Patent Description:
A motorized locomotion assistance exoskeleton device may assist locomotion of a person with a disability in the lower portion of the body. For example, such a device may assist a disabled user to walk or perform other tasks that ordinarily require use of the legs. Such devices have been described, for example, by <CIT> and by<CIT>.

A device as described typically is designed to be attached to parts of the lower portion and part of the trunk of a person's body. Such a described device typically includes motorized joints and actuators for flexing and extending the parts of the body to which it is attached. Such a described device typically includes sensors for ascertaining the state of the device and the body during locomotion. For example, a described device may include one or more angle sensors for measuring angles of the joints, tilt sensors for measuring a tilt angle of the body, and pressure or force sensors for measuring the force exerted on the ground or other surface.

Such a described device may include various controls for controlling the device. For example, the device typically includes a mode selection device for selecting a mode of operation, for example, a gait. Typically, a controller that controls operation of the device is designed to receive signals from the device sensors, and to control operation of the device on the basis of the received sensor signals. For example, the sensor signals may indicate whether a gait or action being performed by the device is proceeding as expected. In addition, a user to whom the device is attached may deliberately perform an action that affects a reading of one or more sensors. The controller may be programmed to initiate, continue, or discontinue performance of an action based on the sensor readings. Thus, the person may at least partially control operation of the device by leaning or performing other actions that may affect sensor readings.

Continuing study and experience with the design and use of motorized locomotion assistance exoskeleton devices have led to increased understanding of their operation. It is an object of the present invention to provide a motorized locomotion assistance exoskeleton device with a novel design based on this increased understanding.

Other aims and advantages of the present invention will become apparent after reading the present invention and reviewing the accompanying drawings.

<CIT> discloses a lower extremity enhancer to be worn by a user to enable the user to carry a load includes two leg supports having a plurality of jointed links. Proximal ends of the leg supports are connected to a back frame adapted to carry the load. Distal ends of the leg supports are connected to two foot links. The leg supports are powered by a plurality of actuators adapted to apply torques to the leg supports in response to movement of the user's legs.

There is thus provided, in accordance with the invention a locomotion assisting exoskeleton device according to claim <NUM>.

Furthermore, in accordance with some embodiments of the present invention, the device includes a remote control.

Furthermore, in accordance with some embodiments of the present invention, the algorithm comprises operating the motorized joint to swing a trailing leg forward when a sensed tilt sensed by the tilt sensor exceeds a threshold value.

Furthermore, in accordance with some embodiments of the present invention, the algorithm comprises operating the motorized joint to extend a leading leg backward when a sensed tilt sensed by the tilt sensor exceeds a threshold value.

Furthermore, in accordance with some embodiments of the present invention, a joint is provided with an angle sensor for sensing an angle between the two braces connected by the joint.

Furthermore, in accordance with some embodiments of the present invention, the algorithm includes instructions for actuating the motorized joints in accordance with the sensed angle.

Furthermore, in accordance with some embodiments of the present invention, the algorithm includes halting forward motion of a leg when the sensed angle is within a predetermined range of angles.

In order to better understand the present invention, and appreciate its practical applications, the following Figures are provided and referenced hereafter. It should be noted that the Figures are given as examples only and in no way limit the scope of the invention. Like components are denoted by like reference numerals.

However, it will be understood by those of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, modules, units and/or circuits have not been described in detail so as not to obscure the invention.

Embodiments of the invention may include an article such as a computer or processor readable medium, or a computer or processor storage medium, such as for example a memory, a disk drive, or a USB flash memory, encoding, including or storing instructions, e.g., computer-executable instructions, which when executed by a processor or controller, carry out methods disclosed herein.

A locomotion assisting exoskeleton device in accordance with embodiments of the present invention typically includes one or more braces or supports. Each brace may be strapped on, or otherwise attached to, a part of the body of the user. Typically, one or more trunk supports may be attached to the trunk, in particular, the lower torso, of the user. Other braces may be attached to sections of the user's legs. Each brace or support of the apparatus is typically joined via a joint or other connection to one or more other components of the apparatus. A joint may enable relative movement between the joined components. For example, a joint may enable relative motion between a brace and an adjacent brace.

The locomotion assisting exoskeleton device may include one or more motorized actuation assemblies. A motorized actuation assembly may be operated to move one or more parts of the user's body. For example, a motorized actuation assembly may bend a joint. Coordinated bending of one or more joints may propel one or more limbs of the user's body.

