Embodiments of the present disclosure generally relate to an assistive movement device; and more specifically to posture assistance devices to aid user mobility.
Some users have conditions in which they are often unable to move to a desired postural position. Sometimes this may be caused by medical conditions such as, for example multiple sclerosis. Sometimes users experience such conditions long term; other times such conditions are temporary.
The disclosure describes posture assistance devices, which according to some embodiments include a motor coupled to a frame. The frame can be attached to a wheelchair and a shaft can be coupled to the motor, where the motor is configured to rotate the shaft. An extension arm can be attached to the frame, where the extension arm includes a redirection surface. The extension arm can be selectively adjustable to change a distance between the redirection surface and the shaft. The device can include a connection line coupled to the shaft and configured to engage with the redirection surface, such that rotation of the shaft changes a length a fed-out portion of the connection line. The device can include an attachment mechanism configured to couple the connection line to a user.
In some embodiments, the extension arm includes an adjustable rail, the redirection surface being disposed on the adjustable rail.
In some embodiments, the extension arm includes an attachment rail and an adjustable rail, the attachment rail being attached to the frame, and the adjustable rail being selectively adjustable with respect to the attachment rail.
In some embodiments, the attachment rail includes multiple first holes each configured to receive a pin, and the adjustable rail comprises multiple second holes each configured to receive the pin, the pin being insertable simultaneously in one of first holes and one of the second holes.
In some embodiments the pin is a first pin, and a second pin is insertable simultaneously in a second of the plurality of first holes and a second of the plurality of second holes to create a fixed relationship between the attachment rail and the adjustable rail.
In some embodiments, the frame is configured to be attached to a back of the wheelchair.
In some embodiments, the redirection surface is a surface of a roller wheel.
In some embodiments, the connection line is a belt.
In some embodiments, the belt includes a first belt segment and a second belt segment, wherein the belt further comprises hook and loop fasteners attaching the first belt segment to the second belt segment.
In some embodiments, the device includes a ratchet wheel and a pawl, the ratchet wheel being coupled to the shaft, and the pawl being configured to selectively engage with the ratchet wheel.
In some embodiments, the extension arm is a first extension arm, and the connection line is a first connection line, wherein the posture assistance device further comprises a second extension arm and a second restrainer line.
The disclosure describes posture assistance devices, which according to some embodiments include a motor coupled to a frame. The frame can be attached to a wheelchair and a shaft can be coupled to the motor, where the motor is configured to rotate the shaft. An extension arm can be attached to the frame, where the extension arm includes a redirection surface. The extension arm can be selectively adjustable to change a distance between the redirection surface and the shaft. The device can include a connection line coupled to the shaft and configured to engage with the redirection surface, such that rotation of the shaft changes a length a fed-out portion of the connection line. The device can include an attachment mechanism configured to couple the connection line to a user. The device can also include a controller, where the controller is configured to receive a motor speed signal representing a speed of the motor. In some embodiments, the controller is configured to operate in a lifting mode, wherein in the lifting mode, the controller is configured to send a drive signal to the motor, the drive signal being based on a comparison between the speed of the motor and a reference speed.
In some embodiments, the controller is configured to operate in the lifting mode in response to a first user command, wherein in the lifting mode the torque signal causes the motor to rotate in a first direction that causes the length of the fed out portion of the connection line to decrease.
In some embodiments, the controller is configured to operate in a lowering mode in response to a second user command, wherein in the lowering mode the torque signal causes the motor to rotate in a second direction that causes the length of the fed out portion of the connection line to increase.
In some embodiments, a Hall effect sensor is in a fixed relationship with the frame, the Hall effect sensor being configured to send a proximity signal to the controller when a magnet is in proximity to the Hall effect sensor.
In some embodiments, the magnet is fixed to the connection line at a predetermined location.
In some embodiments, the controller is configured to operate in a stop mode in response to receiving the proximity signal from the hall effects sensor, wherein the controller is further configured to operate in the stop mode in response to receiving a stop command from the user.
Some embodiments include a ratchet wheel coupled to the shaft, wherein, when the controller is operating in the stop mode, the controller is configured to actuate a pawl to engage with the ratchet wheel to maintain the shaft in a static position.
In some embodiments, the extension arm includes an adjustable rail, the redirection surface being disposed on the adjustable rail.
Corresponding reference characters indicate corresponding parts throughout the several views.
While the disclosure is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the disclosure to the particular embodiments described. On the contrary, the disclosure is intended to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure as defined by the appended claims.
