Lock-in thermography for imaging of modulated flow in blood vessels

Abstract

While conventional thermographic applications to the human body aim at revealing local temperature changes normally related with the beginning of a pathologic process, this paper shows how lockin thermography can be modified in order to meet medical needs in the visualization of functionality of blood vessels. A compression cuff is used in connection with the lockin system to create a modulation in the blood flow. The amplitude and phase images thus obtained can provide infonmation about the blood flow in the vessels.

Visualization of body thermoregulation by infrared imaging

“…1(b)), with five reference settings for the hand. The support allowed the subject to keep the forearm still, thus minimizing movement artifacts in the results of the lock-in thermography technique (Wu et al, 1997;Wu and Busse, 1998).…”

Thermal imaging of a vein of the forearm: Analysis and thermal modelling

“…In order to overcome the difficulties related to the influence of the external environment, several approaches were suggested. Lock-in infrared thermography associated to a periodical constriction of the venous flow has been studied [13], while more classical studies have measured the infrared emission after cold or hot stimulations [5,10,14,15].…”

Thermal imaging of the skin blood flow oscillations in extremities: modification of the spectral components

“…Первое связано с решением задачи визуализации сети венозных или артериальных сосудов без учета количественной связи с кровотоком в них. При этом технология визуализации может предполагать регистрацию тепловой реакции на окклюзионное воздействие в области плеча [13], реакции на периодическую модуляцию кровотока с помощью плечевой манжеты (lock-in thermography) [5,6,17], реакцию на внешний нагрев [4,10] или охлаждение [8].…”