, anchor assembly  37  is supported by lifting bar section  23  within the region of its ends, near the location of connection of lifting bar section  23  and lifting bar extension  24 . The anchor assembly  37 , for example, also may include a pair of confronting plates for receipt of the linkage arm  26 . A pivot pin (not shown) is received through the plates to secure the linkage arm for movement following movement of the bolt/nut assembly unit  99 , as will be discussed. The bolt/nut assembly unit  99  may be connected to the linkage arm  26  by any means that may be convenient and applicable for the movements to be obtained. 
   The lifting bar drive mechanism  46 , referring now to  FIG. 5B , includes a sleeve assembly  70  having a pair of spaced legs extending from a web elongated in length. The web is secured along its length to the rear surface, on the “right-side”, as seen  FIG. 1B , of frame member  1  in any convenient manner. The spaced legs define a channel, and a lip extending along each leg serves to retain the bolt/nut assembly  99  within the channel permitting only movement in one linear direction of the other. 
   With reference to  FIG. 5B , the lifting bar drive mechanism  46  includes a motor  90 , a gear box  97 , a screw drive unit  98 , and a screw holder switch unit  100 . The screw drive unit  98  is coupled to the gear box  97  and supported by the screw holder switch unit  100  for during the bolt nut assembly unit  99 , as determined by reversible motor  90 . 
   A cutoff switch  135  is located within the sleeve assembly  70  in position for engagement by bolt/nut assembly unit  99  when it reaches its maximum point of travel in one direction. Therefore, when bolt/nut assembly unit  99  completes the path of travel in that direction it contacts and activates the cutoff switch  135 . Similarly, when bolt/nut assembly unit  99  reaches its maximum point of travel in the other direction it contacts and activates screw holder/switch unit  100 . 
   Operations of similar nature to that described through movement of the lifting bar handle  19  of the lifting bar assembly are carried out in response to actions in the collapse of lifting bar sections  3  and  23 , together with lifting bar extension sections  4  and  24  of the right-side and left-side lifting bar handle, respectively, and leg segments  8  and  28 , together with leg segments  9  and  29  of the right-side and left-side segment units B R  and B L , respectively. 
   Referring to  FIG. 5C , lifting bar section  3  is cylindrical in cross-section and includes a short-length cylindrical section having an outer diameter of slightly smaller dimension than the inner diameter of the major length. The outer cylinder is fixed while the short-length section is supported in movement and adapted to slide within the larger cylinder of the lifting bar section  3  to and fro between opposite, predetermined limit positions. 
   A motor  107  and a gear box unit  106  coupled to the motor are fixed within the major length of lifting bar section  3  by a pair of set screws  110 C and  110 D that cooperate within openings in the cylinder. A screw drive unit  103  is coupled to the gearbox unit  106  at one end and supported at the other end by a housing of cut-off switch  101 . A bolt nut assembly  102  is carried by the screw drive unit  103  and driven in one direction or the other by the motor  107 . The short-length cylinder is connected to the bolt nut assembly  102  by a set screw  110 A and  110 B in the manner of mounting motor  107 . Thus, the short-length cylindrical section and bolt nut assembly  102  move in unison under control of the motor. Cutoff switch  101  is activated by the bolt nut assembly  102  following movement to a predetermined limit in one direction and cutoff switch  104  is activated by the cylindrical surface of the short-length cylinder following movement in the opposite direction to a predetermined limit. The motor  107  is activated to drive in one rotational direction of the other determined by the positioning of switch  72  of the left-side control unit  21  (see  FIG. 4A ). 
   The left-side lifting bar handle including lifting bar section  23  and lifting bar extension section  24  may be collapsed and then returned to the operating mode of the walker apparatus, providing the same functions and switch activations discussed above. 
   Turning to  FIG. 5D , lifting bar section  23  is cylindrical in cross-section and includes a short-length cylindrical section having an outer diameter of slightly smaller diameter than the inner diameter of the major length. The outer cylinder is fixed while the short-length section is supported in movement and adapted to slide to and fro between opposite, predetermined limit positions. 
   A motor  114  and a gear box unit  113  coupled to the motor are fixed within the major length of lifting bar section  23  by a pair of set screws  110 G and  110 H that cooperate within openings in the cylinder. A screw drive unit  111  is coupled to the gearbox unit  113  at one end and supported at the other end by a housing of cut-off switch  108 . A bolt nut assembly  109  is carried by the screw drive unit  111  and driven in one direction or the other by the motor  114 . The short-length cylinder is connected to the bolt nut assembly  109  by a set screw  110 E and  110 F in the manner of mounting motor  114 . Thus, the short-length cylindrical section and bolt nut assembly  109  move in unison under control of the motor. Cutoff switch  108  is activated by the bolt nut assembly  109  following movement to a predetermined limit in one direction and cutoff switch  112  is activated by the cylindrical surface of the short-length cylinder following movement in the opposite direction to a predetermined limit. The motor  114  is activated to drive in one rotational direction of the other determined by the positioning of switch  92  of the left-side control unit  39  (see  FIG. 4B ). 
   The following discussion is directed to the structure of leg support units B R  and B L  and particularly the action of collapsing leg segments  8  and  9 , and leg segments  28  and  29 , as well as the return of the leg segments to the operative positioning. 
   Referring to  FIG. 5E , leg segment  8  is cylindrical in cross-section and includes a short-length cylindrical section having an outer diameter of slightly smaller dimension than the inner diameter of the major length. The outer cylinder is fixed while the short-length section is supported in movement and adapted to slide to and fro between opposite, predetermined limit positions. 
   A motor  120  and a gear box unit  119  coupled to the motor are fixed within the major length of leg segment  8  by a pair of set screws  110 K and  110 L that cooperate within openings in the cylinder. A screw drive unit  117  is coupled to the gearbox unit  119  at one end and supported at the other end by a housing of cut-off switch  115 . A bolt nut assembly  116  is carried by the screw drive unit  117  and driven in one direction or the other by reversible motor  120 . The short-length cylinder is connected to the bolt nut assembly  116  by a set screw  110 I and  110 J in the manner of mounting motor  120 . Thus, the short-length cylindrical section and bolt nut assembly  116  move in unison under control of the motor  120 . Cutoff switch  115  is activated by the bolt nut assembly  116  following movement to a predetermined limit in one direction and cutoff switch  118  is activated by the cylindrical surface of the short-length cylinder following movement in the opposite direction to a predetermined limit. The motor  120  is activated to drive in one rotational direction of the other determined by the positioning of switch  73  of the left-side control unit  21  (see  FIG. 4A ). 