Fig. I shows device 100 coupled to the back 12 of a seat 1 according to one embodiment. The device 100 is coupled to a chair frame 20 of the chair 1. Device 100 is configured to raise, lower, and/or support the torso of a user sitting in the chair 1. This is accomplished using connection lines 5, which are coupled to the user via an attachment mechanism 7. In some modes of operation, the length of a fed-out portion of the connection lines 5 (fed-out from device 100) is adjusted to raise or lower a torso of the user seated in the chair 1. In other modes of operation, the length of a fed-out portion remains constant to support the user in a desired position. Device 100 includes cover 135, according to some embodiments. Device 100 further includes one or more extension arms 140 and a roller wheel 150 disposed on each extension arm 140. The roller wheel 150 redirects the connection line 5 toward a user sitting in the chair 1.
As used herein, the term “coupled” is used in its broadest sense to refer to elements which are connected, attached, and/or engaged, either directly or integrally or indirectly via other elements, and either permanently, temporarily, or removably.
In the embodiment shown in
A user 3 in the upright position shown in
While the user 3 is being raised or lowered, the user 3 may give a stop command indicating a desire for the device 100 to stop raising or lowering the user and for the connection line 5 to be locked in place, according to some embodiments.
In one embodiment, one or more tracks 175 are attached to cover 135. For example, two tracks 175 may be attached to an outside of the body inner cover 136A. The tracks 175 may be affixed to a bottom plate 131 of frame 130 (
The variable position of the mounting members 180 with respect to the tracks 175 allows the device 100 to be adjusted vertically with respect to the back of the chair 1. For example,
When the device 100 is mounted on the bottom of the chair 1, as shown in
The arrangement of tracks 175 and cross members 181 as shown in
Multiple sets of shaft collars 51 and frame collars 53 may be used to mount the device 100 to the chair 1.
In one embodiment, the strap 64 is fabric. In other embodiments, the strap 64 is rubber, polymer, nylon, string, rope, braided textile, woven textile, cord, chain, and/or any strong, flexible material.
The collars 51, 53, 61, 71, 76, may be split collars each having two halves that may be screwed together to tighten around a cross member 181 or the chair frame.
Any combination of the mounting arrangements described above may be used to mount the device 100 to the chair 1. The use of the rails 175 and cross members 181 in conjunction with different mounting arrangements allows the device 100 to be mounted to a variety of commercial chairs and wheelchairs.
Each connection line 5 is coupled to the belt shaft 125. Rotation of the belt shaft 125 in a clockwise direction decreases the length of the fed-out portion of the connection line 5, and rotation of the belt shaft 125 in a counter-clockwise direction increases the length of the fed-out portion of the connection line 5. Other embodiments use the reverse arrangement such that the rotation of the belt shaft 125 in a clockwise direction increases the length of the fed-out portion of the connection line 5, and rotation of the belt shaft 125 in a counter-clockwise direction decreases the length of the fed-out portion of the connection line 5.
The belt shaft 125 may have clamps to secure the end of each connection line 5 to the belt shaft 125. Alternatively, there may be slots in the belt shaft 125 such that the end of the connection line 5 may pass through the slot, loop around a portion of the belt shaft, 125, and be sewn to an adjacent portion of the connection line 5. The connection line 5 may also be secured to the belt shaft 125 by any other suitable arrangement ensuring that the connection line 5 remains coupled to the belt shaft 125 during rotation of the belt shaft 125.
In an alternate embodiment, the motor and/or gearbox 115 may directly rotate the belt shaft 125.
The device 100 includes frame 130, according to some embodiments. The frame 130 includes the bottom plate 131, a first side wall 133, a second side wall 132, and a front wall 134.
The battery 190 provides power to various components of the device 100. The power regulation board 165 receives power from the battery 190 and distributes power to various components at appropriate voltages. The motor control board 160 includes a main microcontroller unit (MCU) 362. A voice processing board 170 processes voice commands from the user. The battery 190, voice processing board 170, and motor control board 160 are attached to the bottom plate 131, in some embodiments. Motor control board 160 may support Brushless DC motor (BLDC) drive stage board 361 according to some embodiments. In some embodiments, the battery 190 and the boards 160, 165, 170, 361 are each be attached to the bottom plate 131 directly. In other embodiments some of all of the battery 190 and the boards 160, 165, 170, 361 are indirectly attached to the bottom plate 131 via any number of intervening components.
In some embodiments, the adjustable rail 143 includes a smooth, stationary surface instead of a roller wheel, such that the connection line 5 may slide over the smooth stationary surface, which redirects the connection line 5 toward the user.
