Patent Application
20180360686
This invention relates generally to assistive mobility devices and more particularly to a collapsible upright wheeled weight-bearing walker.
Assistive mobility devices, including walkers, are well-known in the art as useful means for reducing the disadvantages of mobility impairment suffered for many different reasons 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 for improved mobility assistance devices adaptable for improving ambulation for mobility-limited persons.
Martins et al. [Martins et al., Assistive Mobility Devices focusing on Smart Walkers: Classi-fication and Review, Robotics and Autonomous Systems 60 (4), April 2012, pp. 548-562] classifies mo-bility assistance devices into the alternative devices intended for those with total loss of independent mobility (wheelchairs or autonomous powered vehicles) and assistive or augmentative devices for those with residual mobility capacity (prostheses, crutches, canes and walkers). For several reasons, most impaired individuals prefer to avoid association with the alternative devices associated with total incapaci-ty. Similarly, the rehabilitation profession strongly prefers the assistive devices, which can be used for physical therapy and as mobility-training devices. Accordingly, there has long been a growing demand for improved assistive devices adapted for use by the less disabled among those who otherwise cannot move independently with existing assistive devices and rely on alternative devices such as wheelchairs and powered scooters.
Mobility and manipulation are critical to living independently and are often strongly associated with the ability to continue to live safely in one's home. Simple assistive devices such as crutches, canes, walkers, and rollators (rolling walkers) can assist a person who has the endurance and strength to walk distances, but these devices must also provide some support or feedback to keep the person from losing their balance or enable the person to rest, when necessary. Although an impaired individual may eventually need an alternative device like a wheelchair or powered scooter, most strongly desire to retain the independence of the simpler assistive device for as long as possible. For this reason, there is a well-known and long-felt need for assistive device improvements that facilitate independent ambulation for the progressively more impaired individuals.
Although popular, the most common assistive devices known in the art (canes, walkers and rollators) have many well-known disadvantages; even for the relatively mobile individual.
The typical wheeled walker known in the art has many well-known disadvantages; such as requiring a stooping or a forward leaning posture to avoid a hobbled gait, difficulty in smooth transition over irregular terrain, little or no upper body and arm support, and requiring significant hand and arm strength to maneuver and to operate any available hand brake, for example. A stooping posture stresses the user's back and arms and risks tipping forward when encountering terrain obstacles. And most devices known in the art have no wheels or wheels too small to negotiate even small surface irregularities safely. Some devices are too heavy and awkward for an unassisted user to lift into a car trunk or van, which limits independent unassisted use. Walker brakes are often either nonexistent or ineffective for the unassisted impaired user, which adds risk of falls and injury and limits independence.
The typical wheeled walker known in the art is neither designed nor intended to support significant user weight during use. As with a cane, the accepted purpose of a wheeled walker is simply to provide assistance in balance and gait, like an elaborate cane system. So the user engages 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. Some wheeled walkers eliminate the seat to afford a more open walking footprint for the user. While this permits an improved and more natural walking position but offers no improved weight bearing capability and many users need an included seat to facilitate independent use over longer distances.
The mobility assistance art is replete with suggestions for improving wheeled walkers.
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.
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.
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.
Some practitioners propose improving the walker mobility aid by adding upper support means for supporting the user'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's arms.
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. Similarly, in U.S. Pat. No. 8,740,242, Slomp discloses a foldable posterior walker with an anteriorly open frame that permits an upright user to step forward within the walker footprint but having little or no weight bearing capability.
Improving a the wheeled walker by adding an upper-body support is advantageous because it facilitates an upright walking and standing posture, improved gait and comfort. But adding significant user body weight to the wheeled walker is also disadvantageous for stability. The increased weight borne on each wheel affects walker stability, braking, and terrain handling. For example, adding significant upright weight support to the wheeled walker introduces new disadvantages of increased lateral and longitudinal instability, risking falls and affecting user safety. Adding more weight support at a higher point on the walker increases the tipping torque at the wheels because of the increased force and distance. 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 the fluctuating wheel loads imposed by the applied user weight during stepping, intro-ducing a new lateral instability.
Several practitioners suggest improvements to mitigate the wheeled walker longitudinal stability problem with braking system improvements. For example, in U.S. Pat. No. 8,998,223, Chang discloses a wheel braking system for a rollator with a “dead-man brake” whereby the wheels are halted upon the release of the user's hands from the handles, improving user safety on slopes. Similarly, in U.S. Pat. No. 9,221,433, Dunlap discloses a safety braking system for a rollator that includes a park mode, a walk mode and a brake mode with a handlebar control mechanism.
Recognizing these new instability problems, practitioners have suggested turning to a powered vehicle to permit some user weight support in assistive devices. 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 under the armpits, but such support does little to improve user posture or stability while walking with the passive device. And, 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 surround-ings to assess the danger level to the user, moving as necessary to avoid danger to the user based on the danger level detected.
Others have proposed elaborate powered control systems to address these stability and other user safety problems. For example, in U.S. Pat. No. 7,708,120, Einbinder discloses an 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 such devices may be generally perceived by users as alternative devices (such as powered wheel chairs, stair climbers and vehicles) and do not represent the improved assistive device sought by most users.
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, seating, weight support and portability problems discussed above.
These unresolved problems and deficiencies are clearly felt in the art and are solved by this invention in the manner described below.
This invention solves the well-known walking posture, instability and portability problems described above in a single apparatus by integrating for the first time folding improvements that stabilize the walker frame during use, adjustable forearm rests (for upper body support), an open rigidized frame permitting the user to stand and step within a polygonal footprint defined by the front and rear wheels, and adjustable handles elevated to permit the upright walking posture necessary for better health. The following description and drawing disclose for the first time how these advantageous features may be implemented in a single collapsible wheeled walker.
