Patent Publication Number: US-2017357241-A1

Title: System, method, and devices for reducing concussive traumatic brain injuries

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     Embodiments of the present invention relate to devices, systems, and methods configured to reduce traumatic brain injuries in football players and other athletes and users. 
     Description of the Related Art 
     Closed-head traumatic brain injury (TBI) is typically a result of the brain impacting the interior of the skull. Forces acting on the body or the head generally accelerate the brain. High positive acceleration or negative acceleration may cause the brain to contact the skull with enough force to cause damage. The types of damage may be categorized as concussive TBI, blast TBI, or mild TBI. Concussive TBI may be suffered by athletes in sports such as hockey, boxing, or American football. Blast TBI may be experienced by military or law enforcement personnel while on patrol or traveling in a vehicle. Mild TBI may be experienced by anyone suffering a fall, a minor vehicular accident, or the like. Furthermore, the direction and location of the impact and the resulting motion of the head may determine the severity of the injury. Studies have shown that a side impact to the head, or the body, that results in the head rotating (about the roll axis) to the left or right shoulder may lead to a greater chance of suffering a TBI, as compared with impacts from other directions. 
     Helmets are available to athletes, military personnel, law enforcement personnel, and the like. While helmets generally provide protection for skull fractures upon direct impact, they do not provide protection from rotational forces to the head and may not reduce the occurrence or severity of a concussive TBI (cTBI). Even when wearing a helmet, the head, and the brain within, may experience an acceleration of a great enough magnitude to cause a cTBI. 
     Implementing a rigid linkage between the helmet and the body of the helmeted person has been proposed in prior art as a means to reduce concussive traumatic injuries. In concussions, however, impact energy can act on the head within 20-50 milliseconds of impact. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present invention solve the above-mentioned problems and provide methods, devices, and systems that are utilized with head gear and body wear to reduce traumatic brain injuries. One aspect of the present invention attempts to reduce traumatic brain injuries of athletes and others by anticipating when the athletes are about to collide with other persons or objects and then triggering protective gear worn by the athletes to protect them from the anticipated impact. 
     A method of reducing traumatic brain injuries in accordance with an embodiment of the invention comprises the steps of: determining locations of a user as the user moves; determining if the user is likely to impact another person or object based on the locations of the user and the other person or object; and transmitting a locking signal to a head-stabilizing component worn by the user when it is determined the user is likely to impact another person or object so as inhibit motion of the user&#39;s head relative to the user&#39;s torso. The method may further comprise the steps of determining an approximate force at which the user is likely to impact the other person or the object based on the locations, velocities, and accelerations of the user and transmitting the locking signal to the head-stabilizing component only if the approximate force at which the user is likely to impact the other person or object is likely to cause injury. 
     A system for reducing traumatic brain injuries of athletes on a sports field constructed in accordance with another embodiment of the invention includes a plurality of transmitters configured to be worn by at least some of the athletes; a plurality of sensors configured for placement on or near the sports field for receiving signals from the transmitters as the athletes move on the sports field; a head-stabilizing component worn by at least one of the athletes; and a processing element coupled with the sensors and in communication with the head-stabilizing component. The processing element determines locations of the athletes on the sports field based on the signals transmitted from the transmitters worn by the athletes; determines if the athletes are likely to impact one another or other objects based on the locations of the athletes; and transmits an activating signal to the head-stabilizing component if the athlete is likely to impact another athlete to inhibit motion of the athlete&#39;s head. The processing element may be further programmed to determine a force at which the athletes are likely to impact based on the signals transmitted from the transmitters and to transmit the activating signal to the head-stabilizing component only if the force is likely to cause injury. In one embodiment, the head-stabilizing component includes a head component configured to be worn on the athlete&#39;s head, a body component configured to be worn on the athlete&#39;s body, and a linkage element that connects the head component and the body component. The activating signal from the processing element switches the linkage element to a more rigid state to reduce relative movement between the athlete&#39;s head and torso. 
     This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other aspects and advantages of the current invention will be apparent from the following detailed description of the embodiments and the accompanying drawing figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       Embodiments of the present invention are described in detail below with reference to the attached drawing figures, wherein: 
         FIG. 1  is a perspective view of a device for reducing traumatic brain injury constructed in accordance with a first embodiment of the current invention and utilized with an American football helmet and shoulder pads, the device including a first sensor and one linkage mechanism; 
         FIG. 2  is a rear view of a first alternative embodiment of the device of  FIG. 1  utilized with military or law enforcement body armor, the device including two linkage mechanisms; 
         FIG. 3  is a rear view of a second alternative embodiment of the device of  FIG. 1  utilized with military or law enforcement body armor, the device including three linkage mechanisms; 
         FIG. 4  is a perspective view of a second sensor of the device of  FIG. 1  being utilized with a mouthpiece to be worn in a user&#39;s mouth; 
         FIG. 5  is a perspective, exploded view of the linkage mechanism of the device of  FIG. 1 ; 
         FIG. 6  is a schematic block diagram of other components of the device of  FIG. 1 ; 
         FIG. 7  is a rear view of a system for reducing traumatic brain injury constructed in accordance with a second embodiment of the current invention; 
         FIG. 8  is a schematic block diagram of other components of the device of  FIG. 7 ; 
         FIG. 9  is an overhead view of a system for reducing traumatic brain injury for a group of people constructed in accordance with a third embodiment of the current invention; 
         FIG. 10  is a schematic block diagram of other components of the system of  FIG. 9 ; 
         FIG. 11  is a side view of a system for reducing traumatic brain injury for a group of people in a vehicle constructed in accordance with a fourth embodiment of the current invention; 
         FIG. 12  is a schematic block diagram of other components of the system of  FIG. 11 ; 
         FIG. 13  is a flow diagram of at least a portion of the steps of a method of reducing traumatic brain injury in accordance with a fifth embodiment of the current invention; 
         FIG. 14  is a block diagram of components of a system constructed in accordance with another embodiment of the invention; 
         FIG. 15  is a perspective view of selected components of the system of  FIG. 14  shown attached to or worn by an athlete playing American football; 
         FIG. 16  is a schematic diagram of an American football field showing an exemplary placement of components of the system of  FIG. 14 ; and 
         FIG. 17  is a schematic diagram of an American football field showing representations of the positions of several athletes on the field over time. 
     
    
    
     The drawing figures do not limit the current invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The following detailed description of the invention references the accompanying drawings that illustrate specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. The scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled. 
     In this description, references to “one embodiment”, “an embodiment”, or “embodiments” mean that the feature or features being referred to are included in at least one embodiment of the technology. Separate references to “one embodiment”, “an embodiment”, or “embodiments” in this description do not necessarily refer to the same embodiment and are also not mutually exclusive unless so stated and/or except as will be readily apparent to those skilled in the art from the description. For example, a feature, structure, act, etc. described in one embodiment may also be included in other embodiments, but is not necessarily included. Thus, the current technology can include a variety of combinations and/or integrations of the embodiments described herein. 
     Certain aspects of the inventions described in the present application are described in U.S. patent application Ser. No. 14/554,141, titled “DEVICE AND SYSTEM TO REDUCE TRAUMATIC BRAIN INJURY”, filed Nov. 26, 2014. The earlier-filed patent application is hereby incorporated by reference, in its entirety, into the current patent application. Aspects of the inventions described in the present application are also described in U.S. patent application Ser. No. 14/959,083, titled “DEVICE TO REDUCE TRAUMATIC BRAIN INJURY”, filed Dec. 4, 2015. This earlier-filed patent application is also hereby incorporated by reference, in its entirety, into the current patent application. 
