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[in Japanese]
1989 Volume 18 Issue 2 Pages
429
Published: April 15, 1989
Released on J-STAGE: October 07, 2011
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K. KOJA, Y. KUNIYOSHI, K. IHA, M. AKASAHI, T. KUGAI, M. SHIMABUKURO, Y ...
1989 Volume 18 Issue 2 Pages
431-434
Published: April 15, 1989
Released on J-STAGE: October 07, 2011
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The partial cardiopulmonary bypass techniques for operation on the descending aorta has been used. Comparative study was done to determine the effectiveness of pulmonary artery drainage when using such left heart bypass. Experimental circuit was provided with three drainage sites (F. V., L. A., P. A. ) and pump oxygenatoro To clarify the usefullness to get same flow rate of each drainage site, the difference of the height between left atrium and blood surface of the oxygenator were measuredo PA drainage needed most little difference and LA followedo Clinical use of PA drainage was done on eight patients. The aortic clamp time were 24-207 minuteso Postoperative course was good in this group (no operative death).
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H. TAKANO, H. MATSUDA, S. NAKANO, K. SAKAI, M. OHTANI, A. KAWAGUCHI, S ...
1989 Volume 18 Issue 2 Pages
435-439
Published: April 15, 1989
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Hepatic venous oxygen saturation (Shvo
2) monitoring was performed in four patients undergoing mechanical circulatory support; two with intra-aortic balloon pumping (IABP), one with veno-arterial bypass (VAB) and one with left heart bypass (LHB). One with IABP showed low Shvo
2 values (below 30%) in spite of circulatory support with IABP, and developed subsequent hepatic dysfunction and multiple organ failure. There was a significant correlation between lactate removal by the liver assessed by splanchnic excess lactate and Shvo
2. This monitoring method may be useful in the management of critical patients in evaluating hepatic circulation and preventing hepatic dysfunction.
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T. MASAI, H. MATSUDA, S. NAKANO, M. OHTANI, Y. SASAKO, R. MATSUWAKA, N ...
1989 Volume 18 Issue 2 Pages
440-443
Published: April 15, 1989
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A simplified veno-arterial bypass without reservoir, consisted of a centrifugal pump (Bio-Pump) and an extracapillary blood flow type membrane oxygenator (Sarns16310) was evaluated in 5 open chest dogs (average 9.4kg). Bypass flow was obtained from 25 to 65ml/kg with bypass ratio of 30 to 70%. Under these conditions left and right ventricular stroke work decreased significantly compared to the prebypass value. Using mock circulation flow capacity was tested with various size of the pumps, arterial and venous cannulae and blood flow up to 2.5l/min, which may be sufficient for adult patients, was obtained. The result indicates that this system of simple and small priming volume may be useful for temporary circulatory support for cardiogenic shock utilizing peripheral approaches.
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M. OKADA, M. KUBOTA, M. IMAI, K. ATAKA, T. OHTA, K. HISANO, C. YAMASHI ...
1989 Volume 18 Issue 2 Pages
444-447
Published: April 15, 1989
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During a last decade sixty-seven patients with thoracic-and thoracoabdominal aneurysm were operated upon in our surgical department. From these clinical experiences, the key points to keep excellent operative results were to decide the optimal time of operation and to select the best way of temporary bypass method during aortic cross clamp. Recently, Bio-pump was successfully employed in the surgical treatment for the six patients with thoracic-and thoracoabdominal aneurysm. Bypass route with Bio-pump was made between the left atrium and the femoral artery. Bypass flow ranged from 0.8-2.7l/min and the pressure of the dorsal pedic artery was adequately controlled between 60 and IIOmmHg during temporary bypass, by which urinary volume could be satisfactorily obtained. Thus, good hemodynamics could be maintained by means of Bio-pump. Operation was successfully carried out in all patients whose postoperative courses were uneventful. There were no remarkable changes in enzyme activity and freehemoglobin. Bio-pump was obviously useful in the field of thoracic and cardiovascular surgery.
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R. MATSUWAKA, H. MATSUDA, S. NAKANO, M. OHTANI, Y. SASAKO, H. TAKAMI, ...
