Registration of head impact detection assembly

Abstract

Systems and methods are provided for registering a sensor assembly, implemented on a base apparatus, to a desired location associated with a head of a user. A position of a reference point on the base apparatus is determined relative to an external anatomical landmark of the user. A position of the external anatomical landmark is determined relative to the desired location. The position and orientation of the sensor assembly is determined relative to the desired location according to the determined position and orientation of the sensor assembly relative to the reference point, the determined position of the reference point relative to the external anatomical landmark, and the position of the external anatomical landmark relative to the desired location.

1 . A method for registering a sensor assembly, implemented on a base apparatus, to a desired location associated with a head of a user, comprising:
 determining a position of a reference point on the base apparatus relative to an external anatomical landmark of the user;   determining a position of the external anatomical landmark relative to the desired location;   determining the position and orientation of the sensor assembly relative to the desired location according to a position and orientation of the sensor assembly relative to the reference point, the determined position of the reference point relative to the external anatomical landmark, and the position of the external anatomical landmark relative to the desired location; and   initializing the sensor assembly for the user with the determined position and orientation of the sensor assembly relative to the desired location.   
     
     
         2 . The method of  claim 1 , further comprising determining the position and orientation of the sensor assembly with respect to the reference point on the base apparatus. 
     
     
         3 . The method of  claim 2 , wherein determining a position and orientation of the sensor assembly with respect to a reference point on the base apparatus comprises:
 establishing an apparatus reference frame having its origin at the reference point; and   determining a location and orientation of each sensor within the apparatus reference frame.   
     
     
         4 . The method of  claim 1 , wherein the external anatomical landmark is one of an external auditory meatus, a tragion, an orbitale, a nasion, a glabella, an inion, and an orbital rim. 
     
     
         5 . The method of  claim 1 , further comprising:
 measuring an acceleration at the sensor assembly; and   determining an acceleration at the desired location from the measured acceleration and the determined location and orientation of the sensor assembly relative to the desired location.   
     
     
         6 . The method of  claim 5 , wherein the location of the external anatomical landmark relative to the desired location is determined as a time-varying relationship, such that the location and orientation of the sensor assembly relative to the desired location is determined as a function of the measured acceleration at the sensor assembly. 
     
     
         7 . The method of  claim 5 , further comprising calculating at least one kinematic parameter from the determined acceleration at the desired location. 
     
     
         8 . The method of  claim 7 , further comprising classifying an impact associated with the measured acceleration into one of a plurality of event classes according to the calculated at least one parameter. 
     
     
         9 . The method of  claim 1 , wherein the base apparatus is a mouthpiece, and the reference point is located on one of a nub, a ridge, a tab, and a external protrusion on an anterior portion of the mouthpiece. 
     
     
         10 . The method of  claim 9 , wherein determining a position of the reference point on the mouthpiece relative to an external anatomical landmark of the user comprises:
 positioning the mouthpiece within a mouth of the user;   determining an orientation of a mouthpiece reference frame relative to the mouth reference frame, the mouthpiece reference frame having its origin at the reference point;   determining an origin of a mouth reference frame from at least one landmark associated with one of the face and mouth;   determining a location of the reference point in the mouth reference frame.   
     
     
         11 . The method of  claim 10 , wherein the at least one landmark associated with one of the face and mouth includes one of the central incisors, the lateral incisors, the canines, the first premolars, the second premolars, the first molars, the second molars, the third molars, the alare, the subnasale, the labiale superius, the left and right labiale superius, the chelion, the stornion, the labiale inferius, the sublabiale, the pogonion, and the menton of the user. 
     
     
         12 . The method of  claim 10 , wherein determining a position of the reference point on the mouthpiece relative to an external anatomical landmark of the user further comprises:
 determining an orientation of the mouth reference frame relative to a head surface reference frame; and   determining an origin of a head surface reference frame from the external anatomical landmark.   
     
     
         13 . The method of  claim 12 , wherein determining an origin of a head surface reference frame from the external anatomical landmark comprises determining a relative position of the mouth and the external anatomical landmark via photogrammetry. 
     
     
         14 . The method of  claim 12 , wherein determining an origin of a head surface reference frame from the external anatomical landmark comprises:
 measuring at least one anthropometric parameter; and   determining the origin of the head surface reference frame from the determined origin of the mouth reference frame and the measured at least one anthropometric parameter.   
     
     
         15 . The method of  claim 12 , wherein determining an origin of a head surface reference frame from the external anatomical landmark mapping the surface of the head via a set of digitized points. 
     
     
         16 . The method of  claim 1 , wherein the desired location is a center of gravity of the head of the user. 
     
     
         17 . An impact monitoring system for measuring an acceleration associated with an impact to a head of a human being, the system comprising:
 a mouthpiece assembly comprising a plurality of sensors configured to measure at least one of a linear acceleration at a mouth of the human being, an angular acceleration at the mouth, an angular velocity at the mouth, and an orientation of the head during the impact to the head; and   a processing component comprising:
 a sensor interface configured to receive a measured position of an external anatomical landmark on the head relative to a reference point on the mouthpiece assembly and at least one anthropometric parameter of the head and determine an acceleration of a desired point within the head from the measured position, the at least one anthropometric parameter, and the at least one of a linear acceleration, an angular acceleration, an angular velocity and an orientation of the head at the associated measurement point during the impact to the head; and 
   a post-processing component configured to communicate the determined acceleration at the desired point within the head to an observer via an associated output device.   
     
     
         18 . The system of  claim 17 , wherein the least one anthropometric parameter of the head comprises one of a head breadth, a head depth, a head length, an auditory length, and a head circumference. 
     
     
         19 . The system of  claim 17 , the mouthpiece assembly comprising a external protuberance configured to remain external to the mouth when the mouthpiece is worn by the user, the reference point being located on the external protuberance. 
     
     
         20 . (canceled) 
     
     
         21 . A method for registering a sensor assembly, implemented on a base apparatus, to a desired location associated with a head of a user, comprising:
 determining a position and orientation of the sensor assembly with respect to the reference point on the base apparatus   determining a position of a reference point on the base apparatus relative to an external anatomical landmark of the user;   determining a position of the external anatomical landmark relative to the desired location;   determining the position and orientation of the sensor assembly relative to the desired location according to the determined position and orientation of the sensor assembly relative to the reference point, the determined position of the reference point relative to the external anatomical landmark, and the position of the external anatomical landmark relative to the desired location; and   initializing the sensor assembly for the user with the determined position and orientation of the sensor assembly relative to the desired location.