US20150157080A1

US20150157080A1 - Device to reduce head injury risk

Info

Publication number: US20150157080A1
Application number: US14/566,567
Authority: US
Inventors: David B. Camarillo; Fidel Hernandez; Gabriel N. Sanchez; Scott C. Anderson
Original assignee: Leland Stanford Junior University
Current assignee: Leland Stanford Junior University
Priority date: 2013-12-11
Filing date: 2014-12-10
Publication date: 2015-06-11

Abstract

Described herein is a wearable device for redirecting head impact force from the head of a person to other body part or parts of the person, the device comprising: a helmet wearable on the head of the person; a brace wearable on the body of the person; and at least one force redirecting unit configured for connection to the helmet and the brace, wherein at least one of the force redirecting unit is configured to be compressed to carry compressive load, and at least one of the force redirecting unit is configured to be extended to carry tensile load.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application Ser. No. 61/914,574 filed on Dec. 11, 2013, the disclosure of which is incorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure, in general, relates to a device for redirecting the head impact force to reduce the risk of head injury.

BACKGROUND

The following discussion of the background of the disclosure is merely provided to aid the reader in understanding the disclosure and is not admitted to describe or constitute prior art to the present disclosure.
Head injuries arise from damaging forces applied directly to the head or to the body that result in a rapid acceleration of the head. The resulting translation and rotation of the head have both been linked to neurological outcomes associated with brain injury. Brain injury may occur due to either (1) focal trauma from concentrated forces causing a rapid, focal translational acceleration that may lead to skull fracture or deformation that impinges on the brain, a severe form of traumatic brain injury (TBI); or (2) diffuse trauma from acceleration that causes inertial loading deep within the brain. Mild TBI (mTBI) is mostly associated with the rotation of brain that produces neuronal damage in shear.
TBI has been identified as a major public health concern by the U.S. Center for Disease Control and Prevention, and is a leading cause of death and disability worldwide. Most of these injuries are caused by falls, motor vehicle collisions, sports activity, recreation, and violence. mTBI accounts for about 75% of all reported TBI incidents. It is estimated that about 1.6 to 3.6 million sports-related mTBIs are diagnosed each year in the United States.
Therefore, a system is needed to reduce the head acceleration resulting from a damaging force to the head or body, thus reducing the risk of mTBI without increasing the risk of other types of head and neck injury.

SUMMARY

The present disclosure provides, in some embodiments, a device for redirecting a head impact force from a head of a person to other part or parts of a body of the person, the device comprising: a helmet wearable on the head of the person; a brace wearable on the body of the person; and at least one force redirecting unit configured for connection to the helmet and the brace, wherein at least one of the at least one force redirecting unit is configured to be compressed to carry compressive load, and at least one of the at least one force redirecting unit is configured to be extended to carry tensile load.
In some embodiments, the brace of the device for redirecting the head impact force comprises at least one of a shoulder pad, a vest, a body harness, and a hood. In some embodiments, the brace comprises a protruding platform, and the at least one force redirecting unit is configured for connection to the brace on the protruding platform.
In some embodiments, the device for redirecting the head impact force further comprises a plurality of force redirecting units such that at least one of amplitudes and durations of accelerations in three dimensions of translation and three dimensions of rotation can be reduced.
In some embodiments of the device for redirecting the head impact force, the at least one force redirecting unit comprises at least one of a telescopic strut, a viscoelastic hood, and an assembly of a cable and a compressive member; and the at least one force redirecting unit is configured to respond to an acceleration caused by the head impact force while permitting motion of the person.
In some embodiments, the telescopic strut is a telescopic damper comprising a piston, at least one control valve, and at least one chamber containing a fluid, wherein the at least one control valve is configured to funnel the fluid into or out of the chamber to resist motion of the piston caused by the head impact force.
In some embodiments, the telescopic damper defines a stepped orifice for transporting the fluid into and out of the chamber, wherein the stepped orifice comprises a small orifice and a large orifice; and the telescopic damper further comprises a spring at least partially disposed within the large orifice, and a ball connected to the spring, wherein the ball is configured to be moved by the fluid to an entrance of the large orifice to block the large orifice.
In some embodiments, the telescopic damper defines an upper chamber and a lower chamber, and further includes two valves connecting the upper chamber and the lower chamber, wherein a first valve allows the fluid to flow from the upper chamber to the lower chamber, and a second valve allows the fluid to flow from the lower chamber to the upper chamber.
In some embodiments, the telescopic strut of the device comprises at least one of a latch and a hook on at least one end of the telescopic strut for release from at least one of the helmet and the brace.
In some embodiments, the viscoelastic hood of the device for redirecting head impact force comprises a viscoelastic material that is viscous at rest and is configured to be stiffened to maintain a head posture in response to an acceleration caused by the head impact force. In some embodiments, the acceleration is detected by a sensor configured to detect the neuromuscular impulse of muscles in response to the head impact force.
In some embodiments, the compressive member of the device comprises an inflatable unit configured to inflate to maintain a head posture during an impact.
The present disclosure also provides, in some embodiments, a device for reducing head and neck injury during an impact. The device comprises a helmet wearable on a head of a person; a brace wearable on a body of the person; a first force redirecting unit configured for connection to the helmet and the brace, and configured to resist compressive strain in response to an impact force exerted on the helmet; and a second force redirecting unit configured for connection to the helmet and the brace, and configured to resist tensile strain in response to the impact force exerted on the helmet.
In some embodiments, the first force redirecting unit and the second force redirecting unit of the device for reducing head and neck injury during an impact comprise any combination of a telescopic strut, a viscoelastic hood, and an assembly of a cable and a compressive member.
In some embodiments, the telescopic strut of the device comprises at least two stages. In some embodiments, the telescopic strut comprises a motor for actuating the telescopic strut, and a controller for sensing an acceleration caused by the head impact force and controlling the motor based on the sensing. In some embodiments, the motor is configured for connection to the brace.
In some embodiments, the device for reducing head and neck injury comprises a motion sensor for detecting an acceleration caused by the impact force. In some embodiments, the motion sensor for detecting the acceleration is at least one of an accelerometer sensor, a gyroscope sensor, a pressure sensor, a strain gauge, a centrifugal force meter, and a velocity meter.
In some embodiments, the centrifugal force meter in the device for reducing head and neck injury comprises: a drum for transforming a linear motion into an angular motion; a wheel including a movable tab connected to the wheel through a torsional element; a pinion gear connecting the drum and the wheel; and a clutch including an indention in an inner surface of the clutch; wherein the movable tab is configured to contact the indention in the inner surface of the clutch to stop a rotation of the wheel when a centrifugal force of the movable tab caused by a rotation of the wheel exceeds a threshold level.
Other aspects and embodiments of the disclosure are also contemplated. The foregoing summary and the following detailed description are not meant to restrict the disclosure to any particular embodiment but are merely meant to describe some embodiments of the disclosure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a model of a device for redirecting head impact force from the head of a person to the shoulder or torso of the person.

