Abstract:
An upright wheeled walker with bilateral stabilizing wheel suspensions, and an automatic braking system integrated with obstacle avoidance systems, terrain sensors and user feedback controls. The walker provides user upper body weight support in a wheeled walker with a user safety system including a plurality of sensor, processor and control elements and an automatic braking system for avoiding unseen obstacles and automatic speed limiting on inclines.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application is filed under 35 U.S.C. §111(a) pursuant to 37 C.F.R. §1.53(b) claiming the benefit under 35 U.S.C. §119(e) of Provisional Patent Application No. 62/308,050 filed on Mar. 14, 2016, which is entirely incorporated herein by reference. 
         [0002]    This application is related by common inventorship and subject matter to the commonly-assigned U.S. patent application Ser. No. 15/012,784 filed on Feb. 1, 2016, which is entirely incorporated herein by reference. 
         [0003]    This application is related by common inventorship and subject matter to the commonly-assigned U.S. patent application Ser. No. 15/148,993 filed on May 6, 2016, now U.S. Pat. No.______, which is entirely incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0004]    1. Field of the Invention 
         [0005]    This invention relates generally to mobility-assistance devices and more particularly to a smart upright walker that facilitates a natural upright gait and provides haptic signaling to the user responsive to obstacle sensor signals. 
         [0006]    2. Description of the Related Art 
         [0007]    Assistive mobility devices, including walkers, are well-known in the art as useful means for reducing the disadvantages of mobility limitations suffered by many people, permitting more efficient ambulation over distance and thereby increased independence. Data from the National Long Term Care Survey suggests that increased use of assistive technology may have helped reduce disability at older ages [Manton, et al., Changes in the Use of Personal Assistance and Special Equipment from 1982 to 1989: Results from the 1982 and 1989 NLTCS,  Gerontologist  33(2):168-76 (April 1993)]. Although mobility device users represent a relatively small minority of the population with disabilities, their importance transcends their numbers because mobility devices are visible signs of disability and have become symbols of the very idea of disability. And the mobility-impaired population is increasing much faster than the general population [LaPlante et al., Demographics and Trends in Wheeled Mobility Equipment Use and Accessibility in the Community,  Assistive Technology,  22, 3-17, (2010)]. Accordingly, there has long been a growing demand in the U.S. and throughout the world for improved mobility assistance devices adaptable for improving ambulation for rapidly growing numbers of mobility-limited persons. 
         [0008]    Martins et al. [Martins et al., Assistive Mobility Devices focusing on Smart Walkers: Classification and Review,  Robotics and Autonomous Systems  60 (4), April 2012, pp. 548-562] classify mobility assistance devices as Alternative Devices (for users with total in-capacity) and Augmentative Devices (for users with residual mobility). Mobility and manipulation are critical to living independently and are often strongly associated with the ability to continue to live safely in one&#39;s home. Simple augmentative devices such as walkers and rollators (wheeled walkers) can assist an impaired person who has the endurance and strength to walk distances, but many also need some support and feedback to avoid loss of balance and to enable the person to rest when necessary. Although the impaired individual eventually may be obliged to use more elaborate alternative devices such as wheelchairs and powered mobility devices, most people strongly desire to retain the independence of a simpler augmentative device for as long as possible. For this reason, there is a well-known need for improvements that permit the simpler wheeled walker to facilitate the natural upright ambulation of progressively larger numbers of impaired individuals. 
         [0009]    Of the many different solutions proposed by practitioners of the art, an important approach to mobility assistance is the so-called Smart Walker. By allowing the user varying degrees of control, from complete to collaborative, these intelligent wheeled walkers afford the user with the feeling of control, while improving the ease and safety of their daily travels. The control systems of these walkers differ from those of other mobility aids and robots because they must both assist mobility and provide balance and support. See, for example, Wasson et al., Effective Shared Control in Cooperative Mobility Aids,  Proc.  14 th Int. Florida Artificial Intelligence Research Society Conf  May 2001, pp. 5509-518. 
