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Customizations
Full scale range may be tailored for specific applications, by adjusting
the thickness of the stainless micro-structure in the area where the strain
gauge is bonded. We utilize finite element analysis to facilitate these
design modifications.
Measuring Soft Tissue Forces
As tissue fiber bundles come under tension, the walls of the probe are
squeezed. This uniaxial tension produces transverse forces that elastically
deform the probe, which changes its output. Signals from the probe's circuitry
can be related to uniaxial tension by calibration. The device is constructed
of biocompatible materials, and is fully encapsulated for protection against
moisture, however, the instrument is not FDA approved for implant in live
humans.
Excitation and Measurement
High performance carrier-type instrumentation amplifiers are available
from MicroStrain®. Along with our Data Acquisition and Display software, and a personal computer,
probe output may be displayed in real-time, and saved for analysis.
Electrical Specifications
| Excitation |
8 ma D.C. |
| Sensitivity |
30 µV/ma/N |
| Non-Linearity |
± 1.5% over 1/2 FS, ± 2.5%
over FS |
| Hysteresis |
0.3% FS |
| Repeatability |
0.3% FS |
| Temp. Coeff. Offset |
± .013% FS/C degrees |
| Temp . Coeff. Span |
+ 0.2%/C degrees |
Mechanical Specifications
| Full scale (FS) |
16 N (standard) |
| Length |
5 mm |
| Cross section |
Elliptical; 1.4 mm by 1.8 mm |
| Leadout type |
Polyimide/copper tape cable, 20 cm long |
| Stiffness (approx.) |
1.5 N/micron |
| Fatigue life |
Approx. 106 cycles at 50% FS unidirectional loading |
U.S. Patent 5083573
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