Patent Application
20200289879
The present disclosure relates generally to an exercise machine or a rehabilitation machine with a simulated flywheel.
Improvement is desired in the construction of adjustable rehabilitation and exercise devices. Adjustable rehabilitation and exercise devices allow customization of rehabilitation and exercise for an individual. Some devices include pedals on opposite sides to engage a user. See, e.g., U.S. Pat. No. 10,173,094, titled Adjustable Rehabilitation and Exercise Device, issued to Gomberg, et al., which is hereby incorporated by reference in its entirety. Stationary exercise machines typically have high mass flywheels to simulate the inertial force of riding a bicycle. However, such high mass flywheels can be difficult to adjust and increase material and shipping costs for the exercise machines.
Accordingly an exercise or rehabilitation machine having a simulated flywheel is provided.
In general, the present disclosure provides example embodiments of a pedal or pedal system to be engaged by a user to provide exercise or rehabilitation.
In one aspect, an electromechanical device for exercise and rehabilitation is disclosed. The electromechanical device includes one or more pedals coupled to one or more radially-adjustable couplings connected in turn to an axle. The pedals include one or more sensors to measure pedal force applied to the pedals. The electromechanical device further includes a pulley fixed to the axle, with the axle defining a rotational axis for the pedals. The electromechanical device further includes an electric motor coupled to the pulley to provide a driving force to the pedals via the pulley. The electromechanical device further includes a control system that includes one or more processing devices operably coupled to the electric motor to simulate a flywheel. The processing devices are configured to receive a sensed-force value applied to the pedals by a user. The processing devices are further configured to determine a pedal rotational position. The processing devices are further configured to determine a rotational velocity of the pedals. The processing devices are further configured to, based on the sensed-force value and the pedal rotational position, detect a pedaling phase. The processing devices are further configured to, if the pedaling phase is not in a coasting phase and the sensed-force value is in a set range, maintain a current driving force of the electric motor to simulate a desired inertia on the pedals. The processing devices are further configured to, if the pedaling phase is in the coasting phase and the rotational velocity has not decreased, decrease the driving force of the electric motor and maintain a decreasing inertia on the pedals. The processing devices are further configured to, if the pedaling phase is not in the coasting phase and the rotational velocity has decreased, increase the driving force of the electric motor to maintain a desired rotational velocity.
In another aspect, an electromechanical device for exercise and rehabilitation is disclosed. The electromechanical device includes one or more pedals coupled to one or more radially-adjustable couplings connected in turn to an axle. The electromechanical device further includes one or more force sensors on the pedals to sense pedal force applied to the pedals by a user. The electromechanical device further includes a wheel fixed to the axle and defining a rotational axis for the pedals. The electromechanical device further includes an electric motor coupled to the wheel to provide a driving force to the pedals via the wheel and the radially-adjustable couplings. The electromechanical device further includes a control system including one or more processing devices operably coupled to the electric motor to simulate a flywheel. The processing devices are configured to receive a sensed-force value representing a pedal force applied onto the pedals by the user. The processing devices are further configured to, if the sensed-force value is in a desired range, maintain the driving force at a present drive state. The processing devices are further configured to, if the sensed-force value is above the desired range, decrease the driving force to the pedals. The processing devices are further configured to, if the sensed-force value is below the desired range, increase the driving force to the pedals.
In yet another aspect, a method of electromechanical rehabilitation is disclosed. The method includes receiving a pedal force value from a pedal sensor of a pedal. The method further includes receiving a pedal rotational position. The method further includes, based on the pedal rotational position over a period of time, calculating a pedal velocity. The method further includes, based at least upon the pedal force value, a set pedal resistance value, and the pedal velocity, outputting one or more control signals causing an electric motor to provide a driving force to control simulated rotational inertia applied to the pedal.
Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims.
Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term “couple” and its derivatives refer to any direct or indirect communication between two or more elements, independent of whether those elements are in physical contact with one another. The terms “transmit,” “receive,” and “communicate,” as well as derivatives thereof, encompass both direct and indirect communication. The terms “transmit,” “receive,” and “communicate,” as well as derivatives thereof, encompass both communication with remote systems and communication within a system, including reading and writing to different portions of a memory device. The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and/or. The phrase “associated with,” as well as derivatives thereof, means to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The term “controller” means any device, system (e.g., control system), or part thereof that controls at least one operation. Such a controller may be implemented in hardware or a combination of hardware, software, or firmware. Such a controller may include one or more processing devices. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase “at least one of,” when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be needed. For example, “at least one of: A, B, and C” includes any of the following combinations: A; B; C; A and B; A and C; B and C; and A, B, and C.
Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a flash drive, a compact disc (CD), a digital video disc (DVD), solid state drive (SSD), or any other type of memory. A “non-transitory” computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” “top”, “bottom,” and the like, may be used herein for ease of description to describe one element's or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated degrees or at other orientations) and the spatially relative descriptions used herein interpreted accordingly.
Definitions for other certain words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many if not most instances, such definitions apply to prior as well as future uses of such defined words and phrases.
For a more complete understanding of this disclosure and its advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:
In general, the present disclosure provides example embodiments of an exercise/rehabilitation system using pedals and an electric motor responsive to control signals to simulate a flywheel. The control signals can be produced according to a program, which in some example embodiments receives position or force signals from the pedal itself. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the present disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail, as they will be readily understood by the skilled artisan in view of the disclosure herein.
The electric motor in the present system can control the force at the pedals. This will allow a rehabilitation medical professional to determine the force that a user-patient can apply to the pedals. Thus, a user can engage in range of motion rehabilitation exercises before the user has the strength to begin to rotate the simulated flywheel. This allows the rehabilitation/exercise system to be lightweight and free of a flywheel, resulting in a significant reduction of mass relative to the entire system.
A rail 330 is fixed in the housing 321 above the drivescrew 325. The rail 330 is elongate and defines a travel path of the spindle 103. The rail 330 includes a top guide edge 331 at the top of the rail and a bottom guide edge 332 at the bottom of the rail.
The carriage 304 includes a top member 336 configured to mechanically engage the rail 330 to guide the carriage 304 along the longitudinal length of the rail 330. The carriage 304 includes a bottom member 337 to engage the drivescrew 325 to provide the motive force to move the carriage in the housing 321. The top member 336 is fixed to the bottom member 337. In an example embodiment, the top member 336 and bottom member 337 are formed from a unitary block of a rigid material (e.g., a metal or rigid polymer). A plurality of upper bearing blocks 341 fixed to the top member 336 is slidably engaged on the top guide edge 331. A plurality of lower bearing blocks 342 fixed to the top member 336, below the upper bearing blocks 341, is slidably engaged on the bottom guide edge 332. The bottom member 337 includes a throughbore 348 to receive the drivescrew 325. In an example embodiment, the throughbore 348 is threaded to engage threads of the drivescrew 325. In the illustrated example, a carriage coupling 339 is fixed to the bottom member 337 at the throughbore 348. The carriage coupling 339 is internally threaded to mate with the external threads of the drivescrew 325. In operation, the electric motor 305 turns the drivescrew 325, and the carriage 304 through the carriage coupling 339 translates the rotational motion of the drivescrew to linear movement of the carriage 304 on the rail 330.
The carriage 304 includes a spindle engagement 345 to fix the spindle 103 thereto. The spindle engagement 345 can include a threaded recess to receive a threaded carriage end of the spindle 103.
A cover plate 322 is provided on the housing 321 to cover the recesses 323 receiving the internal components. The cover plate 322 includes the aperture 303 through which the spindle extends. The aperture 303 and the spindle engagement 345 are aligned to allow the spindle 103 to travel on the carriage 304 in the aperture 303.
A slide plate 350 is provided on the bottom member 337. The slide plate 350 slidably engages the housing (e.g., laterally adjacent the drivescrew 325) to assist in preventing rotation of the carriage 304 in the housing.
Further, a computing device arm assembly 421 may be secured to the frame and a computing device mount assembly 422 may be secured to an end of the computing device arm assembly 421. A computing device 423 (e.g., controller 112) may be attached or detached from the computing device mount assembly 421 as desired during operation of the system 400.
At 502, the radial position of a pedal relative to the axle is electrically adjusted in response to a control signal output by the controller 112 to control the electric motor 305 to position the carriage 304, and hence the pedal 102, through the spindle 103. In an example embodiment, the electric motor 305 is connected to the carriage 304 through a linkage (e.g., the drivescrew 325 to linearly move the spindle 103). In an example embodiment, the radial position of the pedal is adjusted, during a revolution of the pedal, to produce an elliptical pedal path relative to the axle. The radial position of the pedal can be adjusted in response to the control signal during a user pedaling the pedal.
