Method for determining in vivo, bone strength

Abstract

A system for establishing, in vivo, the strength of bone in a live being such as, for example, a horse. The system permits determination of the speed of travel of sound through the bone and the strength of the bone is assessed on the basis of said speed of travel. The questions raised in reexamination request No. 90/000,815, filed 07/22/85, have been considered and the results thereof are reflected in this reissue patent which constitutes the reexamination certificate required by 35 U.S.C. 307 as provided in 37 CFR 1.570(e).

What is claimed is: .[.1. Apparatus for establishing, in vivo, the strength of a bone member, that comprises, in combination: 
     
        said first and second transducer means are mounted..]. .Iadd.3.  A method for establishing, in vivo, the strength of a bone, that comprises the steps of: a. providing: (1) a linear scale;   (2) first transducer means having a sending surface to launch an acoustic pulse through a bone and surrounding soft tissue;   (3) second transducer means having a receiving surface to receive the pulse after transmission through a bone and surrounding soft tissue, said receiving surface being parallel to and facing said sending surface so that said soft tissue surrounding a bone may be positioned between and in contact with both of said surfaces;   (4) said first and second transducer means being mechanically interconnected by said linear scale so that the distance between said sending surface and said receiving surface may be measured; and   (5) means for measuring the transit time of the pulse from the first transducer means to the second transducer means to permit determination of the velocity of the propagated signal through a bone and soft tissue;     b. conducting the following steps (1)-(4) a first time: (1) launching a pulse through a bone and surrounding soft tissue with said first transducer means;   (2) measuring the distance between said sending and receiving surfaces with said linear scale;   (3) measuring the transit time of the pulse from the first transducer means to the second transducer means with said means for measuring transit time and;   (4) determining the effective velocity of the pulse through said bone and surrounding soft tissue by dividing the measured distance by the measured transit time;     c. conducting the steps (b.1) through (b.4) at least one additional time; and   d. comparing the effective velocity determined by conducting steps (b.1) through (b.4) the first time with the effective velocity determined by conducting steps (b.1) through (b.4) at least one additional time with respect to a bone at a location corresponding to the location at which the first pulse was launched through the bone through which the first pulse was launched; and   e. assessing the strength of the bone through which each pulse has been launched on the basis of the comparison. .Iaddend. .Iadd.4. The method of claim 3 further wherein the step of assessing the strength of the bone is made on the basis that a difference, between the effective velocity of the acoustic pulse launched through a bone and surrounding soft tissue and the effective velocity of an acoustic pulse launched at least one additional time through a corresponding location on a bone and surrounding soft tissue, of greater than about 5 percent indicates a weakness in the bone through which the acoustic pulse propagated at the lower effective   
     
     
        velocity. .Iaddend. .Iadd.5.  A method for establishing, in vivo, the strength of a bone that comprises the steps of: a. providing: (1) a linear scale;   (2) first transducer means having a sending surface to launch an acoustic pulse through a bone and surrounding soft tissue;   (3) second transducer means having a receiving surface to receive the pulse after transmission through a bone and surrounding soft tissue, said receiving surface being parallel to and facing said sending surface so that said soft tissue surrounding a bone may be positioned between and in contact with both of said surfaces;   (4) said first and second transducer means being mechanically interconnected by said linear scale so that the distance between said sending surface and said receiving surface may be measured; and   (5) means for measuring the transit time of the pulse from the first transducer means to the second transducer means to permit determination of the velocity of the propagated signal through a bone and soft tissue;     b. conducting the following steps (1)-(4) a first time: (1) launching a pulse through a first bone and surrounding soft tissue with said first transducer means;   (2) measuring the distance between said sending and receiving surfaces with said linear scale;   (3) measuring the transit time of the pulse from the first transducer means to the second transducer means with said means for measuring transit time and;   (4) determining the effective velocity of the pulse through said bone and surrounding soft tissue by dividing the measured distance by the measured transit time;     c. conducting the steps (b.1) through (b.4) at least one additional time, with respect to a second bone at a location corresponding to the location at which the first pulse was launched through the first bone through which the pulse was launched; and   d. comparing the effective velocity determined by conducting steps (b.1) through (b.4) the first time with respect to said first bone with the effective velocity determined by conducting steps (b.1) through (b.4) the at least one additional time through said second bone; and   e. assessing the strength of the bone through which each pulse has been   
     
     
        launched on the basis of the comparison. .Iaddend. .Iadd.6.  The method of claim 5 further wherein the step of assessing the strength of the bone is made on the basis that a difference of greater than about five percent, between the effective velocity of the acoustic pulse launched through a bone and surrounding soft tissue and the effective velocity of an acoustic pulse launched at least one additional time through a corresponding location on a different bone and surrounding soft tissue, indicates a weakness in the bone through which the acoustic pulse propagated at the lower effective velocity. .Iaddend.