Electrical stimulation for orthopedic devices

Abstract

An orthopedic device includes a brace support having at least one strap for providing corrective orientation of a joint and unloading of the joint, and an electrical stimulation system for providing an electrical signal to a user's musculature at or proximate to the joint. The electrical stimulation system provides at least one electrical pulse to the musculature in supplement to the corrective orientation of the joint to induce contraction of the musculature. The electrical stimulation system may include at least one electrode for generating the electrical pulse, and a sensor module for determining movement and orientation of a user's limb for selectively activating the at least one electrode according to predefined criteria and feedback from the sensor module.

Claims

1. An orthopedic device comprising: a brace support arranged for a knee and having at least one dynamic force strap for providing corrective orientation of a knee joint and unloading of the knee joint, the at least one dynamic force strap arranged to secure to upper and lower frame portions connected to one another by an upright including a hinge, a first end of the at least one dynamic force strap connected to the upper frame portion and a second end of the at least one dynamic force strap connected to the lower frame portion, the at least one dynamic force strap urging a force toward the upright during extension of the knee joint; and an electrical stimulation system including a control unit, at least one electrode, and a sensor module, the sensor module arranged to detect movement and orientation of a user's leg, the control unit selectively operating the at least one electrode according to feedback from the sensor module, the feedback from the sensor module, the electrical stimulation system arranged to selectively generate, at certain stages of a user's gait, an electrical impulse by the at least one electrode delivered to a user's vastus medialis to provide stimulation to the vastus medialis depending on a load level going through an affected knee compartment in supplement to the corrective orientation of the knee joint resulting from the force applied by the at least one dynamic force strap.

2. The orthopedic device of claim 1, wherein the control unit is on a garment that holds the control unit as a user wears the device and undergoes movement, the control unit connects to the at least one electrode mounted on a thigh liner carried by an upper frame of the brace support.

3. The orthopedic device of claim 1, wherein the at least one electrode is located on a medial side of the brace support, and the at least one dynamic force strap including first and second dynamic force straps arranged to extend above and below, respectively, a knee joint on a lateral side of the brace support, the first and second dynamic force straps intersecting between the lateral and medial sides of the brace support.

4. The orthopedic device of claim 1, wherein the orthopedic device includes a garment disposed between the brace support and the user's leg, the garment arranged as a sleeve.

5. The orthopedic device of claim 4, wherein the upper frame portion is semi-rigid and the garment is substantially flexible and compressible, the at least one dynamic force strap is arranged to spiral between the upper frame portion and the lower frame portion.

6. The orthopedic device of claim 1, further comprising a garment located between the brace support and the user's leg, the garment carrying the at least one electrode.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The inventive orthopedic device is described referring to the accompanying drawings showing preferred embodiments according to the device described. The device as disclosed in the accompanying drawings is illustrated for example only. The elements and combinations of elements described below and illustrated in the drawings can be arranged and organized differently to result in embodiments still within the spirit and scope of the device described.

(2) FIGS. 1A and 1B are schematic views showing loads on a leg of a user from an osteoarthritis knee support.

(3) FIG. 2 is a schematic view showing an embodiment of an orthopedic device.

(4) FIG. 3 is a schematic view showing another embodiment of an orthopedic device.

(5) FIG. 4 is a schematic view showing another embodiment of an orthopedic device over the leg of the wearer.

(6) FIG. 5 is a detailed view showing the orthopedic device of FIG. 4.

(7) FIG. 6 is a detailed view of a liner used in the orthopedic device of FIG. 5.

(8) FIG. 7 is an exemplary graph showing the stimulation over positions of gait.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

A. Overview

(9) A better understanding of different embodiments of the disclosure may be had from the following description read with the accompanying drawings in which like reference characters refer to like elements.

(10) While the disclosure is susceptible to various modifications and alternative constructions, certain illustrative embodiments are in the drawings. They also will be described below. It should be understood, however, there is no intention to limit the disclosure to the specific embodiments disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, combinations, and equivalents falling within the spirit and scope of the disclosure and defined by the appended claims.

(11) It will be understood that, unless a term is expressly defined in this disclosure to possess a described meaning, there is no intent to limit the meaning of such term, either expressly or indirectly, beyond its plain or ordinary meaning.

(12) Any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. §112, paragraph 6.

