DESC:
FIELD OF THE INVENTION
[0001] The present disclosure relates to the field of walking aid. In particular, the present disclosure pertains to a system and method for measuring gait intention for a self propelled active walker.

BACKGROUND
[0002] The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Assistive technology (AT) is primarily used to increase, maintain, or significantly improve working capabilities of people who are physically challenged. Technology supported medical devices such as electric wheel chair, transfer devices, prosthesis and walking aid devices are used by physically challenged persons/patients as per their requirement.
[0004] Walking aid devices are used by people who are physically challenged, aged, and/or face the risk of falling down while walking, wherein the walking aid devices help avoid such discomforts. Various walking assistance devices such as a wooden/metallic sticks, wheel chairs, self-powered wheel chairs, and walkers are used to enhance mobility of people, wherein walkers are of different forms such as walkers with two/four wheels, brakes, or are electronic supported so as to enable a person to start walking quickly without a surgeon/physical therapist.
[0005] There are multiple types of walkers that are used by people, one walker being a passive walker that is driven by human force, and other being an active walker that is driven by one or more electrical actuators/motors, wherein the passive walker can be further classified as posterior walker and anterior walker. Posterior walkers are used by patients who can support their weight partially on their legs and can walk, but do not have adequate body strength or balance, and hence use walker frame support available at back of walker to prevent from falling backward while walking. The anterior walker support frame is provided on the front side of the body, and therefore it is useful for those who have a tendency to fall forward while walking. Further, anterior walkers, are grossly classified as passive anterior robotic walker (PARW) and active anterior robotic walker (AARW), wherein PARW is designed with brakes on the wheels after assessing the use’s gait intention and obstacles on the way, whereas AARW includes brakes and provides assistance for moving the walker forward in uphill.
[0006] In existing AARW and PARW, gait intention is assessed by measuring force that is exerted by a patient on a handle, or based on motor current measurement, or by dynamically determining leg position by laser ranging, changes for every patient. It is difficult to detect the intention of the patient to walk forward only through leg motion as the leg motion can be a general motion and not always meant with the intention to walk. Further, there is no active posterior walker that exists in the market.
[0007] There is therefore a need in the art for an active walker to measure gait intention by using different body parts other than leg such as by sensing waist profile of the patient with respect to a walker frame by using sensors.
[0008] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0009] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0010] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0011] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0012] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

OBJECTS OF THE INVENTION
[0013] A general object of the present disclosure is to provide a walking aid for people who are physically challenged, aged, and/or face the risk of falling down while walking.
[0014] An object of the present disclosure is to provide a self-propelled walking aid that works like an active walking aid.
