Patent Application
20150223542
This invention is in the field of devices that are designed to prevent concussions of the brain that frequently occur from blows to the head in certain sports such as football, lacrosse, field hockey, etc.
There are an estimated 1.6 to 3.6 million sport's related concussions occurring annually just in the USA (J A Langlois, W Rutland Brown, M M Wald. (2006) The epidemiology and impact of traumatic brain injury: a brief overview. J Head Trauma Rehabil., 21(5):375-8). In addition to the professional sports, a greater percentage of these injuries occur in children, high school and college athletes who are also susceptible to severe negative effects of sport related concussions with a potentially greater negative impact on long-term quality of life.
The kinematics that induce a concussion are thought to consist primarily of rotational acceleration-deceleration motions of the head. While existing protective helmets are effective at reducing the direct blunt force trauma, injuries caused by indirect collision effects and the resulting angular accelerations of an oblique impact remains problematic. Consequently, for any device to be effective in preventing concussion, it needs to provide a constraint for head accelerations to below concussive-inducing threshold levels that occur when the individual is subject to a high impulsive force. In addition, such devices need to be compact and place minimal impediments to the normal motion of the head to allow the user unobtrusive and unhindered operation. This presents a design challenge due to the exposed nature of the head/neck region and the complex range of motion that the multi-articulated joints of the spine permit for the head.
The prior art in this area has largely focused on the use of standard linear damper technology (either pneumatic or hydraulic) (H. A. Kiem, U.S. Pat. No. 5,371,905) or the use of mechanical clutch mechanisms (M. Salkind, et al, US Patent Appl. No. 20110277225A1 and S. W. Nagely, et al, US Patent Appl. No. 20130205480A1) to control load distribution to the torso when impact occurs (see Figures below). While based on mostly proven technology, these existing proposed implementations usually suffer from complexity, high cost and being intrusive in their size and placement, and to our knowledge, have yet to see adoption in any venue. Furthermore, each of these prior art examples would cause significant constraint on the freedom of head motion. Still further, each of these designs could cause serious injury to any football player who would be tackling an opponent who would have such protrusions from his shoulder pads to his helmet. It is therefore obvious that a much-improved design is needed to solve the problem of reducing brain concussions for athletes playing football or any other sport that allows contact between players.
The present invention is a “SuperSpine” device that acts as a damping means for connecting helmet and shoulders (or torso) to decrease the effective angular acceleration of the head under concussive impact loading while presenting minimal impediment to the normal motion of the head (degrees of freedom, range of motion, force required to move at typical rates). The device is closely conformal to the body to present minimal obstruction. The fundamental premise of this device is to provide a nearly rigid connection between the head and torso (via the shoulder pads) under impact conditions, such that the impact load is transferred to the body, and hence greatly reduces the angular acceleration of the head relative to the body. The key component for the functioning of the device is the use of a “smart fluid” to act as a damping material with the special properties that its resistance to shearing motion is increased in a non-linear manner in relation to applied shear rates. This can be achieved through use of a passive shear-thickening (ST) suspension, or through implementation of active systems using magnetorheological (MR) fluids and appropriate sensor and control electronics. The present invention focuses on the use of shear-thickening fluids, which are passive materials that show a sudden solidification upon externally applied stress and quick refluidization after the removal of that stress. Although shear-thickening fluids have been incorporated into protective padding (closed-cell foams or honeycomb structures), utilizing them in a multi-degree-of-freedom damper to prevent brain concussion for football players is truly a novel implementation of this technology.
The preliminary evidence supporting this concept has consisted of mechanical testing of ST fluids under controlled impact conditions to note their response and improved ability to design and model systems subjected to transient impulsive loadings. Most existing literature has focused on the periodic or quasi-steady response of such fluids and appropriate models and data available for impulsive conditions is limited or does not yet exist. ST impact test cells have been created and have been subjected it to a range of impact energies (up to 10 Joules), impact velocity (up to 2.5 meters/sec) and peak impact force (up to 3 kNewtons), for a range of gap spacing (from 0.2 to 2 mm). The results show that at our current maximum impact loads, the energy of the impact is absorbed with a stroke of only several millimeters, depending on the gap thickness. These results verify the potential of the present invention.