Typically, a joint may be provided with one or more sensors for sensing the relative positions and orientations of various components of the apparatus. The relative positions of components of the apparatus may indicate the relative positions of body parts to which the components are attached. For example, a sensor may measure and generate a signal indicating, for example, the angle between two braces joined at a joint. The locomotion assisting exoskeleton device includes one or more tilt sensors. Experience acquired with regard assisted walking with an exoskeleton device has shown that a forward tilt of a user wearing the exoskeleton device may be effectively utilized for operation of the device. For example, a forward tilt of the user may indicate that the user wants to walk forward. For example, when the user is tilting forward, the apparatus may be operated to initiate a forward step. For example, walking forward may include a repeated sequence of leg swings. A leg swing may include a sequence of operations that includes raising a trailing leg, extending the raised leg forward, and lowering the leg. Typically, user's hands may move forward to cause a forward tilt (or "prevented fall"),, raising a trailing leg from the ground. When the trailing leg is clear of the ground, the exoskeleton device may initiate a the above sequence of operations. The above sequence of operation may thus swinging the initially trailing leg forward to rest on the ground at a point ahead of the initially leading leg. In this manner, the apparatus may assist the user to walk forward.

Therefore, a tilt sensor of a locomotion assisting exoskeleton device in accordance with embodiments of the present invention is located on a part of the apparatus that tilts with the device. For example, the tilt sensor may be located on a brace of the apparatus that is designed to attach to the lower or upper torso of the user. For example, the tilt sensor may be mounted on a side, back, or front panel of a trunk support designed to be attached to the user's lower torso. The tilt sensor may alternatively be mounted on any component of the exoskeleton device that is substantially rigidly attached to such a brace. For example, a backpack of the exoskeleton device may be rigidly attached to a trunk support, or attached via a substantially rigid connector that enables no more than a small amount of give. In such a case, the tilt sensor may be mounted on or within the backpack.

<FIG> is a side view of a locomotion assisting exoskeleton device in accordance with some embodiments of the present invention. <FIG> is a front view of the apparatus shown in <FIG>. <FIG> is a block diagram of control of the apparatus shown in <FIG>.

Components of exoskeleton device <NUM> may be attached to the body of a user. For example, a trunk support <NUM> may attach to the user's lower torso above the pelvis. Leg segment braces <NUM> may each attach to a section of the user's leg. Bands or straps, such as straps <NUM>, connected to trunk support <NUM> and leg segment braces <NUM>, may at least partially wrap around parts of the user's body. Thus, straps <NUM> may ensure that each component brace of exoskeleton device <NUM> attaches to an appropriate corresponding part of the user's body. Thus, motion of the component brace may move the attached body part. Typically, components of exoskeleton device <NUM> may be adjustable so as to enable optimally fitting exoskeleton device <NUM> to the body of a specific user.

Component braces of exoskeleton device <NUM>, such as trunk support <NUM> and leg segment braces <NUM>, may connect to one another via joints <NUM>. For example, two leg segment braces <NUM> may connect at knee joint 16a. A leg segment brace <NUM> and trunk support <NUM> may connect at hip joint 16b. Each joint <NUM> may include an actuator <NUM> for actuating relative angular motion between components connected by each joint <NUM>.

Each actuator may be controlled by controller <NUM>. For example, controller <NUM> may be located in backpack <NUM> of exoskeleton device <NUM>. Alternatively, components of controller <NUM> may be incorporated into trunk support <NUM>, leg segment braces <NUM>, or other components of exoskeleton device <NUM>. For example, controller <NUM> may include a plurality of intercommunicating electronic devices. The intercommunication may be wired or wireless. Similarly, communication between controller <NUM> and components of exoskeleton device <NUM>, such as an actuator <NUM> or a sensor or control, may be wired or wireless.

Controller <NUM> may be powered by power supply <NUM>. For example, power supply <NUM> may include one or more rechargeable batteries and appropriate electronic circuitry to enable recharging of the batteries (e.g. by connection to an external power supply). Power supply <NUM> may be located in backpack <NUM>.

Each joint <NUM> may also be provided with an angle sensor <NUM> for sensing a relative angle between components connected by joint <NUM>. An output signal from each angle sensor <NUM> may be communicated to controller <NUM>. The output signal may indicate a current relative angle between connected components.