[0015] Another object of the present disclosure is to provide an active walking aid that automatically propels forward based on sensed intention of a user to move forward.
[0016] Yet another object of the present disclosure is to provide an active walking aid that also enables storage of gait data for analysis.
SUMMARY
[0017] Aspects of the present disclosure relate to an active walking aid for people who are physically challenged, aged, and/or face the risk of falling down while walking. In an aspect the disclosed walking aid is an active self-propelled walking aid that automatically propels forward based on sensed intention of a user to move forward.
[0018] In an aspect, the disclosed walking aid comprises a walker frame having a left hand assembly and a right hand assembly, and a barrier with one end of the barrier connected to the left hand assembly and the other end of the barrier connected to the right hand assembly. The disclosed walking aid further comprises a sensor array including a plurality of sensors fixed on the barrier. In an aspect, each of the plurality of sensors of the sensor array is configured to measure distance between the sensor and body of a user using the walking aid. In an aspect, the sensor array is used to sense if a user intends to walk.
[0019] In an aspect, the disclosed walking aid further comprises at least one pair of motorized wheels fixed to lower part of the walker frame, and a control unit operatively coupled to the sensor array and the pair of motorized wheels and configured to determine, based on inputs from the sensor array, nature of waist motion of the user, and interpret the determined waist motion as walking.
[0020] In an aspect, the control unit is further configured to actuate the pair of motorized wheels to make the walking aid move when the determined waist motion is interpreted as walking, thus providing an active self-propelled walking aid that automatically propels forward based on sensed intention of a user to move forward.
[0021] In an aspect, the walker frame further incorporates a pair of front legs comprising a left leg and a right leg, wherein the left leg and right leg respectively connect the left hand assembly and the right hand assembly to a base, and wherein the at least one pair of motorized wheels is fixed to the base.
[0022] In an aspect, the walking aid further includes a storage means to store a user’s locomotion data comprising waist motion with respect to the barrier.
[0023] In an aspect, the data comprising waist motion with respect to the barrier includes change in angle of waist of the user with respect to the barrier.
[0024] In an aspect, wherein the walker frame is a posterior walker frame or an anterior walker frame.
[0025] In an aspect, the disclosed walking aid further includes a left wheel displacement/velocity sensor configured on a left motorized wheel out of the at least one pair of motorized wheels, and a right wheel displacement/velocity sensor configured on a right motorized wheel out of the at least one pair of motorized wheels; the displacement/velocity sensors configured to sense displacement/velocity of the respective wheels, wherein the wheel displacement/velocity sensors are operatively coupled to the controller to provide feedback.
[0026] In an aspect, the disclosed walking aid further includes any or a combination of a GPS device, an illuminating device, a clock or any other useful device/accessary that can be helpful to user of the walking aid.
[0027] In an aspect, the disclosed walking aid can be used to measure gait velocity of a patient, and to furtherto measure physiological cost index (PCI) of a patient by measuring gait velocity of the patient and increase in his pulse rate over the his resting pulse rate.
[0028] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components