1989 Volume 18 Issue 2 Pages
448-451
Published: April 15, 1989
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The applicability of LFSR to assess the left ventricular function under unloaded conditions was studied in seven canine heart under CPB(n=4) and left heart bypass(LHB, n=3). Instantaneous pressure-volume(P-V) data utilizing micromanometer and conductance catheter was obtained during transient(15sec) acute volume loading under CPB and LHB. The correlation(r) between stroke work determined as P-V curve area and end diastolic volume was high as ranging from 0.967 to 0.991. This highly linear relationship indicated that LFSR may be applicable to the partially unloaded left ventricle under assisted circulation.
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[in Japanese]
1989 Volume 18 Issue 2 Pages
452
Published: April 15, 1989
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A. SAITO, H. MORO, S. EGUCHI, T. YOKOSAWA
1989 Volume 18 Issue 2 Pages
453-456
Published: April 15, 1989
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The left heart bypass was performed in seven mongrel dogs for 4 hours using a protease inhibitor(FUT) as an anticoagulant.Assisting bypass flow was 200ml/min(20% of cardiac output), and FUT was infused continuously via the inflow cannula. ACT, platelet counts, APTT and FDP were measured during the bypass. The result shows that nafamostat mesilate is a useful and safe anticoagulant for mechanical circulatory support.
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[in Japanese]
1989 Volume 18 Issue 2 Pages
457
Published: April 15, 1989
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K. MIZUGUCHI, S. KIYSMUTA, Y. KOH, K. KAWACHI, H. KOBAYASHI, R. MORITA ...
1989 Volume 18 Issue 2 Pages
458-461
Published: April 15, 1989
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We simulated 2 types of bi-ventricular failure (BVF) with elevated pulmonary arterial resistance (PAR) and normal PAR using our in-vitro assist circulatory model. A LVAD and BVAD were tested in these BVF circulatory models and their hemodynamic effectiveness were comparatively evaluated. A BVAD was more effective than a LVAD for BVF with increased PAR, in termes of increasing cardiac output (3.7±0.1→4.2±0.3l/min:p%lt;0.001) and decreasing RAP (14±2→6±1mmHg:p<0.001).
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M. SHIONO, T. HASEGAWA, S. KITAMURA, M. OHIRA, H. RIKUKAWA, S. SHINDA, ...
1989 Volume 18 Issue 2 Pages
462-466
Published: April 15, 1989
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Since 1982 ventricular assist devices were applied clinically for 13 cases with profound pump failure. Left ventricular assist device was used in 11 cases that had revealed cardiopulmonary bypass dependent or postcardiotomy low output syndrome. 8 cases could wean from LVAD and 3 could not. Longterm survival was obtained only 2 cases (18%), and the remaining 9 cases were died from multiple organ failure, bleeding or heart failure. Various types of problems were encountered clinically, and we evaluated these problems and limitations of LVAD. It was suggested that strict selection of pump size and type of cannula had to be done individually for each pathophysiologic condition. There were some severe cases in which LVAD had been ineffective. Prophylaxis of infection and MOF had been usually necessary for LVAD cases.
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T. MATSUKAWA, R. HASHIMOTO, S. HOSAKA, A. UENO
1989 Volume 18 Issue 2 Pages
467-470
Published: April 15, 1989
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A 78-year-old women underwent the surgery for ventricular septal perforation and then LVAD was used for 23 days. Reninangiotensin system activated in the whole postoperative period, especially for angiotensin II in 2nd, 14th and after third week. The change of noradrenaline was similar to that of angiotensin II, but adrenaline was not changed. Aldosterone increased after two weeks postoperatively. On the other hand, clinical laboratory data showed that hyperbilirubinemia appeared 2 weeks and then S-GOT, LDH, S-amylase and CK-BB elevated simultaneously 3 weeks postoperatively. On the 26th day, patient died from acute hepatic failure clinically. Autopsy revealed acute hepatic and pancreatic necrosis.
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S. KYO, R. OMOTO, T. IMOUE, R. YOZU, H. KOYANAGI, T. INO, T. SAKAKIBAR ...
1989 Volume 18 Issue 2 Pages
471-475
Published: April 15, 1989
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A ventricular assist device system (VAD) produced by TOYOBO, was clinically evaluated at 15 institutes in Kanto district. 11 pts with profound heart failure were treated. 7 pts were weaned from VAD and 2 pts were long-survivors. The anti-thrombogenicity and durability of pump and the function of drive unit were both excellent. In conclusion, this VAD system is effective and reliable to treat profound-heart-failure patients.
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T. TSUTSUI, T. MURAI, N. ATSUMI, H. NAKAJIMA, T. ASAKURA, H. IJIMA, T. ...