   Referring to  FIG. 5F , leg segment  28  is cylindrical in cross-section and includes a short-length cylindrical section having an outer diameter of slightly smaller dimension than the inner diameter of the major length. The outer cylinder is fixed while the short-length section is supported in movement and adapted to slide to and fro between opposite, predetermined limit positions. 
   A motor  126  and a gear box unit  125  coupled to the motor are fixed within the major length of leg segment  28  by a pair of set screws  110 O and  110 P that cooperate within openings in the cylinder. A screw drive unit  123  is coupled to the gearbox unit  125  at one end and supported at the other end by a housing of cut-off switch  121 . A bolt nut assembly  122  is carried by the screw drive unit  123  and driven in one direction or the other by reversible motor  126 . The short-length cylinder is connected to the bolt nut assembly  122  by a set screw  110 M and  110 N in the manner of mounting motor  126 . Thus, the short-length cylindrical section and bolt nut assembly move together under control of the motor. Cutoff switch  121  is activated by the bolt nut assembly  122  following movement to a predetermined limit in one direction and cutoff switch  124  is activated by the cylindrical surface of the short-length cylinder following movement in the opposite direction to a predetermined limit. The motor  126  is activated to drive in one rotational direction of the other determined by the positioning of switch  93  of the left-side control unit  39  (see  FIG. 4B ). 
   A non-skid assembly unit  10  is mounted to the underside of the leg support unit B R  substantially along the length of segment  7 . A similar non-skid assembly unit  30  is mounted to the underside of the leg support unit B L  substantially along the length of segment  27  (see  FIGS. 1A ,  1 B, and  1 D). The lower surface of non-skid assembly units  10  and  30  contains an irregular pattern and also has a capability of creating a force of suction between the non-skid assembly unit and the surface on which the walker apparatus resides during the lifting/lowering operations of the lift bar assembly. 
   The lifting bar assembly B 1 , deployed in the manner of operation, includes a support  49  and a seat  40  secured to the support in a cantilever fashion, see  FIG. 1E . Support  49  extends between a pair of spaced lifting bar mechanisms  45  and  46  described heretofore in connection with the discussion directed to  FIGS. 5A and 5B , and is connected to the former by means of the nut/bolt assembly unit  88  of the lifting bar drive mechanism  45 , and to the latter by means of nut/bolt assembly unit  99  of lifting bar mechanism  46 . Thus, support bar  49  moves in concert with the moving cycle of the lifting drive mechanisms  45  and  46 , upward and downward, under control of the reverse drive imparted to each nut/bolt assembly unit by motor  77  and  90 , respectively. The drive of the motor  77  is controlled by control  71  of the left-side control unit  21 , and the drive of the motor  90  is controlled by control  91  of the right-side control unit  39 . Both controls are located on the handle  19  of the lifting bar assembly B 1  and control up-down movement of seat  40 . 
   Seat  40  is also mounted on the left side by a support brace  41  and a support bracket  47  connected to the support brace  41  and received by a mounting rail  43 . The mounting rail  43  that guides the support bracket  47  in movement a may comprise a portion of the lifting bar drive mechanism  45 . The structures are duplicated on the right side by a support brace  42  and a support bracket  48  connected to the support brace  42  and received by a mounting rail  44 . The mounting rail  44  that guides the support bracket  48  in movement may comprise a portion of the lifting bar drive mechanism  46 . Support brace  41  and support brace  42  are connected within the region of the cantilever extension of seat  40  thereby to introduce an added measure of stability to the seat  40 . 
   A compartment  131  supported on the front planer surface of frame member  1  may be used for any purpose, for example, to carry groceries, books, and so forth. 
   Finally, before a commencing on a full and complete discussion of the electronics configuration, reference is directed to  FIGS. 2A and 2B , each illustrating a cross-sectional view taken generally along the plane of the main front to rear axis of the walker apparatus to provide a full understanding of the drive mechanism unit  20  and its operation. 
   Drive mechanism unit  20  is supported within a housing unit  51  that also support the leg segments units B R  and B L  and main incline struts  2  and  22  comprising the legs of the frameworks seen in  FIGS. 1A and 1B . 
   Drive mechanism  20  includes drive motors  52  and  62 , both capable of providing a reverse driving output. The drive motor  52  controls an actuating means described below to activate alternately micro-switches  136  and  137 . The drive motor  62 , on the other hand, controls a drive wheel unit  60  for driving the walker apparatus in the forward and rearward directions. The drive mechanism  20  provides an engaged mode for both the powered and virtual mode versions of the walker apparatus of the invention. 
   Drive motor  52  is coupled to gearbox  53  which in turn is mounted to drive a rack assembly mounted for movement under control of the motor  52  either upward or downward as seen in  FIGS. 2A and 2B . Particularly, the rack assembly unit  55  under control of motor  52  drives a cylindrical body including a sleeve bearing unit  56 , a hollow rotary sleeve unit  54  on the opposite side of the sleeve bearing unit  56 , a rotary joint assembly  57  at the top of the cylindrical body and a rotary joint assembly  58  at the bottom of the cylindrical body. Each rotary joint assembly  57  and  58  is connected to the hollow rotary sleeve unit  54 . 
   The hollow rotary sleeve unit  54  as configured is capable of withstanding transverse loads that may be expected in operation of the drive mechanism  20 , that act in any direction. 
   The cylindrical body including the sleeve bearing unit  56  and hollow rotary sleeve unit  54  is directly controlled by rack assembly unit  55  under control of the input drive of motor  52 . Thus, motor  52  drives the cylindrical body in movements toward and into engagement with one or the other of micro-switches  136  and  137 . Micro-switch  137  is activated when the drive mechanism  20  acting through the cylindrical body is fully engaged. 
   Wheel unit  60  is mounted for movement on rotary joint assembly  57 . The wheel unit  60  is directly controlled by the motor  62  acting through drive gearbox  61  in both forward and reverse drives. The wheel unit  60  is also controlled in movements to the right and left, thereby controlling the path taken by the walker apparatus. A rotary drive assembly  59  provides this measure of directional input. The rotary drive assembly  59  is mounted within housing unit  51  and coupled to the rotary drive assembly  58 . The driving input to the rotary joint assembly  58  is coupled to the rotary joint assembly  57  through the hollow rotary sleeve  54 . 
   The hollow rotary sleeve unit  54  is attached to each rotary joint assembly  57  and  58  and the input of rotary joint drive assembly  59  controls movement of the wheel unit  60  as the rotary joint assembly  57  moves rotationally around the axis of the sleeve bearing unit  56 . 