Tilt sensor <NUM> may be mounted on trunk support <NUM>. Alternatively, tilt sensor <NUM> may be located on any other component of exoskeleton device <NUM> whose angle of tilt reflects the angle of tilt of the trunk support of exoskeleton device <NUM>. An output signal from tilt sensor <NUM> may be communicated to controller <NUM>. The output signal may indicate, for example, an angle between trunk support <NUM> and the vertical.

Exoskeleton device <NUM>, in accordance with some embodiments of the present invention, may include one or more additional auxiliary sensors <NUM>. For example, auxiliary sensors <NUM> may include one or more pressure-sensitive sensors. For example, a pressure-sensitive sensor may measure a ground force exerted on exoskeleton device <NUM>. For example, a ground force sensor may be included in a surface designed for attachment to the bottom of the user's foot.

Exoskeleton device <NUM> may be provided with one or more controls for enabling user input or other external input. For example, exoskeleton device <NUM> may include a remote control set <NUM>. Remote control set <NUM> may include one or more pushbuttons, switches, touch-pads, or other similar manually operated controls that a user may operate. Typically, remote control set <NUM> may include one or more controls for selecting a mode of operation. For example, operation of a control of remote control set <NUM> may generate an output signal for communication to controller <NUM>. The communicated signal may indicate a user request to initiate or continue a mode of operation. For example, the communicated signal may indicate to the controller to initiate or continue a walking forward operation when appropriate sensor signals are received. As another example, remote control set <NUM> may include a control for turning exoskeleton device <NUM> on or off.

Typically, remote control set <NUM> may be designed for mounting in a location that is readily accessible by the user. For example, remote control set <NUM> may be provided with a band or strap. The strap may enable attaching remote control set <NUM> to the user's wrist or arm (as shown in <FIG>). In this manner, remote control set <NUM> may be conveniently operated by fingers the arm opposite the arm on which it is mounted arm. Alternatively, remote control set <NUM>, or part of it, may be mounted on a crutch, on the front of the user's torso, on the front of trunk support <NUM>, or any other readily accessible location. Alternatively, remote control set <NUM> may include several detached controls, each communicating separately with controller <NUM> and each mounted at a separate location.

A locomotion assisting exoskeleton device in accordance with embodiments of the present invention may be operated to assist a disabled user to walk. For example, one or more joints <NUM> and leg segment braces <NUM> may be controlled so as to move the legs in a manner to enable a selected activity. For example, joints <NUM> and leg segment braces <NUM> may be manipulated in order to enable a user to walk. Control of a joint <NUM> may depend on previous actions performed and on input from at least an angle sensor <NUM> and tilt sensor <NUM>.

<FIG> schematically illustrates a method for controlling a locomotion assisting exoskeleton device in accordance with embodiments of the present invention to enable a user to take a step. <FIG> is a flow chart of a method for taking a step, in accordance with embodiments of the present invention. The illustrated method includes swinging leg 44a, which is initially (stage 40a) a trailing leg, forward. At the conclusion of the step (stage 40j), leg 44a is positioned ahead of initially leading leg 44b. The method may then be repeated with the legs 44a and 44b reversing their roles. The illustrated method assumes that the user is provided with, and is capable of manipulating, a pair of crutches. In the description below, reference is also made to components shown in <FIG>.

In order to be effectively assisted by the illustrated method, a user may require training and practice. For example, training may entail practice sessions using the exoskeleton device in conjunction with such other equipment as parallel bars or a walking frame. Various stages of a training program may teach a user how to maintain balance and how to walk when using the exoskeleton device. In addition, during the training program, a control program stored in a memory associated with controller <NUM> (<FIG>) may be adapted to a particular user. For example, a parameter indicating a threshold tilt angle or joint flexing angle may be adjusted in order to suit the capabilities or preferences of a particular user. The user may learn how to coordinate manipulation of the crutches with actions by the exoskeleton device in order to optimize effectiveness of the assisted walking.