It is a purpose of this invention to provide many adjustable features to facilitate unassisted mobility for a wide range of mobility-impaired individuals.
It is an advantage of the apparatus of this invention that lightweight construction materials such as aluminum may be employed to reduce weight, thereby facilitating unassisted handling by a mo-bility-impaired person.
It is an advantage of the apparatus of this invention that the upper arm support elements are each disposed at an ergonometric angle to facilitate a completely upright walking position with substan-tial upper body and arm support while walking within the polygonal footprint defined by the front and rear wheels.
It is an advantage of the apparatus of this invention that facilitating an upright walking posture reduces heart and lung compression, improves circulation, thereby promoting the therapeutic effects of longer walking times after surgery and may ease recovery from injury.
It is a feature of the apparatus of this invention that it may include two pairs of adjustable grips to provide a lower lateral pair for unsupported handling and an upper vertical pair with small short-throw brake levers disposed to facilitate easy braking operation by a user with arthritic hands.
It is an advantage of the apparatus of this invention that the average-sized user, when gripping the upper pair of handles, is standing such that their hips are disposed substantially entirely forward of the line defined by the rear wheel axles.
It is a feature of the apparatus of this invention that it may include dual-shoe adjustable cable-operated wheel brakes to reduce the grip strength required for the unassisted user to safely brake the apparatus.
In an exemplary embodiment, the apparatus of this invention is a collapsible upright wheeled walker apparatus for augmenting an upright partially-supported walking gait on a walking surface for an unassisted user having one or more hands and forearms, comprising: a frame having two frame sides each having a top and a bottom and each frame side being disposed between a front frame portion and a rear frame portion, a plurality of wheel assemblies coupled to the frame for supporting the frame above the walking surface and disposed at the vertices of a polygonal footprint on the walking surface within which the user walks during use; an X-folder apparatus including an anterior element having two ends and a posterior element having two ends, wherein the anterior element is rotatably coupled to the posterior element, a first anterior element end is coupled to a first frame side and the second anterior element end is rotatably coupled to an anterior arm having a distal end that is coupled to the second frame side such that rotation of the anterior element in one direction with respect to the anterior arm is limited to an anterior over-center angle, and a first posterior element end is coupled to the second frame side and the second posterior element end is rotatably coupled to a posterior arm having a distal end that is coupled to the first frame side such that rotation of the posterior element in one direction with respect to the posterior arm is limited to a posterior over-center angle; two upper supports each coupled to and disposed at an adjustable height above a respective frame side; two forearm gutters each coupled to a respective upper support for engaging and supporting one user forearm during use, wherein each forearm gutter has a centerline disposed at a first gutter angle with respect to the walking surface and at a second gutter angle with respect to the other forearm gutter centerline; and two upper handles each coupled to a respective upper support anterior to the respective armrest gutter for gripping by one user hand, wherein each upper handle has a centerline disposed at a forward handle angle with respect to the respective forearm gutter centerline.
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.
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:
Each upper support 120A-B includes a respective forearm gutter 124A-B and a respective upper handle 126A-B, which are described in connection with
Referring to
While the inventors prefer an embodiment with four wheel assemblies, with adjustments to the folder and suspension elements, the apparatus of this invention may also be embodied with three wheels, by using a single front wheel assembly, or with five wheels, by adding a central front wheel assembly, for example, without affecting the other advantages and features described herein.
When folding X-folder apparatus 127, anterior element 128 rotates about X-folder hinge 148 with respect to posterior element 130 and rotation of each respective component also occurs at each of the six hinges 150, 154-155, 160 and 164-165 as may be appreciated from
Similarly, the inventors discovered through testing that the forward handle angle 216A between the gutter axis perpendicular 217A and handle centerline 170A is preferably fixed somewhere in the range of [10, 40] degrees (preferably at about 30 degrees) forward of gutter axis perpendicular 217A or equivalently at about 120 degrees (30+90) forward from the plane defined by gutter axis 214A and about 16 degrees (30-14) forward of true vertical. As seen below in connection with
It is an important aspect of the apparatus of this invention that the upper spreading force at arrows 188A-B across the latched frame bridge 136 eliminates all play or slack at hinges 150, 160, 154-155 and 164-165 and urges frame sides 108A-B into torsion (torques 192A-B in
It may be appreciated from this description of
The anterior and posterior tension adjusters are embodied as stop screws 156 and 166, respectively, abutting the lower ends of the anterior and posterior elements 128 and 130 to limit travel and control the tensions imposed to stabilize frame 102 (
These elements are useful for pre-tensioning the walker frame of this invention. Once adjusted for adequate frame stabilization tension, and verified by forcing frame sides 108A-B together and apart by means of lower handles 142A-B, a thread locking agent (Loctite® 290 or equivalent) may be applied to stop screws 156 and 166. This frame pre-tensioning feature of the walker apparatus of this invention also allow a wider tolerance for component length variation, which reduces fabrication costs.
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.
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 U.S. Patent Application No. 62/162,706 filed on May 16, 2015 and entirely incorporated herein by reference and also claiming the benefit under 35 U.S.C. § 119(e) of U.S. Patent Application No. 62/215,656 filed on Sep. 8, 2015 and entirely incorporated herein by reference. 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.
| Number | Date | Country | |
|---|---|---|---|
| 62215656 | Sep 2015 | US | |
| 62162706 | May 2015 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15415769 | Jan 2017 | US |
| Child | 16114821 | US | |
| Parent | 15148993 | May 2016 | US |
| Child | 15415769 | US |