At 503, the rotational motion of the user engaged with the pedal is controlled. The controller can control the position of the pedal 103 in real time according to the treatment plan. The position of a right pedal can be different than that of the left pedal. The pedal can also change position during the use. The pedal can also sense the force a user is applying to the pedal. A force value can be sent from the pedal to the controller, which can be remote from the pedal.
At 504, the rotational position of the pedal is sensed. The rotational position of the pedal can provide information regarding the use, e.g., to control radial position of the pedal, the rotational motion (e.g., speed, velocity, acceleration, etc.) and the like.
As noted, power transmission to the motor on the pedal arm may be conducted via slip rings. Other embodiments can include a wireless power transmission system that can use transformer coils (such as thin pairs of them) on the main unit and the pedal arm. DC voltage can be wirelessly passed to the pedal arm to charge onboard battery pack(s). The controller can split the charge to left and right controllers for the respective pedal arms. The motor control of the pedal arms can be controlled by the onboard controller. Embodiments of the transformer coils can be similar or identical to retail mobile phone wireless chargers.
Another aspect of the assembly can include limit switches. Some versions comprise microswitches, such as one at each end of the carriage travel. The state of the limit switches can be interpreted by the controller to detect when the carriage/spindle assembly is at either end of travel. The limit switches are optional.
At 802, the pedal rotational position is received, e.g., at the controller 112 or computing device 423. The rotational position of the pedal can be used to compute the rotational velocity or rotational speed of the pedals. Any change in velocity can indicate a change in acceleration.
At 803, motor control signals are output. The one or more control signals output to the electric motor 114 can cause the electric motor 114 to control rotational inertia at the pedals based at least upon the pedal force value, a set pedal resistance value, and a pedal velocity. The pedal velocity can be computed from the position of the pedal over time. The pedal resistance value can be set in during programming an exercise regimen or a rehabilitation regimen, e.g., through an I/O in the base 110 from a remote server and stored in the memory 113. In an example embodiment, if the pedal velocity is being maintained and the pedal force value is within a set range (which can be stored in the memory), a maintain-drive control signal is sent to the electric motor 114. The maintain-drive control signal operates the electric motor 114 to stay at a same mechanical drive output to the pedals, which will maintain a feel at the pedals that is the same, i.e., the inertia remains the same. In an example embodiment, if the pedal velocity is being maintained and the pedal force value is less than a prior pedal force value at a prior pedal revolution (e.g., the pedal velocity is maintained with less force than the previous pedal revolution in the same pedal position but during the immediately prior revolution), the maintain-drive control signal is sent.
In some embodiments, if the pedal velocity is less than a prior pedal velocity during a prior pedal revolution and the pedal force value is less than a prior pedal force value at the prior pedal revolution, an increase-motor-drive control signal can be sent to the electric motor 114. The increase-motor-drive control signal will cause the electric motor to rotate faster, i.e., accelerate, to increase the perceived inertial force at the pedals.
If the pedal force value is greater than the pedal force value during a prior pedal revolution or if the pedal velocity is greater than a prior pedal velocity during the prior pedal revolution, a decrease-motor-drive control signal can be sent to the electric motor. This will slow the electric motor and reduce the force at the pedals. The decrease-motor-drive control signal can be sent when the pedal velocity is more than a prior pedal velocity during a prior pedal revolution. The decrease-motor-drive control signal can be sent when the pedal force value is more than a pedal force value during a prior pedal revolution.
The control signals can cause the electric motor to control simulated rotational inertia applied to the pedals through an intermediate drive wheel connected to a drive axle to the pedals. This will simulate an inertial force perceived at the pedals by the user, where the inertial force would be provided by a flywheel in a traditional stationary exercise machine. This is useful in the present rehabilitation system as the electric motor 114 and any intermediate drive linkage between the electric motor 114 and the pedals (e.g., an intermediate drive wheel or pulley) is essentially free from or without adding inertial energy to the pedals.