     A device  10  for reducing traumatic brain injury constructed in accordance with a first embodiment of the current invention is shown in  FIGS. 1-3  and broadly comprises a first sensor  12 , a second sensor  14 , one or more linkage elements  16 , a processing element  18 , and a memory element  20 . The device  10  may be utilized by a user engaging in activity during which an impact to the head is possible. The activity may include contact sports such as hockey, boxing, American football, snow or ice-related sports such as skiing, snowboarding, sledding, sports in which falling or landing on the head is possible such as skateboarding, bicycling, equestrian activities, motorcycle riding, automobile driving, military combat, and the like. When the device  10  is utilized playing a sport in which there might not be equipment on the body to which the device  10  can couple, such as the shoulder pads in American football, the device  10  may further comprise a body component  22 . The device  10  may also couple to protective equipment that the user may already wear for the activity including a head component  24 , such as a helmet or other headgear. 
     The first sensor  12 , as seen in  FIGS. 1-3 and 6 , generally measures a linear as well as a rotational acceleration of the user&#39;s head due to an impact. In some embodiments, the first sensor  12  may also, or alternatively, measure a velocity of the user&#39;s head or a force of the impact. The first sensor  12  may include motion sensors, velocity sensors, vibration sensors, shock sensors, accelerometers, gyroscope chips, magnetometer chips, inclinometers, angle rate sensors, angular velocity sensors, or the like, or combinations thereof. The first sensor  12  may include technology such as strain gauges, piezoelectric elements, micro electro-mechanical systems (MEMS), nanotechnologies in which a material, solid or liquid, can change it stiffness while modulated by electromagnetic fields, or the like, or combinations thereof. The first sensor  12  may measure linear acceleration, velocity, or force along a single axis or multiple axes, such as any three mutually orthogonal axes, e.g., the X, Y, Z axes, and may record, communicate, or output a sensor measurement. Each sensor measurement may include a plurality of values which may be in the form of vector data or magnitude data. Thus, in various embodiments, the first sensor  12  may generate three or more values for the three linear measurements. In addition or instead, the first sensor  12  may measure angular or rotational acceleration along mutually orthogonal axes, such as pitch, roll, and yaw. With regard to measuring the acceleration of the head, pitch is nodding to gesture yes, roll is bending the head-and-neck toward one or the other shoulder, and yaw is gesturing no or turning the head to watch cars from both directions before crossing a street. Accordingly, the first sensor  12  may generate three or more values for the three angular measurements. 
     The sensor measurements be an analog value, a digital value, a pulse-width modulation (PWM) value, or the like. The first sensor  12  may output the sensor measurements at a frequency ranging from 500 hertz (Hz) to 20 kilohertz (kHz) or higher. This range of frequencies should be great enough to detect an impulse-like impact, whose duration may be range from a fraction of a millisecond to single digits of milliseconds. The first sensor  12  may also include electronic circuitry such as amplifiers, analog-to-digital converters (ADCs), or other conversion circuits. 
     The first sensor  12  may be positioned within the interior of the head component  24  of the user. The head component  24  may be headwear, headgear, a helmet, such as a sports helmet, a motorcycle or automobile helmet, or a combat helmet, or the like. In some embodiments, the first sensor may be integrated or as a part of a head band or skull cap made from wearable material and worn, either along or to be worn underneath the protective helmet. In some embodiments, the first sensor  12  may further include first and second resilient members, such as springs, that are coupled to opposing sides of the first sensor  12 . The first resilient member may contact an inner surface of the head component  24 , and the second resilient member may contact the user&#39;s head. In other embodiments, the first sensor  12 , with or without resilient members, may be coupled to padding on the interior of the head component  24 , or coupled to a hard shell of the head component  24 , such that when the head component  24  is worn, the first sensor  12  may contact the user&#39;s head in order to detect force and other physical parameters related to the force applied to the head or the helmet (it may be advantageous for the first sensor  12  to also analyze the force at the helmet, which is typically of a greater magnitude than the force at the head). 
     The second sensor  14 , as seen in  FIGS. 4 and 6 , may be substantially similar to the first sensor  12  in structure and function and may be positioned within the mouth of the user. In some embodiments, the second sensor  14  may be considered optional. The second sensor  14  may include, be coupled with, or be integrated in a mouthpiece or mouth guard, which is worn in the mouth or on the teeth of the user. Furthermore, the second sensor  14  may include or be in communication with a wireless transmitter to transmit sensor measurements to the processing element  18 . The wireless transmitter may transmit radio frequency (RF) signals and/or data utilizing known communication standards. 
     The linkage element  16 , as seen in  FIGS. 1-3 and 5 , generally provides a link between the user&#39;s head and the user&#39;s body that is normally flexible but becomes rigid upon an impact to the head. If just one linkage element  16  is utilized, as in  FIG. 1 , then it is generally positioned at the rear of the user&#39;s head and the upper central portion of the user&#39;s back. If more than one linkage element  16  is utilized, such as in  FIGS. 2 and 3 , then the device  10  may include a left linkage element  16 A positioned on the left side of the user&#39;s head and the user&#39;s left shoulder, a right linkage element  16 B positioned on the right side of the user&#39;s head and the user&#39;s right shoulder, and a center linkage element  16 C positioned at the rear of the user&#39;s head and the upper central portion of the user&#39;s back. In some embodiments, only the left linkage element  16 A and the right linkage element  16 B are utilized, as shown in  FIG. 2 . Generally, each linkage element  16  may be formed from material or components whose stiffness or rigidity can be controlled, that is, increased and decreased. In exemplary embodiments, each linkage element  16  may be formed from a plurality of components and may include a first anchor  26 , a second anchor  28 , a first end link  30 , a second end link  32 , and at least one middle link  34 . In other embodiments, the linkage element  16  may be formed from a single component with material that has a variable stiffness or rigidity. 
     While the linkage element  16  is in a flexible state, it may seem limp or relaxed and may assume a variety of shapes, positions, and orientations as the user moves his head with respect to his body. This allows the user to have a wide range of motion and freedom of head movement while wearing the device  10 . When the linkage element  16  is in a rigid state, it may maintain the same shape it was in when it transformed from the flexible state to the rigid state. However, the linkage element  16  is in the rigid state for only a short period of time, as discussed in greater detail below. 
     The first anchor  26 , as seen in  FIGS. 1-3 and 5 , generally retains the first end link  30 . The first anchor  26  may include an anchor socket  36  and a locking element  38 . The anchor socket  36  may include a concave, partially spherical chamber which is configured to retain at least a portion of the first end link  30 . The anchor socket  36  may allow rotational, pivotal, and conical motion of the first end link  30 . The locking element  38  generally locks the first end link  30  in position within the anchor socket  36 , restricting or stopping motion of the first end link  30  therein. The locking element  38  may include an electromagnet  40  which can selectively lock the first end link  30  in position within the anchor socket  36 . The electromagnet  40  may include one or more electrical conductors that are wound around a portion of the anchor socket  36 . When the electrical conductors carry electrical current, the electromagnet  40  generates a magnetic field which may strongly attract the first end link  30  and stop the motion thereof. The locking element  38  may further include electronic circuitry such as amplifiers and conversion circuits that convert voltage to current. 
     The first anchor  26  may be attached to the head component  24 . For embodiments in which there is only one linkage element  16 , the first anchor  26  may be attached at a base of the head component  24  on a rear side, roughly in the center. For embodiments in which there are three linkage elements  16 , the device  10  may include a left first anchor  26 A, a right first anchor  26 B, and a center first anchor  26 C. The left first anchor  26 A may be attached to the left side of the head component  24 , generally in the vicinity of the left ear. The right first anchor  26 B may be attached to the right side of the head component  24 , generally in the vicinity of the right ear. The center first anchor  26 C may be attached to the base of the head component  24  on the rear side, roughly in the center. The attachment of the first anchor  26  to the head component  24  is usually rigid and may be accomplished with a plurality of connectors, such as snaps, a plurality of fasteners, such as screws, or the like. In some embodiments, the first anchor  26  may be integrally formed as part of the head component  24 . 