For example, in stage 40a of the illustrated method, it is assumed that leg 44b is initially a leading leg, and leg 44a is initially a trailing leg. Both legs 44a and 44b are initially resting on the ground or other supporting surface, and both legs 44a and 44b approximately equally support the weight of the user's body. The user may signal a desire to walk forward, e.g. by operating a control of remote control <NUM> (step <NUM> of <FIG>). The user may initiate a step by moving crutches <NUM> forward. (Although crutches <NUM> are schematically illustrated in the form of a single line segment, it should be understood that typically a pair of crutches is referred to. The crutches, typically positioned on opposite sides of the user's body, are typically moved forward in parallel with one another. ) As crutches <NUM> are moved forward, exoskeleton device <NUM>, with the user, tilts forward.

During this time, the controller monitors tilt sensor <NUM> (step <NUM> of <FIG>) to determine whether the indicated tilt is sufficient (e.g. greater than a threshold tilt angle value) to enable swinging leg 44a forward (step <NUM>). If the indicated tilt angle is not sufficient, a time of a timer may be compared with a threshold time (step <NUM>). For example, a timer may start when operation of a control of remote control <NUM> indicates a desire to initiate a walk sequence, or when tilt sensor <NUM> indicates beginning to tilt. Alternatively, a plurality of timers (or timer functions) may monitor time elapsed from a plurality of trigger events. If an elapsed time indicates timing out, exoskeleton device <NUM> may initiate a sequence to exit from a walk mode (step <NUM>). For example, exoskeleton device <NUM> may initiate a "standing stance" mode to bring the user to a standing position. Alternatively, operation may stop until a further control signal is received.

If a timeout is not sensed, monitoring of tilt signals continues (returning to step <NUM>).

In stage 40b, the user continues to move crutches <NUM> forward, and exoskeleton device,<NUM> with the user, continues to tilt forward. The weight of the user's body begins to shift toward leg 44b, which is a leading leg.

In stage 40c, crutches <NUM> are in a forward position. The user's elbows begin to bend so as to enable exoskeleton device <NUM> to continue to tilt forward. Leg 44a begins to be raised so as to discontinue contact with the ground. The weight of the user's body is now supported by leg 44b and crutches <NUM>.

In stage 40d, continued bending of the user's elbow may cause exoskeleton device <NUM> to tilt forward sufficiently to trigger exoskeleton device <NUM> to initiate a step. For example, at this point, a tilt sensor <NUM> may generate a tilt signal. The generated tilt signal may be processed (e.g. by controller <NUM>) to indicate that the tilt angle of exoskeleton device <NUM> is equal or greater than a threshold angle. A tilt angle equal to the threshold angle may trigger initiation of a step sequence (step <NUM>). Controller <NUM> may then, upon receiving the generated tilt signal, initiate a control program to operate exoskeleton device <NUM> so as to start a step by swinging leg 44a forward.

In stage 40e, exoskeleton device <NUM> begins to swing leg 44a forward. For example, controller <NUM> may cause knee joint 16a of leg 44a to flex by a predetermined angle. Concurrently, controller <NUM> may cause hip joint 16b of leg 44a to begin flexing forward, thus swinging leg 44a forward (step <NUM>). During motion of leg 44a, controller <NUM> may monitor output signals of one or more angle sensors <NUM> (step <NUM>) to verify that leg 44a is moving in accordance with predetermined criteria. Monitoring of the output signal may also indicate whether the step is complete, or whether to continue forward motion of leg 44a (step <NUM>).

In stage 40f, exoskeleton device <NUM> continues to swing leg 44a forward. For example, controller <NUM> may continue to flex hip joint 16b of leg 44a so as to swing leg 44a forward. Concurrently, hip joint 16b' of leg 44b extends to raise the trunk <NUM> towards an upright position (similar to its position in stage 40a). The user may push downward on crutches <NUM> in order to help this operation.

In stage <NUM>, exoskeleton device <NUM> continues to move leg 44a forward and 44b backward to as to approach each other. For example, controller <NUM> may continue to operate hip joint 16b of leg 44a so as to swing leg 44a forward, and hip joint 10b' and of leg 44b to extend and straighten leg 44b.

In stage <NUM>, exoskeleton device <NUM> continues to move leg 44a forward ahead of leg 44b and to extend leg 44b. For example, controller <NUM> may continue to operate hip joint 16b of leg 44a so as to swing leg 44a forward and hip joint 10b' of leg 44b to straighten leg 44b.

