Patent ID: 6817248
Filing Date: 2004-11-16
Classification: G09B

Abstract:
A human lumbar model structure for simulating pressure applied to nucleus pulposus in the lumbar spine of a human body, said structure comprising:a cylindrical lumbar assembly having an upper body member, an upper lumbar member, an annulus fibrosus member, a lower lumbar member, and a lower body member, which are coaxially arranged around a common center axis and which are superposed vertically from top to bottom in this order; said upper body member comprising a first upper portion having a first diameter and a first lower portion having a second diameter smaller than the first diameter to form a first shoulder portion around the bound between the first upper portion and the first lower portion; said lower body member comprising a second upper portion having a third diameter and a second lower portion having a fourth diameter larger than the third diameter to form a second shoulder portion around the bound between the second upper portion and the second lower portion; said annulus fibrosus member comprising a thick cylindrical ring made of a hard elastic material and having upper and lower parts fitted into said upper and lower lumbar members, respectively, said fibrosus member having an inner cavity filled with a liquid as said nucleus pulposus; an abdominal/back muscle member made of an elastic material in a hollow cylindrical shape, and having an upper and lower cylindrical portion fitted onto said first lower portion of said upper body member and said second upper portion of said lower body member, respectively, so that said abdominal/back muscle surrounds and tightens said lumbar assembly over a center area extending from the first shoulder portion of said upper body member to the second shoulder portion of said lower body member, said abdominal/back muscle member having an outer diameter smaller than said first diameter and the fourth diameter; and a pressure sensor arranged along a center axis of said lower lumbar member in direct contact with said liquid as the nucleus pulposus for detecting the variation of the pressure of said liquid in said fibrous member.