     The second anchor  28 , as seen in  FIGS. 1-3 and 5 , generally retains the second end link  32 . The second anchor  28  may have substantially the same structure as the first anchor  26  and may include an anchor socket  42 , a locking element  44 , and an electromagnet  46  that function in a substantially similar fashion to the same-named components of the first anchor  26 . 
     The second anchor  28  may be attached to the body component  22 . For embodiments in which there is only one linkage element  16 , the second anchor  28  may be attached along or near the center of the body component  22 . Alternatively, the second anchor  28  may connect to body equipment such as body armor, a flak jacket, or the like, when the body component  22  is not needed. For embodiments in which there are three linkage elements  16 , the device  10  may include a left second anchor  28 A, a right second anchor  28 B, and a center second anchor  28 C. The left second anchor  28 A may be coupled to body equipment, generally at the left shoulder. The right second anchor  28 B may be coupled to body equipment, generally at the right shoulder. The center second anchor  28 C may be attached to the body component  22 , typically along or near the center of the body component  22 . Alternatively, the center second anchor  28 C may connect to body equipment, when the body component  22  is not needed. 
     As with the first anchor  26 , the attachment of the second anchor  28  to the body component  22  is usually rigid and may be accomplished with a plurality of connectors, such as snaps, a plurality of fasteners, such as screws, or the like. In certain embodiments, the second anchor  28  may be integrally formed as part of the body component  22 . In other embodiments, the first anchor  26  and the second anchor  28  may be of the same dimension so that part of the linkage element  16  may be readily replaced or repaired with components from another part of the linkage element  16 . This configuration may provide an advantage for soldiers in combat situations. 
     The first end link  30 , as seen in  FIGS. 1-3 and 5 , may include a first ball component  48 , a second ball component  50 , and a shaft  52 . The first ball component  48  and the second ball component  50  may each be roughly spherical shaped and may each include a circular opening on an outer surface. In addition, the first ball component  48  and the second ball component  50  may be formed from a magnetic metal, such as iron or steel. The shaft  52  may be roughly cylindrical shaped and may be hollow or solid. A first end of the shaft  52  may be positioned in the opening of the first ball component  48  and rigidly coupled thereto. An opposing second end of the shaft  52  may be positioned in the opening of the second ball component  50  and rigidly coupled thereto. 
     The first end link  30  may be positioned such that the first ball component  48  is retained in the anchor socket  36  of the first anchor  26 . In some embodiments, the first ball component  48  and the second ball component  50  may be interchangeable, such that the second ball component  50  is retained in the anchor socket  36 . As mentioned above, the first end link  30  may be able to rotate, pivot, or move in a conical fashion with respect to the first anchor  26  until the locking element  38  locks the first end link  30  in position. 
     The second end link  32 , as seen in  FIGS. 1-3 and 5 , may be substantially similar to the first end link  30  and may include a first ball component  54 , a second ball component  56 , and a shaft  58  that are substantially similar to the same-named components of the first end link  30 . The second end link  32  may be positioned such that the first ball component  54  is retained in the anchor socket  42  of the second anchor  28 . In some embodiments, the first ball component  54  and the second ball component  56  may be interchangeable, such that the second ball component  56  is retained in the anchor socket  42 . Furthermore, the second end link  32  may be able to rotate, pivot, or move in a conical fashion with respect to the second anchor  28  until the locking element  44  locks the second end link  32  in position. 
     The middle link  34 , as seen in  FIGS. 1-3 and 5 , may include a first socket  60 , a second socket  62 , and a shaft  64 . The first socket  60  may include a concave, partially spherical chamber which is configured to retain at least a portion of the first end link  30 , specifically, either the first ball component  48  or the second ball component  50 . The first end link  30  and the middle link  34  may be able to rotate, pivot, or move in a conical fashion with respect to one another. The second socket  62  may be substantially similar to the first socket  60  in structure and may be configured to retain at least a portion of the second end link  32 , specifically, either the first ball component  54  or the second ball component  56 . The second end link  32  and the middle link  34  may be able to rotate, pivot, or move in a conical fashion with respect to one another. In various embodiments, the first socket  60  and the second socket  62  may be interchangeable such that the first socket  60  retains a portion of the second end link  32  and the second socket  62  retains a portion of the first end link  30 . The shaft  64  may be roughly cylindrical shaped and may be hollow or solid. A first end of the shaft  64  may rigidly couple to the first socket  60 , while an opposing second end of the shaft  64  may rigidly couple to the second socket  62 . 
     In various embodiments, the end links  30 ,  32  may be removable from the anchors  26 ,  28  such that the user can easily disengage the body component  22  from the head component  24 . Thus, first ball component  48  may be removable from first anchor socket  36 , and first ball component  54  may be removable from second anchor socket  42 . 
     The linkage element may alternatively be a hydraulic mechanism with a pneumatic chamber and plunger as described in the Serial No.  62 / 088 , 181  application referenced above. 
     The processing element  18 , as seen in  FIG. 6 , may include processors, microprocessors, microcontrollers, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), analog and/or digital application-specific integrated circuits (ASICs), or the like, or combinations thereof. The processing element  18  may generally execute, process, or run instructions, code, code segments, software, firmware, programs, applications, apps, processes, services, daemons, or the like, or may step through states of a finite-state machine. The processing element  18  may be operably coupled to the memory element  20 . In some embodiments, the processing element  18  may further include or be in communication with a wireless receiver configured to receive sensor measurements from the wireless transmitter coupled to the second sensor  14 . 
     The processing element  18  may receive sensor measurements from the first sensor  12  and the second sensor  14  and may determine, among other things, if the sensors  12 ,  14  indicate the presence of a potentially dangerous and injurious impact force. The processing element  18  may receive at least three linear acceleration measurements, at least three angular acceleration measurements, or a combination of both. In some embodiments, the processing element  18  may calculate a magnitude and direction of the acceleration or motion of the head based on the sensor measurements. The magnitude and direction calculation may include a linear acceleration as well as an angular or rotational acceleration. The processing element  18  may consider the magnitude and direction separately and may determine whether the magnitude is greater than or equal to an injury level—i.e., a level at which damage to the recipient may occur. If so, then the processing element  18  may generate or assert a locking signal that is transmitted to the one or more linking elements  16 . If the magnitude is less than the injury level, then the processing element  18  may do nothing. For example, the processing element  18  may generate the locking signal if the value of the linear acceleration is greater than or equal to, say, 50 G (the acceleration due to the Earth&#39;s gravity) in any direction. The threshold may also be a dynamic threshold that varies depending upon the person being monitored and other factors. In some cases, the injury level value of the magnitude may change depending on the direction, so that the injury level may be 50 G in some directions and greater than 50 G in other directions. To continue the example, the processing element  18  may generate the locking signal if the value of the angular acceleration is greater than or equal to, say, 4000 rad/sec 2  in any direction. As with the linear acceleration, the injury level magnitude may change depending on the direction. 
     In other embodiments, the processing element  18  may evaluate the sensor measurements individually. If the measurements include linear acceleration values such as along the X, Y, and Z axes, then the processing element  18  may generate the locking signal if the linear acceleration value along any of the axes is above the injury level. Alternatively, each axis may have its own injury level value, so that there is an X-axis injury level, a Y-axis injury level, and a Z-axis injury level. Accordingly, the processing element  18  may generate the locking signal if the linear acceleration value along the X-axis is greater than or equal to the X-axis injury level or if the linear acceleration value along the Y-axis is greater than or equal to the Y-axis injury level or if the linear acceleration value along the Z-axis is greater than or equal to the Z-axis injury level or combinations thereof. Furthermore, the processing element  18  may apply an algorithm or a set of steps to the linear acceleration values to determine whether to generate the locking signal. 