In some embodiments, an adjustable rail 143 may be used without a fixed rail 141. For example, the adjustable rail 143 may be directly secured to the frame 130 of the device 100 at various positions. In other embodiments, the extension arm 140 includes rods coupled by adjustable hinges, which can be secured at different positions to achieve an adjustable overall length. In other embodiments, the overall length of the extension arm 140 may be adjustable by means of one or more folding mechanisms, one or more sliding mechanisms, and/or one or more telescoping mechanisms, to make the distance between the roller wheel 150 and the belt shaft 125 adjustable.
According to some embodiments, one or more proximity sensors 199 are attached to the frame 130. The proximity sensor 199 is configured to detect the proximity of a magnet 6 that is attached to the connection line 5, and to send a signal to the controller 362. The proximity sensor 199 may send a “1” to the controller 362 when the magnet 6 is close to the sensor 199, indicating that the connection line 5 is in the upright position. In one embodiment, the proximity sensor 199 is a Hall effect sensor.
In some embodiments, as shown in
In some embodiments, more than two pins are used to secure the fixed rail 141 to the adjustable rail 143. In other embodiments, only one pin is used, and the fixed rail 141 provides rotational structural support to the adjustable rail 143, for example with one or more flanges or one or more additional walls. In some embodiments, one or more of the pins only pass through one side wall of the fixed rail 141A and one side wall of the adjustable rail 143A.
In some embodiments, alternate mechanisms may be used to secure the adjustable rail 143 to the fixed rail 141 instead of or in addition to the pins 145, 147. For example, the adjustable rail 143 can be secured to the fixed rail 141 with one or more clamps, one or more bolts, one or more screws, one or more pins, one or more collars, or any combination thereof.
In some embodiments, the fixed rail 141 and/or the adjustable rail 143 have more than two side walls. In other embodiments, the fixed rail 141 and/or the adjustable rail 143 have only one wall. Where the adjustable rail 143 has only one wall, the adjustable rail 143 may be branched at the end to accommodate the roller wheel 150, or alternatively, the adjustable rail 143 may have a smooth surface to redirect the connection line 5.
In some embodiments, the end wall 141B of the fixed rail 141 is coupled to the front wall 134 of the frame 130. In some embodiments, the end wall 141B is affixed to the front wall 134 by bolts, welding, brazing, or attachment technique of sufficient structural strength.
The front wall 134 has two slots 139 through which the connection line 5 passes, one of which is shown in
The magnet 6 is coupled to the connection line 5. For example, in some embodiments the magnet 6 is sewn into the connection line 5 or inserted into a pocket in the connection line 5. The magnet 6 is at a location such that the proximity sensor 199 senses proximity of the magnet 6 when the connection line 5 is in the upright position, in which the user is sitting upright. An attachment mechanism 7 is attached at one end of the connection line 5.
In some embodiments, the attachment mechanism 7 is a D-ring that is attached to the connection line 5 and is configured to couple to a harness or item of clothing worn by the user. In other embodiments, the attachment mechanism may be a circular ring, a loop, or a buckle. In one embodiment the attachment mechanism is a breakaway buckle configured to fail above a predetermined force. In some embodiments the connection line 5 is a belt. In other embodiments the connection line is a cable, rope, cord, or strap.
The hook and loop fasteners 9A, 9B maintain the tension in the connection line 5A, 5B below a desired threshold. If the tension in the connection line 5A, 5B, exceeds a threshold, the hook and loop fasteners 9A, 9B separate, thus separating the first belt segment 5A from the second belt segment 5B.
A magnet 6 is coupled to the first belt segment 5A In one embodiment, the magnet 6 is sewn into the first belt segment 5A or inserted into a pocket in the first belt segment 5A The magnet 6 is at a location such that the proximity sensor 199 senses proximity of the magnet 6 when the connection line 5A, 5B is in an “Upright position” in which the user is sitting in an upright position. An attachment mechanism 7 is attached at one end of the connection line 5A, 5B.
In some embodiments, the attachment mechanism 7 is a D-ring that is attached to the connection line 5 and is configured to couple to a harness or item of clothing worn by the user. In other embodiments, the attachment mechanism may be a circular ring, a loop, or a buckle. In some embodiments the attachment mechanism is a breakaway buckle configured to fail above a predetermined force.