1989 Volume 18 Issue 2 Pages
476-479
Published: April 15, 1989
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Animal experiments were performed to obtain an adequate parameter for choosing the optimal systemic blood flow during pulsatile artificial circulation. Aortic characteristic impedances were constant for excessive systemic blood flows, but were increased as given systemic flows were decreased bellow the control level. Results indicate that it seems to be possible to determine the optimal systemic blood flow during the pulsatile artificial circulation by detecting the changing pattern of the aortic characteristi impedance.
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[in Japanese]
1989 Volume 18 Issue 2 Pages
480
Published: April 15, 1989
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K. IMANISHI, K. IMACHI, Y. ABE, K. MABUCHI, K. MAEDA, K. ATUMI, T. CHI ...
1989 Volume 18 Issue 2 Pages
481-483
Published: April 15, 1989
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To save the acute circulatory failure patient, a new assist circulatory system was developped which is percutaneously accessible. In this method, a cannula was inserted from brachial artery or subclavian artery to near the coronary artery and the other end of cannula was connected to a sac type blood pump which has 20ml of volume and has not valve. The pump was counterpulsated to heart beat and was synchronized with IABP. In mock circulation studis, 20ml of maximum stroke volume was obtained using 5mm diameter canula (driving condition; +200mmHg, -100mmHg, S/D ratio 50%, pulse rate 100/min). The effect of diastolic augmentation was evident in vivo experiments, and marked increase in aortic pressure at the diastolic phase and coronary flow was observed. It can be concluded that the method is available for clinical use
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H. ARAI, T. YOSHIDA, T. MARUYAMA, J. AMANO, T. SAKAMOTO, A. SUZUKI, T. ...
1989 Volume 18 Issue 2 Pages
484-486
Published: April 15, 1989
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During the employment of IABP in post-operative cardiac patients, the platelet count (PC) decreases and large volume of platelet infusions is occasionally needed. This phenominon is suspected to result from the mechanical injury on platelets by balloon pumping. Since 1984, we employed IABP for more than 3 days postoperatively in 28 patients. These patients were devided into 3 groups according to the combined use of Balloon (B) and Driver (D) as follows; group-A: Kontron-(B)-surgical 40cc+Kontron-(D)-Model-10, group-B: Aries-(B)-40cc or 30cc+Kontron-(D)-Model-10, group-C: Aries-(B)-40cc or 30cc+Aries-(D)-M-700. In each group, PC was maintained between 9 and 10×10
4/μl by platelet infusions during IABP support was the largest. We concluded that the mechanical-related platelets' injury in group-C was more severe than was in the other 2 groups. And the platelet distribution width in all patients with IABP support was wider than that in the non IABP-supported patients.
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Y. YOSHIOKA, H. NISHIDA, I. AKIYAMA, H. ENDOH, H. KOYANAGI, N. TSUTSUI
1989 Volume 18 Issue 2 Pages
487-490
Published: April 15, 1989
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To optimize intraaortic balloon pulsation, the inflation and deflation mechanisms of different intraaortic balloons were studied in a model aorta with pressure volume characteristics approximating those of a natural aorta. Four types of balloons of identical volume and diameter which had different position of inner catheter were compared under controlled condituion. It could be demonstrated that inflation of usual balloon type A began at the tip and proceeded from these to the end of the balloon. The inflation of new balloon type B began at the end of balloon and proceeded to the top of it. These results will be applied to small-than average adult and children.
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M. FUKUTOMI, S. KITAMURA, K. KAWACHI, T. NISHII, S. TANIGUCHI, S. KOBA ...
1989 Volume 18 Issue 2 Pages
491-494
Published: April 15, 1989
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The early and late clinical results of 62 patients requiring intraaortic balloon pumping after cardiac surgery were analyzed. Fifty one patients were successfully weaned from suport and 46 (74%) were subsequently discharged from the hospital. Patients were followed-up for a mean period of 19 months with 8 late deaths mostly due to the cardiac causes. The influence of risk factors on survival was evaluated by the multivariate analysis using the Cox proportional hazards model which demonstrated the patient's age to be the most important discriminating factor for long-term survival.
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H. OKABAYASHI, H. HIROSE, H. OGINO, K. JINNO, K. NISHIMURA, M. MATSUMO ...