(13) FIG. 2 provides an exemplary embodiment of an orthopedic device 2 having both a knee support 10 and a garment 12. The knee support 10 is in the form of an OA brace generally of the type described in U.S. Pat. No. 7,198,610, whereas the garment 12 is in the form of a sleeve. The garment 12 includes an electrical stimulation system including a controller/processor 14 and a plurality of electrodes 16 connected to the controller 14. At least one sensor or accelerometer 18, 20 is either on the OA brace 12 (such as on the struts 22) or on the garment 12.

(14) As shown in FIG. 2, the first and second straps 24, 26 secure to upper and lower frame portions 25, 27. The upper and lower frame portions 25, 27 are connected to one another by an upright 29 including a hinge 31, as discussed in connection with U.S. Pat. No. 7,198,610. The first and second straps 24, 26 are arranged to urge a dynamic force counteracted by the upright 29 depending upon articulation of the hinge 31.

(15) Support may be of any type of brace, and is not limited to the leg or knee. The garment may be formed from a textile or other suitable material providing a low-profile, lightweight soft device.

(16) The OA brace 10 includes straps 24, 26 applied a load to the knee, which the quadriceps resists at least in part the load on the knee. From this recognition, the user can strengthen or at least use the quadriceps to inhibit the possibility of atrophy. When combined with the garment 12, the electrodes 16 can activate certain muscles, such as the quadriceps, at certain stages of the gait cycle (such as at extension). Alternatively, the electrodes 16 may provide a signal to the user to activate certain muscles on his own to know when to tighten, contract or otherwise employ, his muscles at particular stages of the gait cycle and activate muscles despite wearing a knee support. In yet another alternative, the electrodes can be arranged to block pain at strategic locations about the knee.

(17) When used in supplement to the OA brace, the electrical stimulation system allows for improved activation of certain muscles by electrical stimulation, enhancing the impact from the OA brace. In the instance of an OA brace configured to provide pain relief from compartmental arthritis of the knee, the electrical stimulation system can strengthen the certain muscle groups and cause them to activate in a timely manner.

(18) The electrical stimulation system can be adapted so it is dynamically increased or decreased over the gait cycle or activated from on and off settings at certain positions of the gait cycle. The electrical stimulation system can adapt to various walking conditions, such as inclines and stairs, to provide the stimulation over changed conditions.

(19) The garment 12 may be worn over the leg with or without the OA brace. If the user has reached a certain strength level of the leg and respective muscles and the OA brace is unnecessary, the garment 12 be used alone as a reminder to the user of when to use certain muscles in a gait cycle, or can activate muscles at certain movements.

(20) The embodiment of FIG. 3 exemplifies a garment 28 not limited locally to the OA brace 10, but extends to certain muscles including the gluteus medius with electrodes 30. It has been found that knee issues are related to the hip muscles so that working the quadriceps may not be sufficient for some users. Connection of electrodes 30 to the gluteus medius and/or other relevant muscles may attribute to enhanced realignment of the knee in combination with the OA brace.

(21) The electrical stimulation system, at least for treatment of osteoarthritis of the knee, may be arranged according to the adduction moment gait waveform of the user or may be selectable among a variety of osteoarthritis stages. The controller/processor may include a menu by which the user can select different levels of electrical stimulation indexed to various adduction moment gait waveforms. As the user goes through the gait cycle, and the movement of the user is tracked by the electrical stimulation system, the electrical stimulation is activated according to a selected level. The electrical stimulation is dynamic in that it varies according to the gait cycle.

(22) In the embodiment of FIGS. 4-6, an orthopedic device 50 includes a brace support 56 having the general configuration of the OA brace 10 having at least one strap 58, 60) for providing corrective orientation of a joint and unloading of the joint. The OA brace 56 includes an upper frame 62 connected to a lower frame 64 mounted on the lower leg portion LL by upper and lower struts 72, 74 secured to one another by a hinge 66.

(23) The orthopedic device 50 has an electrical stimulation system 51 for providing an electrical signal to a user's musculature at or proximate to the joint. The electrical stimulation system 51 provides at least one electrical pulse to the musculature in supplement to the corrective orientation of the joint to induce contraction of the musculature. The electrical stimulation system may include at least one electrode (70) for generating the electrical pulse and a control unit 52 connected at the user's hip H or waist and the at least one electrode 70.