         [0010]    Although popular, the most common augmentative devices known in the art have many well-known disadvantages; even for relatively capable individuals. The typical wheeled walker known in the art has many well-known disadvantages; such as requiring a stooping or a forward leaning posture and a hobbled gait, difficulty in smooth transition of irregular terrain, offering little or no upper body and arm support, and requiring significant hand and arm strength to maneuver and operate the hand brakes when available, for example. Obliging the user to stoop over and lean forward to use a walker, which stresses the user&#39;s back and arms, also risks tipping forward when encountering obstacles. And most wheeled devices known in the art have one or more supports without wheels or with wheels too small to safely negotiate even small surface irregularities. Some devices are too heavy and awkward for an unassisted impaired user to lift into a car trunk or van, which limits independent unassisted use. Wheeled walker brakes are often either nonexistent or ineffective for the unassisted impaired user, which risks falls and injury and limits independence. 
         [0011]    The typical wheeled walker known in the art is neither designed nor intended to support significant user weight during use for walking. Both designer and user assume without critical thought that the wheeled walker purpose is simply to provide assistance in balance and gait; like an elaborate cane system. So the user is generally obliged to reach down and engage the walker with hands and wrists alone, often with a stooping or leaning posture. The impaired user generally lacks the hand and wrist strength needed to continuously support significant upper body weight while walking in a stooped or forward-leaning position. The mobility assistance art is replete with suggestions for improving wheeled walkers to mitigate one or more of these well-known problems. 
         [0012]    For example, in U.S. Pat. No. 8,100,415, Kindberg et al. disclose a wheel suspension that facilitates curb climbing when used with large wheels in, for example, a rollator. But Kindberg et al. limit their teachings to negotiating uneven terrain such as curbs. In U.S. Pat. No. D561,065, Kindberg et al. also disclose a walker frame design. 
         [0013]    And, for example, in U.S. Pat. No. 8,840,124, Serhan et al. disclose a safety brake in a rollator that improves the safety of seated users by using a braking system that locks the rollator wheels when the user sits down on the rollator seat, and releases the wheels when the user stands up. As another example, in U.S. Pat. No. 7,052,030, Serhan discloses a wheeled walker with cross-member supports adapted to permit both seat and basket with wheel sizes greater than seven to eight inches. In U.S. Pat. No. 6,886,575, Diamond discloses a locking assembly for use with a walker having foldable side members. And, for example, in U.S. Pat. No. 8,678,425, Schaaper et al. disclose a wheelchair having a moveable seat element facilitating use as a rollator. 
         [0014]    In U.S. Pat. No. 8,740,242, Slomp discloses a posterior walker configured to encourage a neutral spine during use. And, for example, in U.S. Pat. No. 7,559,560, Li et al. discloses a rollator having a foldable seat element. 
         [0015]    Some practitioners propose improving the walker mobility aid by adding upper support means for supporting the user&#39;s forearms, hands or shoulders to improve user comfort and posture. For example, in U.S. Pat. No. 5,657,783, Sisko et al. disclose accessory forearm rests that may be mounted to any conventional invalid walker, preferably disposed above the normal hand-grips to provide support for the user&#39;s arms. 
         [0016]    Such an upright wheeled walker may permit the user to walk upright but the wheeled walker known in the art is not adapted to support any user body weight beyond the relatively small portion in the forearms and hands. For example, in U.S. Pat. No. 8,540,256, Simpson discloses a walker with a forearm support frame to permit an upright user to step forward with the walker footprint but little weight bearing capacity. 
         [0017]    Introducing ergonomic upper-body support in a wheeled walker is advantageous because it facilitates better walking and standing posture, improved gait and comfort. But adding significant user body weight to the wheeled walker during use is also disadvantageous because the increased weight borne on each wheel during use affects walker stability, braking, and terrain handling, all functions that affect user safety. For example, adding significant upright weight support to the wheeled walker introduces the new disadvantages of lateral and longitudinal instability during use and thus imperils user safety. Any wheeled walker has longitudinal stability problems when rolling on slopes and over irregular terrain, which may imperil user safety by causing falls during use. This longitudinal instability problem is exacerbated by adding upright weight support because of increased wheel loads imposed by the applied user weight, which not only increases unwanted longitudinal instability but introduces a new lateral instability arising from alternating wheel load fluctuations created by the stepping of a weight-supported user. 