BRIEF DESCRIPTION OF DRAWINGS
[0029] FIG. 1A illustrates an exemplary top view of a position sensor array in a posterior walker frame in accordance with an embodiment of the present disclosure
[0030] FIG. 1B illustrates an exemplary top view of a position sensor array in an anterior walker frame in accordance with an embodiment of the present disclosure.
[0031] FIG. 2A illustrates exemplary sensing of gait intention by measuring body position for a posterior walker in accordance with embodiments of the present disclosure.
[0032] FIG. 2B illustrates exemplary sensing of gait intention by measuring body position for a anterior walker in accordance with embodiments of the present disclosure.
[0033] FIG. 3 illustrates a schematic diagram of an active walker incorporating gait measurement mechanism in accordance with an embodiment of the present disclosure.
[0034] FIG. 4 illustrates an exemplary block diagram of an active walker incorporating gait measurement mechanism in accordance with an embodiment of the present disclosure.
[0035] FIG. 5A shows a clinical evaluation performed on even surface in accordance with an embodiment of the present disclosure.
[0036] FIG. 5B shows a clinical evaluation performed on uneven surface in accordance with an embodiment of the present disclosure.
[0037] FIG. 5C shows a clinical evaluation performed on ramp surface in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION
[0038] One should appreciate that the disclosed techniques provide many advantageous technical effects including, but not limited to, efficient communication between local patients.
[0039] The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.
[0040] The present disclosure relates to the field of walking aid system. In particular, the present disclosure pertains to a system and method for measuring gait intention for a self propelled active walker.
[0041] Posterior walker frame and anterior walker frame incorporate multiple different components such as front legs, rear legs, wheels etc. For example, one configuration of a posterior walker frame includes a pair of front legs and a pair of rear legs, wherein front legs and rear legs are terminated with pivoted wheels. Posterior walker frame can further include two adjustable handle assemblies that extend from the top of front legs to the top of rear legs and a barrier that connects top of the front legs. Handle assemblies can also be incorporated to enable a patient to hold the walker and balance his/her weight while walking. Alternatively, posterior and/or anterior walker frames can incorporate other components.
[0042] FIG. 1A illustrates an exemplary top view of a position sensor array in a posterior walker frame in accordance with an embodiment of the present disclosure.
[0043] In an exemplary embodiment, posterior walker frame 100 can include a position sensor array 106 that can include a plurality of sensors such as sensors 106a, 106b …106n forming an sensor array 106 positioned on a barrier 102. The barrier 102 can have one of its ends connected with left hand assembly 108a and the other end connected with right hand assembly 108b, wherein each sensor of sensor array 106 can measure the distance (X0…Xn) between the sensor and body 104 (which can be waist of a user and therefore interchangeably referred to as waist) of a user. The measured distance can be processed to assess current waist motion of patient body 104 with respect to posterior walker frame 102. Two handle assemblies 108a and 108b can be used by the user to enable him to hold the walker for walking. Posterior walker can further assess waist motion only if patient’s body 104 is within a certain range from barrier 102.e.g. a patient’s body can be tracked if it is in between a distance of Xs and Xm from the barrier 102, such that beyond this range, walker frame cannot assess waist motion.
[0044] In an exemplary embodiment, position sensor array 106 can be configured on one side of the walker frame. In an alternate embodiment, position sensor array 106 can be configured on any side of the posterior walker frame.
[0045] Although not being limited to, in one exemplary implementation, posterior walker can include a storage configured to store, including but not limited to, sensed distances between patient and sensors, patient specific gait pattern, number of steps patient walked, walking time and the like, as known to persons ordinary skilled in the art.
[0046] In an exemplary embodiment, measured and/or storage data can be sent to one or more remote devices such as to a doctor’s device, through a wired or a wireless network.
[0047] In an exemplary embodiment, walker frame can be foldable and/or the sides/legs/handle assemblies can be detachable.
[0048] The present disclosure, as elaborated above using FIG.1A, can also be configured for an anterior walker frame as elaborated in FIG.1B, which illustrates an exemplary top view of a position sensor array in the anterior walker frame in accordance with an embodiment of the present disclosure.
[0049] FIG. 2A illustrates exemplary sensing of gait intention by measuring body position in a posterior walker in accordance with embodiments of the present disclosure.
[0050] In an exemplary embodiment, posterior walker frame 200 can include position sensors 206a and 206b on a barrier 102 with one of its ends connected with left hand assembly 108a, and the other end connected with right hand assembly 108b. In another aspect, when a patient stands and holds walker handle assemblies 108a and 108b for walking, position sensors 206a and 206b can measure extreme distances between the patient body and the sensors as Xa and Xb and can store it in an operatively coupled storage (which can also be remote from the walking aid in an exemplary embodiment) as initial reference position 202 of the patient’s waist with respect to the posterior walker. When patient changes his/her orientation and/or moves forward or backward, waist position 202 gets changed and a new waist position 204 can be sensed by the sensors 206a and 206b, wherein sensors 206a and 206b can also store new sensed distance between the waist and sensors as and in the coupled storage.
[0051] In an aspect, sensors 206a and 206b can also estimate and store body angle with respect to the walker frame in initial waist position 202 as ‘a’, and in new waist position as ‘a+?’, and use the estimated angles in both the positions for determining rotation motion of the patient. The angular displacement ‘?’ can be evaluated by using following formula.