(24) The connection of the control unit 52 may be to a belt or garment that holds the control unit as the user wears the device and undergoes movement. The control unit 52 connects to the least one electrode 70 mounted on a thigh liner 68 carried by an upper frame 62 of the OA brace extending over the upper leg portion UL.

(25) The orthopedic device includes a sensor module for determining movement and orientation of a user's limb for selectively activating the at least one electrode according to predefined criteria and feedback from the sensor module. The sensor module may include sensors 76, 78 at various locations of the brace support 56.

(26) Force straps 58, 60 extend between the upper and lower frames 62, 64, and arranged to spiral about the user's upper and lower leg portions UL, LL. The force straps 58, 60 tighten around the upper and lower leg portion UL, LL and exert forces on the knee F1, F2 when the user's leg goes into extension.

(27) The electrode 70 is aligned or arranged proximate to the vastus medialis 54 of the user's upper leg portion UL. Placing the electrode 70 on the liner 68 assures proper alignment of the electrode 70 with the vastus medialis. The electrode 70 may be secured to the liner by glue or detachably secured by hook and loop fasteners, or by other means. The liner may be of the type described in U.S. patent application publication no. 2011/0218471, published on Sep. 8, 2011 and incorporated in its entirety. Multiple electrodes may be installed on the liner or at other select portions of the OA brace or separate components.

(28) The control unit 52 is arranged to provide a signal to the electrode 70 depending on a variety of factors. The control unit can have both pre-set programs arranged to deliver both TENS and NMES signals depending on the desired treatment.

(29) According to a variation, the control unit has a gait setting arranged to change control to an accelerometer attached to the lower frame of the device 50. The accelerometer can detect changes in gait speed and the type of gait the person of walking. Differences in gait include walking on level ground, up/down stairs or incline, or the speed of the gait such as for walking or running. Depending on the type of gait, the electrode is controlled or modified in intensity and function to provide stimulation to the vastus medialis depending on the load level going through the affected compartment. The function of the electrode may be activated only as needed, just as the force straps of the OA brace only apply force as need.

(30) The control unit may be arranged to allow the user to adjust the level of stimulation applied both during the present conditions and during the gait pattern control. This arrangement considers a predetermined severity of osteoarthritis in correlation to the pain the user experiences prior to getting the orthopedic device. Users having more pain may require a higher level of stimulation during gait than users with less pain.

(31) In observing FIG. 7, a graph shows how the orthopedic device affects the user's pain over a gait cycle. The x-axis is the range of motion of the knee showing the complete stance phase, and the y-axis is the adduction moment going through the knee. The peak A represents the highest adduction moment going through the knee right after heel strike at 0 degrees. The peak B is at push off with the knee at full extension.

(32) Reference line 80 illustrates a user having osteoarthritis pain over gait with the peaks representing extension and flexion, and reference line 86 represents a user without osteoarthritis pain. Reference line 82 contrasts the user's pain with an OA brace versus reference line 84 representing a user wearing the orthopedic device including both the OA brace and the controllable electrode. The overall pain is reduced compared to using an OA brace, and is much closer to that of the reference line 84 for a user without osteoarthritis.

(33) At least one electrode and/or at least one sensor can be incorporated into the liner body itself or may alternatively be placed on the frames, struts or hinge of the brace support, or remotely from the brace support either on a garment or by themselves or by other known means. In another variation, at least one electrode and/or at least one sensor may be separately applied to the user's leg, both upper and/or lower leg portions, and/or at the knee by a garment or other type of attachment means. At least one electrode and/or at least one sensor may be placed into or onto sleeves, socks, bands, or as other layers of material that may be incorporated into the OA brace or other devices placed over the user's limbs.

(34) At least one electrode and/or at least one sensor may be held in place through grooves, channels, pockets, and/or other attachment means. The pockets may have opened or closed ends for selectively installing or removing the at least one electrode and/or at least one sensor. Further, an array or electrodes and/or sensors may extend over the liner or other portions of the OA brace or separate components aimed to carry the at least one electrode and/or at least one sensor. The electrodes and/or sensors may be made of rigid, soft, or a combination of rigid and soft materials.

(35) The control unit may be wirelessly connected or wired to the electrode or a plurality of electrodes at locations on the OA brace. The control unit may have a display and control keys permitting the user to select the various programs for activating the electrode. Various sensors or sensor modules may be located within the control box or placed at locations along the OA brace, as shown in FIG. 5 with sensors 76, 78 on the upper and lower frame elements 62, 64. These sensors may also be at the hinge 66, and/or the struts 72, 74.