         [0018]    Instead of proposing solutions to these new stability problems, practitioners have generally offered various powered vehicles to facilitate some weight-bearing in assistive devices with sufficient weight and stability for user safety. For example, in U.S. Pat. No. 8,794,252, Alghazi discloses a mobility apparatus with an integrated power source and four wheels so a user can stand on it and drive it as an electric mobility device, or disable it and use it as a passive walker. His device is collapsible and includes a pair of supporting beams disposed to support the user weight under the armpits, but such support does little to improve user posture or stability. 
         [0019]    Similarly, for example, in U.S. Pat. No. 8,234,009, Kitahama discloses an autonomous mobile apparatus that moves autonomously along near a specified person (user) while detecting and evaluating the surroundings to assess the danger level to the user, moving as necessary to avoid danger to the user based on the danger level detected. But such devices are generally perceived as alternative devices (such as powered wheel chairs, stair climbers and vehicles) by the user and do not represent improvements to the assistive devices preferred by most users. 
         [0020]    In U.S. Pat. No. 7,708,120, Einbinder discloses a useful improvement to user safety consisting of a walker braking system using a controller and electrically actuated wheel brakes to provide push-button user control over braking and processor-controlled braking responsive to, for example, user hand position and the terrain slope. But Einbinder limits his teachings to braking control systems and neither considers nor suggests upright posture, weight-support, lateral stability nor haptic user feedback. 
         [0021]    These and other examples of the mobility assistance art demonstrate that there is a continuing long-felt need for improved solutions to the walking posture, upper body weight support and user safety problems discussed above. 
         [0022]    These unresolved problems and deficiencies are clearly felt in the art and are solved by this invention in the manner described below. 
       SUMMARY OF THE INVENTION 
       [0023]    This invention solves the walking posture, upper body weight support and user safety problems by introducing for the first time an upright wheeled walker with bilateral stabilizing wheel suspensions, and an automatic braking system integrated with obstacle avoidance systems, terrain sensors and user feedback controls. 
         [0024]    It is an advantage of the walker of this invention that it provides significant user upper body support in a wheeled walker without lateral or longitudinal instability. 
         [0025]    It is a purpose of the walker of this invention to provide user upper body weight support in a wheeled walker with an automatic braking system for avoiding unseen obstacles and automatic speed control on inclines. 
         [0026]    It is an advantage of the walker of this invention that it provides automatic braking upon detection of the user departing from the user footprint when, for example, releasing the handles. 
         [0027]    It is a purpose of the walker of this invention to provide user upper body weight support in a wheeled walker with an automatic tactile feedback to the user signaling the presence of obstacles or hazards. 
         [0028]    It is a purpose of this invention to provide an upright wheeled walker that improves posture and comfort while also improving stability and safety through new automatic braking features and an intuitive haptic control system that facilitates safe use by users who may be otherwise too impaired to safely use the assistive motility devices known in the art. 
         [0029]    In one aspect, the invention is a wheeled walker for a user having one or more hands and forearms, comprising a frame having a front and a rear, an upper body support assembly coupled to the frame, including gutter means for supporting the one or more user forearms, and handle means for touching by the one or more user hands, a plurality of wheel assemblies coupled to the frame and disposed to support the frame on a surface and to define a polygonal footprint on the surface, each wheel assembly disposed at a vertex of the polygonal footprint and including one or more rear wheel assemblies each including a wheel disposed generally at the rear of the frame, and one or more front wheel assemblies each including a wheel disposed generally at the front of the frame, at least one sensor disposed to produce an obstacle detection signal responsive to the presence of an obstacle in the vicinity of the wheeled walker, a signal processor coupled to the sensor for producing a user alert signal responsive to the obstacle detection signal, and at least one kinetic motor coupled to the processor and disposed in the upper body support assembly to produce a haptic sensation in the user responsive to the user alert signal. 
