1. Field of the Invention
The present invention generally relates to orthotic devices, and, more particularly, to actively controlled orthotic devices having active components that can dynamically change the structural characteristics of the orthotic device according to the orientation and locomotion of the corresponding body part of the subject, or according to the changing needs of the subject over a period of use.
2. Description of Related Art
Conventional treatments of gait pathologies, such as drop-foot, spasticity, contractures, ankle equinus, crouch gait, etc., associated with neuromuscular disorders, such as cerebral palsy, may employ a passive mechanical brace to support the body parts involved in balance and gait. Depending on the severity of the gait pathology, the brace may be applied to the hip, knee, ankle, or any combination thereof to improve balance and gait and to help prevent injuries.
While passive mechanical braces may provide certain benefits, they may also lead to additional medical problems. For example, a typical treatment for preventing the foot from dragging on the ground in the case of drop-foot requires the patient to use an ankle foot orthotic (AFO). Rigid versions of the AFO constrain the ankle to a specific position, while hinged or flexible versions of the AFO allow limited plantar and dorsal flexion. By limiting the range of ankle motion, the toe can clear the ground thus allowing gait to progress more naturally and promoting increased walking speeds, increased step lengths, and reduced energy consumption during gait when compared to a subject without the device. However, the use of the AFO may result in a reduction in power generation at the ankle, as the AFO limits active plantar flexion. Additionally, the use of the AFO may lead to increased transverse-plane rotation on the knee depending on the AFO alignment. As such, the use of the AFO may yield new gait abnormalities and knee problems over time. Moreover, rigid versions of the AFO may lead to disuse atrophy of the muscles, such as the tibialis anterior muscle, potentially leading to long-term dependence on the AFO.
To address the problems caused by the rigidity of conventional orthotic devices, attempts have been made to increase the flexibility of orthotic devices and to allow a greater range of motion. However, some designs for flexible orthotic devices often fail to provide sufficient flexibility to overcome the disadvantages of a typical rigid device and to provide a desired range of motion. Moreover, although other designs of orthotic devices may provide sufficient flexibility, they generally fail to take into account the individual characteristics of the subject's movement and the subject's other possible pathological conditions. Indeed, designs for flexible orthotic devices are typically passive. As such, the devices cannot be dynamically adjusted to accommodate characteristics specific to a subject during the subject's movement. In addition, the devices cannot be dynamically adjusted to accommodate the changing needs of the subject over a period of use. In general, typical flexible orthotic devices fail to provide appropriate levels of support and assistance during the subject's movement.
To address the deficiencies of typical orthotic devices, systems and methods according to aspects of the present invention include an actively controlled orthotic device having active components that can dynamically change the structural characteristics of the orthotic device according to the orientation and locomotion of the corresponding body part, or according to the changing needs of the subject over a period of use. Accordingly, the orthotic device according to aspects of the present invention can be effectively employed to provide locomotion assistance, gait rehabilitation, and gait training.
In one embodiment, an orthotic system includes: a garment formed from a flexible material and shaped to be worn over a body part; at least one sensor coupled to the garment, the at least one sensor providing information indicating an orientation of the body part; at least one active component incorporated with the garment, wherein in response to an actuation signal, the at least one active component changes state and causes the garment to be structurally modified; and a control system coupled to the sensor and the at least one active component, the control system being configured to receive the orientation information from the at least one sensor and provide the actuation signal to the at least one active component according to the orientation information, whereby the modification of the garment encourages a change in the orientation of the body part or provides a different level of orthotic support to the body part.
In another embodiment, an orthotic system includes: a garment formed from a flexible material and shaped to be worn over a body part; at least one active component incorporated with the garment, wherein in response to an actuation signal, the at least one active component changes state and causes the garment to be structurally modified; and a control system coupled to the at least one active component, the control system being configured to provide different actuation signals to the at least one active component over a period of use corresponding to a rehabilitation of the body part, the state of the at least one active component being modified according to the different actuation signals, whereby the garment provides different levels of assistance or support to the body part over the period of use.
