Patent Abstract:
The magnetorheological (MAR) medical brace includes a flexible outer shell that fits around the anatomical area to be braced and a plurality of adjustable straps for securing the shell onto the anatomical area. The shell encases a MAR pack filled with magnetorheological fluid or gel. A plurality of magnets is attached to or encased in the shell to provide a magnetic field acting on the MAR pack. The interaction of the magnetic field with the MAR pack adjustably increases or decreases the stiffness of the shell depending on the strength of the magnetic field, A control mechanism is provided for selective adjustment of the magnetic field and other functions.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/510,432, filed Jul. 21, 2011. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to medical devices and particularly to a magnetorheological medical brace with controlled stiffness for optimal support and recovery. 
       DESCRIPTION OF THE RELATED ART 
       [0003]    Any type of trauma or injury to a limb or bone requires a relatively long time to heal. In many cases, the physician usually recommends at least six weeks of recovery time. To ensure proper recovery, the limb or bone is immobilized either by braces, splints or a cast depending on the extent of damage. This stabilizes the bone or limb so as to prevent, in the case of broken bones, undesirable misalignment of the set bone or in the case of sprains or other types of injuries, any movement that may cause further injury or unnecessary pain. While such measures are quite sufficient, the immobilized limb and the surrounding muscles tend to atrophy due to lack of physical movement. It is not unusual for a patient to struggle through a post-recovery regimen of physical exercise or therapy in order to gain the prior musculature and strength in the injured anatomy. 
         [0004]    Another complication to such healing is a matter of comfort and convenience. As the patient endures the period of healing, the recovering area tends to itch, which is usually a positive symptom that recovery is going well. However, for some types of braces, it may be challenging for the patient to reach the agitated area to scratch, which often ends in frustration and irritation. For some, it may even reach unendurable proportions such that the patient is forced to remove the brace, splint or cast, which can jeopardize the healing progress. Moreover, attempts to clean the injured limb can be challenging. Since removal of the brace, splint or cast prior to complete healing is not usually recommended, the patient typically forgoes cleaning of the injured area during the period of recovery. This can lead to unsightly accumulation of dirt and grime or potential infections, especially for patients who had undergone surgery for the injury. 
         [0005]    In order to accelerate healing, re-strengthening of the injured area and increase comfort and convenience for the patient, it would be more effective for a brace, splint or cast to be progressively loosened during the period of recovery such that the patient has some limited movement for exercising the limb as the limb heals, at least for a relatively short period of time. This can be conventionally facilitated by frequent visits to the health care facility for doctor consultation and replacement or adjustment of the medical device. However, frequent visits can be costly in terms of finances and time. 
         [0006]    Sports braces such as those for the joints, e.g., ankles, wrists, knees and elbows, also suffer from similar effectiveness deficiencies. Most sports braces do not have any means of selectively increasing or decreasing the stiffness of the brace. The inherent stiffness of a prescribed sports brace may be sufficient for most, but it could be problematic for those suffering from weak joints or other joint related complications. For example, the stiffness of the brace may dramatically hinder movement, which decreases the benefits of the sports activity and/or the enjoyment thereof. Moreover, as time passes, the user may require more or less support from the brace due to extended movement of the joint or from physical expenditure. 
         [0007]    In light of the above, it would be a benefit in the medical arts to provide an immobilizing device with adjustable stiffness for more effective healing, support, convenience and comfort. Thus, a magnetorheological medical brace having easily adjustable stiffness is needed to solve the aforementioned problems. 
       SUMMARY OF THE INVENTION 
       [0008]    The magnetorheological (MAR) medical brace includes a flexible outer shell that fits around the anatomical area to be braced and a plurality of adjustable straps for securing the shell onto the anatomical area. The shell encases a MAR pack filled with magnetorheological fluid or gel. A plurality of magnets is attached to or encased in the shell to provide a magnetic field acting on the MAR pack. The interaction of the magnetic field with the MAR pack adjustably increases or decreases the stiffness of the shell depending on the strength of the magnetic field. A control mechanism is provided for selective adjustment of the magnetic field and other functions. 
         [0009]    These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is an environmental, perspective view of a magnetorheological medical brace according to the present invention. 
           [0011]      FIG. 2  is a perspective view of the magnetorheological medical brace according to the present invention. 
           [0012]      FIG. 3  is a perspective view of an alternative embodiment of a magnetorheological medical brace according to the present invention. 
           [0013]      FIG. 4  is a perspective view of another alternative embodiment of a magnetorheological medical brace according to the present invention. 
           [0014]      FIG. 5  is a perspective view of a still further alternative embodiment of a magnetorheological medical brace according to the present invention. 