         [0030]    The foregoing, together with other objects, features and advantages of this invention, can be better appreciated with reference to the following specification, claims and the accompanying drawing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]    For a more complete understanding of this invention, reference is now made to the following detailed description of the embodiments as illustrated in the accompanying drawing, in which like reference designations represent like features throughout the several views and wherein: 
           [0032]      FIG. 1  is an oblique view of a first exemplary embodiment of the upright wheeled walker of this invention having four wheel assemblies each defining one of the four vertices of a polygonal walker footprint; 
           [0033]      FIG. 2  is a functional block diagram showing an exemplary embodiment of a walker control system, including exemplary sensor, processor, controller and kinetic motor signal embodiments, suitable for use with the walker of this invention; 
           [0034]      FIG. 3  is a right side view of a second exemplary embodiment of the upright wheeled walker of this invention having four wheel assemblies each defining one of the four vertices of a polygonal walker footprint; 
           [0035]      FIG. 4  is a top view of the walker embodiment of  FIG. 1  illustrating the operation of several exemplary obstacle sensor embodiments responsive to several exemplary nearby obstacles in accordance with this invention; 
           [0036]      FIG. 5  is an oblique view of the upper body supporting elements of the walker embodiment of  FIG. 1  illustrating an exemplary embodiment of a plurality of handle and armrest kinetic motors suitable for providing haptic feedback signals to the user in accordance with this invention; 
           [0037]      FIG. 6  is an oblique view of the upper body supporting elements of  FIG. 5  illustrating exemplary dispositions of a graphical User Interface (GUI), processor assembly and user sensing camera suitable for use with the walker of this invention; 
           [0038]      FIGS. 7A-B  illustrates exemplary dispositions of haptic signaling elements and exemplary user hands and forearms while the user stands in a supported position within the footprint of the walker embodiment of  FIG. 1 ; 
           [0039]      FIGS. 8A-B  are sketches illustrating exemplary embodiments of a forward-looking infrared (IR) obstacle sensor and an audio speaker suitable for use with the walker of this invention; 
           [0040]      FIG. 9  is a functional block diagram of a first exemplary embodiment of a control system, including sensor output signals, processor signals, kinetic motor signals and kinetic motors, suitable for use with the walker of this invention; 
           [0041]      FIG. 10  is a functional block diagram of a second exemplary embodiment of a control system, including sensor output signals, processor signals, kinetic motor signals and kinetic motors, suitable for use with the walker of this invention; 
           [0042]      FIG. 11  is a schematic diagram of an exemplary infrared obstacle sensor detector circuit known in the art that is suitable for use with the walker of this invention; 
           [0043]      FIG. 12  is a schematic diagram of an exemplary sensor detection circuit known in the art that is suitable for use with the walker of this invention; 
           [0044]      FIG. 13  is a close-up oblique view of an exemplary left front wheel assembly embodiment from the upright wheeled walker of  FIG. 1 , including a hydraulic brake disk and caliper housing, suitable for use with the walker of this invention; 
           [0045]      FIG. 14  is a schematic diagram of an exemplary electrohydraulic braking system embodiment suitable for use with the walker of this invention; 
           [0046]      FIG. 15  is a close-up right side view of an exemplary right rear wheel assembly embodiment from the upright wheeled walker of  FIG. 3 , including a circumferential brake disk and braking element housing, suitable for use with the walker of this invention; 
           [0047]      FIG. 16  is a cross-sectional view of an exemplary embodiment of a circumferential braking system for the upright wheeled walker of  FIG. 3 , including a brake handle, hydraulic linkages and the circumferential disk and braking elements, suitable for use with the walker of this invention; 
           [0048]      FIG. 17  is an oblique view of the circumferential braking system embodiment of  FIG. 16 , including the brake handle, hydraulic linkages and the circumferential disk and braking elements, suitable for use with the walker of this invention; 
           [0049]      FIGS. 18A-B  illustrates an exemplary embodiment of an electromechanical fail-safe user braking control apparatus suitable for use with the walker of this invention; 
           [0050]      FIG. 19  is functional diagram illustrating an alternative embodiment of a Graphical User Interface (GUI) touch panel display suitable for use with the walker of this invention; and 
           [0051]      FIGS. 20A-F  are sketches illustrating several exemplary signal specifications, including an alternative haptic signal specification of haptic signal frequency versus obstacle distance, suitable for use with the walker of this invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0052]      FIG. 1  shows a first exemplary embodiment of an upright wheeled walker  100  with a frame  102  supported above a surface  104  on four wheel assemblies  106 A-D, which each define one of the (in this example) four vertices of a polygonal walker footprint  103  on surface  104 , and with an upper body support assembly  108 . Wheel assemblies  106 A-D may be appreciated with reference to the left front wheel assembly  106 B (see  FIG. 13 ), which includes a wheel  110 B and a wheel suspension assembly  112 B that is fixed to frame  102  at a junction  114 B. The polygonal walker footprint may, of course, be defined by three wheels located at three vertices or any larger number as well. 