A further embodiment provides a method for operating an orthotic system, the orthotic system including a garment positioned over a body part, the garment being formed from a flexible material, the method including: receiving, from at least one sensor coupled to the garment, information indicating an orientation of the body part; and in response to receiving the information from the at least one sensor, sending an actuation signal to at least one active component incorporated with the garment, wherein in response to an actuation signal, the at least one active component changes state and causes the garment to be structurally modified, whereby the modification of the garment encourages a change in the orientation of the body part or provides a different level of orthotic support to the body part.
Yet a further embodiment provides a method for operating an orthotic system, the orthotic system including a garment positioned over a body part, the garment being formed from a flexible material, the method including: receiving, from at least one sensor coupled to the garment, information indicating an orientation of the body part; and in response to receiving the information from the at least one sensor, sending different actuation signals to the at least one active component over a period of use corresponding to a rehabilitation of the body part, the state of the at least one active component being changed according to the different actuation signals, whereby the garment provides different levels of assistance or support to the body part over the period of use.
These and other aspects of the present invention will become more apparent from the following detailed description of the preferred embodiments of the present invention when viewed in conjunction with the accompanying drawings.
Referring to
Although the garment 12 of the orthotic system 10 is specifically shaped as a knee brace, other embodiments according to aspects of the present invention may additionally or alternatively be applied to other parts of the subject's body. For example, an embodiment may include a garment that is shaped as a sock, where the active components assist with pronation and supination in addition to plantar and dorsal flexion of the foot and ankle. The sock-shaped garment can be applied exclusively or in combination with the knee-brace-shaped garment 12 shown in
Referring to
The sensors 110 shown in
The active components 120 include variable and adaptable materials that can be actively controlled to change the material characteristics of the garment 102 in response to changes in orientation and locomotion state. The active components 120 can be directly or indirectly connected to the portable power source 130 and the control system 140. The portable power source 130, for example, can be a portable battery pack. Meanwhile, the control system 140 can include a control board with computer processing hardware, e.g., a microprocessor, that executes programmed instructions stored on a readable storage medium, e.g., non-volatile memory. In particular, the control system 140 dynamically receives orientation information, i.e., signals, from the sensors 110, processes the signals, and actively controls the active components 120 to apply varying assistive and supportive contact to the corresponding body part.
The portable power source 130 can be attached to the garment 102 or can be carried separately on another part of the subject's body. For example, the portable power source 130 can be worn on a belt around the waist. Alternatively, the portable power source 130 may be stored in a shoe proximate to the position of the garment 102. Preferably, in some embodiments, the garment 102 is not coupled to components that are not wearable or otherwise portable. In other words, aspects of the orthotic system 100, including the battery pack 130 and the control system 140, are conveniently combined to be easily portable, and the garment is not connected by wires to a separate external computer, plug-in power supply, etc., which may prevent the subject from moving to desired locations while wearing the garment 102.
As shown further in
In some embodiments, the movement assistance 122 can be achieved by employing shape memory alloy wires 123 in varying arrangements as illustrated in
For some materials, such as shape memory alloys, subsequent forces may be necessary to return the materials to a neutral state. In some embodiments, the orthotic system 100 can employ a configuration of opposing active components 120, for example, where the material of a particular active component is returned to a neutral state by actuating the opposing active component. For example, the wires 123 disposed along the back of the knee 2 shown in
By way of example,
Although
Thus, materials for the active components 120 can include, but are not limited to, shape memory alloys (e.g., Nitinol), shape memory polymers, ferro-fluids, magnetorheological fluids, electrorheological fluids, piezoelectric polymers, mechanochemical polymers, electroactive polymers, conductive polymers, electrostatic devices, pneumatic actuators, traditional electromagnetic devices (e.g., rotary motors and linear actuators), or any combination thereof. When actuated by the control system 140, these materials convert electrical energy as supplied by the portable power source 130 into mechanical energy.