     FIG. 2A  illustrates the drive mechanism  20  in the engaged, basic powered and virtual mode of operation possibly following activation of micro-switch  137 , and  FIG. 2B  illustrates the drive mechanism  20  in the disengaged position. 
   The Electronics Configuration Powered Mode of Operation 
   The electronics for the basic powered version of the walker apparatus is illustrated in the block diagram of  FIG. 6A , while the electronics for the virtual mode version of the walker apparatus is illustrated in the block diagram of  FIG. 6B . 
   The block diagram of  FIG. 6A  includes a raise/lower lift bar electronic circuit  151 , a height adjustment for lift bar electronic circuit  152 , an outrigger extension/contraction electronic circuit  153 , an engage/disengage drive mechanism electronic circuit  154 , a steering mechanism electronic circuit  155 , a forward/reverse drive electronic circuit  157 , a power source  170  (not shown), and a controller unit or transceiver unit  21 ,  39 . Each circuit  151 - 155  and  157  is connected directly to controller unit  21 ,  39 . Speed control electronic circuit  156 , on the other hand, is connected to controller unit  21 ,  39  through forward/reverse drive electronic circuit  157  providing speed control of the drive in both directions of movement. The block diagram comprises the circuitry illustrated in  FIGS. 6C-6K . The specifics of the circuitry will be discussed in greater particularity as the description continues. 
   Referring to  FIG. 4A , controller unit  21  is made up of several controls  71 - 76 ,  132 ,  138  and  140  for controlling aspects of operation of the basic powered and virtual mode version of the walker apparatus. The individual controls are located on the bar handle  19  (see  FIG. 1D ) of the lifting assembly mechanism, previously discussed. 
   Control  71 , located on the bar handle  19  within the region of the left side a illustrated in  FIG. 1D , is the left-side lifting bar handle up/down switch; control  72  is the left side lifting bar extension/retraction switch; control  73  is the left side support legs (support legs B R  and B L ) extension/retraction switch; control  74  functions to engage/disengage drive mechanism unit  20  from the left side; control  75  functions as a variable resistor providing steering signals from the left side; control  76  functions as a variable resistor providing speed signals to the drive motor  62  from the left side; control  132  is an on/off basic powered and virtual mode switch for the power drive unit; control  138  is the left-side activation switch; and control  140  is the forward/reverse switch for the left side. 
   Referring to  FIG. 4B , controller unit  39  likewise is also made up of several controls  91 - 96 ,  133 ,  139  and  141  also operative for the basic powered and virtual mode version of the walker apparatus. The individual controls are located on the bar handle  19  of the lift mechanism. Similar to the arrangement of  FIG. 4A , the controls are located on the bar handle  19  of the lift mechanism and the first of the controls is positioned on the bar handle  19  within a right hand location. The first control, control  91 , is the right-side lifting bar handle up/down switch; control  92  is the right side lifting bar extension/retraction switch; control  93  is the right side support legs (support legs B R  and B L ) extension/retraction switch; control  94  functions to engage/disengage drive mechanism unit  20  from the right side; control  95  functions as a variable resistor providing steering signals from the right side; control  96  functions as a variable resistor providing speed signals to the drive motor  62  from the right side; control  133  is an on/off basic powered and virtual mode switch for the power drive unit; control  139  is the right-side activation switch; and control  141  is the forward/reverse switch for the right side. 
     FIG. 6B  illustrates the electronics for the virtual mode version of the walker apparatus. The circuit configuration of  FIG. 6B  duplicates the circuit configuration of  FIG. 6A , and includes, in addition, the circuitry of block  159  electronically connected to control unit  21 ,  39  through forward/reverse drive electronic circuit  157 . Block  159  is connected to CPU  190  (see  FIG. 6J ) providing an input control of the walker apparatus for both speed and direction. The circuitry of block  159  will be described with the other electronics in connection with the discussion directed to  FIGS. 6C-6J . 
   Turning to  FIG. 6C , the walker apparatus is readied to both the basic powered and virtual modes of operation by a sequence of operations starting with the operation of raising or lowering the lifting bar assembly (illustrated in  FIG. 1D , including opposed lifting bar sections  3  and  23 , lifting bar section extensions  4  and  24 , as well as lifting bar handle  19 ) through activation of one or the other of a left-side switch  138  or right-side switch  139 , respectively. For example, the user may select the left-side switch  138  and determine one of two functions of raising or lowering the lifting bar under control of switching member  71 . 
   Similarly, the user may select the right-side switch  139  to determine the same functions of raising and lowering the lift bar under control of switching member  91 . If the lifting bar is to be raised, the switch member  71  is raised (the “Up” direction in  FIG. 1D ). If the switch member  71  is lowered the lift bar likewise will be lowered. The same operation will be achieved through use of the right-side switch  139  and switch member  91 . 
   The electrical system introduces several safety features will become apparent through a consideration of the logic illustrated in the circuitry switch to minimize the likelihood of injury being sustained by the user of the walker apparatus. 
   First, the lifting bar extension section  4  not only must be fully extended it must be properly assembled with lifting bar section  3 , and remain in the proper assembled condition, for activation of switch  80 . As will be recalled, with further reference to  FIG. 3A , switch  80  is engaged when those conditions are fulfilled and the locking mechanism  127  is engaged. 
   Switches  82 ,  84 , and  86  are activated under similar conditions, all as previously discussed with reference to  FIGS. 3B-3D . The sequence of operation that follows may be to assemble lifting bar extension section  24  and lifting bar section  23 , fully extend the components and insert locking mechanism  129  to activate switch  84 ; assemble leg segment  9  and leg segment  8 , fully extend the components and insert locking mechanism  128  to activate switch  82 ; and assemble leg segment  29  and leg segment  28 , fully extend the components and insert locking mechanism  130  to activate switch  86 . 
   When these conditions are attained both AND gates  200  and  204  will provide a logic output. 
   The logic output at AND gate  200 , and similarly the logic output at AND gate  204 , provides one of several inputs controlling AND gates  203  and  207 , respectively, to electrically connect switches  138  and  139  through their let and right switch arms A and B (the positions in  FIG. 6C , for example) to power at +V 1 . 
   Several operations are required to provide a logic output at AND gate  205 . Particularly, lifting bar assembly handle  19  (through full extension of lifting bar extension section  4  in relation to lifting bar section  3  must be fully extended to activate switches  101 , and lifting bar extension section  24  in relation to lifting bar section  23 ) must be fully extended to activate switches  105 ,  108  (see  FIGS. 5C and 5D ). Similarly, leg segments  9  and  29  must be fully extended in relation to leg segments  8  and  28  for activation of switches  115  and  121 , respectively. 
