Influence of blood flow and millimeter wave exposure on skin temperature in different thermal models.
Recently we showed that the Pennes bioheat transfer equation was not adequate to quantify mm wave heating of the skin at high blood flow rates. To do so, it is necessary to incorporate an "effective" thermal conductivity to obtain a hybrid bioheat equation (HBHE). The main aim of this study was to determine the relationship between non-specific tissue blood flow in a homogeneous unilayer model and dermal blood flow in multilayer models providing that the skin surface temperatures before and following mm wave exposure were the same. This knowledge could be used to develop multilayer models based on the fitting parameters obtained with the homogeneous tissue models. We tested four tissue models consisting of 1-4 layers and applied the one-dimensional steady-state HBHE. To understand the role of the epidermis in skin models we added to the one- and three-layer models an external thin epidermal layer with no blood flow. Only the combination of models containing the epidermal layer was appropriate for determination of the relationship between non-specific tissue and dermal blood flows giving the same skin surface temperatures. In this case we obtained a linear relationship between non-specific tissue and dermal blood flows. The presence of the fat layer resulted in the appearance of a significant temperature gradient between the dermis and muscle layer which increased with the fat layer thickness.
Alekseev
S I
SI
Center for Biomedical Physics, Temple University Medical School, Philadelphia, Pennsylvania 19140, USA.
Ziskin
M C
MC
D001783:Blood Flow Velocity / Q000502:physiology* / Q000528:radiation effects*; D003198:Computer Simulation; D004781:Environmental Exposure; D006801:Humans; D008872:Microwaves; D008954:Models, Biological; D012867:Skin / Q000098:blood supply*; D012881:Skin Temperature / Q000502:physiology* / Q000528:radiation effects*
Appl Human Sci. 1997 Mar;16(2):61-75
9164010
J Appl Physiol. 1976 Dec;41(6):826-31
1002638
J Biomech Eng. 1990 Feb;112(1):80-7
2308308
J Appl Physiol (1985). 2006 Jan;100(1):221-4
16150842
Bioelectromagnetics. 2007 Jul;28(5):331-9
17429851
J Appl Physiol. 1961 Jul;16:734-40
13786029
J Clin Invest. 1937 Jul;16(4):533-40
16694500
Pain. 2000 Feb;84(2-3):133-9
10666517
IEEE Trans Biomed Eng. 1978 May;25(3):313-6
680769
J Appl Physiol. 1948 Aug;1(2):93-122
18887578
Anesthesiology. 1990 Sep;73(3):541-5
2393139
J Biomech Eng. 1989 Nov;111(4):271-5
2486364
Bioelectromagnetics. 2005 Sep;26(6):489-501
15931684
Int J Hyperthermia. 2001 Nov-Dec;17(6):483-98
11719965
IEEE Trans Biomed Eng. 1976 Nov;23(6):434-44
977011
Health Phys. 2004 Feb;86(2):115-20
14744044
Bioelectromagnetics. 2008 Jan;29(1):65-70
17929264