Voltage from the battery 190 is directly supplied to the 3-phase Brushless DC motor (BLDC) drive stage 361. The voltage regulator 367 on the power regulation board 165 supplies power to other components at their respective operating voltages. The voltage regulator 367 provides a voltage, for example 9V, to the voice control micro-controller unit (MCU) 372. The voltage regulator 367 also provides a voltage, for example 24 volts, to the H-Bridge driver 368, which drives the actuator 330. The voltage regulator 367 also provides a voltage, for example 5V, to the proximity sensors 199 and the proximity sensor circuitry 369. The voltage regulator also provides a voltage, for example 5V, to the motor hall sensors 320 and the motor hall sensor circuitry 366. In one embodiment, the voltage regulator 367, the proximity hall sensor circuitry 369, the H-bridge driver 368, and the motor hall sensor circuitry 366 are all located on the power regulation board 165.
In some embodiments the electronic system 300 includes both a voice processing board 170 and a wired remote control board 335. In another embodiment, the voice processing board 170 and the wired remote control board 335 are integrated on single board. In another embodiment, system 300 employs a voice control processing board 170 but not a remote control board 335. In yet another embodiment, system 300 employs a remote control board 335 but not a voice control processing board 170.
A user control MCU 337 may be utilized to receive signals from the voice control MCU 372 and from the buttons 336 and convert them to a uniform signal to send to the main MCU 362. In one embodiment, a micro controller such as the Arduino Pro Mini may be used as the user control MCU 362. User control MCU 337 may be located in the wired remote control board 335 that is wired to the main MCU 362.
In one embodiment, as shown in
The voice control module 371 receives a signal from a microphone 315 which receives a voice input from the user. In one embodiment, the voice control module 371 is implemented using a multi-purpose speech recognition module such as the Fortebit Easy VR 3 Plus. The voice control module 371 connects to the Voice Control MCU 372, which is an Arduino Uno in some embodiments. The Voice Control MCU 372 is wired to the User Control MCU 337 located in the wired remote control board 337.
The voice control MCU 372 may be configured to receive a voice command indicating that the user desires to be lifted up (a raising command, such as “Lift me up”), a voice command indicating that the user desires to be let down (a lowering command, such as “Let me down”), and a voice command indicating that the user desires for the connection line 5 to be locked in place (a stop command such as “Stop”). In some embodiments, the voice control MCU 372 is also configured to receive an initiation command (such as “Initiate”) indicating that a user desires to give a raising command or a lowering command. A speaker 325 is used to send audible feedback to the user to verify whether or not a voice command was recognized by the Voice Control MCU 372.
At block Kc1 440 the PWM commands used to control the motor (from 440) are calculated, based on the RPM comparison at 420. This calculation centers the control output around the reference speed 410 and sets output boundaries to select a PWM setpoint output that does not exceed minimum and maximum PWM values, for example minimum and maximum physically achievable PWM values, according to some embodiments of the present disclosure. The gain Kg 460 represents the adjustment accounting for the gear ratio of the motor 110.
The output speed of the motor is read by the motor Hall sensors 320 that are acting as encoders, according to some embodiments. This data is fed back into the Main MCU 362, where encoder pulses are continually counted within a set time window (for example, 100 microseconds) to convert the encoder pulses into a measured speed. Kc2 480 represents the conversion from encoder pulses to the measured motor speed in RPM. This measured speed from Kc2 480 is compared (at 420) with the reference speed 410, and the PWM control signal from the Main MCU 362 to the motor 110 is adjusted at 440 based on the comparison 420 to maintain a constant speed.
The speed control system allows the system to automatically adjust the torque supplied to the user depending on the current ability of the user to move their body in the chair by themselves, according to some embodiments. For users with less ability to move themselves, the system adjusts to supply more torque to move the user's weight. By using a control system to set the motor to run at a slow and constant speed, the torque that the motor 110 provides will automatically adjust based on the weight and strength of the user, according to some embodiments.
A software state machine 500 for the device 100 is shown in
The state machine 500 is in the LOCKED UPRIGHT 530 state when the user is in the upright position, according to some embodiments. The system enters this state when the motor encoder count is greater than or equal to TOP 521 or the proximity sensor 199 is activated 522. The motor 110 is turned off in this state, and the actuator 330 is in a DOWN position such that the pawl 196 is engaged with the ratchet wheel 134, thus locking the connection line 5 in place and supporting the user.
