Patent Application
20210169373
The present disclosure relates to a gait profiler system and method for determining the gait profile of a user.
Assistive mobility device, such as actuated orthoses, providing optimal knee assistance (i.e. energy injection during more than 99% of the user's activities) require knowledge of the state of the leg of the user, that is either a) in a stance state (i.e. in contact with the ground or b) in a swing state.
A common method of accomplishing this is using pressure sensors. However, this method has drawbacks, mainly:
Accordingly, there is a need for a gait profiler system and method for determining the gait profile of a user that overcomes the pressure sensor's drawbacks.
The present disclosure provides a gait profiler system for determining the gait profile of a user, comprising:
The present disclosure also provides a gait profiler system as described above, wherein the first and second sets of external sensors include a pair of inertial sensors configured to be positioned at respective right and left leg-knee or thigh-hip structures and a plurality of sensors providing information indicative of the angular positions of the right and left knee and thigh of the user.
The present disclosure further provides a gait profiler system as described above, wherein the various sensors are provided by an exoskeleton or orthotic devices worn by the user.
The present disclosure further provides a gait profiler system as described above, wherein the step of merging the locomotion-related information of the right foot and of the left foot of the user is performed using a sensor fusion algorithm comprising the sub-steps of:
The present disclosure still further provides a gait profiler system as described above, wherein the step of generating the gait profile of the user includes the sub-steps of:
Embodiments of the disclosure will be described by way of examples only with reference to the accompanying drawings, in which:
Similar references used in different Figures denote similar components.
Generally stated, the non-limitative illustrative embodiment of the present disclosure provides a system and method for determining the gait profile of a user. The gait profiler system uses sensing systems that include inertial sensors configured to be positioned at the right and left foot-ankle structure, as well as spatial orientation of lower extremity body segments (shanks, thighs, and trunk) of the person for which the gait profile is to be determined. In an illustrative embodiment, the gait profiler system uses two additional inertial sensors at the left and right leg-knee or thigh-hip structure as well as sensors providing information indicative of the angular positions of the left and right knee and thigh, which may be provided by an exoskeleton or orthotic devices worn by the user, such as described, for example, in U.S. Pat. No. 9,370,439 entitled “LOAD DISTRIBUTION DEVICE FOR HUMAN JOINTS”. This determination of the gait profile of the user is performed using biomechanics information about the user from the inertial sensors combined with the knee and hip angles.
Referring to
Each of the sensing systems 20a, 20b includes, respectively, an associated inertial sensor 22a, 22b (providing biomechanics information about a respective foot of the user) and a securing mechanism 24a, 24b configured to secure the sensing systems 20a, 20b, for example, right below the medial malleolus of an associated foot of the user.
In an illustrative embodiment of the gait profiler system 10, shown in
It is to be understood that the knee and hip angular position sensors 30′a, 30′b may take the form of any sensors providing information indicative of angular position or from which angular position may be generated as the knee and hip angles may be determine by direct measurement or deduced from biomechanics information provided by a variety of types of sensors.
Referring to
The process 100 starts at block 102 where the biomechanics information and knee and hip angles from the associated inertial sensors 20a, 20b and the external sensors 30a, 30b are provided to the one or more processor 12.
At block 104, optionally, the velocity is calculated by integrating the acceleration expressed in the global coordinates system.
At block 106, optionally, the velocity is corrected and integrated to obtain the position since the last step.
Then, at block 108, the position and velocity (if optional steps 104 and 106 are performed), acceleration, rotation and orientation are merged with a sensor fusion algorithm in order to calculate the locomotion state (i.e. stance or swing state) of the user.
Finally, at block 110, the process 100 provides the stance or swing state of the user and the the locomotion-related information of each foot of the user to the gait profile calculation process 200.
Referring to
At block 1082, the static state of each of the right foot and left foot of the user is determined using the biomechanics information, i.e. is the foot in contact with the ground and is motionless or not, etc.
Then, at block 1084, the dynamic state of each of the right and left foot of the user is determined using the biomechanics information, i.e. is the foot in motion, is it part of a locomotion cycle or not, etc.
Finally, at block 1086, the algorithm determines the locomotion state (i.e. stance or swing state) of the user. To this end, the static and dynamic states of the right foot and the left foot are used (i.e. static right foot, static left foot, dynamic right foot, dynamic left foot), the various combinations of the right foot and left foot states determining if the user is in a stance or swing state. It is to be understood that other biomechanics information may be used to complement the static and dynamic states of the right foot and the left foot.
Referring now to
The process 200 starts at block 202 where the locomotion state (i.e. stance or swing state) of the user and the the locomotion-related information of each foot of the user is obtained from the state calculation process 100 (see
At block 204, the secondary gait information such as user activity, slope, cadence, etc., is calculated from the biomechanics information and knee and hip angles.
At block 206, a torque profile is calculated based on the stance or swing state of the user. Each state is provided with a model torque profile, i.e. stance state torque and swing state torque profiles
Then, at block 208, the torque profile is optimized based on the user secondary gait information. This means that when a change of locomotion state and/or secondary gait information is detected, the torque profile is adjusted in order to limit the effects of those changes on the gait of the user.
Finally, at block 210, the process 200 provides the torque profile (i.e. gait profile) of the user.
It is to be understood that in alternative embodiments the state calculation process 100 and the gait profile calculation process 200 may be executed on a single or separate processors 12 and that the state calculation process 100 may be executed on separate processors 12 for the right and left foot of the user, the inertial sensors 20a, 20b and external sensors 30a, 30b providing their information directly to their associated processor 12.
Although the present disclosure has been described by way of particular non-limiting illustrative embodiments and examples thereof, it should be noted that it will be apparent to persons skilled in the art that modifications may be applied to the present particular embodiment without departing from the scope of the present disclosure as hereinafter claimed.
This application claims the benefits of U.S. provisional patent application No. 62/286,902 filed on Jan. 25, 2016, which is herein incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CA2017/000016 | 1/25/2017 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62286902 | Jan 2016 | US |