1989 Volume 18 Issue 2 Pages
495-498
Published: April 15, 1989
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From February 1984 through March 1988, intraaortic balloon pumping (IABP) was used in 8 patients. IABP was used intraoperatively in five patients, after surgery in two patients, and before surgery in one. Patient weight ranged from 6.1kg to 42kg. Balloon volumes between 4ml and 40ml were used. Five of the balloon catheters were made by Toray Industry and three by SMEC Inc. In three patients, suprasystolic diastolic augmentation was obtained. There were two survivors who underwent IABP. IABP was very effective in pediatric patients for the management of perioperative low cardiac output syndrome.
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T. SUGIMOTO, M. KAJI, K. SASAKI, T. ASANO, M. IKESHITA, S. TANAKA, T. ...
1989 Volume 18 Issue 2 Pages
499-502
Published: April 15, 1989
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We have developed a device which automatically measures SDR, diastolic pressure time index devi ded by tension time index, which was introduced by Dr. Buckberg, We have improved it so that we may make instant bedside measurments of the balance between supply and demand of O
2 in the myocardium. We can measure SDR in arrhythmias and in cases using intraaortic ballon pumping (IABP). In six cases of IABP after open heart surgery and two during acute myocardial infarction, we found that SDR, during IABP equals 1.64±0.20 and SDR following IABP equals 1.06±0.20. Moreover, in unsuccessful cases of IABP weaning, SDR was found to decline.
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K. NEYA, S. TAKAMOTO, T. NAKANO, S. KYO, Y. YOKOTE, R. OMOTO
1989 Volume 18 Issue 2 Pages
503-506
Published: April 15, 1989
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During LVAD and IABP, the coronary flow (CF) of proximal left anterior descending coronary artery of 41-year woman was measured with TE-2DD after left atrial myxomectmy. All beats were classified into 4 groups according to the on-off mode of LVAD and IABP: Beatl (LVAD on IABP on), Beatll (LVAD on IABP off), Beatlll (LVAD off IABP on), and BeatlV (LVAD off IABP off). The average peak velocities in diastole were 64.6±4.3cm/sec in BeatI, 48.8±1.7cm/sec in BeatII, 40.4±8.0cm/sec in BeatIII, and 29.2±3.8cm/sec in BeatIV. The peak velocities were in direct proportion to mean aortic diastolic pressure and EVR. Combination of LVAD and IABP effectively recovered the damaged myocardium with increased CF by raising the diastolic pressure and EVR.
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H. MORO, K. TOGASHI, S. TSUCHIDA, Y. FUJITA, H. OZEKI, J. HAYASHI, Y. ...
1989 Volume 18 Issue 2 Pages
507-510
Published: April 15, 1989
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Cardiac function and renal hemodynamics were investigated in ten dogs. Renal hemodynamics study included renal blood flow (RBF), renal vascular resistance (RVR). We studied the effects of IABP on the renal hemodinamics and influence of the denervation of the renal nerves. The results were as follows: 1. The increase in RBF undergoing IABP was mainly produced by the decrease in RVR. 2. By denervation of the renal nerves, RVR was persisted low, regardless of the IABP support. And the effect of the IABP support was exceed by denervation. 3. RVR is controlled by the renal sympathetic nerve activity. IABP support produced the decrease in RVR as same as the effects of denervation.
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[in Japanese]
1989 Volume 18 Issue 2 Pages
511-512
Published: April 15, 1989
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H. TAKAGI, A. OKAMOTO, M. TAKAMATU, T. TAKAGI
1989 Volume 18 Issue 2 Pages
513-516
Published: April 15, 1989
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Different size of the left ventoricular assist devic in baby size has been developed in our laboratory and tested in vitro by pumping under the automtic control of our cont roland driving machine. Their chamber were 6ml, 5ml, 4ml, 3ml, and 2ml in capacity and valve-orfice were 2mm, 3mm, and 4mm in diameter respectively. The result obtained suggested that the device of 3-5ml chamber with 4mm valve can be used as the left ventricular assist device in baby size.
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H. YAMADA, K. KAWAKATSU, M. KARITA, H. FUKUMASU, S. YUASA, T. AKUTSU
1989 Volume 18 Issue 2 Pages
517-520
Published: April 15, 1989
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Linear motor driven artificial heart consists of a linear pulse motor (short in LPM) and blood pumps coupled mechanically each other, the mock circulation test was checked.
