| Autor: |
Clarke, Ian, Fiske, Chuck, Amstutz, Harlan, Clarke, I C, Fiske, C, Amstutz, H C |
| Předmět: |
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| Zdroj: |
Medical & Biological Engineering & Computing; 1979, Vol. 17 Issue 2, p155-160, 6p |
| Abstrakt: |
The accuracy of sphericity measurements on human hip joints was studied with two types of 3-legged micrometer gauges. Initial calibration work on metal cylinders (30-65 mm diameter) achieved an error range of 4-8%. Correction was then made for this degree of error on a nomogram which reduced the errors in subsequent measurements to 0·-1·5%. The problem was that the percentage error in the micrometer reading was directly reflected in the percentage error in diametrical calculation. To achieve an acceptable accuracy of ±1%, the micrometer readings had to be accurate to within ±(15-23) μm, i.e. 0·0006-0·0009 in. (average of five measurements). This was only achieved in the metal calibration studies ±(0-15) μm, but not for the hip joint or its replicas, ±(7-109) μm. It was concluded that 3-legged gauges were a very unreliable method of taking diametrical measurements from human joint surfaces. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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