When the state machine 500 is in the IDLE state 510, the motor 110 is off and the user is free to move without being locked in the upright position. The system enters the IDLE state 510 when the connection line 5 is fed out from the motor shaft 116 until the encoder count reaches the value “BOT” 553, indicating that the connection line 5 is in the lowered position. The difference between BOT and TOP is the distance, in encoder counts, between the most downward position of the user and the upright position of the user. The system only transitions out of the IDLE state 510 upon receipt of a raising command 515 from the user. Commands may be received through the microphone 315 and/or the buttons 336, among other possible command inputs. Upon receipt of the raising command 515, the system may enter the MOVING UP STATE 520. In the IDLE state 510, the actuator 330 is in an UP position such that the pawl 196 is not engaged with the ratchet wheel 195, according to some embodiments.
When the state machine 500 is in the MOVING UP state 520, the motor wraps the connection line 5 around the belt shaft 125 to shorten the fed-out portion of the connection line 5, thus pulling the user up. In one example the motor turns in a clockwise direction when the system is in the MOVING UP STATE 520. In other embodiments the motor turns in a counter-clockwise direction when the system is in the MOVING UP STATE 520. If a STOP command 525 is received from the user, the system will transition to the LOCKED MIDWAY state 540, according to some embodiments. If the motor reaches the max encoder number, i.e. MEnc=TOP, 521, or if the proximity sensor is activated, i.e. PSens=1, 522 the system will transition to the LOCKED UPRIGHT state 530 in some embodiments. In the MOVING UP state 520, the actuator 330 is in a DOWN position such that the pawl 196 is engaged with the ratchet wheel 195 in some embodiments. In other embodiments, the actuator 330 is in an UP position in the MOVING UP state such that the pawl 196 is disengaged with the ratchet wheel 195.
When the state machine 500 is in the MOVING DOWN state 550, the device 100 is increasing a length of the fed-out portion of the connection line 5 to let the user down. In one example, the motor 110 is turning counter-clockwise direction in the MOVING DOWN state to lengthen a fed-out portion of the connection line 5. In other embodiments, the motor 110 is turning clockwise in the MOVING DOWN state to lengthen a fed-out portion of the connection line 5. The system will enter the MOVING DOWN state 550 from the LOCKED UPRIGHT state 530 or the LOCKED MIDWAY state 540 upon receiving a lowering command 545 from the user, according to some embodiments. In the MOVING DOWN state 550, the actuator 330 is in an UP position such that the pawl 196 is not engaged with the ratchet wheel 195, according to some embodiments.
The state machine 500 enters the LOCKED MIDWAY state 540 from cither the MOVING DOWN state 540 or the MOVING UP state 520 when a STOP command 525 is received, according to some embodiments. The system can leave this state in response to a raising command 515; the system can also leave this state in response to a lowering command 545. The motor 110 is turned off in this state. In the LOCKED MIDWAY state 540, the actuator 330 is in a DOWN position such that the pawl 196 is engaged with the ratchet wheel 195, according to some embodiments.
The operation of the device according to some embodiments is described here. The user 3 may begin in a down position, as shown in
The user control MCU 337 then sends a signal to the Main MCU 362 indicating that the “lift me up” command was received. The state machine 500 switches to the “MOVING UP” state 520. The user control MCU 337 sends a drive signal to the drive stage 361 of the motor 110 to rotate the motor 110 in a counter-clockwise direction. The user control module 337 also sends a signal to the H-bridge driver 368 to move the actuator 330 to the “down” position such that the pawl 196 is engaged with the ratchet wheel 195. The Main MCU 362 continually monitors the speed of the motor using the signal from the motor Hall sensors 320. The Main MCU adjusts the control signal to the drive stage 361 based on the measured speed, in accordance with the control scheme shown and described in relation to
As the motor 110 turns counter-clockwise, the motor shaft 116 drives the belt shaft 125 in a counter-clockwise direction via the timing belt 120. The connection lines 5 wrap around the belt shaft 125 as it rotates in a counter-clockwise direction. This, in turn, shortens a length of the fed-out portion of the connection lines 5, causing the connection lines to slide over the roller wheels 150 toward the device 100. The torso of the user 3, which is connected to the connection lines 5 via attachment mechanisms 7, is thus pulled up and back toward the upright position.
If the user desires to stop being raised before reaching the upright position the user may press the “Stop” button 336C or give the audible voice command “Stop.” The command is processed and received by the Main MCU 362, and the state machine enters the LOCKED MIDWAY state 540. The Main MCU 363 sends a command to turn the motor 110 off, and the actuator 330 remains in the down position. The ratchet wheel 195 and pawl 196 counteract the weight of the patient on the connection line 5 by maintaining the belt shaft 125 in a static position.