The method 900 then has three different ways it can produce electric motor control signals to control the operation of the electric motor driving the pedals. At 905, if the pedaling phase is not in a coasting phase and the sensed-force value is in a set range, a signal is sent to the electric motor to maintain a current drive of the electric motor at a present drive state to simulate a desired inertia on the one or more pedals. The force value can be set in memory of the device, e.g., as part of the rehabilitation regimen for the user. The force can be set as a value with a +/− buffer to establish a range. For example, when beginning a rehabilitation regimen, the force can be low for the first few pedaling events and increase thereafter. The force can be measured at the pedal using the devices and methods described herein.
At 907, if the pedaling phase is in the coasting phase and the rotational velocity has not decreased, decrease the current drive of the electric motor and maintain a decreasing inertia on the one or more pedals. This should simulate inertia at the pedals, e.g., simulate a flywheel when the system is slowing gradually. The electric motor will continue to apply a force to the pedals, but the force decreases with each revolution of the pedals or over time to simulate the flywheel producing the inertial force.
At 909, if the pedaling phase is not in the coasting phase and the rotational velocity has decreased, increase drive of the electric motor to maintain a desired rotational velocity. That is, the electric motor will accelerate the pedals to maintain the force at the pedals as perceived by the user. The increase in the drive by the electric motor can be maintained for a time period or a number of revolutions of the pedals. In an example embodiment, the electric motor 114 increases the drive for ⅛, ¼, or ⅜ of a revolution of the pedal.
The controller as described herein can output motor control signals that control the force output by the electric motor to the pedals. The controller is configured to increase drive of the electric motor to increase the rotational velocity of the one or more pedals when the one or more pedals are at or below a minimum sensed-force threshold, and to decrease drive to reduce the rotational velocity of the one or more pedals when the one or more pedals are at a maximum sensed-force threshold. The minimum sensed-force threshold and the maximum sensed-force threshold are the forces sensed at the pedals. The values of the minimum and the maximum can be set in the program for an individual's rehabilitation schedule on the rehabilitation system. The program should limit the range of motion of the user by adjusting the radial position of the pedals and control the amount of force that the user can apply to the pedals. For the force to be at any given value, the amount of force applied to the pedals requires that pedals resist the force being applied. That is, if the pedal will free spin above a maximum force, then the user cannot apply more than that force to the pedal. The electric motor can also resist the rotational movement of the pedals by refusing to turn until the minimum force is applied to the pedals. The controller, through output of control signals to the electric motor, simulates a flywheel by controlling operation of the electric motor to drive the pulley (or axle wheel) when the one or more pedals are not rotating in a desired range of either force or rotational velocity.
The force value in the controller can be the sum of forces to maintain a level of drive at the one or more pedals below a peak of the sum of forces and above a valley of the sum of forces. That is, the sum of forces is derived from the forces at both the pedals, one of which can be engaged by a user's good leg and the other by the user's leg in need of exercise or rehabilitation.
The foregoing description of the embodiments describes some embodiments with regard to exercise system or a rehabilitation system or both. These phrases are used for convenience of description. The phrases exercise system or rehabilitation system as used herein include any device that is driven by or causes motion of a person or animal, typically to provide travel of body parts. The exercise system can include devices that cause travel of an extremity or appendage, i.e., a leg, an arm, a hand, or a foot. Other embodiments of exercise systems or rehabilitation systems can be designed for range of motion of joints.
The foregoing description describes a pedal, which is engaged by a user's foot to impart force to the pedal and rotate the pedals along a travel path defined by the position of the pedal relative to the rotational axis of the device. The description relating to a pedal herein can also be applied to handgrips such that a user can grip the handgrips and the device can operate in the same manner as described herein. In an example embodiment, the term pedal can include a handgrip.
The rehabilitation and exercise device, as described herein, may take the form as depicted of a traditional exercise/rehabilitation device which is non-portable and remains in a fixed location, such as a rehabilitation clinic or medical practice. In another example embodiment, the rehabilitation and exercise device may be configured to be a smaller, lighter and more portable unit so that it is able to be easily transported to different locations at which rehabilitation or treatment is to be provided, such as a plurality of patients' homes, alternative care facilities or the like.
Consistent with the above disclosure, the examples of systems and method enumerated in the following clauses are specifically contemplated and are intended as a non-limiting set of examples.