   The operations of full extension of all structures resulting in an input at each input terminal of AND gate  205 , also result in the presence of a signal at each respective input of AND gate  201 , and consequently a logic output at AND gate  201 . 
   As previously discussed, cut-off switch  101  is activated to the “on” condition from a condition normally “off” when bolt nut assembly unit  102  reaches a limit location corresponding to maximum travel in the opposite direction nut bolt assembly unit  102  reaches its limit location corresponding to maximum travel in the opposite direction nut bolt assembly  102  activates cut-off switch  104  to the “off” condition from a normally “on” condition. Thus, when lifting bar section  3  and lifting bar extension section  4  are fully “embedded” the control at the input of AND gate  205  responsive to that action is lost. AND gate  205 , thus, has no logic output. 
   The cooperative actions of other structures illustrated in  FIGS. 5D-5F  are the same, and together with the cooperative action of the structures illustrated in  FIG. 5C . affects the presence or absence of an input at the respective input terminals of AND gates  201  and  205 . To this end, each input of AND gate  205  is controlled by a cut-off switch that normally is in the “off” condition and activated to the “on” condition representing full extension of a pair of cooperating structures. AND gate  201 , on the other hand, provides an output at all times, except when any or all pairs of cooperating structures are fully “embedded”. AND gate  205  will have lost its output when any or all pairs of cooperating structures release from the fully extended position in collapse in the fully “embedded”. 
   The final conditions to meet in the lift bar assembly raising mode is that both the left-side lift motor cut-off switch  134  and right-side lift motor cut-off switch  135  are engaged, and the drive mechanism  20  is also in the disengaged mode under condition that switch  136  is activated “on”. If the several conditions are met, AND gate  202  will provide an output logic signal. Assuming, the conditions are met, AND gate  202  will produce a logic output. 
   In the lowering mode of operation, AND gate  206  will produce an output logic signal under the conditions that the left-side lift motor cut-off switch  89  is not engaged and the right-side lift motor cut-off switch  100  is also not engaged, and the drive mechanism unit  20  is in the disengaged mode with switch  136  engaged. 
   The operation of AND gate  202  is controlled by lifting bar assembly handle  19  in the bar raising mode. A logic output will appear at AND gate  202  under conditions that both the left and right-side lift motor cut-off switches  134  and  135  are not engaged, and drive mechanism unit  20  is in the disengaged mode with switch  136  engaged. Likewise, AND gate  206  will provide a logic output under conditions that both left and right-side lift motor cut-off switches  89  and  100  are not engaged, and drive mechanism  20  is in the disengaged mode with switch  136  engaged. 
   As described, a logic output will exist at AND gate  203  under circumstances of a logic output at each of AND gates  200 ,  201 , and  202  in the raising mode of operation. The logic output at AND gate  203  is recognized at OR gate  209  through either switch  71  or  91 . In the lowering mode of operation an output will exist at AND gate  207  under circumstances of a logic output at each of AND gates  204 ,  205 , and  206 . The logic output at AND gate  207  is recognized at OR gate  209  through either switch  71  or  91 . 
   The direction of the drive of reversible motors  77  and  90  is determined by operation of OR gates  208  and  209 , and an H-bridge network comprising resistors  210 ,  215 ,  216 , and  221 ; diodes  212 ,  213 ,  218 , and  219 ; and NPN power transistors  211 ,  214 ,  217 , and  220 . The resistors provide proper bias for the transistors, and eliminate any excessive current that may overheat and/or destroy a transistor. 
   The H-bridge is wired in a manner that only two transistors are “on” at any time. For example, when transistors  214  and  220  are “on”, the motors (M)  77  and  90  turn in one direction. When transistors  211  and  217  are “on”, the motors  77  and  90  turn in the opposite direction. When all transistors  211 ,  214 ,  217 , and  220  are “off”, the motors  77  and  90  are still. As a power saver, switches  71 C and  91 C serve to connect/disconnect power source +V 2  from the H-bridge. The logic circuits are powered by a power source +V 1 . 
   It goes without saying that motors  77  and  90  controlled by the H-bridge in  FIG. 6C , as well as the motors  107  and  114  controlled by the H-bridge in  FIG. 6D , for example, could be replaced by a single motor, and likewise, the motor  52  controlled by the H-bridge in  FIG. 6F , for example, could be replaced by a pair of motors. The particular selection of one or a pair of motors in the several figures, however, has been determined primarily by a consideration of size and weight of the walker apparatus thereby to provide ease in handling and overall convenience in operation. 
   The details of operation of the H-bridge in each of electronic circuit  152  ( FIG. 6D) and 153  ( FIG. 6E ) are identical in operation to that operation discussed in connection with electronic circuit  151 . Similarly, the H-bridge is connected to power source +V 2  by a dual-operating switch, like switch  71 C and  91 C. And, the H-bridge is controlled by logic output of a pair of OR gates, like OR gates  208  and  209 . The details of operation of the H-bridge in electronic circuit  154  ( FIG. 6F ) substantially duplicates the operation of the electronic circuit  151  ( FIG. 6C ) except for the use of a single motor  52  having a reversible drive, rather than a pair of motors like motors  77  and  90  of electronic circuit  151 . The difference in these electronic circuits regarding operation is in the operation of the logic of each circuit in the control of operation of the OR gates providing an input to the H-bridge. 
   The logic providing an output at AND gates  233  and  237  of the height adjustment circuit for controlling the height of the lift bar, at AND gates  263  and  267  of the outrigger extension/contraction circuit, and at AND gates  293  and  297  of the engage/disengage drive mechanism circuit differ somewhat in connection with the security features incorporated into the logic circuit, but the circuit controlled by the logic applications is the same as the circuit discussed in connection with the discussion of  FIG. 6C . 
   Turning to the height adjustment circuit for controlling the height of the lift bar ( FIG. 6D ), the user of the walker apparatus in both the basic powered and virtual modes selects either the left-side switch  138  or the right-side switch  139  to commence movement of the lift bar assembly for adjustment or any other purpose. At that point in time, a selection of a particular function may be made, such as extending or retracting the lift bar assembly. The selection may be made by moving control switch  72 , assuming the left-side switch  138  was selected to extend the lift bar assembly or retract the lift bar. The same selection may be made by moving control  92 , assuming the right-side switch  139  was selected. 