         [0053]    During use, a user  300  (see  FIG. 7B ) stands between the two anterior frame elements  116 A-B within polygonal walker footprint  103  and grasps each of the upper handles  118 A-B with a respective hand  302 A-B ( FIG. 7B ) while resting a respective forearm  304 A-B ( FIG. 7B ) in each of the armrest gutters  120 A-B, thereby resting at least some weight on upright wheeled walker  100  and surface  104 . The user may then walk forward in the direction shown by the arrow  122  as upright wheeled walker  100  rolls over surface  104  while supporting at least some weight, thereby assisting the user to walk over surface  104 . 
         [0054]      FIG. 1  also illustrates an X-folder element  124  and an upper folder element  126  that are useful for collapsing upright wheeled walker  100  for convenient storage and transportation. The elevation adjusters  128 A-B are useful for adjusting the elevation of upper body support assembly  108  above surface  104  for a particular user height and each of the angle adjusters  130 A-B are useful for adjusting the angle of the respective upper handle  118 A-B. The lower handles  132 A-B are useful for several purposes such as providing user support when arising from a seated position (not shown), for example. 
         [0055]      FIG. 1  also shows exemplary dispositions for the various sensor, processor and control elements of walker  100 . For example, several small microwave Doppler sensors  134 A-D are shown (see also  FIG. 4 ) attached to a respective wheel suspension assembly exemplified by the microwave Doppler sensor  134 B shown attached to wheel suspension assembly  112 B. And the incline sensors  136 A-B are each shown attached to a respective lower frame element  138 A-B to detect longitudinal tilting of lower frame elements  138 A-B. The 3D infrared (IR) sensors  140 A-B are each shown attached to a respective posterior frame element  142 A-B to detect mid-level obstacles. A system controller assembly  144  is shown attached to one side of upper folder element  126  in a disposition permitting folding (not shown) of the walker without interference. A Graphical User Interface (GUI) display  146  is disposed within convenient reach of the user and a loud-speaker (not shown) for emitting audio signals to the user may also be provided nearby (see  FIG. 8A , for example). A simple optical sensor  148  is shown attached to upper body support assembly  108  in a position that operates as a user sensing means for producing a user detection signal responsive to a user disposed properly within the polygonal walker footprint. 
         [0056]    Finally,  FIG. 1  shows an exemplary disposition of a plurality of kinetic motors, exemplified by the kinetic motor  150 A in right armrest gutter  120 A, the kinetic motor  150 B in left armrest gutter  120 B, the kinetic motor  152 A in right upper handle  118 A and the kinetic motor  152 B in left upper handle  118 B (see also  FIG. 5 ). According to this invention the kinetic motors are disposed to provide haptic signaling to the user for a variety of purposes, such as alerting the user to obstacles and terrain hazards, suggesting a steering operation, for example. Similarly, the handle touch sensors  154 A-B are each shown disposed on a respective upper handle  118 A-B to produce a user touch signal responsive to touching of the respective upper handle  118 A-B by the user. According to this invention, this user touch signal may be used in a user safety controller ( FIG. 2 ) to operate an automatic electrohydraulic braking system ( FIGS. 13-14 ), for example. 
         [0057]    The various signal and power connections among the various sensor, processor and control elements attached to walker  100  are not shown in  FIG. 1  but may be appreciated with reference to the following  FIGS. 2-20 . 