MR fluids are popular for active control damping, and have seen commercialization in the automotive, aerospace and defense industries and in the prosthetics sector. The fluids consist of a suspension of magnetic micro-particles, which become aligned when subjected to an external magnetic field, forcing the fluid to behave like a visco-elastic solid. Actively controlled electromagnetics are typically employed to “turn on” the fluid when a high-yield stress state is required. This requires the use of an additional power, electromagnets and sensor system to activate the device under appropriate conditions. The advantage of this complexity is that it naturally lends itself to the including impact monitoring as part of the system with minimal additional development.
The present invention focuses on the use of shear-thickening fluids to prevent brain concussions. ST fluids are passively activated under impact conditions, thus forgoing the need of sensors, a power source and electromagnets. ST fluids are less well-developed and commercialized than MR fluids, but are currently seeing use in flexible protective body armor as an additive to prevent puncture wounds, as limited-slip differentials in automotive applications, and as an encapsulate in closed cell foam to create a soft padding material that stiffens under impact. ST materials function as a result of a shear-induced transition of the particle spacing within the fluid. Under low shear rates, the particles remain separated by intermolecular forces, providing a small additional stress. At high shear rates, the particles are forced together by the increased shear forces, causing the formation of so-called “hydroclusters”, inducing a jammed state and a greatly increased viscosity and resistance to motion. This has the desirable effect of producing a greater resistive force and a shorter stopping distance for higher acceleration rates.
ST and MR fluids have not yet been proposed or adapted for use in devices to prevent brain concussions as, for example, the novel design as described herein. For the ST and MR fluids to function effectively, they need to be forced to undergo a shearing motion with a wetted area sufficiently large to provide appropriate restraining forces. Additionally, such actuators need to be compact and unobtrusive while allowing sufficient degrees of freedom to permit the user a natural head motion under non-impact conditions. The present invention satisfies those design objectives.
The primary feature of the present invention is a mechanism that consists of a series of interleaved bi-layer spherical shell elements that effectively creates a telescoping mechanism to allow rotational motions about two orthogonal axes simultaneously (superior-inferior and lateral axis). In addition, the telescoping motion of the plates places the ST fluid in a repeatable and consistent shearing motion as the head is moved. Rotation about the third axis (posterior-anterior) is controlled by an ST fluid enabled rotational damper, which is constructed with a shear-pin anchored quick-disconnect to allow easy and rapid removal of the SuperSpine from the helmet. Although the present invention as described herein refers to the use of the SuperSpine only with male athletes, it should be understood that the device as taught herein could be used with either male or female athletes.
Thus one object of the present invention is to prevent brain concussions for athletes who are hit on the head or body in such a manner as to create a high rate of angular acceleration of their head by the use of special damping fluids in a mechanism that connects the athlete's helmet to his shoulder pads.
Another object of this invention is to utilize smart fluids in a SuperSpine device to dramatically reduce any angular acceleration onto an athlete's head to prevent brain concussions.
Still another object of this invention is to be able to have a quick release means to separate the SuperSpine either from the athlete's helmet or from his shoulder pads.
Still another object of this invention is to have a SuperSpine design that would not harm a first player who is hitting a second player in the region of his head.
These and other objects and advantages of this invention will become obvious to a person of ordinary skill in this art upon reading the detailed description of this invention including the associated drawings as presented herein.
The primary components of the spherical shell shear plates assembly (as shown in
The rotational actuator provides the third axis about which the helmet can rotate.
As shown in
The SSSP Assembly is connected to the helmet through a quick-release Rotational Shear Anchor (RSA) 110, as shown in
Various other modifications, adaptations and alternative designs are of course possible in light of the teachings as presented herein. Therefore it should be understood that, while still remaining within the scope and meaning of the appended claims, this invention could be practiced in a manner other than that which is specifically described herein.
