The objectives of this research are (1) to further develop and extensively apply the thermal pulse decay (TDP) method to measure the blood perfusion in various organs and tissues; (2) to evaluate the influence of various vascular architectures on the convective heat transfer in the tissue; (3) to develop and evaluate a modified version of the TPPD method (MTPD) that is based on a more detailed description of heat transfer within the tissue that accounts for the convective contribution due to blood flow. The main measurement devices will be arrays of two or three thermistor probes in various configurations. Each microprobe in such arrays will be similar to the one used by the present TPD method. Thus the MTPD method will possess all of the advantages of the TPD method resulting from the small size of the probe and the transient nature of the measurement. The results obtained from the in vivo and in vitro (fixed tissue phatoms) experiments applying the MTPD method will be compared with other of blood flow measurement (microspheres, EM blood flowmeter, etc.) and the results critically discussed, analyzed, and evaluated, based on some new theoretical models of heat transfer in living tissues proposed recently by others and by the applicants. The proposed MTPD method of measuring local tissue perfusion has application in numerous areas of cardiovascular study. Quantitative blood flow measurements can be obtained in organs or tissues which have been proven difficult to evaluate in the past, e.g., cortico-medullary junction in the kidney, intestine, skin, etc. Of additional importance, the theoretical contribution of the proposed research will provide a better understanding of the modes of heat transfer in biological tissues.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL027011-04A1
Application #
3338848
Study Section
Surgery and Bioengineering Study Section (SB)
Project Start
1982-01-01
Project End
1989-11-30
Budget Start
1986-12-01
Budget End
1987-11-30
Support Year
4
Fiscal Year
1987
Total Cost
Indirect Cost
Name
University of Illinois Urbana-Champaign
Department
Type
Schools of Veterinary Medicine
DUNS #
041544081
City
Champaign
State
IL
Country
United States
Zip Code
61820
Beasley, V R; Lovell, R A; Holmes, K R et al. (2000) Microcystin-LR decreases hepatic and renal perfusion, and causes circulatory shock, severe hypoglycemia, and terminal hyperkalemia in intravascularly dosed swine. J Toxicol Environ Health A 61:281-303
Xu, L X; Holmes, K R; Moore, B et al. (1994) Microvascular architecture within the pig kidney cortex. Microvasc Res 47:293-307
Arkin, H; Xu, L X; Holmes, K R (1994) Recent developments in modeling heat transfer in blood perfused tissues. IEEE Trans Biomed Eng 41:97-107
Xu, L X; Chen, M M; Holmes, K R et al. (1993) Theoretical analysis of the large blood vessel influence on the local tissue temperature decay after pulse heating. J Biomech Eng 115:175-9
Moore, B J; Holmes, K R; Xu, L X (1992) Vascular anatomy of the pig kidney glomerulus: a qualitative study of corrosion casts. Scanning Microsc 6:887-97;discussion 897-8
Moore, B J; Holmes, K R (1991) Timed acid bath effects on kidney podocytes prepared for scanning electron microscopy. Scanning Microsc 5:445-9;discussion 449-50
Benkeser, P J; Frizzell, L A; Holmes, K R et al. (1990) A perfused tissue phantom, for ultrasound hyperthermia. IEEE Trans Biomed Eng 37:425-8
Arkin, H; Holmes, K R; Chen, M M (1989) A technique for measuring the thermal conductivity and evaluating the ""apparent conductivity"" concept in biomaterials. J Biomech Eng 111:276-82
Bottje, W G; Holmes, K R; Neldon, H L et al. (1989) Relationships between renal hemodynamics and plasma levels of arginine vasotocin and mesotocin during hemorrhage in the domestic fowl (Gallus domesticus). Comp Biochem Physiol A Comp Physiol 92:423-7
Bottje, W G; Holmes, K R (1989) Effect of hemorrhage on hepatic tissue blood flow in the domestic fowl (Gallus domesticus). Comp Biochem Physiol A Comp Physiol 93:725-7

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