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A. YAGURA, Y. TAENAKA, H. TAKANO, H. NODA, M. KINOSHITA, E. TATSUMI, H ...
1989 Volume 18 Issue 2 Pages
521-524
Published: April 15, 1989
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A left ventricular assist system composed of a pusher-plate type blood pump and an electrohydrauric linear actuator weighing 1.8kg and displacing 0.8L was developed. Performance studies with using a goat of 57kg showed that this system yielded the maximum pump flow of 3.9L/min against the afterload of 80mmHg and stably functioned in various animal conditions. This system can become one of the most promissing totally implantable artificial heart systems.
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N. KABEI, R. TSURU, Y. SAKURAI, K. TSUCHIYA
1989 Volume 18 Issue 2 Pages
525-528
Published: April 15, 1989
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We developed a portable left ventricular assist device. An electromagnet which has decoupling springs to increase the energy conversion efficiency was chosen as the energy converter. The blood pump was pusher plate type. The armature of the electromagnet supplied the driving force to the pusher plate through the plate springs and links which are magnify the stroke of the armature. The maximum energy conversion efficiency of the electromagnet itself was 10%. The blood pump driving mechanism was 1.4Kg in weight. The total energy conversion efficiency was 6%. The total system can be driven for 52 minutes by the Ni-Cd battery which had the electric energy of 15wh.
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S. FUKUNAGA, Y. HAMANAKA, H. ISHIHARA, T. SUEDA, K. KANEHIRO, T. MATSU ...
1989 Volume 18 Issue 2 Pages
529-532
Published: April 15, 1989
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A pusher plate type artificial heart with an ultrasonic motor is assembled and examined. Two kinds of the artificial heart drivers are made, one equipped with a crank chain to convert rotation of the motor into reciprocation of the pusher plates, the other with a plate cam. The percentage systole of the crank chain type driver is fixed at 50%, while that of the plate cam one is designed at 40%. The two sacs, blood chambers, are 51mL (left) and 44mL (right) in volume and are made of polyurethane rubber. Bjork-Shiley monostrut valves are placed at the inflow and outflow of the sacs. The main body of the driver is made of aluminum alloy and carbon steel. The weight of the artificial heart is about 800g. The artificial heart worked at the driving rate of 57-95bpm with a flow rate of 2.3-4.1L/min during mock test. Good circulatory assistance is observed by an animal experiment with great satisfaction at this stage.
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K. KOSHIJI, K. MASUDA, E. SHU, T. UTSUNOMIYA, S. TAKATANI, T. TAKANO, ...
1989 Volume 18 Issue 2 Pages
533-536
Published: April 15, 1989
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An improved TET system for driving the pulsatile type artificial heart is obtained by taking into consideration the fluctuation of the load impedance with pulsation. For the case of using two pairs of coils in the TET system, which may be necessary when, for instance, transmitting a large power to rapidly charge the internal battery, the energy transmission efficiency of the system is analyzed and measured, and the temperature rises in the coils are also measured. A combined charging system of constant-current charging and trickle charging is employed in order to rapidly and safely charge the battery.
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-MINIATURIZATION AND IMPROVEMENT OF EFFICIENCY AND DURABILITY-
E. OKAMOTO, K. HOSOOKA, T. YAMAGUCHI, Y. MITAMURA, T. MIKAMI
1989 Volume 18 Issue 2 Pages
537-540
Published: April 15, 1989
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Efficiency and durability of an implantable motor-driven artificial pump have been improved by using polyimide bushes instead of linear ball-bearings. And also we have developed a miniature (volume of 350cc), low power consumptive control system including a transcutaneous energy transmission system. In-vitro experiment showed efficincy increased to 10.8% from 8.3% of the proto-model and excellent durability.
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[in Japanese]
1989 Volume 18 Issue 2 Pages
541-542
Published: April 15, 1989
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T. AIZAWA, J. NINOMIYA, T. SHOJI, Y. NOSÉ
1989 Volume 18 Issue 2 Pages
543-546
Published: April 15, 1989
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Newly developed compact portable centrifugal pump for assist circulation has been evaluated as to its basic properties and performance in vitro and in vivo tests. With the adoption of rotary sealing, the pump attained noleakage running over 200 hours under the condition of 5000rpm and outlet pressure of 120mmHg in vitro tests. It also showed acceptably small extent of hemolysis under the same condition. However in animal tests employing adult dogs, unacceptable hemolysis was observed especially when out flow of the pump was considerably reduced due to high artery pressure and poor blood supply to the pump, whereas LAP, CVP, AP and RBC, WBC, PLT, Ht, erythrocyte fragility (EF) remained almost constant. Further improvement and long term animal tests are necessary to prove its feasibility for clinical application.