     If the measurements include angular acceleration values such as about the pitch, roll, and yaw axes, then the processing element  18  may generate the locking signal if the angular acceleration value about any of the axes is above the injury level. In some cases, the value of the angular acceleration about the roll axis may be considered most critical. Thus, the processing element  18  may generate the locking signal if the angular acceleration value is greater than or equal to the injury level even if the other values are less than the injury level. As with the linear acceleration values, each axis may have its own injury level value, so that there is a pitch-axis injury level, a roll-axis injury level, and a yaw-axis injury level. The values may also be different for different people (e.g. higher for adults than children). Accordingly, the processing element  18  may generate the locking signal if the linear acceleration value about the pitch-axis is greater than or equal to the pitch-axis injury level or if the linear acceleration value about the roll-axis is greater than or equal to the roll-axis injury level or if the linear acceleration value about the yaw-axis is greater than or equal to the yaw-axis injury level or combinations thereof. Furthermore, the processing element  18  may apply an algorithm or a set of steps to the angular acceleration values to determine whether to generate the locking signal. 
     The locking signal generated by the processing element  18  may include a binary data value, a binary logic level, a pulse-width modulated signal, a voltage value, a current value, or the like. Furthermore, the processing element  18  may include or have access to timer or clock circuitry, which may be utilized in order for the processing element  18  to generate the locking signal for a predetermined time period. In various embodiments, the period for the locking signal may range from approximately 100 milliseconds (ms) to approximately 300 ms (although the most critical period for the locking action is close to 100 milliseconds). 
     The memory element  20 , as seen in  FIG. 6 , may include data storage components such as read-only memory (ROM), programmable ROM, erasable programmable ROM, random-access memory (RAM), hard disks, floppy disks, optical disks, flash memory, thumb drives, universal serial bus (USB) drives, or the like, or combinations thereof. The memory element  20  may include, or may constitute, a “computer-readable medium”. The memory element  20  may store the instructions, code, code segments, software, firmware, programs, applications, apps, services, daemons, or the like that are executed by the processing element  18 . The memory element  20  may also store settings, data, documents, sound files, photographs, movies, images, databases, and the like. The processing element  18  may be in communication with the memory element  20  through address busses, data busses, control lines, and the like. In various embodiments, the processing element  18  and memory element  20  may be positioned with or packaged with the first sensor  12 . 
     The body component  22 , as seen in  FIGS. 1-3 , generally provides load bearing contact with the body and may be formed from semi-rigid materials such as hardened plastics, although portions of the body component  22  could be flexible. Accordingly, the body component  22  may be not only sufficiently rigid to be effective for energy dissipation but also sufficiently flexible to be comfortable to the user. The body component  22  may include an elongated bar that extends across the width of the user&#39;s back at the shoulder level. The body component  22  is generally worn underneath protective equipment such as shoulder pads, commonly utilized in American football, or such as a body armor, commonly utilized in military combat apparel. The body component  22  may further include padding or foam material to provide comfort to the user. The body component  22  may be connected rigidly or removably to the second anchor  28 . 
     The device  10  may operate as follows. The first sensor  12  may be installed within the head component  24 , either positioned between the inner surface of the head component  24  and the user&#39;s head or connected to padding on the interior of the head component  24 . If utilized, the second sensor  14  may be coupled to or integrated with a mouth guard, which is worn in the user&#39;s mouth. For embodiments in which there is one linkage element  16 , the first anchor  26  may be attached to the head component  24 , and the second anchor  28  may be attached to the body component  22 . For embodiments with more than one linkage element  16 , at least the left first anchor  26 A and the right first anchor  26 B may be attached to the head component  24  and the left second anchor  28 A and the right second anchor  28 B may be attached to body equipment. 
     The first sensor  12  and the second sensor  14  may measure the force of impacts on the head component  24  and may communicate the sensor measurements to the processing element  18  at frequency rates ranging from 500 Hz to 20 kilohertz (kHz) or higher. While the values of the sensor measurements are less than the injury level (which should be most of the time), the linkage element  16  may be fully flexible—allowing the head component  24  nearly complete freedom of movement with respect to the body component  22 . 
     When the head component  24  receives an impact with a force that could potentially cause traumatic brain injury to the user, then various components of the sensor measurements from the first sensor  12  and/or the second sensor  14  have a value greater than or equal to the injury level. In some embodiments, there may be more than one injury level value associated with the sensor measurements. The processing element  18  receives the sensor measurements and makes a determination as to whether the injury levels have been reached or exceeded using the methods and techniques described above. Upon determination that a dangerous impact has occurred, the processing element  18  may generate or assert the locking signal to the locking elements  38 ,  44  of the first anchor  26  and the second anchor  28  of the one or more linkage elements  16 . The locking signal may activate or energize the electromagnets  40 ,  46 , which generate a strong force of attraction to the first ball components  48 ,  54  of the first end link  30  and the second end link  32 . As a result, the first end link  30  and the second end link  32  may be locked in their position just after the impact was received. Furthermore, with the first end link  30  and the second end link  32  locked in position, the middle link  34  may become locked in position as well, rendering the entire chain of the one or more linkage elements  16  rigid. When the one or more linkage elements  16  are rigid, the head component  24  becomes rigidly integrated with the body component  22  such that energy imparted to the head component  24  is transferred to the body component  22  and absorbed by the body. This also reduces the magnitude of the acceleration or deceleration of the head, thereby reducing the possibility or severity of concussive traumatic brain injury. For embodiments with more than one linkage element  16 , the left linkage element  16 A and the right linkage element  16 B being positioned on the left and right sides of the head may provide a greater reduction of the magnitude of the acceleration or deceleration of the head from side impacts. 
     Mechanisms other than electromagnets may also be utilized in order to generate the necessary rigidity for energy dissipation. These mechanisms may include, but are not limited to, linear solenoids with fast respond times, among others. For embodiments with bypass valves and solenoid valves, similar switching mechanisms are involved. 
     The duration of the transmission or assertion of the locking signal, and thus the rigidity of the one or more linkage elements  16 , may range from approximately 100 ms to approximately 300 ms. After that time period, the locking signal is no longer transmitted or asserted, and the one or more linkage elements  16  are again flexible. 
     A system  100  for reducing traumatic brain injury constructed in accordance with a second embodiment of the current invention is shown in  FIG. 7  and broadly comprises a first sensor  112 , a second sensor  114 , one or more linkage elements  116 , a processing element  118 , a memory element  120 , a head component  122 , and a body component  124 . The system  100  may be utilized by a user engaging in activity that does not normally include a head component or a body component, such as some forms of boxing, wrestling, and martial arts. 
     The first sensor  112 , the second sensor  114 , the one or more linkage elements  116 , the processing element  118 , and the memory element  120  are substantially similar to the first sensor  12 , the second sensor  14 , the one or more linkage elements  16 , the processing element  18 , and the memory element  20  of the device  10 . 
     The head component  122  is generally worn on the head of the user. Typically, the head component  122  covers at least a portion of the top, the sides, and the rear of the head. In some embodiments, the head component  122  may include a plurality of rigid or semi-rigid straps that cover the crown and a portion of the top of the head. In other embodiments, the head component  122  may include headgear, a helmet, or the like. The head component  122  may also retain the first sensor  112  and the processing element  118 . 
     The body component  124  is generally worn on the body of the user. In some embodiments, the body component  124  may include a body harness with a plurality of rigid or semi-rigid straps extending from the back of the upper torso to the front of the upper torso of the user over the shoulders and/or under the arms. In other embodiments, the body component  124  may include shoulder pads, a ballistic vest, body armor, a backpack, or the like. In all embodiments, the body component  124  may be not only sufficiently rigid to be effective for energy dissipation but also sufficiently flexible to be comfortable to the user. 
     The one or more linkage elements  116  may couple to the head component  122  and the body component  124  in a similar fashion to the one or more linkage elements  16  and the head component  24  and the body component  22  in the device  10  described above. 