         [0058]      FIG. 2  is a functional block diagram of an exemplary walker control system embodiment  149  illustrating the relationship among several control system elements and signals provided for automatic obstacle avoidance and user safety in an exemplary walker embodiment. The various elements are labeled with the numerals used above with respect to  FIG. 1 . Additionally, system controller assembly  144  includes a microprocessor  155 , with a Random Access Memory (RAM)  156  coupled by means of a digital data bus  157  to GUI  146  and the other elements substantially as shown. One such element is the electrohydraulic braking system  158  coupled to data bus  157 , which includes a braking controller  159 , a hydraulic system  160  for producing pressure in a hydraulic line  161 , and a plurality of caliper pistons  162 A-B each disposed to impose a braking force on a respective caliper assembly (see  FIGS. 13-14 ). Handle touch sensors  154 A-B are each shown producing a user touch signal that is coupled to microprocessor  155  by means of digital data bus  157 . Incline sensors  136 A-B are each shown producing an incline detection signal that is coupled to microprocessor  155  by means of digital data bus  157 . A plurality of kinetic motors exemplified by kinetic motors  150 A-B and  152 A-B are disposed ( FIG. 1 ) to produce a haptic sensation in the user responsive to a user alert signal  141  transferred on digital data bus  157 . Microwave Doppler sensors  134 A-B and 3D IR sensors  140 A-B each produce a respective obstacle detection signal exemplified by the obstacle detection signal  143 , which is also transferred on digital data bus  157  to microprocessor  155  for use in computing user alert signal  141 . A loudspeaker  163  may be coupled through an audio controller  164  to data bus  157  for creating audio response to a second user alert signal  145  as desired. User alert signals  141  and  145  are produced by microprocessor  155  according to a stored program from RAM  153  responsive to the several sensor output signals exemplified by obstacle detection signal  143  (see also  FIGS. 20A-F ). 
         [0059]    Finally,  FIG. 2  shows the plurality of kinetic motors exemplified by kinetic motors  150 A-B to each include a respective haptic controller  166 A-B to facilitate coupling to user alert signal  141  presented on data bus  157 . 
         [0060]      FIG. 3  shows a second exemplary embodiment of an upright wheeled walker  400  with a frame  402  supported above a surface on four wheel assemblies exemplified by wheel assemblies  406 A-B, which each define one of a plurality of vertices of a polygonal walker footprint on a surface (see the above discussion of  FIG. 1 ), and with an upper body support assembly  408 . The four wheel assemblies, exemplified by the visible wheel assemblies  406 A-B in  FIG. 3 , may be better appreciated with reference to  FIG. 15  detailing right rear wheel assembly  406 A, which includes a wheel  410 A and a wheel suspension assembly  412 A that is fixed to frame  402  at a junction  414 A. The circumferential brake housing  416 A housed and partially conceals a circumferential brake disk  506  and a circumferential braking element  508  that are discussed below in connection with  FIGS. 16-17 . 
         [0061]      FIG. 4  illustrates the operation of the obstacle avoidance features of upright wheeled walker  100  mentioned above in connection with  FIG. 2  and described in more detail hereinbelow. The various elements are labeled with the numerals used above with respect to the discussion of  FIG. 1 . Exemplary obstacles and hazards such as a curved wall  168 , a curb  170  and a stairway  172  are illustrated to improve appreciation of the function and operation of Doppler microwave sensors  134 A-D and 3D infrared (IR) sensors  140 A-B. 
         [0062]      FIG. 5  is an oblique view of the upper body supporting elements of the walker embodiment of  FIG. 1  illustrating an exemplary disposition of the plurality of upper handle touch sensors  154 A-B, upper handle kinetic motors  152 A-B and armrest gutter kinetic motors  150 A-B suitable for providing haptic feedback signals to the user grasping upper handles  118 A-B during use. 
         [0063]      FIG. 6  is an oblique view of the upper body supporting elements of  FIG. 5  illustrating exemplary dispositions of GUI display  146 , processor  144  and a user sensing camera  174  on upper folder element  126  for producing a user detection signal. 
         [0064]      FIG. 7A  illustrates a closer view of upper handle kinetic motors  152 A-B and armrest gutter kinetic motor  150 A from  FIGS. 1 and 5  for providing haptic feedback signals to the user.  FIG. 7B  shows how the user  300  may engage these haptic feedback elements with hands  302 A-B and forearms  304 A-B while standing and walking within the polygonal walker footprint (see also  FIGS. 1 and 5 ). 
         [0065]      FIGS. 8A-B  show other exemplary embodiments and dispositions of a forward-looking infrared (IR) obstacle sensor  176  (directed along the arrow  122  in  FIG. 1 ), a system controller and speaker assembly  178  and a cell phone GUI display  180  suitable for use with the walker of this invention. GUI display  180  may be embodied with, for example, an iOS or Android cell phone OS and connected to system controller and speaker assembly  178  with, for example, a data cable, a Bluetooth link or a Wi-Fi link (not shown). A dedicated software application (a Walker App, for example) may be adapted to log and track bioinformatics and link to a central server (not shown). The relevant bioinformatics database maybe maintained on a remote or local server including hosting and load balancing functionality. Biometric data collected from the user may be provided by external or internal user devices and transmitted to, for example, a Walker App hosted in the cell phone comprising GUI display  180 . 