[0052] In an aspect, effective forward motion of patient’s body with respect to the walker frame, along the X-axis, can be estimated as least value between ?Xa and ?Xb, wherein and .
[0053] It would be appreciated that the mechanism to calculate angular displacement and forward motion estimation, are completely exemplary in nature, and any other suitable mechanism can be utilized to enable aspects of the present disclosure, and all such possible mechanisms are completely within the scope of the present disclosure.
[0054] The invention as elaborated above using FIG. 2A can also be configured for an anterior walker frame as elaborated in FIG. 2B, which illustrates an exemplary sensing of gait intention by measuring body position in an anterior walker in accordance with embodiments of the present disclosure.
[0055] FIG. 3 illustrates an exemplary schematic diagram of an active posterior walker incorporating gait measurement mechanism in accordance with an embodiment of the present disclosure.
[0056] In an aspect, active posterior walker frame can include a pair of front legs 314a and 314b that terminate at a base, wherein the base includes a left side 312a, a front side 312c, and a right side 312b, wherein endpoints of left side 312a and right side 312b are pivoted with a pair of motorized wheels and a pair of castor wheels 310. Walker can further include an adjustable left handle assembly 316a, a right handle assembly 316b, and barrier 316c in ‘U’ shape on top of front legs 314a and 314b, wherein barrier 316c is configured with gait intention sensor array 302 that extends from left handle assembly 316a to right handle assembly 316b. Left handle assembly 316a and right handle assembly 316b can be used to enable a patient to hold the walker for walking.
[0057] In an embodiment, when patient holds left handle assembly 316a and right handle assembly 316 and within sensor array range, gait intention sensor array 302 analyzes patient’s locomotion, in particular waist motion with respect to barrier 316c on which gait intention sensor array 302 can be configured. The sensor array 302 can measure gait intention as walking and can accordingly control right motor with shaft encoder 306 and a left motor with shaft encoder 308.
[0058] In an embodiment, when gait intention sensor array 302 senses waist motion as walking, gait intention sensor array 302 can automatically send signal to motors to propel motorized wheels thereby, drives walker for turning and/or moving in forward direction.
[0059] In an embodiment, the active walker can work normal on any ground condition such as even surface, uneven surface and ramp by automatically adjusting its height.
[0060] In an embodiment, the walker can include brakes for stopping or slowing down the speed of the walker.
[0061] In an embodiment, the walker can include a basket to carry items, including but not limited to, medicines, food, phone, and the like, as known to persons ordinary skilled in the art.
[0062] FIG. 4 illustrates an exemplary block diagram of an active walker incorporating gait measurement mechanism in accordance with an embodiment of the present disclosure. FIG. 4 illustrates an exemplary process for feeding waist position data sensed by the sensors to a microcontroller that can control the one or more motors.
[0063] In an exemplary embodiment, the proposed disclosure can include a gait intention sensor array 402 to sense patient’s body/waist position data with respect to the active walker, wherein the sensed patient’s body/waist position data can be fed into a microcontroller board 404 that can be configured to process received body/waist position data and to send control signals to two motor drivers 406a and 406b. Motor drivers 406a and 406b can actuate left motor 408a and 408b respectively, both of which rotate motor wheels and drive the walker forward, wherein shaft encoders 410a and 410b can be configured with left motor 408a and right motor 408b respectively to measure motor displacement, position information and can provide closed loop feedback signals to microcontroller board 404.
[0064] In an aspect, left wheel displacement/ velocity sensor 412 and right wheel displacement/velocity sensor 414 can be configured to sense displacement/velocities of left motor propelling wheels and right motor propelling wheels respectively, and feed the sensed velocities into microcontroller board 404.
[0065] In an embodiment, controller 404 can include, but is not limited to, microcontroller, microprocessor, system on chip, application-specific integrated circuit (ASIC), and the like, known to persons ordinary skilled in the art can be used for controlling motors.
[0066] In an embodiment, communication between gait intention sensor array 402 and microcontroller 404 can be enabled by any suitable communication protocol configured to enable aspects of the present disclosure, and all such possible communication protocols are completely within the scope of the present disclosure.
[0067] In an exemplary embodiment, two motors 408 are utilized to drive the walker, whereas in an alternate embodiment, one or any other number of motors can be configured to drive the walker.
[0068] In an embodiment, components, including but not limited to, a GPS device, an illuminating device, a clock, and the like, known to persons ordinary skilled in the art can also be configured on the posterior and/or anterior walker.
[0069] FIGs. 5A to 5C shows the clinical evaluation performed on even, uneven and ramp surfaces respectively in accordance with an embodiment of the present disclosure. To substantiate the principle and working of an active walker on even surface, uneven surface and a ramp surface, a clinical evaluation was performed for disabled children of age group between 4 to 10 years who can initiate gait, but need a walker support. Children were introduced to a passive walker before they started to use the proposed active posterior walker, and performance of child’s gait is evaluated with both passive and active walkers by using physiological cost index (PCI) as an indicator of energy expenditure of gait. PCI can be evaluated by following formula:
PCI = (Final Pulse rate - Resting pulse rate) /Gait Velocity
[0070] PCI value and energy-efficiency of gait are inversely proportional and hence, PCI of a gait disabled person is greater than that of a healthy person. Walking tests are performed on three different surfaces along with various parameters e.g. 50 meter walking test on uneven ground outdoors, 50 meter walking test on even surface indoors, and 10 meter walking test on positive ramp with 15° inclination, time taken, initial heart rate, after walking heart rate, wherein heart rate is measured by palpatory mechanism, below cited data shows walking test data of five patients:

