Biological Imaging and Sensing from Basic Techniques to Clinical Application - Biological Imaging and Sensing - page 40

Table 1.1. Factors affecting skin surface temperature

are observed. From these, the laser trapping NSOM can be seen to have the
ability to image biomolecules fixed on a substrate.

1.7 Physiological Function Analysis of the Human

Body and Organ-Using Far-Infrared Imaging

The surface temperature of the human body and organs is determined by
the blood-flow rate, the structure of surface tissue, and the activities of the
neurohumoral system, which regulate heat dissipation from the body surface.
Because of this, we can detect distributions of many physiological functions
from thermal images of the surface of the human body and organs obtained
by far-infrared (FIR) imaging.

1.7.1 Static Analysis of Abnormal Temperature Distribution

on the Skin [57]

In clinical practice, for thermal comfort, we set the examination room to an
ambient temperature that is relatively warm. We refer to this as a thermally
neutral condition, and the patient's body is able to maintain thermal equili-
brium. The equilibrium condition is at 29-31 ◦ C when light clothes are worn.
Under thermally neutral conditions, heat production and loss by the body are
equal, and the skin-surface temperature is controlled only by the blood-flow
rate of the cutaneous tissue. Under these conditions, it is possible to classify
abnormal thermogram patterns according to their physiological origins. As
shown in Fig. 1.40, many control factors are involved in determination of the
skin-surface temperature [58,59].
The five parameters listed in Table 1.1 might be regarded as the most
fundamental physiological causes of abnormality. In the table, the termino-
logy used is of thermatomes for the specific temperature patterns. The word
thermatome originated in (neuro-)dermatome ,andwascoinedbyP.LeRoy
as defining an abnormal segmental pattern of a thermogram caused by di-
sturbances of somatosensory and sympathetic pathways [60]. It is possible to
expand the definition because the word thermatome is appropriate for descri-
bing a regional pathophysiological abnormality. Therefore, a thermatome is