FIG. 2 illustrates one embodiment of the device for redirecting head impact force where certain force redirecting units carry tensile load and other force redirecting units carry compressive load during an impact.

FIG. 3 illustrates an embodiment of the device for redirecting head impact force used in American Football, which includes a plurality of force redirecting units.

FIG. 4 illustrates an embodiment of the device for redirecting head impact force where the force redirecting units can be placed on a protruding platform on the brace or at a lower portion on the brace to allow wider range of motion.

FIG. 5 illustrates an embodiment of a telescopic strut in the form of a telescopic damper.

FIG. 6A provides a zoom-in view of a stepped orifice on a telescopic damper at a low flow rate.

FIG. 6B provides a zoom-in view of a stepped orifice on a telescopic damper at a high flow rate.

FIG. 7 illustrates the relationship between the velocity and the damping force in the embodiment illustrated in FIGS. 6A and 6B.

FIG. 8 illustrates an embodiment of a double-acting telescopic damper.

FIG. 9 illustrates an embodiment of a device for redirecting head impact force using cables, clutches, and compressive members.

FIG. 10 illustrates an embodiment of a centrifugal clutch.

FIG. 11 illustrates different embodiments of mechanism for locking the cable.

FIG. 12 illustrates an embodiment of a device for redirecting head impact force in the form of a head hood using a viscoelastic material and neuroadaptive sensors.

FIG. 13 illustrates an embodiment of a device for redirecting head impact force in the form of a neck hood using a viscoelastic material and neuroadaptive sensors.

FIG. 14 illustrates an embodiment of a device for redirecting head impact force using a combination of different types of force redirecting unit.

Some or all of the figures are schematic representations by way of example; hence, they do not necessarily depict the actual relative sizes or locations of the elements shown. The figures are presented for the purpose of illustrating one or more embodiments with the explicit understanding that they will not be used to limit the scope or the meaning of the claims that follow below.

DETAILED DESCRIPTION

The following examples and embodiments serve to illustrate the present disclosure. These examples are in no way intended to limit the scope of the disclosure.
To reduce the incidence of fatalities and severe TBI, helmets are designed with the goal of reducing the amplitude and duration of translational acceleration. Two basic principles are employed in helmets. First, a rigid outer shell spreads a contact force over a larger area on the helmet and the head thereby reducing stress on the skull. Second, an inner padding material deforms during collision, which lengthens the time of the impulse while reducing the maximum force.
Focal brain trauma is largely a solved issue today as helmets can effectively distribute concentrated forces. However, because mTBI and severe TBI have different physical injury mechanisms, modern shell helmets are not sufficient to address both forms of TBI. While reported cases of severe TBI have been dramatically reduced, diffuse inertial injury appears to be on the rise despite of the use of helmets. The starkest example is in American football, where about 200,000 concussions were reported in 2009 among about 5 million helmeted players.
The level of forces that persist in football, warfare, and cycling is clearly too high for a human head to resist to prevent acceleration injury. Even with an ideal helmet material that maintains a constant force during deformation, there is a practical limitation because a wearable helmet has to be of certain thickness. A second fundamental limitation of helmets is that the force reduction using a helmet is achieved by extending the impulse duration, which is worse for inertial loading of the brain because the longer a given acceleration is held, the further it can penetrate into the brain. Therefore, an ideal solution to the problem would reduce both acceleration amplitude and duration.
Improvements in materials and testing standards of helmets in the 20th century have nearly eliminated skull fracture and focal injury in American football. However, as discussed above, using helmets to reduce the contact force on the head has its practical and theoretical limitations, ultimately relying on the neck to do the critical work to prevent diffuse injuries caused by inertial acceleration. But the human neck is one of the weakest link on the body. The added weight of the hard shell helmet further stresses the neck such that the risk of mTBI is greater.
Among primates, humans have the smallest neck to head area ratio. The relatively weak human neck is ineffective at restraining head acceleration during collision. Primates with larger necks are more resistant to diffuse brain injury, and primates equipped with a restraining neck collar show dramatically increased tolerance to collision. When exposed to high energy impacts, the 5 Kg human head is susceptible to inertial injury unless the neck is augmented with a restraint system that can restrain head acceleration while not impeding normal voluntary motion.
The neck musculature may not be able to provide sufficient force to reduce acceleration amplitude and duration in many scenarios. Cables can be used to redirect the damaging force to the head to reduce the acceleration of the head in rotation. While cables may resist tensile strain to reduce the effect of damaging force that could produce mTBI, they could not carry compressive load and may load the neck with additional compression force, which may have damaging effects that produce other forms of injury.
The device in some embodiments of the present disclosure helps to carry both the tensile load and the compressive load normally carried by the head and neck of a person during impact while transferring the impact force to the shoulders and torso. The device also permits voluntary, low acceleration rate motion of the person in the absence of impact.
In some embodiments of the present disclosure, as illustrated by the model in FIG. 1, the device for redirecting head impact force from a head of a person includes a helmet 102 and a brace 104 that are wearable by the person, and a plurality of force redirecting units 106 configured to connect to both the helmet 102 and the brace 104. The plurality of force redirecting units 106 are configured to carry both compressive load and tensile load that would otherwise be carried by the neck 108 of the person. In some embodiments, the plurality of force redirecting units 106 can independently telescope to selectively allow and inhibit rotation and translation.
As illustrated in FIGS. 1 and 2, any number of force redirecting units 106 or 206, such as two or more, three or more, or five or more, in any combination of angles, could be used to achieve a desired amount of restraint. The attachment sites for the force redirecting units 106 or 206 to be connected to the helmet 102 or 202 can be along the center diameter of the helmet 102 or 202. Additionally or alternatively, the force redirecting units 106 or 206 can be connected to the helmet 102 or 202 off-center along chords. In some embodiments as illustrated in FIG. 2, the force redirecting unit 206 has a latch or a hook 210 on at least one end for easy release from the helmet 202 or the brace 204. In some embodiments, the connection between the force redirecting unit and the helmet or the connection between the force redirecting unit and the brace can be permanent.
As illustrated in FIGS. 1 and 2, the combination of the force redirecting units helps to reduce the amplitudes and durations of accelerations in three dimensions of translation and three dimensions of rotation by redirecting the impact force to the larger body from a head. More importantly, the combination of the force redirecting units also helps to carry both the tensile load and the compressive load at the same time during the impact to reduce the tensile load and compressive load on the neck. For example, when the head is impacted from the left and rotates to the right, if the force redirecting units only carry tension (like a cable), the force redirecting units on the left are stretched and carry a tensile load, but the force redirecting units on the right are in slack and do not carry any load. Thus, the neck would have to carry a compressive load to balance the tensile load carried by the force redirecting units on the left. With force redirecting units that carry both compressive load and tensile load, opposing force redirecting units balance one another. For example, as illustrated in FIG. 2, the force redirecting unit 206 on the right would be able to carry the compressive load applied by the impact force 208 and the force redirecting unit 206′ on the left, thereby offloading the neck. As a result, the motion of the helmet 202 and the head can be restrained, and the head can approximately maintain its posture during the impact while the impact force is being transferred to the body through the force redirecting units 206 without overloading the neck.
In some embodiments, each force redirecting unit is configured to carry both types of loads, with a subset of the units carrying one type of load during an impact event, and another subset of the units carrying another type of load during that impact event. In other embodiments, a subset of the units is specifically configured to carry one type of load, and another subset of the units is specifically configured to carry a different type of load.
In some embodiments, the compressive load carried by the force redirecting units is at least about 1.000 Newton (N); at least about 2,000 N; at least about 3,000 N; at least about 4,000 N; at least about 5,000 N; at least about 7,500 N; or at least about 10,000 N. In some embodiments, the tensile load carried by the force redirecting units is at least about 1,000 N; at least about 2,000 N; at least about 3,000 N; at least about 4,000 N; at least about 5,000 N; at least about 7,500 N; or at least about 10,000 N
In some embodiments, at least one force redirecting unit undergoes compression to yield a percentage change in at least one dimension (e.g., a longitudinal dimension) of at least about 1%, at least about 2%, at least about 3%, at least about 4%, at least about 5%, or at least about 10%, and up to about 20% or more, expressed as an absolute value of a difference between uncompressed and compressed states relative to uncompressed state.
In some embodiments, at least one force redirecting unit undergoes extension to yield a percentage change in at least one dimension (e.g., a longitudinal dimension) of at least about 1%, at least about 2%, at least about 3%, at least about 4%, at least about 5%, or at least about 10%, and up to about 20% or more, expressed as an absolute value of a difference between unextended and extended states relative to unextended state.
In some embodiments, the force redirecting units respond to impact with compressive load or tensile load in less than about 20 millisecond (ms), less than about 10 ms, less than about 5 ms, less than about 3 ms, less than about 2 ms, or less than about 1 ms.
While the device disclosed in the present disclosure is not limited to any particular sport or activity, an embodiment of the device in the context of American Football is illustrated in FIG. 3. The device illustrated in FIG. 3 includes a plurality of force redirecting units 306 that connect to a helmet 302 and a brace 304. The brace 304 can be a wearable fixture that covers the shoulders and wraps around a person's torso. The brace 304, which can be worn above or below a player's garments, provides a rigid support for the force redirecting units 306. The force redirecting units 306 are configured to connect to the brace 304 and the helmet 302, and carry both compressive load and tensile load.
The attachment of the force redirecting units 306 to the brace 304 and helmet 302 can be made permanent so that the entire device is a single unit, or they can be configured for easy detachment with connectors, such as a latch or a hook, such that the elements can disconnect from one another. The embodiment illustrated in FIG. 3 includes three force redirecting units 306: one on the left, one on the right, and one to the posterior of the helmet 302. However, the device disclosed herein could include any number of force redirecting units 306 depending on the context.
In some embodiments as illustrated in FIG. 4, the posterior force redirecting unit 406 can be placed on a protruding platform 408 on the brace 404 or at a lower portion on the brace 404 to allow wider range of motion. Additionally or alternatively, some force redirecting units 406 can be placed higher on the brace 404. The force redirecting units 406 can also be connected to the helmet 402 at different locations.
In some embodiments, the brace can be a shoulder pads, a vest, a body harness, or a hood. The brace is configured for tightly coupled to the body of a person to provide support for the force redirecting units and to transfer the impact force to the body, which can carry the load without injury.
In some embodiments, the force redirecting unit includes a telescopic strut, each end of which includes a connector configured to connect to the helmet or the brace. In some embodiments, as illustrated in FIG. 5, the telescopic strut includes a telescopic damper 500. The telescopic damper 500 includes a piston 502; a chamber 504 defined by the wall of the telescopic damper 500; a fluid 506, such as a viscous liquid, in the chamber 504; and an orifice 508 defined by the wall of the telescopic damper 500 for transferring the fluid 506 into or out of the chamber 504. The telescopic damper is sealed such that the fluid 506 will not leak even if the pressure in the chamber 504 builds up. The dampening function is achieved through the piston 502 which pushes the fluid 506 into the chamber 504. The telescopic damper 500 can also be configured to resist tension. Wider ranges of motion can be achieved by making the telescopic dampers any number of stages, such as two stages, three stages or more. In addition, the telescopic damper 500 includes a locking feature 510 to engage a second telescopic damper such that multiple telescopic dampers can work in series to provide even wider range of motion.
In some embodiments, the telescopic damper resists compression by incorporating a stepped orifice such that the telescopic damper has low resistance to slow motions and strong resistance to motions beyond a certain threshold. One embodiment of the stepped orifice in the telescopic damper is illustrated in FIGS. 6A and 6B, which includes a large orifice 602 and a smaller orifice 604 defined by the wall of the telescopic damper 600. In the embodiments illustrated in FIGS. 6A and 6B, the telescopic damper 600 also includes a ball valve guide 610 and a ball 606 that can travel within the ball valve guide 610. The telescopic damper 600 further includes an elastic element, such as a spring 608, connected to the ball 606. At least a portion of the spring 608 is disposed in the large orifice 602 and can be connected to the telescopic damper 600.
When the flow rate of the fluid 612 within the telescopic damper 600 is low, as illustrated in FIG. 6A, the drag on the ball 606 by the flow of the fluid 612 is low as well. The force exerted on the ball 606 by the spring 608 can keep the ball 606 away from the entrance of the large orifice 602, thus allows the fluid 612 to easily flow in and out of the large orifice 602. As a result, the pressure of the fluid 612 inside the telescopic damper 600 is low and the pressure of the fluid on the ball 606 is low as well, which also helps to keep the ball 600 away from the entrance of the large orifice 602. Because the pressure within the telescopic damper 600 is low, the resistance to the piston (not shown in FIGS. 6A and 6B) that pushes the fluid 612 is low as well. Thus the person can move freely with little resistance.
When the flow rate increases, as shown in FIG. 6B, the drag and the pressure on the ball 606 increases until it overcomes the resistance of the spring 608 and forces the ball to the entrance of the large orifice 602 to block the larger orifice 602. At this point, the small orifice is selectively open such that the pressure inside the telescopic damper 600 builds up and the resistance to the piston caused by the pressure is high, which causes the damper to be stiff and limits the motion of the person.
The relationship between the velocity and the damping force in the embodiment illustrated in FIGS. 6A and 6B can be illustrated by curve 702 in FIG. 7. Using a stepped orifice, a dramatic rise in damping force can be achieved when the extension or compression of the telescopic strut exceeds a certain velocity (or other threshold level) indicated by point 704. Design parameters of the telescopic strut can be adjusted to set this particular velocity to a threshold limit that is unsafe for head motion.
The principle described above can also be employed in a double-acting telescopic damper as illustrated in FIG. 8. In some embodiments as illustrated in FIG. 8, the telescopic damper 800 includes an enclosed outer tube 802; an open-ended inner tube 804; a piston 806 that separates the inner space of the outer tube 802 into an upper chamber 808 and a lower chamber 810; a lower control valve 812; and an upper control valve 814. The piston 806 is connected through a rod 816 to a first connector 818 for connecting to the helmet or the brace. The telescopic damper 800 also includes a second connector 820 for connecting to the brace or the helmet. In some embodiments, the first connector 818 and the second connect 820 can be configured as a latch or a hook. The inner space of the outer tube 802 contains a fluid, such as a viscous liquid, and is in fluid communication with a reservoir through a pipe 822.
During compression, the piston 806 is pushed down and the telescopic damper 800 shortens. A working cylinder 824 at the end of the piston 806 pushes the fluid in the lower chamber 810 down. When the entire lower chamber 810 is filled with the fluid, the pressure in the lower chamber 810 builds up, which resists further downward compression of the piston 806. The pressure causes the upper control valve 814 to open and allows the fluid to escape from the lower chamber 810 into the upper chamber 808. This allows for damped compressive motion.
During tension, the piston 806 is pulled up and the telescopic damper 800 elongates. The piston 806 pulls the working cylinder 824 up against the fluid in the upper chamber 808. The pressure in the upper chamber 808 builds up and resists further tensioning of the telescopic damper 800. The high pressure in the upper chamber 808 causes the lower control valve 812 to open, and allows fluid in the upper chamber 808 to escape into the lower chamber 810. This allows for damped tensile motion.
Several design parameters can affect the amount of damping in tension and compression of the embodiment of the telescopic damper 800. For example, the size and quantity of the control valves 812 and 814 control the damping force in tension and compression. When there are several large control valves, fluid is allowed to escape the pressurized chamber quickly, reducing the amount of force with which it resists the working cylinder 824. With few small control valves, the fluid is inhibited from escaping the pressurized chamber, such that the motion of the piston 806 is more heavily resisted.
The amount of tension and compression carried by the telescopic strut can also be independently controlled by separately varying the size and number of the upper control valves 814 for compression and the lower control valves 812 for tension.
The telescopic damper 800 can be connected to a reservoir through a pipe 822 such that fluid may be let in or released from the inner space of the outer tube 802 for additional control of the damping force. The reservoir can include a thin chamber surrounding part of the brace. Fluid with a specific density can also be used to set a specific volume-to-pressure ratio.
In some embodiments, the telescopic strut can also include a motor for actuating the telescopic strut, and a controller for sensing an acceleration caused by the head impact force and controlling the motor based on the sensing. In some embodiments, the motor is configured for connection to the brace. In some embodiments, the controller includes a motion sensor for detecting the head motion caused by impacts. In some embodiments, the motion sensor is at least one of an accelerometer sensor, a gyroscope sensor, a pressure sensor, a strain gauge, a centrifugal force meter, and a velocity meter.
These design parameters of the telescopic struts can thus be tuned to enable normal motion of a person while resisting motion caused by impact force. The telescopic struts can be designed to allow a large range of motion. When a person wearing the device disclosed herein moves his or her head slowly within the normal range of head motion, the fluid transfer between the upper and lower chambers can be configured to keep up with this motion. These design parameters also can be set such that the fluid transfer between the chambers lags behind the motion of the head caused by an impact. This lag allows the pressure to build up in one of the chambers and resist motion of the piston. For example, in the case of head rotation to the right cause by an impact force from the left, the telescopic strut on the left elongates while it is being resisted by the fluid in the upper chamber. The telescopic strut on the right compresses while it is being resisted by fluid in the lower chamber. Both telescopic struts support the tension and compression caused by head impact, and as a result, relieve the neck from carrying the tensile load and compressive load.
In some embodiments, the combination of cables and compressive members carries both the compression load and the tension load. In some embodiments as illustrated in FIG. 9, the device for redirecting head impact force incudes cables 906 connected to the helmet 902 and the brace 904; and a compressive member 910 comprising an inflatable unit, such as an inflatable airbag. The cables 906 are connected to the brace 904 through clutches 908 that are attached to the brace 904. The clutches 908 are configured to engage at a high speed extension of the cables 906.
In some embodiments, the clutch is a centrifugal clutch 1000 as illustrated in FIG. 10. In the embodiment illustrated in FIG. 10, a cable 1016 is attached to the centrifugal clutch 1000 by wrapping around an external drum 1002. A pinion gear 1004 which engages with the external drum 1002 has a smaller radius than the external drum 1002, thus amplifies the motion of the external drum 1002 induced by the motion of the cable 1016. On the same axis of the pinion gear 1004 is a wheel 1006. The wheel 1006 includes a moveable tab 1008 that is attached to the wheel 1006 at one corner via a torsional element 1010, such as a spring. When the cable 1016 is pulled, the drum 1002 rotates, and the pinion gear 1004 rotates faster that the drum 1002. The rotation of the pinion gear 1004 causes the wheel 1006 to rotate at the same angular speed as the pinion gear 1004, thus causing the attached moveable tab 1008 to rotate outward when the centrifugal force is large than the force applied to the moveable tab 1008 by the torsional element 1010. When the moveable tab 1008 rotates outward far enough, a flat surface 1012 on the moveable tab 1008 makes contact with an indentation 1018 in the inner surface of the centrifugal clutch casing 1014. This contact provides a hard stop to the wheel 1006, pinion gear 1004 and drum 1002, and in turn, restrains the cables 1016. The velocity at which this hard stop is triggered can be adjusted by tuning the stiffness of the torsional element 1010 to which the moveable tab 1008 is attached. In addition, an appropriate gear ratio between the drum 1002 and the pinion gear 1004 can amplify the sensitivity of the clutch 1000 to specific velocities. Free range of head and neck motion is thus enabled because a slow extension of the cable 1016 does not cause the moveable tab 1008 to open radially and engage with the indentation 1018.
Some other embodiments of the mechanism for locking the cable are illustrated in FIG. 11, such as a linear dashpot 1102, a torsional dashpot 1104, an air based dashpot 1106, and a preloaded spring 1108. These cables and clutches or dashpots could carry the tensile load of head acceleration caused by impact. They can be supplemented with an inflatable element, such as the compressive member 910 shown in FIG. 9 to carry the compressive load.
In some embodiments, the compressive member 910 illustrated in FIG. 9 is an airbag that can be deployed upon impact. The airbag could be disposed within the helmet and be deployed in the inferior direction toward the shoulder. Alternatively or additionally, the airbag can be contained in a shoulder pad system and expand in the superior direction toward the head when deployed. Upon impact, the airbag can be inflated to carry compressive load on the side opposite to the side where the cable is stretched. The airbag can be triggered when an impact is detected by devices such as a sensor or the aforementioned centrifugal clutch. The airbag can be retractable for repeated use, or it could be disposable. The airbag can also be disposed under the shoulder pads such that, when deployed, it pushes the shoulder pads superiorly to limit the head motion, even without a helmet. When not deployed, the airbag allows free range of head motion. Thus, the combination of cables and compressive members offloads the head and neck from tension and compression, and redirects the impact force from the head onto the shoulders and torso.
FIGS. 12 and 13 illustrate some other embodiments of the force redirecting unit that uses a viscoelastic material disposed in a helmet, a neck hood or on a shoulder pad for restraining the head motion during impact and maintaining a specific head posture. The force redirecting unit 1200 illustrated in FIG. 12 uses neuroadaptive sensors 1204 to monitor the neuromuscular activity of the muscle. The viscoelastic material can be anchored on the shoulders either at the shoulder pads or through a helmet or a head hood 1202, and can extend up above the C1 vertebrae 1206. The force redirecting unit illustrated in FIG. 13 is in the form of a neck hood 1300 with similar neuroadaptive sensors 1302 and viscoelastic material disposed within the hood. The viscoelastic material is configured to be viscous at rest when the amount of electrical activity in the surrounding musculature is normal. With the application of impact force, the material can stiffen upon the detection by the neuroadaptive sensors the neuromuscular impulses of the surrounding muscles fired in response to the load. In some embodiments, the viscoelastic material provides general stabilization, resists rotary forces, resists side bend, and resists flexional extension.
A force redirecting unit based on the viscoelastic material described above can maintain stability of the cervical spine and decelerates the head from impact in multiple planes, with less invasion and obstruction of normal motion. Upon detecting the activities of the muscles in response to impact, the viscoelastic material in the force redirecting unit could respond accordingly and provide resistance to tension and compression. The viscoelastic material could then be deactivated when the stimulus is removed, and thus would eliminate the need for re-deployment or re-application. Furthermore, since the viscoelastic material and the neuroadaptive sensors can be deployed under the helmet, the possibility for additional risks associated with devices that are outside of the current helmet/shoulder pad system can be reduced. The viscoelastic material and the neuroadaptive sensors can be used in any brand of helmet that is currently available on the market.
In some embodiments, helmets with permanent or electromagnetic magnets can be used to control head motion. The helmets of colliding athletes can be set to opposite polarities such that the helmets repel each other and prevent the heads from colliding. The magnets could also be placed inside of a player's shoulder pads along the clavicle and trapezius to repel or attract the helmet during an impact. Magnets on opposite sides can be set to different polarities upon the detection of an impact to carry both tensile load and compressive load, and offload the neck. When a player's head rotates in one direction during an impact, some magnets on the shoulders could carry the compression load by repelling the helmet and pushing the head back up to a normal position; while some other magnets on the opposite side can carry the tensile load by attracting the helmet and pulling the head back to the normal position.
In some embodiments, a single, rigid device can be used to connect the head, neck and torso. The device can lock head posture into a specific position known to decrease injury risk, such that all of the forces can be carried down through the device to the shoulders and torso. In some embodiments, the device can be configured to lock only selective planes of rotation. In some embodiments, the device can be combined with at least one camera to provide a person with increased field of view.
In some embodiments, a helmet can be combined with a vacuum splint-style brace around the neck. The vacuum splint-style brace can include air pockets containing small beads. In regular operation, the pockets are filled with air at low pressure to allow free motion of the head. During impact, the air in the pockets can be drawn out of the pockets by a component, such as a pump, leaving the small beads to maintain a rigid structure. As a result, head motion would be restricted during a head impact. The vacuum splint-style brace can carry both compression and tension to offload the head and neck from carrying the damaging force of impact.
In some embodiments, the device for redirecting a head impact force is an exoskeleton device configured to enclose the neck and provide additional support. In some embodiments, the device comprises artificial muscles that can mimic or augment the muscles in the neck to provide better reaction to impact and better support for the head. The exoskeleton device can be configured to allow a free range of motion absence of impact. During impact, the exoskeleton device actuates artificial muscle contraction that drives the head for motion opposite to that caused by the impact. The exoskeleton device can respond faster than the real muscles in the neck which has inevitable bioelectrical delay of activation.
In some embodiments, the head can be enclosed in a transparent, rigid sphere that prevents any direct contact to the head. The sphere allows free range of head motion and reduces the risk of injury by eliminating blunt force trauma to the head.
In some embodiments, shoulder pads can be configured to be thicker to limit the range of head motion. In some embodiments, the shoulder pads can be configured similar to a cowboy collar with thickness around the circumference of the neck varying according to the susceptibility of the head and neck injury in different directions. In some embodiments, the shoulder pads is configured to lay flat against the back in normal position and to flip up via mechanism such as a hinge when triggered upon impact.
Any combination of the above embodiments can be employed to redirect impact force from the head to the shoulders and torso without overloading the neck. One embodiment with a combination of telescopic struts 1402, cables 1404 and centrifugal clutches 1406 is illustrated in FIG. 14.
In some embodiments, the activation of the device for redirecting head impact force can be triggered by a sensing mechanism for detecting head impact or abnormal motion of the head. Detecting head impact or abnormal motion of the head can be done using the aforementioned centrifugal clutch, dashpots and damping mechanisms. Other embodiments of head impact detection can also be used.
In some embodiments, an electromyography of neck musculature can be used to detect muscle activation upon impact. When the electrical activity of the muscle exceeds a certain level, the device for transferring a head impact force can be triggered wirelessly or through electrical wire to provide additional support.
In some embodiments, the activation of the device for head protection can be done by the person wearing the device via a button on the person's hand. The button can be electrically connected to a trigger mechanism on the device, through an electrical wire or wirelessly.
In some embodiments, the device for redirecting head impact is configured to be triggered automatically based on GPS coordinates or by a distance meter. For example, when two devices worn by two people are within certain distance from one another, additional support can be activated to provide support and limit head mobility.
In some embodiments, the device for redirecting head impact force includes at least one motion sensor for measuring head translation and rotation caused by impacts. In some embodiments, the motion sensor is at least one of an accelerometer sensor, a gyroscope sensor, a pressure sensor, a strain gauge, a centrifugal force meter, and a velocity meter. When the measured motion is above a threshold level, the device can be activated, such as through a motor, to provide additional support and restraint.
In some embodiments, the device for redirecting head impact force also includes a memory and a processor. The memory stores codes of a methodology for processing measured signals and controlling other components on the device. The processor is configured to execute the codes stored in the memory to perform the methodology. In some embodiments, a controller is implemented using the memory and the processor.
While certain conditions and criteria are specified herein, it should be understood that these conditions and criteria apply to some embodiments of the disclosure, and that these conditions and criteria can be relaxed or otherwise modified for other embodiments of the disclosure.
As used herein, the singular terms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to an object can include multiple objects unless the context clearly dictates otherwise.
As used herein, the terms “approximately” and “about” are used to describe and account for small variations. When used in conjunction with an event or circumstance, the terms can refer to instances in which the event or circumstance occurs precisely as well as instances in which the event or circumstance occurs to a close approximation. For example, the terms can refer to less than or equal to ±5%, such as less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%.
Some embodiments of the disclosure relate to a non-transitory computer-readable storage medium having computer code thereon for performing various computer-implemented operations. The term “computer-readable storage medium” is used herein to include any medium that is capable of storing or encoding a sequence of instructions or computer codes for performing the operations, methodologies, and techniques described herein. The media and computer code may be those specially designed and constructed for the purposes of the embodiments of the disclosure, or they may be of the kind well known and available to those having skill in the computer software arts. Examples of computer-readable storage media include, but are not limited to: magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD-ROMs and holographic devices; magneto-optical media such as optical disks; and hardware devices that are specially configured to store and execute program code, such as application-specific integrated circuits (“ASICs”), programmable logic devices (“PLDs”), and ROM and RAM devices.
Examples of software, applications, web applications or computer code include machine code, such as produced by a compiler, and files containing higher-level code that are executed by a computer using an interpreter or a compiler. For example, an embodiment of the disclosure may be implemented using Java, C++, or other object-oriented programming language and development tools. Additional examples of computer code include encrypted code and compressed code. Moreover, an embodiment of the disclosure may be downloaded as a computer program product, which may be transferred from a remote computer (e.g., a server computer) to a requesting computer (e.g., a client computer or a different server computer) via a transmission channel. Another embodiment of the disclosure may be implemented in hardwired circuitry in place of, or in combination with, machine-executable software instructions.
While the disclosure has been described with reference to the specific embodiments thereof, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the disclosure as defined by the appended claims. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, method, operation or operations, to the objective, spirit and scope of the disclosure. All such modifications are intended to be within the scope of the claims appended hereto. In particular, while certain methods may have been described with reference to particular operations performed in a particular order, it will be understood that these operations may be combined, sub-divided, or re-ordered to form an equivalent method without departing from the teachings of the disclosure. Accordingly, unless specifically indicated herein, the order and grouping of the operations is not a limitation of the disclosure.

Claims

What is claimed is:

1. A device for redirecting head impact force from a head of a person to other part or parts of a body of the person, the device comprising:

a helmet wearable on the head of the person;

a brace wearable on the body of the person; and

at least one force redirecting unit configured for connection to the helmet and the brace, wherein at least one of the at least one force redirecting unit is configured to be compressed to carry compressive load, and at least one of the at least one force redirecting unit is configured to be extended to carry tensile load.

2. The device of claim 1, wherein the brace comprises at least one of a shoulder pad, a vest, a body harness, and a hood.

3. The device of claim 1, wherein the brace comprises a protruding platform, and the at least one force redirecting unit is configured for connection to the brace on the protruding platform.

4. The device of claim 1, further comprising a plurality of force redirecting units such that at least one of amplitudes and durations of accelerations in three dimensions of translation and three dimensions of rotation can be reduced.

5. The device of claim 1, wherein the at least one force redirecting unit comprises at least one of a telescopic strut, a viscoelastic hood, and an assembly of a cable and a compressive member; and wherein the at least one force redirecting unit is configured to respond to an acceleration caused by the head impact force while permitting motion of the person.

6. The device of claim 5, wherein the telescopic strut is a telescopic damper comprising a piston, at least one control valve, and at least one chamber containing a fluid, wherein the at least one control valve is configured to funnel the fluid into or out of the chamber to resist motion of the piston caused by the head impact force.

7. The device of claim 6, wherein the telescopic damper defines a stepped orifice for transporting the fluid into and out of the chamber, wherein the stepped orifice comprises a small orifice and a large orifice; and wherein the telescopic damper further comprises a spring at least partially disposed within the large orifice, and a ball connected to the spring, wherein the ball is configured to be moved by the fluid to an entrance of the large orifice to block the large orifice.

8. The device of claim 6, wherein the telescopic damper defines an upper chamber, a lower chamber, and further includes two valves connecting the upper chamber and the lower chamber, wherein a first valve allows the fluid to flow from the upper chamber to the lower chamber, and a second valve allows the fluid to flow from the lower chamber to the upper chamber.

9. The device of claim 5, wherein the telescopic strut comprises at least one of a latch and a hook on at least one end of the telescopic strut for release from at least one of the helmet and the brace.

10. The device of claim 5, wherein the viscoelastic hood comprises a viscoelastic material that is viscous at rest and is configured to be stiffened to maintain a head posture in response to an acceleration caused by the head impact force.

11. The device of claim 10, wherein the acceleration is detected by a sensor configured to detect the neuromuscular impulse of muscles in response to the head impact force.

12. The device of claim 5, wherein the compressive member comprises an inflatable unit configured to inflate to maintain a head posture.

13. A device for reducing head and neck injury during an impact, comprising:

a helmet wearable on a head of a person;

a brace wearable on a body of the person;

a first force redirecting unit configured for connection to the helmet and the brace, and configured to resist compressive strain in response to an impact force exerted on the helmet; and

a second force redirecting unit configured for connection to the helmet and the brace, and configured to resist tensile strain in response to the impact force exerted on the helmet.

14. The device of claim 13, wherein the first force redirecting unit and the second force redirecting unit comprise any combination of a telescopic strut, a viscoelastic hood, and an assembly of a cable and a compressive member.

15. The device of claim 14, wherein the telescopic strut comprises at least two stages.

16. The device of claim 14, wherein the telescopic strut comprises a motor for actuating the telescopic strut, and a controller for sensing an acceleration caused by the head impact force and controlling the motor based on the sensing.

17. The device of claim 16, wherein the motor is configured for connection to the brace.

18. The device of claim 13, further comprising a motion sensor for detecting an acceleration caused by the impact force.

19. The device of claim 18, wherein the motion sensor for detecting the acceleration is at least one of an accelerometer sensor, a gyroscope sensor, a pressure sensor, a strain gauge, a centrifugal force meter, and a velocity meter.

20. The device of claim 19, wherein the centrifugal force meter comprises:

a drum for transforming a linear motion into an angular motion;

a wheel including a movable tab connected to the wheel through a torsional element;

a pinion gear connecting the drum and the wheel; and

a clutch including an indention in an inner surface of the clutch;

wherein the movable tab is configured to contact the indention in the inner surface of the clutch to stop a rotation of the wheel when a centrifugal force of the movable tab caused by a rotation of the wheel exceeds a threshold level.