Fiber-optic transmission catheter for regional venous oxygen saturation and blood flow

Abstract

We have developed a method for monitoring regional venous oxygen saturation. The key feature of this system is the use of highly flexible polymer fiber optics, and this flexibility allowed the production of a new fiber-optic transmission catheter. The space between the "face-to-face" positioned fiber-optic tips forms a remote catheter-based transmission cell. Our method applies Twersky's theory, in which absorption and scattering can be treated independently. Fresh rabbit blood was pumped through a disk oxygenator in which gas exchange occurred and passed the catheter. Simultaneous results obtained by the catheter and a cuvette oximeter were excellent (r = 0.99, SD = 1.1%). Oxygen saturation measured by this catheter was independent of vessel wall artifacts, blood pH, and flow velocity. Another application of this method is measurement of blood flow by the dye- (indocyanine green) dilution technique. The results of flow measurements by the catheter appeared to be satisfactory (r = 0.99, SD = 1.7%). This study concludes that our method is effective for monitoring the balance between regional oxygen supply and demand.

Measurement of oxygen saturation in venous blood by dynamic near infrared spectroscopy

“…However, in contrast to the routine use of pulse oximetry to SaO 2 measurement, no accepted method for the measurement of SvO 2 is available. Iwasaki et al 9 suggested an invasive method based on introducing a fiber optic transmission catheter into a peripheral vein for the measurement of the regional SvO 2 . Similar to pulse oximetry, venous blood oxygen saturation can be obtained noninvasively by measuring the change in light absorption in two wavelengths after inducing change in the venous blood volume.…”

Continuous measurement of hematocrit using an intravascular catheter equipped with a fiberoptic transmission cell

“…A fiberoptic transmission catheter was fabricated as described by Iwasaki et al [5]. Although plastic fibers are highly flexible, the transmitted light is affected by the bends and movements of the fiber.…”

“…We expected that the fiberoptic transmission catheter reported by Iwasaki et al [5] would be able to provide continuous measurements of hematocrit, thus avoiding the disadvantages of the previous methods. This fiberoptic catheter for the measurement of oxyhemoglobin saturation has a transmission cell composed of face-to-face positioned optic-fiber tips fixed on the catheter, and it can detect the light transmitted through blood samples in vessels.…”

Stellenwert der gemischtvenösen Sauerstoffsättigung für die perioperative Überwachung und Therapie - Eine kritische Bestandsaufnahme

“…Neben den bisher üblichen Lichtreflektionskathetern ist neuerdings ein sogenannter Transmissionskatheter vorgestellt worden (19). Einer der beiden integrierten Lichtleiter ist an der Katheterspitze U-förmig umgebogen, so daß sich die Enden der Lichtleiter unmittelbar gegenüberliegen und nur durch eine Blutschicht von 1,2mm Dicke voneinander getrennt sind.…”

“…Problematisch ist allerdings, dai3 bisher nur zwei Wellenlängen verwendet wurden, und zwar sowohl bei der Katheter-als auch bei der Referenzmessung. Eine weitere Einsatzmöglichkeit fur den Katheter soll in der Messung des Blutflusses nach der Farb stoffverdünnungsmethode liegen (19). -…”