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M. ENDO, S. AOMI, H. TUCHIDA, A. HASHIMOTO, H. KOYANAGI, M. KUSAKABE
1989 Volume 18 Issue 2 Pages
547-550
Published: April 15, 1989
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In cases where a cardiac assist device becomes urgently necessary in the ICU, a time loss occurs in setting up the extracorporeal circulation by the air driving-LVAD. We have experienced 2 long survival cases through an assist deivice using a Bio-pump after cardiac resuscitation in the ICU. And, consequently, these were all with heparinization. This time we developed an all nonthrombogenic-circuit and centrifugal pump free from heparinization.
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T. SHIROYAMA, T. AKAMATSU, H. FUKUMASU
1989 Volume 18 Issue 2 Pages
551-554
Published: April 15, 1989
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The authors have been developing a nutating centrifugal blood pump, so called, Tea-Spoon Pump which avoids the seal problem of conventional centrifugal blood pump. By careful and refined design of profile and size of spiral inlet, outlet diffuser and cudgel impeller, pump performance and efficiency have been much improved. At pump working conditions of flow rate 6l/min and pressure 100mmHg, necessary rotational speed of impeller is lowered fran 3000rpm down to 2500rpm and the efficiency is raised from the previous 35% up to 50%. These two effects must reduce hemolysis. For red blood cell, we sustitute micro dye capsules which are elements of pressure sensing sheet of industrial use. The releaseded dye concentration is related to shear stress in the flow field and this capsule proved to be used for hemolysis test of centrifugal blood pump.
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H. HODA, Y. TAENAKA, H. TAKANO, M. KINOSHITA, E. TATSUMI, A. YAGURA, H ...
1989 Volume 18 Issue 2 Pages
555-559
Published: April 15, 1989
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Six types of inlet conduit of VAD were designed based on the anatomical data obtained from MRI of the normal individuals, mitral stenosis, and cardiomyopathy patients. A L-shaped conduit, which was bent as the configulation of the right atrium, was applicable to the insertion via the right pulmonary vein. The ventricular apex cannula needed opposite turns when the conduit was guided to the abdominal wall. A simple L-shaped conduit was applicable to the other insertion sites. These newly desighned conduits should prevent the inflow obstruction of the pump.
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Y. HAMANAKA, S. FUKUNAGA, H. ISHIHARA, T. SUEDA, Y. MATSUURA
1989 Volume 18 Issue 2 Pages
560-563
Published: April 15, 1989
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An implantable artificial heart was made using ultra-sonic motor which was lighter and smaller than the other motor. The design of the artificial heart for the implantation in the calf was studied. The ultra-sonic motor used in the artificial heart was USR-60-4-100 type made in Shinsei Industry, worked at the driving rate of 40-120rpm controlled electrically from outside. A crank made the one-directional revolution into the reciprocation, then two sacs inside the driver were pushed alternately by the pusherplates at the both ends of the crank. Two sacs, blood chambers, were made of polyurethane rubber. Björk-Shiley valves were placed at inflow and outflow of the sacs. Design of the artificial heart was studied using the model of atrial cuffs and arterial grafts for the implantation of the artificial heart in the calf. The distance between left and right inflow orifices of the sacs was too far, and the position of the outflow orifices was not adequate for the connection to great vessels. It became obvious that the design of the casing of the artificial heart should be changed simultaneously.
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[in Japanese]
1989 Volume 18 Issue 2 Pages
564
Published: April 15, 1989
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K. MAKI, O. MASAYOSHI, I. MASANOO, N. KAZUO
1989 Volume 18 Issue 2 Pages
565-570
Published: April 15, 1989
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The effects of left ventricular, assist device (LVAD) were studied experimentally in swines with cardiogenic shock due to acute myocardial infarction (AMI). Hemodynamics, EVR, LV max dp/dt, TTI and PVR were precisely evaluated in early stage after the initiation of the LVAD. Twenty-one swines were used in this experimental study and AMI was made by means of multiple ligations of the coronary arteries. Ventricular fibrilation occurred in 11 out of 21 swines after production of AMI and mean percentage of the infarcted area of LV free wall by means of NBT staining was 63%. By application of LVAD for the profound failing heart, a significant decrease of LV max dp/dt and TTI and a marked increase of EVR were observed. Besides a diminished left ventricular preload and afterload, a decrease of the cardiac work and an increase of the coronary blood flow could be obtained. During LVAD a satisfactory systemic circulations support could be maintained in aortic pressure more than 90mmHg. However right cardiac iunction was not changed even by utilization of LVAD. The limitation of the effect of left ventricular assist by only LVAD was in about 1800 dyne sec cm-5 from the view of pulmonary vascular resistence (PVR).