Clause 1. An electromechanical device for rehabilitation, comprising:
Clause 2. The electromechanical device of any preceding clause, wherein, for option (c), the one or more processing devices increase drive of the electric motor for between one eighth and three eighths of a revolution of the one or more pedals.
Clause 3. The electromechanical device any preceding clause, wherein the one or more sensors include a toe sensor at a toe end of the one or more pedals and a heel sensor at a heel end of the one or more pedals; and
Clause 4. The electromechanical device any preceding clause, wherein the one or more processing devices are further configured to:
Clause 5. The electromechanical device of preceding clause, wherein the control system simulates the flywheel by controlling the electric motor to provide the driving force to the pulley when the one or more pedals are not rotating within a desired range.
Clause 6. The electromechanical device of preceding clause, wherein the one or more pedals include a right pedal and a left pedal that both alternatingly apply pedal forces to the electric motor through the pulley, wherein the one or more processing devices use a sum of forces from the right pedal and the left pedal to the driving force output by the electric motor.
Clause 7. The electromechanical device of preceding clause, wherein the one or more processing devices use a sum of forces from a right pedal and a left pedal to maintain a level of drive at the one or more pedals below a peak of the sum of forces and above a valley of the sum of forces.
Clause 8. The electromechanical device of preceding clause, wherein the pulley is does not supply inertia through the one or more pedals without the driving force from the electric motor.
Clause 9. An electromechanical device for rehabilitation, comprising:
Clause 10. The electromechanical device of preceding clause, wherein the one or more force sensors include a toe sensor at a toe end of the one or more pedals and a heel sensor at a heel end of the one or more pedals, and wherein the sensed-force value is a calculated force from both the toe sensor and the heel sensor.
Clause 11. The electromechanical device of preceding clause, wherein the electric motor controls a resistance to travel of the one or more pedals.
Clause 12. The electromechanical device of preceding clause, wherein the one or more pedals include a right pedal and a left pedal that both periodically receive applied force from the user and the electric motor resists the applied force, wherein the one or more processing devices use a sum of forces from the right pedal and the left pedal to control the driving force the electric motor to resist acceleration and deceleration of rotational velocity of the one or more pedals.
Clause 13. The electromechanical device of preceding clause, wherein the one or more processing devices use the sum of forces to maintain a desired level of force at the one or more pedals below a peak of the sum of forces and above a valley of the sum of forces.
Clause 14. A method of electromechanical rehabilitation, comprising:
Clause 16. The method of preceding clause, wherein, if the pedal velocity is being maintained and the pedal force value is within a set range, outputting the one or more control signals comprises outputting a maintain-drive control signal to the electric motor; and
Clause 16. The method of preceding clause, wherein, if the pedal velocity is being maintained and the pedal force value is less than a prior pedal force value at a prior pedal revolution, outputting the one or more control signals includes outputting a maintain-drive control signal to the electric motor; and
Clause 17. The method of preceding clause, wherein, if the pedal velocity is less than a prior pedal velocity during a prior pedal revolution and the pedal force value is less than a prior pedal force value at the prior pedal revolution, outputting the one or more control signals includes outputting an increase-motor-drive control signal to the electric motor; and
Clause 18. The method of preceding clause, wherein, if the pedal force value is greater than the pedal force value during a prior pedal revolution or if the pedal velocity is greater than a prior pedal velocity during the prior pedal revolution, outputting the one or more control signals includes outputting a decrease-motor-drive control signal to the electric motor; and
Clause 19. The method of preceding clause, wherein outputting the one or more control signals causes the electric motor to control simulated rotational inertia applied to the pedal through an intermediate drive wheel connected to a drive axle to the pedal; and
Clause 20. The method of preceding clause, wherein the pedal sensor includes a toe sensor at a toe end of the pedal and a heel sensor at a heel end of the pedal; and
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements, assemblies/subassemblies, or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. The benefits, advantages, solutions to problems, and any feature(s) that can cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, sacrosanct or an essential feature of any or all the claims.
This application claims priority to and the benefit of U.S. Prov. Pat. App. No. 62/816,557, filed on Mar. 11, 2019, and U.S. Prov. Pat. App. No. 62/816,550, filed Mar. 11, 2019, each of which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62816550 | Mar 2019 | US | |
| 62816557 | Mar 2019 | US |