         [0066]      FIG. 9  is a block diagram illustrating the operation of a first alternative walker control system embodiment  182 . A plurality of walker sensors each produce a digital sensor output signal, exemplified by the digital sensor output signal  184 A, responsive to a respective sensor input (not shown), such as an input to (see  FIGS. 1-2 ) optical sensor  148 , handle touch sensor  154 A, incline sensor  136 A or Doppler microwave sensor  134 A, for example without limitation. These digital sensor output signals are coupled by means of a data bus  186  to the microprocessor  188  in any useful manner known in the art. Microprocessor  188  produces a digital control output signal  190  responsive to the digital sensor input signals on data bus  186  according to program instructions (not shown) stored in a RAM  192 . Digital control output signal  190  is transferred by data bus  186  to a kinetic motor driver  194 , which produces a kinetic motor driver signal  196 . Kinetic motor driver signal  196 , which may be an analog voltage, for example, is applied to a kinetic motor  198 A to produce a vibration wave responsive to driver signal  196 . As described above, kinetic motor  198 A is disposed in an armrest gutter or an upper handle whereby the vibration wave will be felt by the user in hand or forearm as a haptic feedback signal (see also  FIGS. 2, 5, and 7B ) alerting the user according to the features of the stored program in RAM  192 . 
         [0067]      FIG. 10  illustrates the operation of a simpler walker control system embodiment  200 , showing kinetic motors  198 A-B, microwave Doppler sensors  134 A-B, microprocessor  155 , RAM  156 , 3D infrared (IR) sensor  140 A and a speed-sensitive braking control system the operation of which may be appreciated with reference to the above discussion of  FIG. 2  and the discussion below.  FIG. 11  illustrates an exemplary sensor embodiment  202  known in the art that is suitable for use with the walker of this invention.  FIG. 12  illustrates an exemplary sensor detection circuit embodiment  204  known in the art that is suitable for use with the walker of this invention. 
         [0068]      FIG. 13  shows the detail of wheel assembly  106 B ( FIG. 1 ) to better illustrate the hydraulic brake disk  206  and the brake caliper housing  208 . 
         [0069]      FIG. 14  shows the functional operation of electrohydraulic braking system  158  ( FIG. 2 ). System controller assembly  144  ( FIG. 2 ) produces the digital braking control signal  212  on data bus  157  ( FIG. 2 ), which is received by braking controller  159 . Braking controller  159  produces a brake release signal  214  and a braking signal  216  responsive to digital braking control signal  212 . Signals  214  and  216  may be analog voltages, for example, and each operates a respective hydraulic valve in hydraulic system  160  as follows. Braking signal  216  operates the apply valve  218  to increase the hydraulic pressure in the brake line  220  and brake release signal  214  operates the release valve  222  to reduce the pressure in brake line  220 , thereby closing or opening the brake calipers  224  by moving a piston exemplified by piston  158 A ( FIG. 2 ), thereby seizing or releasing hydraulic brake disk  206  in the usual manner. 
         [0070]      FIG. 15  shows the details of wheel assembly  406 A ( FIG. 3 ) to better illustrate partially-visible circumferential brake disk  506  and circumferential braking element  508  rendered visibly within a partially-transparent rendering of housing  416 A. 
         [0071]      FIG. 16  is a schematic cross-sectional view of an exemplary embodiment of a circumferential braking system  500  of this invention. Circumferential braking element  508  engages with the outer rim  518  of circumferential braking element  508  in the manner shown. Increasing the pressure in a hydraulic chamber  510  forces one side of a lever arm  512  down-ward about the fixed axis  514 , the other side of lever arm  512  urges the coupler  516  upward, drawing circumferential braking element  508  upward to tighten the grip about outer rim  518  of circumferential brake disk  508 . This tightening operates to brake wheel  410 A ( FIGS. 3 and 15 ) by means of the increased friction between outer rim  518  and circumferential braking element  508  in the usual manner. Reducing or releasing the pressure in hydraulic chamber  510  reverses this process and releases the brake at wheel  410 A. User control of circumferential braking system  500  is accomplished by touching and moving the handle  520  about the hinge  522  in a well-known manner to increase the pressure in the hydraulic chamber  524 , which pressure is transferred through the hydraulic line  526  in communication with hydraulic chamber  510 . In this manner, user movement of handle  520  controls the pressure in hydraulic chamber  510 , and the braking of wheel  410 A. 