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K. FUKAMACHI, Y. NAKAMURA, K. KISHIZAKI, T. ASOU, Y. TOSHIMA, M. OE, A ...
1989 Volume 18 Issue 2 Pages
571-574
Published: April 15, 1989
Released on J-STAGE: October 07, 2011
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To assess the effects of left ventricular assist device (LVAD) in mode of synchronous systolic driving, left ventricular assistance (from left atrium to the ascending aorta) was performed in both systolic driving mode (SD) and diastolic driving mode (DD) in seven anesthetized dogs. We measured assisted flow, left ventricular stroke work and coronary arterial flow in both driving modes. Assist flow was significantly increased in SD than DD (p<0.05) and stroke work was significantly decreased in SD than DD (p<0.01). Coronary arterial flow was not changed in both driving modes. We concluded that SD was effective in terms of left ventricular unloading.
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K. NISHIMURA, H. HIROSE, H. OGINO, K. JINNO, H. OKABAYASHI, S. NOMOTO, ...
1989 Volume 18 Issue 2 Pages
575-578
Published: April 15, 1989
Released on J-STAGE: October 07, 2011
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Among 12 patients with LVAD, the withdrawal catheters were placed into the left ventricle through the apex in 3 patients (LV group), and into the left atrium in 9 patients (LA group). Three patients in the LV group and two in the LA group were successfully weaned from LVAD, and consequently one in the LV group could be survived. Although a ventricular withdrawal method has problems of bleeding, additional myocardial damage, and inflow disturbance, it has several advantages compared with an atrial method.: more effective reduction of LV afterload, less stagnation of blood flow, no disturbance of closing the sternum, available even in patients with mild AR, and no occurence of shunt through foramen ovale. Thus, LVAD with a ventricular withdrawal method is more effective in patients with the profound heart failue.
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-Mechanical driving mode and hemodynamic factor-
Y. ORIME, T. HASEGAWA, S. KITAMURA, H. RIKUKAWA, S. SHINDO, M. SHIONO, ...
1989 Volume 18 Issue 2 Pages
579-582
Published: April 15, 1989
Released on J-STAGE: December 02, 2011
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In our clinical 11 cases of LVAD, the relationship between pump flow and mechanical driving mode, hemodynamic factor was studied retrospectively. And the managment to increase pump flow was considered. To obtain satisfactory pump flow (≥2.2l/min), positive pressure was rised to 200-250mmHg and negative pressure, 20-40mmHg, and S/D ratio, duration time were operated in 30-40%, in 200-250msec. As evaluation of hemodynamics, high CVP and SVR had tend to decrease pump flow, in contrast, high PCWP had tend to increase pump flow. In order to increase pump flow of LVAD, mechanical driving mode was thought to be have to set as above described mode, and vasodilator administration, volume loading, and prevention & treatment of right ventricular failure (catecholamine, RVAD, etc.) was necessary.
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[in Japanese]
1989 Volume 18 Issue 2 Pages
583
Published: April 15, 1989
Released on J-STAGE: October 07, 2011
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T. YAMBE, S. NITTA, Y. KATAHIRA, T. SONOBE, M. TANAKA, N. SATOH, M. MI ...
1989 Volume 18 Issue 2 Pages
584-587
Published: April 15, 1989
Released on J-STAGE: October 07, 2011
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To assess effects of LVAD pumping on renal circulatory condition, RSNA and hemodynamic parameters were detected in 7 acute animal experiments. RSNA was significantly inhibited in its frequency and amplitude with both co-pulsation (COP) and counter pulsation (CP) modes compared to off-LVAD especially in CP mode. It is concluded that RSNA measurement is very useful to evaluate the renal circulation in the sence of vascular impedance which affects to cause multiple organ failure (MOF) by increasing arterial impedance.