   The same safety features incorporated in the walker apparatus, as discussed above, affect the operation of the logic in both the basic powered and virtual modes of operation in control of the circuit for the height adjustment capability. 
   Under the criteria previously discussed, each of AND gates  233  and  237  recognize an input and provide an output to one or the other of OR gates  238  and  239  if the safety switches responsive to conditions of proper assembly of components that permit receipt of a locking mechanism, and fully extended leg segment and lift bar section components are “on”, and in the lowering mode the left-side lift motor cut-off switch  89  is not engaged, the right-side motor cut-off switch  100  is not engaged, and the drive mechanism  20  is in the disengaged mode with switch  136  engaged. 
   Turning to the outrigger extension/contraction circuit ( FIG. 6E ), the user of the walker apparatus in both the basic powered and virtual modes selects either the left-side switch  138  or the right-side switch  139  to commence operation in extension/contraction of the outrigger legs. At that point in time, a selection of a particular function may be made, such as extending or retracting the outrigger legs. The selection may be made by moving control switch  72 , assuming the left-side switch  138  was selected to extend or retract the outrigger legs. The same selection may be made by moving control switch  93 , assuming the right-side switch  139  was selected. 
   The same safety features incorporated in the walker apparatus, as discussed above, affect the operation of the logic in both the basic powered and virtual modes of operation in control of the circuit for adjusting (expansion or contraction) of the outrigger legs. 
   Under the criteria previously discussed, each of AND gates  263  and  267  recognize an input and provide an output to one or the other of OR gates  268  and  269 . 
   Turning to the engage/disengage drive mechanism circuit ( FIG. 6F ), the user of the walker apparatus in both the basic powered and virtual modes selects either the left-side switch  138  or the right-side switch  139  to commence the function to perform, i.e., the engagement or disengagement of the drive of the steering mechanism. The selection may be made by moving control switch  73 , assuming the left-side switch  138  was selected to engage the steering mechanism or disengage the steering mechanism. The same selection may be made by moving control switch  94 , assuming the right-side switch  139  was selected. 
   Again, the same safety features incorporated in the walker apparatus, as discussed above, affect the operation of the logic in both the basic powered and virtual modes of operation in control of the circuit for engagement/disengagement of the steering mechanism. 
   Under the criteria previously discussed, each of AND gates  293  and  297  recognize an input and provide an output to one or the other of OR gates  298  and  299 . To this end, AND gates  290  and  294  each provide an output when the components are properly assembled and a locking mechanism is install to secure the components, both of the leg segments are fully extended, and both the left-side lift motor cut-off switch  89  and right-side motor cut-off switch  100  are not engaged. 
     FIG. 6G  illustrates the details of the electronic circuit providing the drive mechanism a measure of steering capability. The particular mode of operation of basic powered or the virtual mode of operation is determined, once again, by selecting either the left-side switch  140 A, or the right-side switch  141 A. Once a selection is made, either the left-side switch  138  or left-side switch  139  is controlled to start the steering control for the drive mechanism unit  20 . 
   A potentiometer  76 , if the left-side switch  138  is selected, induces the drive unit acting through a servomotor to turn in a direction, either left or right. Alternatively, a potentiometer  96 , if the right-side switch  139  is selected, induces the same steering capability. A servomotor, unlike a DC motor, is specifically designed for position control applications. 
   The circuit of  FIG. 6G  includes a timer chip  350  whose function is to generate pulses whose widths vary in length. If the pulse width increases the servo moves counter-clockwise, and if the pulse width decreases the servo moves clockwise. A resistor/capacitor network including resistors  321 ,  351  and the potentiometer combination  76 / 96  and capacitor  355  determine the width duration of each pulse. A resistor  353  and capacitor  355  determine the dwell time between pulses. The angular position of the servomotor is determined by the width (more precisely, the duration of the width) of each pulse. The actual length of the pulse varies with each specific servomotor model. 
   The potentiometer  76 / 96  provides varying voltage to a timer chip  350  for generation of pulses of varying widths. The control circuit within the servomotor correlates the voltage with timing of the incoming digital pulses and generates an error signal if the voltage is incorrect. The error signal is proportional to the difference between the position of the potentiometer and the timing of the incoming timing signal. To compensate, the error signal turns the motor. When voltage from the potentiometer and the timing of the digital pulses match, the error signal generated is zero and the motor stop turning. The servomotor unit in this circuit is denoted as component  59 . 
     FIG. 6H  illustrates the details of the peed speed control electronic unit  156  which is adapted for use with the virtual mode of operation to provide steering control to the servomotor  59 . The user in this adaptation provides sensor information from a shoe-like comprising an aspect of the invention to a transceiver unit  480 A and  480 B, or a transceiver unit  580 A and  580 B. The transceiver unit selected controls microprocessor  190  through UART unit  189 . The output of the microprocessor controls digital potentiometer  191 . Any stray signals are removed by capacitor  193 . 
   The digital potentiometer  191  is connected to timer chip  194  for purposes of generation of pulses of varying width. As indicated, as the pulse increases in width (more precisely, in duration) the servomotor moves counter-clockwise, and when the pulse decreases in width the servomotor moves clockwise. The duration of the pulse width is determined by a resistor/capacitor network including of digital potentiometer  191  and capacitor  195 ; the dwell duration is determined by resistor  192 . The angular position of the servomotor is determined by the width of the pulse that may vary with each servomotor model. 
   The timer chip  194  generates a pulse of varying width in response to the output of the digital potentiometer  191  that varies voltage level. The control circuit within the servomotor correlates the voltage with the timing of the incoming digital pulses and generates an error signal if the voltage is incorrect. The error signal is proportional to the difference between the position of the potentiometer and the timing of the incoming signal. To compensate, the error signal turns the servomotor. When the voltage from the potentiometer and the timing of the digital pulses match, the error signal generated is zero and the servomotor stop turning. The servomotor unit is component  59  of  FIG. 6G . 
     FIG. 6I  illustrates the forward/reverse electronic circuit  158  used in both the basic powered and virtual mode configurations of the walker apparatus. In a manner like the selection process previously described in electric circuit  157 , the user selects either left-side switch  140 B, or the right-side switch  141 B, to connect the power drive of the circuit to a source of power at +V 1 . The circuit is adapted to introduce the capability of speed control for the power drive. 