         [0072]      FIG. 17  provides a schematic oblique view of circumferential braking system  500  of  FIG. 16  to better illustrate the functional relationship among the various elements discussed above in connection with  FIG. 16 . Any other suitable element for transferring force or power, such as cables or electrical power transfer means, for example without limitation, may also be used instead of the exemplary hydraulic elements (e.g.,  510 ,  524  and  526 ) illustrated in  FIGS. 16-17 , as will be readily appreciated by those skilled in the art. 
         [0073]      FIGS. 18A-B  illustrates an exemplary embodiment of an electromechanical fail-safe braking control  228 . In one manner of operation, the user (not shown) grips a handle  118 A (e.g.,  FIGS. 7A-B ) and squeezes the brake handle  532  to force it to turn about the hinge  534  and pull the cable element  536  attached to the underside of a rocker arm  538 . When squeezed by the user, handle  532  draws cable  536  about a pulley  540  to force rocker arm  538  down against a fail-safe switch  542  while rotating about the hinge  544  and compressing the spring element  546 . Fail safe switch  542  is useful for signaling a braking system (for example, electrohydraulic braking system  158  in  FIG. 14 ) to apply braking signal  216  when open and brake release signal  214  when closed to control the wheel brakes in an upright wheeled walker, for example. Referring to  FIG. 18A , fail-safe switch  542  is shown closed under pressure from rocker arm  538 , which is shown depressed against spring element  546  by the combination of user forearm weight and a user touch (not shown) on brake handle  532 . Referring to  FIG. 18B , fail-safe switch  542  is shown open as rocker arm  538  is forced upward by spring element  544  because of the release of all user forearm weight and user touch on brake handle  532 . In another manner of operation, if spring  546  is selected to be sufficiently weak, the weight and pressure of a user forearm (not shown) on top of rocker arm  538  may alone be useful to urge closure of fail-safe switch  542  with no need for a user grip on handle  532 . Either method may serve to control a fail-safe braking system to ensure that upright walker wheel brakes cannot be released without a user grip on brake handle  532  or a user forearm force on rocker arm  538  or some combination thereof. 
         [0074]      FIG. 19  illustrates an alternative GUI touch panel display  226  suitable for use with the walker of this invention. 
         [0075]      FIGS. 20A-F  illustrate several exemplary signal processing specifications suitable for use with system controller  144  ( FIG. 2 ) and each specification may be implemented in the program instructions stored in RAM  156 , for example. These signal specification examples are neither exhaustive nor exclusive.  FIG. 20A  illustrates an exemplary relationship between the obstacle detection signal  552  from Doppler microwave sensor  134 A ( FIG. 1 ) and kinetic motor driver signal  196  to kinetic motors  150 A-B and  152 A-B in the handles and armrest gutters.  FIG. 20B  illustrates an exemplary relationship between the user detection signal  556  from optical sensor  148  and digital braking control signal  212 .  FIG. 20C  illustrates an exemplary relationship between the incline detection signal  558  from incline sensor  136 A and digital braking control signal  212 .  FIG. 20D  illustrates an exemplary relationship between output signal  552  from Doppler microwave sensor  134 A ( FIG. 1 ) and user alert signal  145  ( FIG. 2 ) to speaker  163 .  FIG. 20E  illustrates an exemplary relationship between a user touch signal  560  from handle touch sensor  154 A and digital braking control signal  212 .  FIG. 20F  illustrates an exemplary relationship between the frequency of kinetic motor driver signal  196  and the computed obstacle distance derived from a sensor output signal combination  562  from obstacle sensors such as Doppler microwave sensors  134 A or 3D infrared (IR) sensors  140 A, for example. 
         [0076]    Clearly, other embodiments and modifications of this invention may occur readily to those of ordinary skill in the art in view of these teachings. Therefore, this invention is to be limited only by the following claims, which include all such embodiments and modifications when viewed in conjunction with the above specification and accompanying drawing.