           [0015]      FIG. 6  is a schematic diagram of the controls for a magnetorheological medical brace according to the present invention. 
       
    
    
       [0016]    Similar reference characters denote corresponding features consistently throughout the attached drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    The magnetorheological medical brace, a first embodiment of which is generally referred to by the reference number  10 , provides adjustable stiffness and other features for optimum support, convenience and comfort. The phrase “magnetorheological medical brace” will hereinafter be referred to as “MAR medical brace.” In the exemplary embodiment shown in  FIGS. 1 and 2 , the MAR medical brace  10  may be a leg brace  12  having an elongate shell or cover  14  adapted to be wrapped around the user&#39;s leg L. The shell  14  is substantially semi-cylindrical or semi-frustoconical in shape so that the shell  14  may easily wrap around and conform to the anatomy of leg L. The shell  14  is also relatively stiff or rigid to provide minimum support, as well as to retain the general shape of the shell  14 . However, the shell  14  should also be flexible to allow for some movement without much effort. The shell  14  may be constructed from resilient, polymeric foam with some relative stiffness for minimum rigidity. Other materials such as neoprene, cushioned mats, elastomers, steel, plastics and combinations thereof may also be used as needed for some components of the brace. 
         [0018]    The shell  14  can include a central through hole  18  where a patient&#39;s or user&#39;s knee joint K may protrude. The hole  18  permits flexing of the knee without encumbrance. A plurality of adjustable attachment connectors, such as straps  16 , may be disposed at spaced intervals along the length of the shell  14 . These straps  16  secure the shell  14  onto a wide range of leg girths. The straps  16  may be secured to the user by hook and loop fasteners, buckles, snap-fit fasteners or any other type of adjustable connectors. 
         [0019]    To facilitate adjustable stiffening of the leg brace  12 , the shell  14  includes a magnetorheological (MAR) cell, tube or pack  20  disposed inside the shell  14 . The MAR pack  20  is preferably a packet or durable balloon filled with magnetorheological material in fluid or gel form. MAR material is a substance that can vary the material yield stress characteristics when exposed to a magnetic field. In other words, the stillness or rigidity of the MAR pack  20  varies, depending on the strength of magnetic forces acting thereon. Thus, whenever the MAR pack  20  experiences some degree of magnetic force or field, the whole leg brace  12  correspondingly stiffens or loosens proportionately to the overall rigidity of the MAR pack  20 . One example of such a MAR material is a combination of carbonyl iron powder and silicone oil. It is to be understood that other MAR materials may also be used for the MAR pack  20 . In the preferred embodiment, the leg brace  12  is of unitary construction formed in a molding process with the MAR pack  20  embedded within the shell  14 . As an alternative, the MAR pack  20  may be removably inserted inside a cavity within the shell  14 . 
         [0020]    The magnetic force or field may be supplied by a plurality of magnet packs, consoles or terminals  30  disposed on one or both sides of the leg brace  12 . Each magnet pack  30  can include a permanent magnet or an electromagnet of a given strength. In a preferred embodiment, the magnet packs  30  are magnetically shielded on the outside to ensure that magnetic forces influence the MAR material, rather than anything else that may be nearby, When using permanent magnets, the physician or the user may selectively change one for another of higher or lower strength to adjust the of stiffness of the MAR medical brace  10 . Similar results may be obtained with an electromagnet by using a control mechanism to adjust the magnetic field strength, an example of which will be described below. 
         [0021]    In the preferred embodiment, the control mechanism  40  may be disposed in one of the magnet packs  30 . As shown schematically in  FIG. 6 , the control mechanism  40  includes a processor  42  for controlling the various functions of the control mechanism  40  and is connected to a power source  44  supplying power to the control assembly  40  and the electromagnets in the other magnet packs  30 . In a preferred embodiment, the power source  44  can be a rechargeable and reusable battery, such as lead-acid, nickel cadmium (NiCd), nickel metal hydride (NiMH), lithium ion (Li-ion), and lithium ion polymer (Li-ion polymer). As an alternative, the power may be supplied directly from an AC source. To adjust the strength of the electromagnet, the user can increase or decrease the amount of power being supplied to the MAR pack  20  via the processor  42  to thereby selectively strengthen or weaken the magnetic field. The magnet pack  30  may include an indicator light or display  32  that provides information about the operations of the control mechanism  40 , e.g., ON, OFF and/or remaining power. 