     The system  100  may operate as follows. The head component  122  and the body component  124  may be worn by the user. The second sensor  114 , if utilized, may be integrated with a mouthpiece which is worn in the user&#39;s mouth. The rest of the system  100  may function in a substantially similar fashion to the device  10 , discussed above. In summary, if the processing element  118  determines an impact to the head that is at or above the injury level, then the processing element  118  may send a locking signal to the one or more linkage elements  116  to render them rigid for approximately 100 ms to approximately 300 ms. Afterwards, the locking signal is no longer transmitted or asserted, and the one or more linkage elements  116  are again flexible. 
     A system  200  for reducing traumatic brain injury for a group of people constructed in accordance with a third embodiment of the current invention is shown in  FIG. 9  and broadly comprises a plurality of devices  210  and a plurality of wireless transceivers  230 . The system  200  may be utilized by a group of military or law enforcement personnel who are actively engaging hostile parties in a situation where an attack may be imminent. The members of the group may be in close proximity to one another such that an impact on one member of the group may be felt by other members of the group. Typically, each member of the group is wearing a head component  222  such as a helmet and a body component  224  such as ballistic vests, flak jackets, body armor, and the like. 
     Each device  210 , as seen in part in  FIGS. 9 and 10 , may be substantially similar to the device  10  and may include a first sensor  212 , a second sensor  214 , one or more linkage elements  216 , a processing element  218 , and a memory element  220 , which are all substantially similar to the like-named components described above. Each member of the group may be wearing the device  210 . Furthermore, the device  210  may couple to the head component  222  and the body component  224  in a similar fashion to the device  10  with the head component  22  and the body component  24  described above. 
     Each wireless transceiver  230 , as seen in  FIGS. 9 and 10 , may include antennas, signal or data receiving circuits, and signal or data transmitting circuits. The wireless transceiver  230  may transmit and receive radio frequency (RF) signals and/or data and may operate utilizing communication standards such as cellular 2G, 3G, or 4G, Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard such as Wi-Fi, IEEE 802.16 standard such as WiMAX, Bluetooth™, Bluetooth™ LE, or combinations thereof. Each wireless transceiver  230  may be integrated with or packaged with the processing element  218  and/or the first sensor  212  of each device  210 . 
     Each wireless transceiver  230  may be in communication with the processing element  218  for one device  210 . The processing element  218  may communicate a locking signal to the wireless transceiver  230 , which may wirelessly transmit the locking signal to the other wireless transceivers  230  in the area. In some embodiments, the wireless transceiver  230  may not transmit the locking signal itself, but rather a signal or data that corresponds to the locking signal. The wireless transceivers  230  of other group members may receive the locking signal and communicate it to the associated processing element  218 , the associated one or more linkage elements  216 , or both. Furthermore, in certain embodiments, each wireless transceiver  230  may act as a repeater, wherein if a wireless transceiver  230  receives the locking signal, then it may transmit the locking signal as well. Thus, the transmission range of the system  200  is increased by having all of the wireless transceivers  230  transmit the locking signal whenever any device  210  detects a threatening impact. 
     The system  200  may operate as follows. Each device  210  may be installed or implemented and worn in a similar fashion to the device  10  described above. Given that each wireless transceiver  230  is coupled to a device  210 , the wireless transceiver  230  is worn as well. The first sensor  212  and the second sensor  214  of each device may function similarly to the like-named components of the device  10 , measuring the acceleration resulting from impacts to the head of each group member. 
     When the first sensor  212  or the second sensor  214  of one group member measures a significant impact and the processing element  218  determines that the sensor measurement is at or above the injury level, then the processing element  218  may generate or assert the locking signal and communicate it to the associated one or more linkage elements  216 . In turn, the one or more linkage elements  216  of the directly impacted group member may become rigid, as described above for the device  10 . The processing element  218  may also communicate the locking signal to the associated wireless transceiver  230 , which in turn may broadcast the locking signal to the other wireless transceivers  230  in the vicinity. 
     Each wireless transceiver  230  within range of the originating wireless transceiver  230  may receive the locking signal. In some embodiments, each wireless transceiver  230 , upon receipt of the locking signal, may transmit the locking signal as well, thereby increasing the effective range of the system  200 . On each device  210 , the wireless transceiver  230  may communicate the locking signal to the associated one or more linkage elements  216 , which in turn may become rigid just as if the locking signal were received from the associated processing element  218 . Thus, the linkage elements  216  for all devices  210  in the vicinity of the originating device  210  may become rigid as a result of the impact experienced by the originating device  210 . In effect, an impact on one member of the group becomes an impact to all members of the group. In various embodiments, the linkage elements  216  may remain rigid for a longer period of time as compared with the linkage elements  16  of the device  10 . For example, the linkage elements  216  may remain rigid for 100-300 msec before becoming flexible again. 
     A system  300  for reducing traumatic brain injury for a group of people in a vehicle constructed in accordance with a fourth embodiment of the current invention is shown in  FIG. 11  and broadly comprises a plurality of devices  310 , a plurality of wireless transceivers  330 , a vehicle sensor  332 , a vehicle processing element  334 , and a vehicle transmitter  336 . In various embodiments, each wireless transceiver  330  may be included or integrated as a component of a device  310 . The system  300  may be utilized by a group of military or law enforcement personnel who are in a vehicle which is located in or traveling in a hostile area where the vehicle could come under attack either from airborne projectiles, such as bullets or grenades, or roadway hazards, such as improvised explosive devices or mines. Each member of the group may be wearing a device  310 , a head component  322 , a body component  324 , and a wireless transceiver  330 . 
     The devices  310 , including linkage elements  316 , and the wireless transceivers  330  may be substantially similar to the devices  210 , the linkage elements  216 , and the wireless transceivers  230  of the system  200 . Furthermore, the devices  310  may couple to and interact with the head components  322  and the body components  324  in a similar fashion as the like-named components discussed above for the system  200 . 
     The vehicle sensor  332 , as seen in  FIGS. 11 and 12 , may be substantially similar in structure and function to the first sensor  12  or the second sensor  14  of the device  10  and may measure an acceleration of the vehicle or portions of the vehicle due to an impact. The vehicle sensor  332  may additionally or alternatively measure a velocity of or a force on the vehicle. The vehicle sensor  332  may generate vehicle sensor measurements of the acceleration, velocity, or force. The vehicle sensor  332  may be coupled to the body of the vehicle such as panels or walls on the sides, the front, the rear, the roof, or the undercarriage. In certain embodiments, the system  300  may comprise a plurality of vehicle sensors  332  positioned in various locations on the body of the vehicle. 
     The vehicle processing element  334 , as seen in  FIGS. 11 and 12 , may be substantially similar in structure and function to the processing element  18  of the device  10  and may receive vehicle sensor measurements from the vehicle sensor  332 . The vehicle processing element  334  may determine whether the value of the vehicle sensor measurement is above a critical level at which the vehicle may be damaged and the group members within may be injured. When the value of the vehicle sensor measurement (or any of the vehicle sensor measurements, if more than one vehicle sensor  332  is present) is above the critical level, the processing element  334  may generate or assert a locking signal, which is substantially similar to the locking signal of the device  10 . 
     The vehicle transmitter  336 , as seen in  FIGS. 11 and 12 , generally transmits signals and/or data wirelessly utilizing known RF communication or Bluetooth™ LE standards. The vehicle transmitter  336  may be in communication with the vehicle processing element  334  and may receive the locking signal therefrom. In other embodiments, the vehicle transmitter  336  may be in communication with the vehicle sensor  332  and may receive the sensor measurements therefrom. The vehicle transmitter  336  may wirelessly transmit the locking signal or the vehicle sensor measurements to the wireless transceivers  330  worn by each member of the group. 
     The vehicle transmitter  336  may be integrated with or packaged with the vehicle processing element  334  and/or the vehicle sensor  332 . In embodiments of the system  300  with a plurality of vehicle sensors  332 , there may be a plurality of vehicle transmitters  336 , one vehicle transmitter  336  for each vehicle sensor  332 , or there may be one vehicle transmitter  336 , such that all of the vehicle sensors  332  are connected to the vehicle transmitter  336  through electrical wires or cables. 