(36) A sensor module may include: kinematic sensors, single-axis gyroscopes, single- or multi-axis accelerometers, load sensors, flex sensors or myoelectric sensors. U.S. Pat. No. 5,955,667, granted Sep. 21, 1999, U.S. Pat. No. 6,301,964, granted Oct. 16, 2001, and U.S. Pat. No. 6,513,381, granted Feb. 4, 2003, also illustrate examples of sensors that may be used with embodiments of the disclosure, which patents are incorporated by reference in their entirety and be considered as part of this specification.

(37) In certain embodiments, one or more acceleration sensors may include an XSENS acceleration sensor, such as the MT9 Inertial 3D motion tracker commercially available from XSENS Motion Technologies (Netherlands). In yet other embodiments, other suitable types of acceleration or movement reading sensors may also be used. The sensor module may include a gyroscope configured to measure angular speed. In other embodiments, the sensor module includes a plantar pressure sensor configured to measure the vertical plantar pressure of a specific underfoot area. Other movement signal(s) in a reference plane can also be utilized, such as measurements of centrifugal force, magnetic field and/or electromagnetic field.

(38) A sensor module may be configured to detect gait patterns and/or events. The sensor module may determine whether the user is in a standing/stopped position, is walking on level ground, is ascending and/or descending stairs or sloped surfaces, or the like. The sensor module may detect when the user has moved to a relaxed position, such as sitting, crossing legs, reclining, lying down, crawling, leaning, etc. The sensor module may detect these relaxed positions by measuring combinations of vertical acceleration, horizontal/lateral acceleration, and time. In one embodiment, the measured vertical acceleration corresponds to the force of gravity.

(39) In the embodiment of FIGS. 4 and 5, at least one sensor of the sensor module is incorporated or located with the electrode 70. Sensors may be placed at other locations, such as in the embodiment of FIG. 2.

(40) The accelerometer may measure an angle of the lower limb relative to vertical, which may then determine an angle of the limb relative to the ground. As the limb rotates from the upright, vertical position, the corresponding force of gravity will vary relative to the degree of rotation. For instance, when the limb is in an upright, vertical position, the accelerometer may measure the standard force of gravity, 9.8 m/s2. As the limb rotates from the vertical position, the accelerometer may measure a fraction of the Earth's global force of gravity relative to the changing angle of the limb regarding the ground. A sensor module configured to measure acceleration in the vertical plane may determine the stationary angle of the limb regarding the ground.

(41) In an example, the sensor module may indicate the limb is tilted at an angle of 90 deg. Regarding the ground. This might indicate, for example, that the user is lying completely flat on the back. Alternatively, the sensor module may indicate the limb is at an angle of 45 deg. Regarding the ground. That may indicate perhaps that the user is sitting down with legs outstretched in such a manner as to form a 45 deg. angle regarding the ground.

(42) A ground contact sensor may be used in the orthopedic device wherein axial displacement of the sensor moving part represents the ground contact occurrence. In certain embodiments, the sensor moving part axial displacement is detected and/or measured with load cell, non-contact magnetic sensor, optical encoder, mechanical switch, magnetic switch; inductive sensor, capacitive sensor, magnetic encoder, reflective infrared sensor, piezoelectric sensor, Hall-effect sensor and conductive rubber.

(43) While the exemplary embodiments describe the orthopedic device as used with an OA brace for treating osteoarthritis of the knee, a brace may be employed for treating other joints such as the elbow or shoulder.

(44) The embodiments described may be adapted in prosthetic devices wherein a hard prosthetic socket and liner system may be equipped sensors and/or electrodes for stimulating function of the user's leg outside of the socket. Examples of sockets and liner systems are found in the following patents which are each incorporated in their entirety: U.S. Pat. No. 7,780,741, granted Aug. 24, 2010, U.S. Pat. No. 7,438,843, granted Oct. 21, 2008, and U.S. Pat. No. 5,718,925, granted Feb. 17, 1998. The extension of the orthopedic device embodiments is not limited to prosthetic sockets, but can be employed in other prosthetic components as well for rehabilitating residual limbs and intact limbs.

(45) While the foregoing embodiments have been described and shown, alternatives and modifications of these embodiments, such as those suggested by others, may be made to fall within the scope of the disclosure. The principles described may be extended to other types of prosthetic or orthopedic devices.