[0071] It is to be observed that in all the five cases, walking with the active walker significantly reduces PCI when compared to walking with passive walker over different walking surfaces.
[0072] As used herein, and unless the context dictates otherwise, the term "coupled to" is intended to include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms "coupled to" and "coupled with" are used synonymously. Within the context of this document terms "coupled to" and "coupled with" are also used euphemistically to mean “communicatively coupled with” over a network, where two or more devices are able to exchange data with each other over the network, possibly via one or more intermediary device.
[0073] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C …. and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.

ADVANTAGES OF THE INVENTION
[0074] The present disclosure provides a walking aid for people who are physically challenged, aged, and/or face the risk of falling down while walking.
[0075] The present disclosure provides a self-propelled walking aid that works like an active walking aid.
[0076] The present disclosure provides an active walking aid that automatically propels forward based on sensed intention of a user to move forward.
[0077] The present disclosure provides an active walking aid that also enables storage of gait data for analysis.
,CLAIMS:
1. An active walking aid for persons with gait abnormality, the walking aid comprising:
a walker frame having a left hand assembly and a right hand assembly, and a barrier with one end of the barrier connected to the left hand assembly and the other end of the barrier connected to the right hand assembly;
a sensor array including a plurality of sensors fixed on the barrier, wherein each of the plurality of sensors of the sensor array is configured to measure distance between the sensor and body of a user using the walking aid;
at least one pair of motorized wheels fixed to lower part of the walker frame; and
a control unit operatively coupled to the sensor array and the pair of motorized wheels and configured to determine, based on inputs from the sensor array, nature of waist motion of the user, and interpret the determined waist motion as walking;
wherein the control unit is further configured to actuate the pair of motorized wheels to make the walking aid move when the determined waist motion is interpreted as walking.

2. The walking aid as claimed in claim 1, wherein the walker frame further incorporates a pair of front legs comprising a left leg and a right leg, wherein the left leg and right leg respectively connect the left hand assembly and the right hand assembly to a base, and wherein the at least one pair of motorized wheels is fixed to the base.

3. The walking aid as claimed in claim 1, wherein the walking aid further includes a storage means to store a user’s locomotion data comprising waist motion with respect to the barrier.

4. The walking aid as claimed in claim 1, wherein the data comprising waist motion with respect to the barrier includes change in angle of waist of the user with respect to the barrier.

5. The walking aid as claimed in claim 1, wherein the walker frame is a posterior walker frame or an anterior walker frame.

6. The walking aid as claimed in claim 1, wherein the walking aid further includes a left wheel displacement/velocity sensor configured on a left motorized wheel out of the at least one pair of motorized wheels, and a right wheel displacement/velocity sensor configured on a right motorized wheel out of the at least one pair of motorized wheels; the displacement/velocity sensors configured to sense displacement/velocity of the respective wheels, wherein the wheel displacement/velocity sensors are operatively coupled to the controller to provide feedback.

7. The walking aid as claimed in claim 1, wherein the walking aid further includes a GPS device.

8. The walking aid as claimed in claim 1, wherein the walking aid is used to measure gait velocity of a patient.

9. The walking aid as claimed in claim 8, wherein the walking aid is used to measure physiological cost index (PCI) of a patient by measuring gait velocity of the patient and increase in his pulse rate over the his resting pulse rate.