     The system  300  may operate as follows. The devices  310  and the wireless transceivers  330  may be implemented and may operate in a substantially similar fashion to the like-named components of the system  200 . The vehicle sensor  332  may be making measurements of the acceleration, velocity, or force affecting the vehicle on a regular basis and communicating the vehicle sensor measurements to the vehicle processing element  334 . When the vehicle processing element  334  determines that a value of the vehicle sensor measurement is at or above the critical level, the vehicle processing element  334  may generate or assert the locking signal to the vehicle transmitter  336 , which in turn broadcasts the locking signal to the wireless transceivers  330  of all of the members of the group. Each wireless transceiver  330  may communicate the locking signal to its associated one or more linkage elements  316 , rendering the linkage elements  316  rigid. Thus, when the vehicle comes under attack, the head component  322  and body component  324  of each member of the group may become rigidly integrated in order to protect the members from possible traumatic brain injury as a result of vehicular damage or overturning of the vehicle. As with the system  200 , the linkage elements  316  may remain rigid for  100 -300 msec before becoming flexible again. 
     At least a portion of the steps of a method  400 , in accordance with a fifth embodiment of the current invention, of reducing traumatic brain injury is shown in  FIG. 13 . The steps may be performed in the order presented in  FIG. 13 , or they may be performed in a different order. In addition, some of the steps may be performed simultaneously instead of sequentially. Furthermore, some steps may not be performed. 
     Referring to step  401 , sensor measurements are generated from a first sensor  12 . The sensor measurements may include a linear acceleration or an angular acceleration. The first sensor  12  may include accelerometers or other devices that measure velocities, accelerations, or forces. The first sensor  12  may be coupled or attached to a head component  24 , which may include a helmet worn on a user&#39;s head. Thus, the first sensor  12  may measure a linear or angular acceleration of a user&#39;s head as the result of an impact or blow to the head. The sensor measurements may be received by a processing element  18 . 
     Referring to step  402 , it is determined if a value of the sensor measurements is greater than or equal to one or more injury levels. The sensor measurements may include three orthogonal-axis linear or angular values from which the processing element  18  may determine whether the injury levels have been reached or exceeded using the methods and techniques described above for the device  10 . An example of injury level values may include 50 G, 4000 rad/sec 2 , or a dynamic level. 
     Referring to step  403 , a locking signal is transmitted to a linkage element  16  when the value of the sensor measurements is greater than or equal to the injury level. The locking signal may include a binary data value, a binary logic level, a pulse-width modulated signal, a voltage value, a current value, or the like. 
     Referring to step  404 , a state of the linkage element  16  is switched from a relatively flexible state to a relatively rigid state. The linkage element  16  may be formed from material or components whose stiffness or rigidity can be controlled, that is, increased and decreased. In exemplary embodiments, the linkage element  16  may be formed from a plurality of components and may include a first anchor  26 , a second anchor  28 , a first end link  30 , a second end link  32 , and at least one middle link  34 , as shown in  FIGS. 1-3 and 5  and discussed above. One end of the linkage element  16  may be connected to the head component  24  while the opposite end may be connected to a body component  22 . The body component  22  may include shoulder pads, body armor, or the like. 
     Under normal circumstances, the linkage element  16  is flexible and the links  30 ,  32 ,  34  may rotate freely with respect to one another and with respect to the anchors  26 ,  28  such that the linkage element  16  may assume a variety of shapes and positions. The head component  24  and the body component  22  may also move with respect to one another. When the linkage element  16  receives the locking signal from the processing element  18 , the linkage element  16  becomes rigid and retains its current shape and position. Typically, the linkage element  16  remains rigid for approximately 100 ms to approximately 300 ms. The first and second anchors  26 ,  28  each include a locking element  38 ,  44  that locks the links  30 ,  32 ,  34  in their current positions. Furthermore, with the linkage element  16  momentarily locked in position, the head component  24  and the body component  22  momentarily maintain their relative positions as well, thereby allowing energy received by the head component  24  to be transferred through the linkage element  16  to the body component  22  to be dissipated. 
     Additional embodiments of the present invention are depicted in  FIGS. 14-17 . These embodiments attempt to reduce traumatic brain injuries of athletes or other users by anticipating when a user may suffer an impact and then triggering protective gear worn by the user, such as the devices  10  described above, to protect the user from the anticipated impact. An exemplary method of implementing the invention broadly comprises the steps of: determining locations of a user as the user moves on a football field or other defined area; determining if the user is likely to impact another person or an object based on the locations of the user and the other persons or objects; and transmitting a locking signal to a head-stabilizing component worn by the user when it is determined the user is likely to impact the other person or the object so as inhibit motion of the user&#39;s head. The method may further comprise the steps of determining an approximate force at which the user is likely to impact the other person or the object based on the locations of the user over time and transmitting the locking signal to the head-stabilizing component only if the approximate force at which the user is likely to impact the other person or the object is greater than a threshold force. 
     The above-described method and other aspects of the invention may be implemented with a system  500  for reducing traumatic brain injuries or players on a football field or other sports field. An embodiment of the system  500  is shown in  FIG. 14  and includes a plurality of transmitters  502  configured to be worn by at least one of the players; a plurality of sensors  504  configured for placement on or near the sports field for receiving signals transmitted from the transmitters  502  as the players move on the sports field; a head-stabilizing component  506  worn by at least one of the players that inhibits motion of the player&#39;s head when activated; and a processing element  508  coupled with the sensors  504  and in wireless communication with the head-stabilizing component  506 . 
     As described in detail below, the processing element  508  is programmed for determining locations of each player wearing the transmitters  502 . The processing element determines the locations of the players based on the signals transmitted from the transmitters  502 . The processing element  508  then determines if any of the players are likely to impact one another based on the locations of the players and transmits an activating signal to the head-stabilizing component  506  of a player about to experience an impact to inhibit motion of the player&#39;s head. The processing element  508  may be further programmed to determine a force at which a player is likely to impact based on the signals transmitted from the transmitters  502  and to transmit the activating signal to the head-stabilizing component  506  only if the force exceeds a threshold force value. 
     Each of the components of the system  500  will now be described in more detail. The transmitters  502  may be any devices that can be worn by players or other users and that transmit signals to the sensors  504 . The transmitters  502  may send signals when interrogated by the sensors  504  and/or triggered by internal or external controllers. For example, the transmitters  502  may be radio frequency identification (RFID) tags or transponders that send signals when interrogated by the sensors  504 . Exemplary RFID transmitters are disclosed in U.S. Patent No  6 , 686 , 829 , which is hereby incorporated in its entirety by reference. Each transmitter  502  may include antennas, signal or data receiving circuits, and signal or data transmitting circuits. Each transmitter  502  may transmit and receive radio frequency (RF) signals and/or data and may operate utilizing communication standards such as cellular 2G, 3G, or 4G, Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard such as Wi-Fi, IEEE 802.16 standard such as WiMAX, Bluetooth™, Bluetooth™ LE, or combinations thereof. Each transmitter  502  may be integrated with or packaged with a processing element and/or other electronic device  210 . 
     Any number of the transmitters  502  may be affixed to each user. When used for American football, two transmitters are preferably affixed to or near the shoulder pads of each player as shown in  FIG. 15 . This permits the processing element  508  to determine the position of each player and whether the player is running forward or backward or whether the player is turning his shoulder, possibly cocking up one arm in preparation for a pass or reaching back to catch a pass. Embodiments of the invention may also employ one or more transmitters  502  affixed to the lower trunk of each player at or near waist level also as shown in  FIG. 15 . With the additional transmitter(s), the processing element  508  may extract information on the center of mass of the player and also whether the player&#39;s posture is such that he is upright and most likely on his feet airborne with a supine posture and will subsequently be in free fall to the ground. However, the transmitter placement shown in  FIG. 15  is one example only, as the specific number and positioning of the transmitters can be varied without departing from the scope of the invention. 
