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Volume 23, Issue 5
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[in Japanese]1994 Volume 23 Issue 5 Pages 1053
Published: October 15, 1994
Released on J-STAGE: October 07, 2011
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I YADA1994 Volume 23 Issue 5 Pages 1055-1061
Published: October 15, 1994
Released on J-STAGE: October 07, 2011
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A KIKUCHI, T OKANO1994 Volume 23 Issue 5 Pages 1062-1069
Published: October 15, 1994
Released on J-STAGE: October 07, 2011
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Y ABE, H MATSUURA, A KOUNO, H NOZAWA, K IMANISHI, K ATSUMI, K IMACHI, ...1994 Volume 23 Issue 5 Pages 1070-1076
Published: October 15, 1994
Released on J-STAGE: October 07, 2011
JOURNAL FREE ACCESSIn order to realize a physiological control of total artificial heart (TAH), a new automatic control method (1/R control), in which a TAH could be controlled by the TAH recipient himself, was proposed. The 1/R control function, in which the basic input parameter was the reciprocal of peripheral vascular resistance (1/R: conductance) and cardiac output was controlled by reflecting the activity of β-adrenergic reaction of the nervous system and/or the catecholamine system in peripheral vascular resistance, was applied to 4 TAH goats. The longest survival period of animals was 360 days with this new automatic control method. The hemodynamic parameters were physiologically normal during the experimental period. In the treadmill exercise study, the cardiac output increased automatically with the exercise, and decreased after the exercise, as in the natural heart animal. The results showed that a physiological control of total artificial heart was achieved with the 1/R control.View full abstractDownload PDF (3131K) -
E OKAMOTO, K TOMODA, K YAMAMOTO, M ASADA, K YASUDA, Y MITAMURA, T MIKA ...1994 Volume 23 Issue 5 Pages 1077-1082
Published: October 15, 1994
Released on J-STAGE: October 07, 2011
JOURNAL FREE ACCESSTemperature rise was studied in the motor-driven assist pump implanted in sheep and with a finite element methods (FEM) analysis. When the pump was implanted in fat with an actuator energy loss of 5.2W, postoperative temperatures were 41.0°C on the actuator surface and 39.5°C in the surrounding fat. In the case of an implantation of the pump between fat and skin with an actuator energy loss of 5.4W, the actuator surface temperature reached 40.5°C, and after that, the temperature gradually decreased until 39.2°C. The temperature distribution of the surrounding tissue was calculated with the FEM analysis. The analysis showed a possibility of a heat spot over 42°C on the actuator surface and low heat dissipation toward an inside body through a blood pump housing which is made of epoxy resin. Results of in vivo experiments showed that temperature rise of the motor-driven assist pump was within a safe level, but the FEM analysis suggested that more effective heat dissipation was required from the actuator to meet increase of energy loss with increase of pump output.View full abstractDownload PDF (3012K) -
K TOMODA, E OKAMOTO, K YAMAMOTO, Y MITAMURA1994 Volume 23 Issue 5 Pages 1083-1088
Published: October 15, 1994
Released on J-STAGE: October 07, 2011
JOURNAL FREE ACCESSWe have developed a totally implantable assist pump system with a built-in optical transmission unit to aim at computer-controlled patient monitoring. The main part of a driving control system is composed of small-sized 16-bit and 8-bit micro-processors with high performances. This system enables us to operate the motor-driven assist pump from outside of the body using the transcutaneous optical transmission unit. We can select either the fixed rate mode or the ECG synchronous mode, and adjust the drive rate of the former mode. The motor driving data can also be transmitted from inside of the body, which allows us to calculate the pump stroke volume, the maximum blood pressure, and the mean blood pressure. The whole system performed well during in vitro tests using a mock circulation unit. The pump stroke volume and both blood pressures estimated from the driving data were consistent with actual measured values.View full abstractDownload PDF (920K) -
K TAKAGI, C KONDO, K TANAKA, I YADA, M KUSAGAWA1994 Volume 23 Issue 5 Pages 1089-1094
Published: October 15, 1994
Released on J-STAGE: October 07, 2011