         [0022]    In addition to the basic control of the magnetic field or force, the control mechanism  40  includes other features to help monitor the patient&#39;s or user&#39;s healing and/or exercise progress. The control mechanism  40  can include a sensor  48  that senses various activities such as the frequency of wear, the intensity of the magnetic field, the frequency of limb movement, etc. This data may be recorded on the data recorder  50  and transmitted wirelessly via the wireless transmitter  46  to a monitoring station, such as a central database in a health care facility or to a personal computer, The recorded and transmitted data helps the physician or user calculate and determine physical activity goals as part of the healing process. Moreover, the data may be used to monitor the user&#39;s adherence with the physician&#39;s recommendations. For example, if the physician prescribed a strict guideline and duration of wearing the leg brace  12  and the patient fails to comply, as evidenced by prolonged periods of recorded inactivity, the transmitted data will note the lapse and alert the physician. Then the physician may follow up with the patient in a timely manner to determine the cause. As an alternative, the data stored in the data recorder  50  may be retrieved at the end of a given period of time instead of being transmitted by the wireless transmitter  46 , especially for those who live in areas where wireless communication is not available. 
         [0023]    Data transmission and the data itself may be compromised by the magnets used in the MAR medical brace  10 . The magnets may cause magnetic interference, which can reduce the clarity of transmission from the wireless transmitter  46  and potentially damage the data recorded on the data recorder  50 . Since the control mechanism  40  will be subject to magnetic interference from the magnets and/or electromagnets, at least the wireless transmitter  46  and the data recorder  50  are preferably magnetically shielded to overcome potential magnetic interference. 
         [0024]    While the above describes some of the user or patient defined adjustment of the stiffness of the MAR medical brace  10 , the control mechanism  40  includes programming capabilities that may be preset by the physician or possibly the user. For example, the physician may program the MAR medical brace  10  via the processor  42  to gradually decrease the magnetic strength from the magnet packs  30  over the course of the recommended healing or recovery time. This results in the stiffness or rigidity of the MAR medical brace  10  gradually decreasing as the patient heals and grows stronger over time, which eliminates frequent visits with the physician for similar adjustments. Moreover, the wireless transmitter  46  may also function as a receiver in order to receive programs, physician directed adjustments and other commands remotely. In the case of the MAR medical brace  10  being worn for sports or recreational physical activity, the MAR medical brace  10  may be programmed by the user to increase the stiffness over a user-defined period of time so that proper support is maintained as the user becomes physically fatigued from that activity. This relieves constant manual readjustments from the user. 
         [0025]    Referring to  FIGS. 3-5 , these drawings show alternative arrangements of the MAR pack for selective reinforcement of the brace. In  FIG. 3 , the MAR medical brace  100  in the form of a leg brace includes a plurality of MAR packs  120  embedded in the shell. The MAR packs  120  are shaped as elongate rods for longitudinal reinforcement of the MAR medical brace  100 . The MAR packs  120  are removably inserted into the shell. As an alternative, the elongate MAR packs  120  may be molded with the shell. In  FIG. 4 , the MAR medical brace  200  includes a plurality of relative short MAR packs  220  disposed inside the shell. These MAR packs  220  may be placed in a variety of select locations on the MAR medical brace  200  wherever selective stiffening is desired. In  FIG. 5 , the MAR medical brace  300  includes a MAR pack  320  that is relatively smaller than the one shown in  FIG. 2 . The configuration thereof provides adjustable stiffness in a localized area around the joint. The variety of different MAR pack configurations is subject only to the changing needs of the patient. 
         [0026]    Thus, it can be seen that the MAR medical brace  10 ,  100 ,  200 ,  300  is a highly adjustable brace that promotes optimum healing, convenience and comfort for the user. The MAR packs  20 ,  120 ,  220 ,  320  provide an easy and simple means of adjusting the stiffness and rigidity of the brace for increased comfort and freedom of movement as needed while maintaining the necessary support. The unitary and relatively simple construction also allows the MAR medical brace  10 ,  100 ,  200 ,  300  to be easily and inexpensively manufactured. In addition, the control mechanism  40  provides increased functionality whereby the patient&#39;s progress can be easily monitored and tailored to the individual. 
         [0027]    It is to be understood that the MAR medical brace  10 ,  100 ,  200 ,  300  encompasses a variety of alternatives. For example, although the exemplary embodiments above describes the MAR medical brace  10 ,  100 ,  200 ,  300  in terms of a leg brace, it is to be understood that the teachings thereof equally applies to all types of braces. Moreover, the control assembly  40  is not limited to being installed in one of the magnet packs  30 . Instead, the control assembly  40  can be a separate module or remote that can be carried by the user. Furthermore, it is to be understood that the MAR medical brace  10 ,  100 ,  200 ,  300  is not limited to human subjects or patients. The MAR medical brace  10 ,  100 ,  200 ,  300  may also be used on other subjects, such as animals. 
         [0028]    It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.

Technology Classification (CPC): 0