Abstract
Diagnosis is essential for patient treatment. The diagnosis has two objectives: deciding on
the disease or syndrome and classifying its grade, in which some fuzziness of diagnosis is imbedded.
The purpose of this paper is to examine the relationship between the decision of disease or
syndrome and the classification of grades. To clarify the fuzziness of diagnosis, we analyzed clinical
data on patients with Carpal Tunnel Syndrome (CTS) using multivariate analysis. From the analytical
results, we propose a new diagnostic logic with two diagnostic layers: A first layer for the detection
about CTS by the clinical indicators such as Ring finger sensory splitting and Phalen’s test,
and a second layer for the classification of CTS by indicators of Thenar muscle atrophy and Pinch
disturbance.