If the user does not give a “Stop” command, the connection line 5 will continue to lift the user until the upright position is reached. The upright position is reached when the magnet 6 on the connection line 5 passes close to the proximity sensor 199. The proximity sensor 199 then sends a “1” to the main MCU 362, which enters the LOCKED UPRIGHT state 530 in response. The Main MCU 362 may also detect the upright position by keeping track of the encoder count from the motor Hall sensor 320. The Main MCU 363 sends a command to turn the motor 110 off, and the actuator 330 remains in the down position. The ratchet wheel 195 and pawl 196 counteract the weight of the patient on the connection line 5 by maintaining the belt shaft 125 in a static position.
If the user in the upright position or midway position desires to be let down, he or she may press the “Let me down” button 336B on the wired remote control 335 or give the audible command “Let me down.” The command is received and processed, and the state machine 500 enters the MOVING DOWN state. The main MCU 362 sends a signal to the H-bridge driver 368 to move the actuator to the up position, such that the pawl 196 is disengaged with the ratchet wheel 195. The motor 110 drives the belt shaft 125 in a clockwise direction. The state machine remains in the MOVING DOWN state 550 until receiving a stop command (in which case the state machine 500 enters the LOCKED MIDWAY state 540), or until the encoder count from the motor hall sensor 320 indicates that the device is in the lowered position (in which case the state machine 500 enters the IDLE state 510).
In some embodiments, device 200 operates in substantially the same manner as device 100 discussed above. The motor 210 rotates a belt shaft 225 via a timing belt 220. In other embodiments, the belt shaft 225 may be rotated directly by the motor 210. The connection line 5 is coupled to the belt shaft 225 such that rotation of the belt shaft may lengthen or shorten a length of the fed-out portion of the connection line 5 depending on the direction of rotation of the motor 210 and the belt shaft 225. The device 200 further includes a ratchet and pawl mechanism coupled the belt shaft 225; the ratchet and pawl mechanism being substantially the same as the ratchet and pawl mechanism shown and described in relation to
Further, device 200 may use the electrical system as shown and described in relation to
A posture assistance device 100 according to some embodiments includes a motor 110 coupled to a frame 130, wherein the frame 130 is configured to be attached to a wheelchair 1; a shaft 125 coupled to the motor 110, wherein the motor 110 is configured to rotate the shaft 125; an extension arm 140 attached to the frame 130, the extension arm 140 including a redirection surface 150A, wherein the extension arm 140 is selectively adjustable to change a distance between the redirection surface 150A and the shaft 125; and the extension arm 140 further including a connection line 5 coupled to the shaft 125 and configured to engage with the redirection surface 150A, such that rotation of the shaft 125 changes a length a fed-out portion of the connection line 5; and an attachment mechanism 7 configured to couple the connection line 5 to a user 3.
A posture assistance device 100 according to some embodiments includes a motor 110 coupled to a frame 130, wherein the frame 130 is configured to be attached to a wheelchair 1; a shaft 125 coupled to the motor 110, wherein the motor 110 is configured to rotate the shaft 125; an extension arm 140 attached to the frame 130, the extension arm 140 including a redirection surface 150A, wherein the extension arm 140 is selectively adjustable to change a distance between the redirection surface 150A and the shaft 125; and the extension arm 140 further including a connection line 5 coupled to the shaft 125 and configured to engage with the redirection surface 150A, such that rotation of the shaft 125 changes a length a fed-out portion of the connection line 5; and an attachment mechanism 7 configured to couple the connection line 5 to a user 3; and a controller 362, wherein the controller is configured to receive a motor speed signal (from 320) representing a speed of the motor 110; and the controller 362 is configured to operate in a lifting mode 520, wherein in the lifting mode 520, the controller 362 is configured to send a drive signal to the motor 110, the drive signal being based on a comparison (at 420) between the speed of the motor (from 320) and a reference speed 410.
This application is a continuation of U.S. patent application Ser. No. 18/301,150, filed Apr. 14, 2023, which is a continuation of U.S. patent application Ser. No. 17/522,816, filed Nov. 9, 2021, which claims priority to U.S. Provisional Patent Application No. 63/111,726, filed Nov. 10, 2020, the contents of each of which are hereby incorporated by reference as if fully disclosed herein.
Number | Date | Country | |
---|---|---|---|
63111726 | Nov 2020 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 18301150 | Apr 2023 | US |
Child | 18800051 | US | |
Parent | 17522816 | Nov 2021 | US |
Child | 18301150 | US |