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T. OKAMOTO, T. MASE, H. TAKAGI, T. TAKAGI
1989 Volume 18 Issue 2 Pages
588-591
Published: April 15, 1989
Released on J-STAGE: October 07, 2011
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Baby size left ventricular assist device has been developed and tested in our laborarory in dogs. The device has the chamber of 6ml, 5ml, and 3ml in capacity and the valve of 4mm in inner diameter. Left atrio-aortic bypass was performed in 13 dogs. The results obtained were that the thrombus formation was frequently found at the tip of the metal connecter, though no thrombus formation was found in valve.
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K. OHTAKI, K. SAKAI, T. TANABE, K. HOSOOKA, T. MATSUMOTO, Y. MITAMURA
1989 Volume 18 Issue 2 Pages
592-595
Published: April 15, 1989
Released on J-STAGE: October 07, 2011
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The effect of MD805, a synthetic thrombin inhibitor as anticoagulant after implantation of left ventricular assist device was investigated. Dose of the ND805 was 20mg/day and 50mg/day. Prothrombin time and partial thromboplastin time prolonged in MD805 group more than no MD805 group. There was no difference between MD805 group and no MD805 group on the changes of platelets, fibrinogen, antithrombin-III and FDP. In MD805 group, infarct size of the kidney was decreased and there was few platelets on the blood contact surface of the pump. It is expected that MD805 reduce the dose of heparin.
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-A COMPARATIVE STUDY OF ASYNCHRONOUS PULSATILE, SYNCHRONOUS PULSATILE, AND NONPULSATILE LEFT HEART BYPASS.-
Y. KANAMORI, H, TANABE, T. SIMONO, I. YADA, M. KUSAGAWA
1989 Volume 18 Issue 2 Pages
596-600
Published: April 15, 1989
Released on J-STAGE: October 07, 2011
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We investigated the effects on cardiac performance of the left heart bypass (LHB). Three different LHB mode were used in Mongrel dogs: asynchronous pulsatile, synchronous pulsatile, and nonpulsatile mode. In these modes, the pump flow was changed and then changes in AoSP, LVSP, LAP, CO, PTB, EVR and LVW was simultaneously measured, In asynchronous pulsatile mode the phase analysis was used. The results obtained in these experiments were 1) In high LHB flow, the nonpulsatile LHB was more useful to maintain flow and more effective to reduce the cardiac work than other modes of LHB. However there was no difference between the effects on the cardiac performance when the LHB flow was increased higher. 2) In contrast, when the LHB flow was low, no differential effect were observed between the hemodynamic parameters. Thus, it is concluded that although the cardiac work was reduced in all modes of LHB when the bypass flow was maintained high, the nonpulsatile LHB showed the best performance of all modes of LHB.
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[in Japanese]
1989 Volume 18 Issue 2 Pages
601
Published: April 15, 1989
Released on J-STAGE: October 07, 2011
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Y. ABE, K. IMACHI, T. CHINZEI, K. MABUCHI, K. MAEDA, K. IMANISHI, T. Y ...
1989 Volume 18 Issue 2 Pages
602-606
Published: April 15, 1989
Released on J-STAGE: October 07, 2011
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The separate circulation with artificial heart, in which the natural heart fed upper body and the artificial heart (AH) fed lower, was made. The following result were obtained with the change of AH driving condition; 1) no correlation between total blood flow and central venus pressure, 2) no correlation between total blood flow and heart rate, 3) the correlation between upper peripheral resistance and upper blood flow was not so changed, but the correlation between lower peripheral resistance and lower blood flow changed in groups. To control with peripheral resistance function was indicated to be suitable for more adequate control of AH.
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T. SHIMOOKA, T. KIMEZAWA, Y. MITAMURA, T. YUTA
1989 Volume 18 Issue 2 Pages
607-610
Published: April 15, 1989
Released on J-STAGE: October 07, 2011
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The single or multi-controlled variables adaptive controller for an air driven assist pump was investigated. The LV bypass pump is driven on counterpulsation. The controller consists of a parameter estimator and adaptive controller. The second order time series model and least-square estimation method are used to estimate the system parameters. Based on the estimated parameters, the controller predicts controlled variables such as blood pressures in steady state. And the control input, vacuum pressure, is adjusted so that the performance index is minimum. Feasibility of the controller was demonstrated by computer simulations. The controller produced the desired responses for against the sudden change in the circulatory condition.
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