     The sensors  504  may be any devices capable of receiving signals from the transmitters  502  and conveying the signals to the processing element  508 . For example, the sensors  504  may be radio frequency identification (RFID) interrogators or readers such as those disclosed in the above-identified U.S. Pat. No. 6,686,829. The sensors  504  may alternatively employ any known wireless signal reception technology. 
     When the present invention is implemented on an American football field, the sensors  504  may be spaced along the length of the football field as shown in  FIG. 16 . In one embodiment, two rows of sensors are placed on opposite sides of the football field at  10  yard intervals. The sensors  504  may be mounted near ground level, on raised poles or other platforms, suspended above the field on wires, and/or buried below the playing surface of the field. However, the sensor placement shown in  FIG. 16  is only one example, as the specific number and positioning of the sensors  504  can be varied without departing from the scope of the invention. 
     The head stabilizing component  506  may be any protective device that can be worn by an athlete or other user and that can be switched to a protective state by the processing element  508 . In one embodiment, the head-stabilizing component  506  includes a head component configured to be worn on the user&#39;s head, a body component configured to be worn on the user&#39;s body, and a linkage element that connects the head component and the body component. A locking signal sent from the processing element  508  switches a state of the linkage element from a relatively flexible state to a relatively rigid state so as to more firmly link the user&#39;s head to the user&#39;s body. A particular embodiment of the linkage element is described in detail above and includes a first anchor configured to rigidly couple to the head component; a second anchor configured to rigidly couple to the body component; a first end link coupled to the first anchor and configured to rotate and pivot with respect to the first anchor; a second end link coupled to the second anchor and configured to rotate and pivot with respect to the second anchor; and a middle link coupled to the first anchor and the second anchor and configured to rotate and pivot with respect to both the first anchor and the second anchor. In some embodiments, the head stabilizing component is the device  10  described above with or without the sensors  12 ,  14 . 
     The processing element  508  is coupled with the sensors  504  and is in wireless communication with the head stabilizing component  506 . The processing element  508  is programmed for determining locations of each user wearing the transmitters  502  and actuating one or more of head-stabilizing components  506  when it determines one or more of the players is likely to collide with another player or object on or near the sports field. As explained in more detail below, the processing element  508  determines the locations of the players based on the signals transmitted from the transmitters  502 ; determines if the players are likely to impact one another based on the current locations of the players and/or objects on the field; and transmits activating signals to the head-stabilizing components  506  to inhibit motion of the players&#39; heads before any impact occurs. In some embodiments, the processing element  508  also determines a force at which the players are likely to impact and transmits the activating signals to the head-stabilizing components only if the force exceeds a threshold force value. 
     An embodiment of the processing element  508  may include processors, microprocessors, microcontrollers, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), analog and/or digital application-specific integrated circuits (ASICs), or the like, or combinations thereof. The processing element  508  may generally execute, process, or run instructions, code, code segments, software, firmware, programs, applications, apps, processes, services, daemons, or the like, or may step through states of a finite-state machine. The processing element may be operably coupled to a memory element  510 , which may include, or may constitute, a “computer-readable medium”. The memory element  510  may store data from the transmitters  502  and sensors  504  as well as instructions, code, code segments, software, firmware, programs, applications, apps, services, daemons, or the like that are executed by the processing element  508 . The memory element  510  may also store settings, data, documents, images, databases, and the like. The processing element  508  may be in communication with the memory element  510  through address busses, data busses, control lines, and the like. The processing element further includes or is in communication with a wireless transmitter  512  configured to transmit signals such as the above-described locking signals to the head-stabilizing component  506 . 
     The processing element  508  determines the locations of two or more players and derives data on distances between the players in real time. The locations of fixed objects such as goal posts, benches, walls, etc. may be stored in the memory  510  so the processing element can determine distances between these objects and the players as well. 
     The processing element  508  also derives data on the instantaneous velocities and accelerations of the players in XY coordinates, in real time, from the player location data. The processing element  508  then derives data on the relative instantaneous velocities and accelerations between any two players as a function of the data mentioned above and predicts future locations of the players based on this data. 
     The processing element  508  determines the probability of a collision between any two players and/or a player and an object based on predicted future locations of the players as a function of present and past locations, speeds, and accelerations of the players. For example, the processing element may predict future locations of the players and possible collisions by deriving data on the distances between the players 40 msec into the future, 80 msec into the future, etc. When the physical distance between any two players becomes less than or equal to the approximate dimensions of the players, a collision is to be anticipated. 
     After predicting an impending impact and before the impact actually takes place, the processing element  508  activates the head-stabilizing component worn by at least some of the players. For example, in one embodiment, the processing element sends an activating signal to activate the linkage elements in the device  10  described above and change its linkage elements from a flexible state to a rigid state at the time when the impact is anticipated to occur. The present invention is therefore capable of setting up an impedance-matched pathway for dissipating impact energy to a player&#39;s head immediately at or slightly before the time of a collision. The invention uses a similar strategy to protect a player from a player-ground collision, such as in a fall as a result of a tackle. 
     The processing element  508  de-activates the head-stabilizing component  506  immediately after a collision so that the player may resume play after the collision event is over. For example, when used with the device  10  described above, the processing element terminates the rigidity of the linkage elements within 100-300 msec (for reference purpose, the duration of a typical eye blink is between 300 and 400 msec). 
       FIG. 17  shows the XY coordinates of three American football players on a football field over a period of time such as 80 msec. In this example, the player identified as  1  is being defended by the players identified as  2  and  3 . The representation of  FIG. 17  may be made three-dimensional to include the Z coordinates for each player. The representation may also be made more extensive by including more players and their positions over a longer period of time. 
     In  FIG. 17 , the movement pattern of each player in the past 80 msec is represented by dots connected by lines. Each line is thus expressed by a timed sequence of samples of XY locations expressed as [Xi(t), Yi(t)], where i may be from 1 to 3 for the three players. Each of the dotted line consists of three points. Within a given dotted line, each of its three points represents RFID data or other positional data on the physical location of the player sampled at a specific instant. In the illustrated example, the timed samples are 40 msec apart. This is because the reporting frequency of transmitters in current RFID technology is 25 Hz. The entire duration covered by three consecutive timed samples of location is therefore 80 msec. 
     From the data in  FIG. 17 , the distances between player  1  and the other two players can be computed as a function of time within the 80 msec period. At a specified ti, the distances between player  1  and the other two players may be expressed as vectors, e.g. d12(ti) and d13(ti). 
     From the data in  FIG. 17 , the instantaneous velocities of the three players can be computed as a function of time over the 80 msec period. The instantaneous velocities for each player may be calculated from any two consecutive timed samples of locations from that same player. At a specified time ti, the instantaneous velocities of the three players may be expressed as vectors, e.g. v1(ti), v2(ti), and v3(ti). The most recent instantaneous velocities of players may be calculated with two of the most recent timed data for each of the players on their X Y locations. 
     Furthermore, the relative instantaneous velocities between any two players at a specific time can be computed. At a specified ti, the relative instantaneous velocities may also be expressed as vectors, e.g. v12(ti), v13(ti), v14(ti). For example v12(ti) may be calculated at [v1(ti)−v2(ti)]. 
     As long as the instantaneous velocities of the three players may be expressed as vectors, e.g. v1(ti), v2(ti), and v3(ti), and as long as these vectors may be calculated by using only 2 consecutive timed samples of locations, the anticipated future locations of each player can be computed as a function of some future time. For example, at the instant when the processor has just received the most recent RFID location data from all three players, it is feasible to compute the distances between any two players at a specific future time, e.g. 40 msec into the future, expressed as [x1(ti+40), y1(ti+40)], [x2(ti+40), y2(ti+40)], and [x3(ti+40), y3(ti+40)]. 