   A NAND gate  330  functions as an astable multivibrator or pulse generator for generating pulses of varying width or duration. A potentiometer  342  is controlled for controlling increases and decreases in the duration of the pulses at the output of NAND gate  330 D. The longer the duration of each pulse, the faster the drive of motor  62 . On the other hand, the shorter the duration of each pulse, the slower the motor speed. Speed therefore is determined by the power input to motor  62 . 
   The circuit includes an H-bridge MOSFET circuit to increase the power output. MOSFET circuits do not require resistors for purpose of proving bias, and can carry higher currents than standard transistors. 
   The direction of drive of the motor is determined by the voltage applied to NAND gate  330 A. 
   The user selects either the left-side switch  132  or the right-side switch  133  to select the direction that the walker apparatus will travel. The circuit of  FIG. 6J  provides directional control for the power drive. The direction of the reversible motor  62  is determined by the H-bridge network including the following components: MOSFETs  331 ,  333 ,  337 ,  339 , and  340 ; diodes  332 ,  334 ,  336 , and  338 ; NAND gate  330 B; and capacitors  343  and  374 . The H-bridge is wired in such a way that only two MOSFETs are “on” at any time. When MOSFETs  331  and  338  are “on”, the motor  62  turns in one direction; when MOSFETs  333  and  337  are “on”, the motor  62  turns in the other direction. When all the MOSFETs are “off”, the motor does not turn. 
     FIG. 6J  illustrates the electronic circuit  159  which is used in the virtual mode configuration of use of the walker apparatus. The user selects either the left-side switch  140 C or the right-side switch  141 C to connect digital potentiometer  196  (used in replacement of potentiometer  342  in the electronic circuit  157 ) to a microprocessor  190 . Transceiver units  480 A and  480 B, transceiver units  580 A and  580 B, are also connected to the microprocessor  190  via UART unit  189 . Right-hand pressure  127  and left-hand pressure sensor  150  provide pressure inputs that the user applies to the virtual mode adaptation of the walker apparatus. These inputs along with inputs from the shoe-like sensor determine the speed and direction of movement of the walker apparatus in the virtual mode adaptation. The output of the microprocessor controls digital potentiometer  196  for purpose of speed control. 
     FIG. 6K  illustrates a power supply for the walker portion of the walker apparatus. A source of power  180  of any type, such as a battery, fuel cell, hybrid, and so forth powers the apparatus. A grouping of capacitors  181 ,  182 ,  185 , and  186  provide a filtering capability to remove any high and low frequency ripples that may be present at the voltage output. A voltage regulator module  183  produces +V 1  and voltage regulator  187  produces +V 2 . Capacitors  184  and  185  remove any voltage spikes generated by voltage regulators  183  and  187 . 
   Virtual Mode of Operation 
     FIG. 7A  illustrates the bottom surface of a shoe-like portion (particularly the left shoe-like portion, hereafter referred to as the “left shoe”). A sole plate  401  is supported by the left shoe and, in turn, supports in an embedded manner a plurality of sensors, each at critical locations, capable of generating information used in the control of operation of the walker apparatus in the virtual mode configuration of the present invention. More particularly, the sole plate unit  401  supports the sensor in paired arrangements across the width of the sole plate, in front of the location of the arch, in region generally of the ball of the foot, and on opposite sides of the main axis through the foot from heel to toe. A first pair of sensors  431  and  432  comprises pressure sensors within locations closest to the main axis. The remaining sensors of each pair are located laterally outward of the pressure sensors  431  and  432 , and include X-axis accelerometer sensors  435  and  436 , Y-axis accelerometer sensors  440  and  441 , and Z-axis accelerometer sensors  444  and  445 . 
   A piezo-electric generator element  407  is embedded into and extends across the width of the sole plate unit  401  further toward the heel section  408 , preferably in the region of transition from the arch to the heel. An electronics package  402  is embedded in the sole plate  401  to the rear of piezo-electric generator element  407 , and also extends across its width of the heel portion  408 . 
   A grouping of paired sensors in an arrangement like the arrangement to the front of the left shoe is also supported by the sole portion  401  within the heel portion  408 . The sensors include a second pair of pressure sensors  433  and  434  in the same general location of the sensors  431  and  432 , relative to the main axis. The additional sensors of each pair disposed laterally outward of the pressure sensors  433  and  434  include X-axis accelerometer sensors  437  and  438 , Y-axis accelerometer sensors  442  and  443 , and Z-axis accelerometer sensors  446  and  447 . 
   The output signal from each pressure sensor  431 ,  432 ,  433  and  434 , as well as the signal outputs from the X-, Y-, and Z-axis accelerometers  435 - 438 , and  440 - 447  are sent to a microprocessor unit  451  for processing. 
     FIG. 7B  illustrates the top of the left shoe and a shoe liner  403 . The shoe liner  403  is in the form of a wrap received over the shoe, extending around the heel, forward of the instep region on opposite sides of the ankle, and toward and around the toe. The wrap overlaps along a slit edge  406  and may be secured in place by a strap  405  which may be a cooperating Velcro® type material. An antenna element  404  is built into the material of the shoe liner in position to surround the ankle for transmission and reception of RF signals. 
     FIG. 7C , the side view of the left foot configuration, illustrates the sole plate unit  401 , the electronics package  402 , piezo-electric generator element  407 , shoe liner  403 , and heel section  408 . 
     FIGS. 7D-7F  illustrate the right shoe, duplicating exactly, except for the different foot, the illustrations off  FIGS. 7A-7C  and the previous discussion of several structural configurations, the location of structure, and both the purposes and aims achieved by the structures. To this end,  FIG. 7D  illustrates the bottom surface of a shoe-like portion (particularly the right shoe-like portion, hereafter referred to as the “right shoe”). A sole plate is supported by the right shoe and, in turn, supports in an embedded manner a plurality of sensors, each at critical locations, capable of generating information used in the control of operation of the walker apparatus in the virtual mode configuration of the present invention. 
   As discussed, a sole plate  411  supports front and rear sensors  531 ,  532 , and  533 ,  534 , front and rear X-axis accelerometer sensors  535 ,  536 , and  537 ,  538 , front and rear Y-axis  540 ,  541  and  542 ,  543 , and Z-axis accelerometer sensors  544 ,  545  and  546 ,  547 . In addition, sole plate supports a piezo-electric generator element  417  and an electronics package  412 . 
     FIG. 7E  duplicates  FIG. 7B  and illustrates the right shoe and shoe liner  413 . The shoe liner  413 , the manner of attachment of the wrap at  415 , and the antenna element  414  each duplicate similar structure and functions as illustrated and described in  FIG. 7B .  FIG. 7F  duplicates  FIG. 7C  and illustrates a side view of the right foot configuration including sole plate  411 , the electronics package  412  and piezo-electric generator element  417 , both embedded in the sole plate  411 , shoe liner  413 , and heel section  418 . 