In some embodiments, the stiffening 126 shown in
Accordingly, in one example, a system of sealed capillaries with MR fluids, ferro-fluids, or ER fluids and their corresponding conductive wires can be incorporated into the garment 102 to provide the stiffening 126, while a system of pneumatic actuators can be incorporated into the garment 102 to provide the motion assistance 122. In some cases the garment 102 can include multiple layers, where at least one layer includes at least one pneumatic actuator and at least one separate layer includes the stiffening capillaries. Alternatively, the pneumatic actuators and the stiffening capillaries can be incorporated into the same layer of the garment 102.
Although some embodiments can employ inertial measurement units, accelerometers, or the like to determine orientation of the knee, e.g., the amount of knee bend, the orientation can also be determined by identifying the relative positions of points mapped to the knee, as shown in
In some embodiments, the active components 120 can be coupled to the control system 140 according to separate connections, so that the control system 140 can control each active component 120 individually. As such, the control system 140 has the ability to vary the amplitude and duration of the action by each active component 120. The structural properties of each section of the garment 102 can be selectively controlled to provide the most appropriate combination of movement assistance and support for the body part in response to its orientation and locomotion at a given time. In other words, the active components 120 can be varied in stiffening and force production (amplitudes, durations) to provide effective assistance while still allowing the user to control the preferred motion and have a normal range of motion.
As shown in
With individualized control of each active component 120, the control system 140 can employ the decentralized control framework described in WIPO Publication No. WO/2009/058982 corresponding to PCT Application No. PCT/US2008/081759, filed Oct. 30, 2008 and titled ENVIRONMENTALLY-ADAPTIVE SHAPES WITH A MULTI-AGENT SYSTEM, the contents of which are incorporated entirely herein by reference. As such, the control system 140 can employ several modules that locally perform computations and control the active components 120 in a decentralized manner according to these computations. However, it is understood that the control system 140 can alternatively employ centralized control of the active components 120, where one module is responsible for performing the computations and sending a signal to all actuated components 120. The control system can activate different combinations of actuators in particular sequences, based upon sensor information about the spatial and temporal relationship of ongoing motion of the body segments.
In view of the foregoing, the orthotic device according to aspects of the present invention can be effectively employed to provide locomotion assistance, gait rehabilitation, and gait training. By providing active control in response to sensed orientation and locomotion, embodiments can take the subject's individual characteristics into account and dynamically meet the subject's individual needs. Such active control may promote more appropriate use of muscles and possibly leading to a re-education of the motor system and eventual independence from the orthotic device.
Moreover, some embodiments can provide adaptive control framework such that the level of movement assistance and stiffening provided is reduced, increased, or selectively modified over time based on the abilities of the subject as well as the progress and plan for the subject's rehabilitation and/or gait training. Indeed, aspects of the present invention can involve the use of the garment 102 as a supportive orthotic or a rehabilitative aid. When used as a supportive orthotic, for example, the garment 102 can be worn at all times when support or minor adjustment to gait is required. In this application, the control system 140 may not change the level of support over time. When used as a rehabilitative aid, for example, the garment 102 can be worn while neuromuscular function is gained or regained. In this application, however, the control system 140 can change the level of support over time.
A particular application of orthotic systems according to aspects of the present invention can focus on improving gait due to pathologies associated with cerebral palsy. However, the orthotic system can be applicable to many different mobility-impaired populations, including those with neuromuscular disorders from traumatic brain injury, loss of function due to aging or disease (e.g., MS, diabetes, etc.), or injuries, such as, those sustained during combat.
While the present invention has been described in connection with a number of exemplary embodiments, and implementations, the present inventions are not so limited, but rather cover various modifications, and equivalent arrangements.
This application is a Continuation application of International Application No. PCT/US2010/042106 filed on Jul. 15, 2010, which claims priority to U.S. Provisional Patent Application No. 61/225,788, filed Jul. 15, 2009, the entire contents of both applications are incorporated herein by reference.
Number | Date | Country | |
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61225788 | Jul 2009 | US |
Number | Date | Country | |
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Parent | PCT/US10/42106 | Jul 2010 | US |
Child | 13350031 | US |