     Because the calculations may be carried out by computer operations of the processing element  508 , the entire calculation process may be expected to be nearly instantaneous or take no more than a fraction of a msec. Furthermore, instantaneous velocities of the players is assumed to remain unchanged in the next 40 msec, then the distances between the players 80 msec into the future may be computed as [x1(ti+80), y1(ti+80)], [x2(ti+80), y2(ti+80)], and [x3(ti+80), y3(ti+80)]. The assumption that instantaneous velocities of the players remain constant for 40 msec is well justified. Results from numerous kinematic studies of human movements support this assumption. For example, in a review on human movements by Miall and Wolpert (1996), muscles monitored by EMG (electromyogram) only began to respond 100 msec after the application of a perturbation. The response generally reached peak amplitude in another 100 msec. Preliminary data from applicant&#39;s own studies also support this assumption. These results indicate that it may be feasible to predict future human movement pattern by assuming that the human body continues to move in the same direction as long as the “future” is short-term and is ˜80-100 msec from the present. 
     Using the information described above, the processing element  508  may compute the probability of a collision between any two players at a specific future time. For example, at a specified tj, the collision probabilities are expressed as p12(tj) and p13(tj). Here, the probability is defined by: (1) pmn will be zero if the distance between player m and player n are &gt;&gt; than the dimensions or sizes of players, Sm and Sn (here Sm and Sn may be set to equal to the distance between the two RF transmitters affixed to the shoulder pads of player m and player m, respectively); (2) pmn will be one or 100% if the distance between player m and n are &lt;&lt; than the dimensions or sizes of players, Sm and Sn, (1) pmn will be set to a value that is equal to [2dmn/(Sm+Sn)] if the distance dmn between player m and n are of the same order as Sm and Sn. 
     If predictions of collisions are attempted too far into the future, for example ˜10 seconds into the future, the accuracy may be poor, e.g. ˜0%. If predictions are attempted for ˜1 second into the future, the accuracy may be better, e.g. ˜50%. And if predictions are attempted for ˜0.1 second or 80 msec into the future, the accuracy may be much better, e.g. &gt;95%. This is because the movement pattern of players are determined by (1) volitional movement control by multiple major brain centers including those that are within the non-specific cerebral cortical areas and the cortical pyramidal motor system, (2) subconscious motor control by the extrapyramidal motor system outside of the cerebral cortexes, such as the basal ganglia, the cerebellum, and the brainstem as well as spinal structures governing spinal reflexes, (3) intrinsic skeletomuscular strength, and the inertia of the parts of the human body directly involved in the movement. All these factors combine to determine the trajectory of any human movement. Over a period of 1 second to 10 seconds or longer into the future, the movement patterns in human kinematics are difficult to predict. Within 80 msec, however, the movement patterns in human kinematics are easy to predict as most of the complex mechanisms, e.g. (1) and (2) mentioned above, may not be able to come on-line that quickly. Therefore, predictions into the next 80 msec are quite accurate, e.g. at better than 95% accuracy. This confidence band is supported by numerous studies on human motor control and is also consistent with preliminary results from applicant&#39;s laboratory. 
     The ability to predict a collision or impact event in a period of 80 msec into the future plays a critical role in the implementation of aspects of the present invention. As set forth above, an important technological requirement is that the processing time must be so fast that it takes no more than 5-7 msec to make an accurate determination as to whether the impact event at hand may be injurious to a player. Although it is technologically feasible to satisfy this requirement, the requirement may be burdensome. The application of RFID technology in the present invention may offer a welcome relief in that 80 msec of advance collision warning may be available to protect against concussive traumatic brain injuries. Although this point is not immediately obvious or very useful to the current adopters of RFID technology, being able to predict an impending collision between players 80 msec before the collision takes place is very useful in the application of MEMS (MicroElectro-Mechanical Systems) technology in concussion prevention. 
     Furthermore, it is feasible to issue a locking signal to activate the linkage elements of the devices  10  described above and change the linkage elements from a flexible state to a rigid state. Here the locking signal will be sent based on a prediction of player collision in a future time, e.g. tf. More specifically, the locking signal will be send at (tf−td) where td is the mechanical delay that is required to make the rigidity happen. In this way, the present invention is able to time the locking signal so that the linkage element rigidity will occur at or slightly before a collision will actually occur. 
     Furthermore, it is feasible to de-active the linkage elements and change the linkage elements from a rigid state to a flexible state within 100-300 msec of the collision or impact event. Because the period of rigidity is transient and brief, the rigidity will present minimal interference to the head-and-neck mobility of the athlete. A beneficial corollary is that when implementing protection protocol, the processor that is responsible for issuing the locking signal can err on the side with more protection in mind since the cost of a false-positive (measured by interference to the head-and-neck mobility) is low. 
     Furthermore, if a third transmitter is attached to the player just below waist level as shown in  FIG. 15 , the additional transmitter will provide more information not only on the XY location but also information on the position of the player in the Z axis. This information will be used to anticipate player-ground collisions that result in concussive injuries when a player leaps and focuses on catching a pass while being hard-tackled by a player from the opposite team. The calculation steps are similar to those in player to player collisions but somewhat less tedious since the ground does not move. 
     In some embodiments, the processing element  508  computes the force of magnitude of an anticipated collision. This may be estimated from the changes in instantaneous velocities of a player immediately before and immediately after a collision or impact event. This information is useful when some are instrumented with RFID technology as well as the preventive head stabilizing components of the present invention while others are only instrumented with RFID technology without the preventive protection. It may be feasible to compare collision or impact events of similar energy in order to examine whether players with head stabilizing components of the present invention may be significantly better off in terms of concussive traumatic brain injuries. 
     In some embodiments, the accuracy of the prediction process may be enhanced by statistically interpolating and extrapolating the raw data from the transmitters to generate accuracies in time exceeding the 40 msec limit set by the 25 Hz RF transmitters as well as accuracies in space exceeding the 6 cm or 2 in limit set by the intrinsic resolution of the RF detection system. In essence, the raw RF data contains only a punctate series of numbers at a time resolution of 25 Hz and spatial resolution of ˜2 in, but the processing element may perform additional computation to extract trend information of statistical significance from data points of the recent past. The processing element may further provide a smooth function for the prediction of future location information. Moreover, this information may be compiled on-the-fly or almost in real time. 
     In some embodiments, the processing element  508  may compare the accuracy of the predictive estimates of the anticipated future locations of each player as a function of time. For example, estimates on the anticipated future locations of each player may be compared with data on the actual locations of the players which should arrive at the processor moments (less than 40 msec) after the anticipated locations have been calculated. This comparison helps to generate a feedback as to whether the anticipated or the calculated future locations are indeed accurate. Moreover, this feedback information is useful as the processing element may machine-learn to be more conservative and shorten or to be bolder and lengthen the period for which a prediction of the future location of a player can be made with confidence. In other ways, the feedback may also allow the processing element to optimize computational algorithms by including additional features for the purpose of making more accurate anticipations on the future location of a player. 
     In some embodiments, it may be that the most optimized computation still does not generate a perfect prediction. It is then feasible to compute a system performance level based on the difference between the most optimized prediction of future locations of a player and the actual observed locations of a player. It is feasible to report the performance level of the prediction process to a central processor. Applicant expects the system performance level to be well above 95%. 
     In some embodiments, computations involving distances or relative instantaneous velocities between two players from the same team may be omitted so that the overall speed of the computation may be enhanced. This is because concussive traumatic brain injuries resulted from collision or impact from players of the same team are rare. 
     In some embodiments, computations involving distances or relative instantaneous velocities between two players when they are at a great distance apart (e.g. when the distance between player m and player n are &gt;&gt; than the dimensions or sizes of players, Sm and Sn) may be omitted so that the overall speed of the computation may be enhanced. This is because concussive traumatic brain injuries resulted from collision or impact from players of at a great distance apart is not possible. 
     Although the invention has been described with reference to the embodiments illustrated in the attached drawing figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims.