FIELD OF THE INVENTIONThe present invention relates to head and neck rotation acceleration/deceleration restraint and dampening systems that reduce or eliminate damage to or shearing of brain matter, axons and cervical spinal cord and spine. In particular, this invention provides a dampening device to prevent the brain from substantial rotational acceleration or deceleration that would lead to tearing of brain or cervical spine tissue.
BACKGROUND OF THE INVENTIONThe brain generally consists of an outer layer of grey matter or cortex where neurons are located and white matter or axons, which connect the gray matter areas. Disruption of white matter connections disables brain function. Symptoms can be as mild as memory and attention difficulties, and as serious as a coma state.
Diffuse axonal injury (DAI) results from rotational shear forces that tear white matter tracts. DAI is common in traumatic brain injury (TBI) and accounts for persistent cognitive deficits and symptoms.
Acceleration/deceleration TBI studies in animals and clinical investigations have attributed cognitive deficits to DAI. Distinguished from focal contusion without shearing, DAI is defined as damage to axons at the gray/white matter junction of the cerebral hemispheres, corpus callosum and dorsolateral midbrain and often involves the superior cerebellar peduncles. These deep white matter abnormalities can be detected by a MRI and are associated with poorer neuropsychological test performances and poor long-term outcome.
Rapid acceleration and deceleration of a person's head, especially with a rotational component causes serious damage to the white matter connections in the brain. This is the most common form of brain injury and occurs in car crashes, falls, sporting accidents and recently in war as a consequence of road-side bombs that cause a blast wave to whip the head producing rotational shear injury.
In addition, rapid acceleration/deceleration in flexion, extension or rotation movements can cause fractures, torn ligaments, disc herniations, cervical spine and spinal cord injury and other damage of the neck cervical spine.
This patent application describes embodiments to dampen or minimize the rotational component of rapid acceleration/deceleration that can cause damage to the brain or cervical spine while allowing free movement at lower accelerations. The acceleration/deceleration is calculated for the head and cervical spine with respect to the torso.
An object of the invention is to reduce the incidence of brain, cervical spine, and spinal cord injury in crash victims, athletes and others while providing unencumbered head motion and range during normal circumstances.
Another object is to provide such a device, which can be conveniently worn during normal circumstances and is a device which is simple to use and is automatically displayed.
Still another object of this invention is to provide a device capable of widespread use and exploitation.
Other objects, advantages and features of this invention will become more apparent hereinafter.
SUMMARY OF THE INVENTIONThe invention provides advantages over the prior art by providing automatic dampening of the motion of a user's head when dangerously large accelerations are present, but creating no or very little inconvenience to the user in normal circumstances. In some cases rotational movement may be completely prevented or always allowed, depending on the threshold settings for the restraint system.
BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a side view of a prior art apparatus for restraining head movement during a traumatic event.
FIG. 2 is a front view of the three rotational planes through the head.
FIGS. 3aand3bare side and rear views of the preferred embodiments of this invention.
FIGS. 4aand4bare perspective views of another embodiment of the present invention using an airbag collar, both before and after deployment.
FIG. 5 is a top view of an alternative embodiment of the present invention.
FIGS. 6aand6bare front and top views of a vehicle occupant wearing an embodiment of the present invention head retraining system utilizing tethers and recoiling spools.
FIGS. 7aand7bare side perspective views of another alternative embodiment of this invention.
FIG. 8 is a front view of another embodiment of this invention.
FIGS. 9aand9bare side views of another embodiment of this invention utilizing football helmet type apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTFIG. 1 shows a prior art device (as disclosed in U.S. Pat. No. 6,931,669 to Trevor P. Ashline) to control head movement during rapid acceleration/deceleration which straps a user'shelmet2 to asupport plate4 worn by the user with head strap6.Strap8 further secures thesupport plate4 to the user. A fixed strap system is an improvement and life safer over just wearing a helmet by itself. However this system is not suitable for protecting a person's brain in the event of rapid rotational accelerations of the head, both in vehicular and non-vehicular situations, because there is no way to detect such movement in the device ofFIG. 1. Furthermore, no free movement of the head is allowed.
FIG. 2 shows the three planes in which the head can rotate. Thecoronal plane10 lies roughly parallel to the chest. Moving one's head side to side, or moving the ear toward the shoulder, is an example of head rotation in the coronal plane. Theaxial plane12 perpendicular tocoronal plane10 lies roughly parallel to the top of the head, like the rim of a hat. Shaking one's head to indicate “no, is an example of head rotation in the axial plane. Thesagittal plane14 is perpendicular to bothplanes10 and12, and bisects the left side of the head from the right. Nodding one's head to indicate, “Yes,” is an example of head rotation in the sagittal plane.
FIGS. 3aand3bshow preferred embodiments of this invention in which aperson31 wears ahelmet33 having the appearance of a conventional football helmet with aface guard34. This invention prevents rotation of the head in all three planes with respect to the torso. In a preferred embodiment, it is important to find a fixed reference, which hardly moves with respect to the torso. Such a fixed reference is theneck35 and a neck or collar reference,plate36, similar to a standard collar, which is worn by the user at the base of the neck.FIG. 3ashows a left side view of the invention, and the right side view would be substantially similar. Aside front tether37 is attached between aside front point38 on the helmet and afront collar spool39 and this tether detects extension in the sagittal plane. A siderear tether40 is attached a siderear point43 on the helmet and arear collar spool42 and this detects flexion in the sagittal plane. Tether40ais connected betweenfront helmet attachment38 andmiddle spool41. This tether detects axial rotation or the face rotating away fromspool39. Tether40bis connected between therear side attachment43 andmiddle spool41 and detects axial rotation or the face rotating towardspool39. Tethers40aand40btogether detect coronal movement with the whole head angling away fromspool41.
FIG. 3bshows the preferred embodiment of thecollar plate36 ofFIG. 3aas a fixed reference to the torso in which abody harness44 comprised of achest strap45 and a vertical connectingstrap46 attach to acollar plate36. Arear tether47 is connected between arear collar spool48 and arear attachment point49 on the helmet and this detects flexion in the sagittal plane in addition totethers40.Rear side tethers40 are shown attached betweenback collar spool42 and siderear point43 on the helmet.Harness44 substantially fixescollar plate36 with respect to the torso.
The preferred embodiment of this invention inFIGS. 3a/3buses a series of small tethers or belts attached between thehelmet33 and thecollar reference plate36 that do not significantly interfere with normal motion, but effectively dampen and slow accelerations of the head so as to greatly lessen the likelihood of injury. These tethers can be on a spool or pulley that allows the tether to be extended as the user moves his head, but can lock or slow the tether if there are significant accelerations detected. These tethers may be designed to further extend and dampen the motion of the head when the spools have been locked by an activation module. The spools and/or reference plate may provide some or all of the needed damping. Alternatively, the material used in the tether can have inherent properties to allow stretching at slow but not high accelerations.
FIGS. 4aand4bshow another embodiment of this invention with a different type helmet attached to a shoulder reference plate. While a shoulder reference plate may experience more motion with respect to the torso, it is a valuable alternative because of the size of the shoulder reference plate.Shoulder reference plate120 is similar to shoulder pads and covers some portion of the user's back, continues over the shoulders and covers some portion of the chest withbelt140 to allow the user to adjust the fit.Reference plate120 is generally maintained in place and is the reference or anchor against which rotational movement is prevented.Spools60,70,80,90,100, and110 are mounted on this reference plate. These spools are similar to those inFIGS. 3aand3band are mechanically or electro-mechanically controlled, and in the event of an impact or dangerously large acceleration they will act to slow, dampen and stop the movement of the head relative to thereference plate120. The spool mechanism may also incorporate a pretensioning system to eliminate slack in the tethers and potentially best position the user's head for surviving the impending impact and acceleration.
Spools60 and70, located on top of the right and left shoulders respectively, control head rotation in theaxial plane12 usingtethers62 and72 with attachments to thehelmet104 atpoints64 and74 located to the right and left of the chin. Relocating these components may offer advantages in specific applications.Spools80 and90, also located on top of the shoulders, control head rotation in the coronalplane using tethers82 and92 with attachments to thehelmet84 and94 being near the top or crown of the helmet.Spools100 and110, located near the user's sternum and spine respectively, control head rotation in the sagittalplane using tethers102 and112 withattachments104′ to the helmet near the chin and114 on the back of the helmet.
FIG. 5 shows another embodiment of the invention ofFIGS. 4aand4bin which the tethers' attachment points to the helmet can have alternative locations and still be effective. Specifically it shows tethers62′ and72′ betweenspools60′ and70′ respectively and attachment points,64′ and74′, respectively. These are attached to the back of thehelmet65 instead of near the chin at the front and detects axial movement.
FIGS. 6aand6bshow yet another embodiment that combines the function ofspools60,70,80 and90 ofFIG. 4 into just twospools66 and76 withtethers67 and77 attached to thehelmet69 atconnections68 and78.
There are other ways to protect the head from rapid rotational accelerations, while causing little inconvenience to the wearer.
FIGS. 7aand7billustrate still another embodiment and show ahelmet20 with an inflatable restraining member that stores as acollar22. Anactivation module24 comprises a system of sensors that detect collisions, impacts or large accelerations of a predetermined value, which may be dangerous to the wearer. When thisactivation module24 receives a “deploy” signal from the impact or acceleration sensors that are mounted on the vehicle, or on the user, it can activate the rapid inflation of thecollar22. The collar may deploy like avest30 as shown inFIG. 7, extending down the wearer's chest and back to provide resistance to accelerations of the head relative to the body—especially rotationally. The vest may includearm cutouts32. The collar is similar to airbags used in automobiles. Thecollar22 may also expand to a smaller size thanvest30. When the user wears this helmet, there may be little or no contact between the collar and the wearer, providing unencumbered motion and range. Theactivation module24 can be located on and/or in the helmet, and houses the electronics needed for activating the inflation of the airbag collar or activating some other form of anti-rotational means. Sensors, accelerometers and complete airbag deployment systems may be employed and are common and well known in the art. Examples of these systems and their “sensing module” equivalents can be found in U.S. Pat. Nos. 5,338,062 and 7,165,785, which patents are incorporated herein by reference.
A conventional helmet may also include a see throughvisor26, which can pivot at joint28.
Another embodiment of this invention utilizes a collar50 (FIG. 8) that is connected to the helmet and extends to referenceplate120′, which may be affixed to the torso, shoulders, seat or other component. Whenactivation module24′ receives a “deploy” signal from the impact or acceleration sensors, it will stiffen the collar to dampen acceleration and limit the total travel of the head. This collar may be similar to an airbag, and is stiffened by rapid inflation.
Another embodiment utilizes a collar similar to that shown as50 inFIG. 8 between the helmet and shoulders that is easily flexed and rotated, except during large and dangerous accelerations when it behaves like a much stiffer material—resistant to fast deflection. This material may be a Silicone and/or a foam or fluid.
The tethers shown in the various embodiments are built into a spool and function similar to an ABS disk brake to achieve significant damping rather than sudden stopping. Additionally, the tether could comprise a sacrificial tether material for one time use to be combined with a locking spool. Additionally, the tether material could be formed of the material so described inFIG. 8 which stiffens upon sensing high acceleration.
The sensor used, as described above, may comprise multi-axis accelerometers, rotational accelerometers, contact sensors, and/or position sensors, which measure the movement of the spools.
The placement of the sensors may comprise a coordinated array of sensors which can be located on the vehicle, torso harness and/or helmet to provide early detection of impact independent of where the impact occurs.
FIGS. 9aand9billustrate this invention used with football likehelmets800 which illustratively show a plurality oftethers802 attached to a plurality ofrespective spools804 and also being attached atvarious points806 and808 on the helmet.
It is understood that the various mechanisms to control rotational movement of the head can be “switched” off or physically removed so that the head and torso are free from any possible restraint.
It should be understood that the preferred embodiment was described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly legally and equitably entitled.