Evaluation of an infrared laser-Doppler blood flowmeter

A. P. Shepherd, G. L. Riedel, J. W. Kiel, D. J. Haumschild, L. C. Maxwell

Research output: Contribution to journalArticle

113 Citations (Scopus)

Abstract

Several laser-Doppler blood flowmeters are not commercially available; however, only one utilizes an infrared laser diode (Laserflo, TSI, St. Paul, MN). Because of this end and other unique features such as its microprocessor-based signal analyzer, we evaluated this device's ability to measure tissue perfusion. Initially, we determined whether laser illumination directly affected the microvasculature. Intravital microscopic observations in the hamster cremaster muscle indicated that neither He-Ne nor infrared laser light affected the diameters of arterioles that were responsive to vasoactive agents. To test the flowmeter for linearity and repeatability, we used a rotating disk to simulate a light-scattering, flowing medium. The 'flow' signal was highly correlated (r = 0.99) with the rotational velocity of the disk, was consistent among flow probes, and showed a high degree of reproducibility. The second model consisted of microsphere suspensions pumped through cuvettes. The laser-Doppler velocimeter (LDV) flow signal was linear with respect to pump output. With red blood cells in the perfusate, we examined the effects of blood oxygenation on the flowmeter's performance. The LDV flow signal was unaffected by changes in blood oxygenation. We evaluated linearity in vivo in isolated, perfused rat livers and in isolated canine gastric flaps. We observed linear relationships between total flow and laser-Doppler flow measured on the surface of the liver (r = 0.98) and in the gastric mucosa (r = 0.98), but the slopes of the relationships between total and local LDV flow showed considerable variability not noted in the in vitro studies. We conclude that the TSI laser-Doppler blood flowmeter provides a stable, reproducible, relatively noninvasive method for continuously monitoring tissue perfusion. However, the small volume of tissue in which LDV measures perfusion is not always representative of total blood flow in the whole organ.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Volume252
Issue number6
StatePublished - 1987

Fingerprint

Flowmeters
Lasers
Perfusion
Light
Abdominal Muscles
Semiconductor Lasers
Liver
Microcomputers
Arterioles
Gastric Mucosa
Microvessels
Lighting
Microspheres
Cricetinae
Canidae
Stomach
Suspensions
Erythrocytes
Equipment and Supplies

ASJC Scopus subject areas

  • Gastroenterology
  • Physiology

Cite this

Shepherd, A. P., Riedel, G. L., Kiel, J. W., Haumschild, D. J., & Maxwell, L. C. (1987). Evaluation of an infrared laser-Doppler blood flowmeter. American Journal of Physiology - Gastrointestinal and Liver Physiology, 252(6).

Evaluation of an infrared laser-Doppler blood flowmeter. / Shepherd, A. P.; Riedel, G. L.; Kiel, J. W.; Haumschild, D. J.; Maxwell, L. C.

In: American Journal of Physiology - Gastrointestinal and Liver Physiology, Vol. 252, No. 6, 1987.

Research output: Contribution to journalArticle

Shepherd, AP, Riedel, GL, Kiel, JW, Haumschild, DJ & Maxwell, LC 1987, 'Evaluation of an infrared laser-Doppler blood flowmeter', American Journal of Physiology - Gastrointestinal and Liver Physiology, vol. 252, no. 6.
Shepherd, A. P. ; Riedel, G. L. ; Kiel, J. W. ; Haumschild, D. J. ; Maxwell, L. C. / Evaluation of an infrared laser-Doppler blood flowmeter. In: American Journal of Physiology - Gastrointestinal and Liver Physiology. 1987 ; Vol. 252, No. 6.
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