In stage 40i, exoskeleton device <NUM> continues to move leg 44a forward and leg 44b backward. For example, controller <NUM> may continue to operate hip joint 16b of leg 44a and extend hip joint 16b' of leg 44b so as to swing leg 44a forward. Concurrently, exoskeleton device <NUM> may extend knee joint 16a to straighten leg 44a. For example, controller <NUM> may receive a signal from angle sensors <NUM> of hip joints 16b and 16b'. The sensed signal may indicate that a sensed angle is within a predetermined range of angles indicating a completed step (step <NUM>). Controller <NUM> may then operate knee joint 16a of leg 44a so as to extend and straighten leg 44a. During the straightening operation, controller <NUM> may monitor signals from angle sensors <NUM> of knee joint 16a of leg 44a to verify when the leg is sufficiently straight so as to stop operation of knee joint 16a.

In stage 40j, leg 44a is extended forward and is a leading leg, while leg 44b is a trailing leg. Thus, stage 40j is essentially identical to stage 40a, with the roles of legs 44a and 44b reversed. Thus, exoskeleton device <NUM> has performed a single step. If the walk mode is still selected (step <NUM>), stages 40a-40j may be repeated, with the roles of legs 44a and 44b reversed (return to step <NUM>). Continued operation in this manner may enable a user to whom exoskeleton device <NUM> is attached to walk.

If walk mode is no longer selected, the walking operation may stop. For example, exoskeleton device <NUM> may cause the user to change to a standing stance (step <NUM>). Alternatively, the device may stop operation and ignore any further tilt signals.

As discussed above, a user may practice walking with exoskeleton device <NUM> in order learn to coordinate body movements and crutches movements with operation of exoskeleton device <NUM>. For example, a training program may begin with practicing balance and walking using exoskeleton device <NUM> between parallel bars. The user may then progress to learning to balance using exoskeleton device <NUM> with crutches or a walking frame. Finally, the user may practice walking using exoskeleton device <NUM> and crutches, so as to execute the method illustrated in <FIG>.

In accordance with some embodiments of the present invention, an operation method may include monitoring a signal generated by tilt sensor <NUM> in conjunction with signals generated by one or more angle sensors <NUM>. For example, the signals may indicate an unexpected configuration or combination of sensor readings. In this case, controller <NUM> may execute one or more activities to verify proper operation or to prevent further unexpected situations. For example, controller <NUM> may generate an audible, visible, or palpable alert to the user, using an appropriate warning device. Concurrently, controller <NUM> may pause or stop operation of exoskeleton device <NUM> until receiving a confirmation signal from the user. For example, the user may operate remote control <NUM> to indicate continuation of an operation, or alternatively, aborting an operation. When aborting an operation, controller <NUM> may operate exoskeleton device <NUM> so as to assist in maintaining the stability of the user. Similarly, if the generated signals are consistent with an emergency situation, such as falling, controller <NUM> may operate exoskeleton device <NUM> in a predetermined manner so as to minimize any risk of injury to the user.

In accordance with some embodiments of the present invention, exoskeleton device <NUM> may be provided with one or more ground force sensors. For example, a ground force sensor may be located on a foot support designed to support a foot of the user. For example, execution of an operation by exoskeleton device <NUM> may be dependent on receiving one or more predetermined signals from the ground force sensors.

Claim 1:
A locomotion assisting exoskeleton device (<NUM>) comprising:
a plurality of braces including a trunk support (<NUM>) for affixing, in use, to a part of the torso of a person and leg segment braces (<NUM>), wherein each leg segment brace (<NUM>) connects, in use, to a section of a leg of the person;
at least one motorized joint (<NUM>) for connecting a leg brace (<NUM>) of each leg to said trunk support (<NUM>) and for providing relative angular movement between each leg brace (<NUM>) and the trunk support (<NUM>);
at least one tilt sensor (<NUM>) mounted on the trunk support (<NUM>) for sensing a forward tilt of the trunk support (<NUM>) of the exoskeleton and generating a signal corresponding to the tilt; and
a controller (<NUM>):
for receiving the generated signal from said at least one tilt sensor (<NUM>) and
programmed with an algorithm with instructions for actuating the at least one motorized joint of each leg brace (<NUM>) for forward movement of the exoskeleton in accordance with the sensed signal indicating the person desires to walk forward upon the generated signal indicating the sensed forward tilt being equal to or greater than a threshold value within a threshold time.