     FIG. 8A  is a block diagram for the left foot electronics package configuration. Signals from the several sensors, left foot, and both the front and rear locations, including pressure sensors  431 , . . . , X-axis accelerometer sensors  435 , . . . , Y-axis accelerometer sensors  441 , . . . , and Z-axis accelerometer sensors  444 , . . . are connected to a sensor input sub-system  420 . The outputs from the sensor sub-system  420  in turn are connected to either IR transmitter unit  480 A or RF transmitter unit  480 B through controller sub-system  450  and encoder sub-system  460 . Power sub-system provides the necessary energy to operate the electronics package  402 . 
     FIG. 8B  is a block diagram for the right foot electronics package configuration. Signals from the several sensors, right foot, and both the front and rear locations, including pressure sensors  531 , . . . , X-axis accelerometer sensors  535 , . . . , Y-axis accelerometer sensors  541 , . . . , and Z-axis accelerometer sensors  544 , . . . are connected to a sensor input sub-system  520 . The outputs from the sensor sub-system  520  in turn are connected to either IR transmitter unit  580 A or RF transmitter unit  580 B through controller sub-system  550  and encoder sub-system  560 . Power sub-system provides the necessary energy to operate the electronics package  412 . 
     FIG. 9A  is a block diagram of the sensor input to sub-system  420  generated by the sensors supported on the left foot. Sensor signals from the pressure sensors  431 - 434  are connected to input buffer unit  421 , sensor signals from X-axis accelerometer sensors  435 - 438  are connected to input buffer unit  422 , sensor signals from Y-axis accelerometers  440 - 443  are connected to input buffer unit  423 , and sensor signals from Z-axis accelerometer sensors  444 - 447  are connected to input buffer unit  424 . These sensors generate varying DC voltages, which relate linearly to the pressure that is applied to each sensor, mounted respectively to the front and rear of the insole plate unit  401 . 
     FIG. 9B  is a block diagram of the sensor input to sub-system  520  generated by the sensors supported on the right foot. Sensor signals from the pressure sensors  531 - 534  are connected to input buffer unit  521 , sensor signals from X-axis accelerometer sensors  535 - 538  are connected to input buffer unit  522 , sensor signals from Y-axis accelerometers  540 - 543  are connected to input buffer unit  523 , and sensor signals from Z-axis accelerometer sensors  544 - 547  are connected to input buffer unit  524 . These sensors generate varying DC voltages, which relate linearly to the pressure that is applied to each sensor, mounted respectively to the front and rear of the insole plate unit  411 . 
     FIG. 10A  is a block diagram of the operation of controller sub-system  450  in response to the signals generated by the sensors in the left shoe. Sensor signals within the sensor input sub-system  420  convert the DC voltage analog signals into parallel digital signals, which are then connected to the microprocessor unit  451 . Computer programs are stored in memory unit  452  which process these digital signals from the sensor and generate gait parameters which are stored in memory unit  452  or are transferred to UART unit  454 . The 555-timer unit  453  provides timing for the microprocessor unit  451  and sleep mode control for the electronics package  402 . The microprocessor unit  451  interfaces with encoder sub-system  460  by means of the UART unit  454 . The microprocessor can be directly accessed via the input/output jack  455  by means of the UART unit  454 , which can provide programming instruction to memory unit  452  or be able to access data from memory unit  452  via the microprocessor  451 . 
     FIG. 10B  is a block diagram of the operation of controller sub-system  550  in response to the signals generated by the sensors in the right shoe. Likewise, sensor signals within the sensor input sub-system  520  convert the DC voltage analog signals into parallel digital signals, which are then connected to the microprocessor unit  551 . Computer programs are stored in memory unit  552  which process these digital signals from the sensor and generate gait parameters which are stored in memory unit  552  or are transferred to UART unit  554 . The 555-timer unit  553  provides timing for the microprocessor unit  551  and sleep mode control for the electronics package  412 . The microprocessor unit  551  interfaces with encoder sub-system  560  by means of the UART unit  554 . The microprocessor can be directly accessed via the input/output jack  555  by means of the UART unit  554 , which can provide programming instruction to memory unit  552  or be able to access data from memory unit  552  via the microprocessor  551 . 
     FIG. 11A  shows the overall block diagram of the left foot encoder sub-system  460 . A microprocessor is connected to remote control encoder unit  461 , where resistors  462  and  464  and capacitor  463  set the frequency of the on-chip oscillator which in turns controls the width of the transmitted pulse. The output of the remote control encoder unit  461  is connected to either the IR transmitter sub-system  480 A or the RF transmitter sub-system  480 B. 
     FIG. 11B  shows the overall block diagram of the right foot encoder sub-system  560 . A microprocessor is connected to remote control encoder unit  561 , where resistors  562  and  564  and capacitor  563  set the frequency of the on-chip oscillator which in turns controls the width of the transmitted pulse. The output of the remote control encoder unit  561  is connected to either the IR transmitter sub-system  580 A or the RF transmitter sub-system  580 B. 
     FIG. 12A  is the schematic diagram for the power unit  470  for the left foot electronics package  402 . Piezo-electric transducer  471 A and  471 B generate an AC voltage when they are compressed or they expand which is rectified by the bridge diodes  472 A,  472 B,  472 C, and  472 D and connected by load resistor  473  to an energy storage capacitor  474 . The energy storage capacitor  474  stores the rectified power to a predetermined energy level. At this energy level the output of the energy storage capacitor  474  is connected to voltage regulator unit  475  which is in turn is connected to battery unit  477 . Capacitor  474  provides filtering to the rectified DC from energy storage capacitor  474 . The battery unit  477  in turn is connected to another voltage regulator unit  478 , which is set to provide the correct DC voltage to the electronics package  402 . Capacitor  479  provides additional filtering of DC output from voltage regular unit  478 . Switch  456  is the on/off switch for the electronics package  402 . Jack  476  is the input connector for an external battery-charging unit (not shown). 