JOURNAL FREE ACCESSThe effect of Nafamostat mesilate (FUT-175), a protease inhibitor, on platelet morphology were analyzed using electron microscopy. Fourteen adult patients undergoing aortocoronary bypass surgery with cardiopulmonary bypass (CPB) were randomly distributed into an FUT treated group (8 patients) and a contol group (6 patients). In the FUT-treated group in addition to the usual treatment with heparin (300 U/kg), FUT-175 was infused continuously at a rate of 2mg/kg/h during CPB. Platelet surface morphology observed by scanning electron microscopy was classified into three grades (Grade A to C). In the control group, Grade A decreased during CPB, reaching 9.0±2.0% at 120 min of CPB. In the FUT-treated group, it showed significantly higher level of 50.4±17.0%. Platelet degranulation cavitation and glycogen storage with transmission electron microscopy at 120 min of CPB increased in the control group compared with that in the FUT-treated group. Ristocetin (1.2mg/min)-induced platelet agglutination in FUT-treated group was significantly preserved, 69.9±5.6% vs. 32.0±11.3% in control group at 60 min of CPB (p<0.05). We conclude that FUT-175 protects alterlations of the morphology of platelets.View full abstractDownload PDF (7612K) -
M HORIKOSI1994 Volume 23 Issue 5 Pages 1095-1101
Published: October 15, 1994
Released on J-STAGE: October 07, 2011
JOURNAL FREE ACCESSPumpless AV ECMO (AV group, n=9) and centrifugation pump-driven VV ECMO (VV group, n=12) were compared in gas exchanging capacity, blood injury and pulmorary hyperfine structural changes in a model of hypoventilation acute respiratory failure using adult mongrel dogs. Dogs of a non-ECMO group (n=5) were separately prepared as controls. The gas exchanging capacity and blood injury were not significantly different between the AV and VV groups. In the hyperfine structure of the lung, blood-air barrier and interstitial edematous changes were severer in the AV group than in the VV. Edematous change was semiquantified by measuring the thickness of basement membrane by the pointcount method. The value was significantly higher in the AV group than in the VV. Compared to the two ECMO groups, considerably sever edematous and destructive changes were noted in the control dogs with a significantly greater thickness of basement membrane. As another laboratory experiment of hemodynamics, change in AP, PAP and CO were compared between the AV(n=6) and VV(n=6) ECMO groups. In the AV group significant increases in CO and PAP were observed in association with an increase in volume. In the VV group on the other hand there was no such change occurring. These results suggest that for ECMO treatment of alveolar hypoventilation type of respiratory failure the VV bypass method should be superior to the AV one in terms of hemodynamic and hyperfine structure of the lung.View full abstractDownload PDF (6188K) -
—Development of automatic coagulation measurement method using plasma samples—T SUGIYAMA, N KANAMORI, S UDA, F KOIWA, T AKIZAWA, S KOSHIKAWA1994 Volume 23 Issue 5 Pages 1102-1108
Published: October 15, 1994
Released on J-STAGE: October 07, 2011
JOURNAL FREE ACCESSPlasma Xa activated coagulation time (PXCT) method was developed for the monitoring of low molecular weight heparin (LMWH) during hemodialysis (HD). PXCT increased linearly with the increase of LMWH concentration (0-0.8 IU/ml). The fact that PXCT increased more significantly with heparin than LMWH and also was increased by a synthetic thrombin inhibitor, indicated that PXCT was affected not only by anti-Xa activities but also by anti-thrombin activities. HD was conducted using bolus and continuous administration of LMWH. The PXCT and APTT were measured together with the whole blood Xa activated coagulation time (XCT), which is currently said to be useful for monitoring LMWH. In both methods of administration, the response of APTT was too low, therefore it was determined to be unsuitable for these purposes. However, a parallel increase of PXCT and XCT, suggested that these two parameters reflected the effects of LMWH. It was thus concluded that PXCT would be a useful monitoring method of LMWH. The added advantages of its using plasma samples would be ease of sample storage and large number of sample handling.View full abstractDownload PDF (1014K) -
[in Japanese]1994 Volume 23 Issue 5 Pages 1109-1110
Published: October 15, 1994
Released on J-STAGE: October 07, 2011
JOURNAL FREE ACCESSDownload PDF (293K)
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