Page 7 - Clinical-Medical Physical Properties of Biomaterial

Mechanical Evaluation of Bone—Fatigue and Endurance Testing Human Femoral Osteotomy—Load Testing After Fixation Standard
Evaluation of Biological Samples simple static testing, it is extremely important to mechanically evaluate bones through fatigue and the greater trochanter and lesser trochanter, to which the muscles attach, and the spherical femoral head that Human Evaluation of Biological Samples
compression
The femur is a long tubular bone that forms the central axis of the thigh. It is the longest bone in the human body.
Bones are not subjected to constant loads; they experience forces in all directions due to a
plate
combination of various factors during walking and other movements. Consequently, instead of
The central portion is the femoral body, which is cylindrical. The top of the femur features two protrusions called
Strain
gauge
forms the hip joint. At the bottom of the femur are two protrusions called the medial condyle and lateral condyle.
endurance testing by applying repeated test forces.
The femoral bones play an extremely important role in human bipedal locomotion. Femoral neck fracture is the
To accurately evaluate biological samples and bones, it is essential to firmly fasten the test sample
against the mechanical forces and displacements. This is doubly important during fatigue and
most common fracture that occurs when elderly people fall. The number of people bed-ridden due to this injury is
increasing as society ages.
endurance testing in which repeated test forces are applied over a long period of time.
bone
Against this background, accurate measurements of the mechanical properties of femoral bones provide extremely
The table-top servo-hydraulic fatigue and endurance tester is an overhead-actuator type fatigue tester.
important data for the development of femoral implants. The Autograph series is widely used for the evaluation of
Despite the small capacity, the overhead-actuator type tester can be applied to a wide range of tests,
bone joint strength and junction materials.
from small mouse bones to full-scale testing of comparatively large test samples and implant materials.
Servopulser EHF Series Table-Top Servo-Hydraulic
The tester can faithfully reproduce various entered waveforms, including walking waveforms.
technologies using these materials is a focus in medical fields.
Bone with Fixation
Cantilever Bending Testing Fatigue and Endurance Tester (with hydraulic supply stowed) Dramatic technical innovations have occurred in ceramic and plastic composite materials, and developing Load Testing of Femoral
Physiological Saline Solution Immersion Tester
This tester permits cantilever bending tests on bones and their replacement materials.
Evaluation of Biomaterials Bone Compression plate Pin Plaster model their normal environment. Evaluation of Biomaterials
It is sometimes necessary to test bone, biological samples, and biomaterials under conditions that
The jigs to hold or compress the sample are immersed in a water bath, where the sample can be
subjected to static tensile and compression testing, or dynamic fatigue and endurance testing.
This tester permits testing of samples immersed in physiological saline solution or some other
prescribed solution that is maintained at a constant temperature ranging between +30ºC and
+40ºC. A solution circulator is available as an accessory.
Four pins are inserted into the bone to mount it in the
test jig. (Sometimes the bones and pins are fixed
together using plaster.) The jig holder construction
Tilt angle adjuster Torsion Testing Device
allows it to be tilted to any angle to perform bending
testing or fatigue and endurance testing at any angle.
Bones are not only subject to uniaxial tensile and compressive loads, but to complex forces that include
shearing and torsional components. Bones can fracture in many ways, including shear fracture due to
Evaluation of Medical Equipment attached to an Autograph static tester to permit uniaxial torsion testing and repeated torsion testing Evaluation of Medical Equipment
the actions of shear forces perpendicular to the long axis of the bone, compression fracture due to
excessive compressive loads on the bone, spiral fracture (torsion fracture) due to torsional loads on the
bone, and bending fracture due to forces acting to bend the bone. The torsion testing device is
of bone and artificial bone samples, including biological samples, metals, and resins.
The torsion testing device also supports fatigue and endurance testing. The rapid test cycles reduce the
time required for the test.

Compression load jigs
Punch
Tensile Testing of Hair
The strength of hair is dependent on moisture content, daily UV exposure, static electricity, and daily hair care.
Sample fixing screw
Tensile testing was performed on hairs taken from a single subject under the same conditions. Sample A was untreated, while
Sample retaining plate Bending punch Samples B and C were degraded using different chemicals. These samples were mounted using pneumatic capstan type yarn grips.
Evaluation of Pharmaceuticals and Packaging Base Bone that the chemical treatment reduced the strength of the hair but increased its elasticity. (mm) Evaluation of Pharmaceuticals and Packaging
Bone
The results show the relationship between stress (test force divided by the sample cross-sectional area) and
Grip
displacement (movement of the crosshead). Sample A showed higher tensile strength values than the chemically-
Reinforced cement
Vice
treated Samples B and C, while Samples B and C showed higher displacement values. Therefore, it can be said
240
220
200
180
A
160
B
Stress (MPa)
140
Tensile strength Max. displacement
Sample
120
Sample
(MPa)
code
100
C
60
173.3
41.8
40
20
40.9
173.4
This is an example of a bending tester for a rat bone and orthopedic member. Designing
25
20
30
15
the vice shape to match the sample shape permits the testing of various samples. Table 80 0 0 5 10 Displacement (mm) 35 40 50 Hair A B C 198.4 37.8
Physical Property Testing Equipment
for Biomaterials and Medical Applications
6 Solutions for Biomedical Testing 7