     FIG. 12B  is the schematic diagram for the power unit  570  for the right foot electronics package  412 . Piezo-electric transducer  571 A and  571 B generate an AC voltage when they are compressed or they expand which is rectified by the bridge diodes  572 A,  572 B,  572 C, and  572 D and connected by load resistor  573  to an energy storage capacitor  574 . The energy storage capacitor  574  stores the rectified power to a predetermined energy level. At this energy level the output of the energy storage capacitor  574  is connected to voltage regulator unit  575  which is in turn is connected to battery unit  577 . Capacitor  574  provides filtering to the rectified DC from energy storage capacitor  574 . The battery unit  577  in turn is connected to another voltage regulator unit  578 , which is set to provide the correct DC voltage to the electronics package  412 . Capacitor  579  provides additional filtering of DC output from voltage regular unit  578 . Switch  556  is the on/off switch for the electronics package  412 . Jack  576  is the input connector for an external battery-charging unit (not shown). 
     FIG. 13A  is the schematic and block diagram of the IR transmitter sub-system  480 A for the left foot. The digital output from remote control encoder unit  461  is connected to CMOS NAND gate  481 . A timing chip  482  set the modulation rate of the IR transmitter lamp  490 . Resistors  483  and  484  and capacitor  485  determine the modulation frequency. Capacitor  486  set the control voltage within the timing chip  482 . The output of CMOS NAND  481  is connected to a limiting resistor  487 , which is connected to a NPN transistor  488 . Resistor  487  limits the base current in the NPN transistor  488 . The resistor  489  limits the current through the collector of the NPN transistor  488 . 
     FIG. 13B  is the left foot schematic diagram of the RF transmitter unit  480 B. The digital output of the remote control encoder unit  461  is connected to RF transmitter unit  492  by coupling resistor  491 . While capacitor  493  is the DC bypass capacitor to shunt any unfiltered DC to ground. Capacitors  494  and  495  are RF bypass capacitors to shunt any stray RF. RF coils  496  and  497  are used to tune the antenna element  498 . RF coil  497  is used as a shunt-tuning coil, while RF coil  496  is used as a series-tuning coil. 
     FIG. 13C  is the schematic and block diagram of the IR transmitter sub-system  580 A for the right foot. The digital output from remote control encoder unit  561  is connected to CMOS NAND gate  581 . A timing chip  582  set the modulation rate of the IR transmitter lamp  590 . Resistors  583  and  584  and capacitor  585  determine the modulation frequency. Capacitor  586  set the control voltage within the timing chip  582 . The output of CMOS NAND  581  is connected to a limiting resistor  587 , which is connected to a NPN transistor  588 . Resistor  587  limits the base current in the NPN transistor  588 . The resistor  589  limits the current through the collector of the NPN transistor  588 . 
     FIG. 13D  is the right foot schematic diagram of the RF transmitter unit  580 B. The digital output of the remote control encoder unit  561  is connected to RF transmitter unit  592  by coupling resistor  591 . While capacitor  593  is the DC bypass capacitor to shunt any unfiltered DC to ground. Capacitors  594  and  595  are RF bypass capacitors to shunt any stray RF. RF coils  596  and  597  are used to tune the antenna element  598 . RF coil  597  is used as a shunt-tuning coil, while RF coil  596  is used as a series-tuning coil. 
     FIG. 14A  is the schematic diagram of the remote IR receiver unit  600 . The IR signals from the IR transmitters units  480 A and  580 A are detected by IR receiver module  601  and outputted to a NAND gate  602  which is connected to the remote control decoder unit  605 . In order to match the IR transmitter oscillator frequency, resistor  603  and capacitor  604  set the timing that discriminates between narrow and wide pulses. Resistor  606  and capacitor  607  set the timing that detects the end of an encoded word and the end of a transmission. The output from the remote control decoder unit  605  is connected to a microprocessor  631 . 
     FIG. 14B  is the remote RF receiver unit  610 . The digital outputs from the RF transmitter units  480 B and  580 B are detected antenna  611 , which is then connected to the RF tuning coils  612  and  613 . RF coil  613  is used as a shunt-tuning coil, while RF coil  612  is used as a series-tuning coil. The output is the feed into receiver module  615 . The output is the connected to a coupling resistor  620 , which in turn is connected to a bipolar NPN transistor  621 , a buffer amplifier, which provides buffering between the receiver module  615  and the remote control encoder unit  605 . This in turn is connected to microprocessor unit  631 . Resistor  622  is the current limiter in buffer amplifier  621 . Capacitor  614  is to provide as a RF bypass. Capacitor  619  provides coupling of internal components within the receiver module  615 . Resistor  616  sets the modulated pulse rate, while resistor  617  sets the modulated pulse width. Resistor  618  sets the low pass filter circuit. 
     FIG. 15  is the block diagram for the remote electronics configuration for the apparatus. The remote electronics configuration of the apparatus comprises of digital and control inputs from the remote decoder units  605  and  608 , which is connected to microprocessor  631 . Programming and data storage is provided by memory unit  632 . Outputs from the microprocessor unit  631  are connected to UART  633 , which in turn is connected to several choices of outputting devices. These include cassette recorder unit  640  or solid state recorder  650  or remote storage device  670  or remote computer terminal  660  or virtual walker  680 . 
   The remote computer terminal  660  allows a qualified practitioner to program the microprocessor unit(s)  431 ,  531  and/or  631  for specific settings for the control of the apparatus by the user. The input/output UART unit  633  provides a communication path for transferring data to and from the microprocessor unit  631 . 
   The microprocessor units  431 ,  531  and  631  have memory in the form of a multi-section storage memory. The memory stores at least one program that dictates the desired maximum speed of the apparatus. The microprocessor memory can also store a plurality of programs of different parameters, where the programs are selectable automatically or external inputs via the remote computer terminal  633  inputs. The programs are preferably stored in secure memory. Alternately, the microprocessor units  431 ,  531  and  631  can be programmed by an external programming source to adjust the parameters by which the apparatus will operate. The external programming will come via some external-programming source such as an external computer. This allows a qualified practitioner to program the microprocessor for specific needs of the user. Data of interest to the clinician (such as user&#39;s stride, force differentials between limbs and etc.) is stored in data storage units  640 ,  650  and/or remote computer terminal  660 . 
   All RF transmissions are subject to noise, interference and fading. Most short-range RF wireless data communications use some form of packet protocol to automatically assure information is received correctly at the correct destination. A packet generally includes a preamble, a start symbol, routing instruction, packet ID, message segment, error correct bits, and other information (if required). Various correction schemes can be employed to minimize transmission errors. 
   In describing the invention, reference has been made to a preferred embodiment and illustrative advantages of the invention. Those skilled in the art, however, and familiar with the instant disclosure of the subject invention, may recognize that numerous other modifications, variations, and adaptations may be made without departing from the scope of the invention. With these modifications, variations and adaptations can be applied to the various units within the apparatus.