Scientific Exhibitions

Exhibition Address List

1. Pneumatic Driving Unit for Ventricular Assist and Intra-Aortic Balloon Pump (IABP) Aisin Human Systems Co. Ltd. 2-3 Showa-cho, Kariya, Aichi 448, Japan

2. Baxter Novacor Wearable Electrical Left Ventricular Assist System (LVAS) Baxter Limited Novacor Project, Product Development, Cardiovascular Group 4 Rokuban-cho, Chiyoda-ku, Tokyo 102, Japan

3. DeBakey Ventricular Assist Device (VAD) Eiki Tayama Department of Surgery, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA

4. The Chang Heart Assist Device - An Inexpensive "Bridge" System CHAD Research Laboratories PO Box 264, Surry Hills, NSW 2010, Australia

5. Eccentric Roller Type Artificial Heart Shintaro Fukunaga The First Department of Surgery, Hiroshima University School of Medicine, 1-2-3 Kasumi, Minami-ku, Hiroshima 734, Japan

6. Totally Implantable Motor-Driven Assist Pump System Eiji Okamoto Department of Electronic and Information Engineering, Hokkaido Tokai University, 5-1-1-1 Minamisawa, Minami-ku, Sapporo, Hokkaido 005, Japan

7. Centrifugal Pump with a Magnetically Suspended Impeller: Kyoto - NTN Pump Kazunobu Nishimura Department of Cardiovascular Surgery, Kyoto University Faculty of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606, Japan

8. Artificial Hearts Developed at the National Cardiovascular Center, Osaka, Japan Yoshiyuki Taenaka, Tom Masuzawa, and Eisuke Tatsumi Director, Department of Artificial Organs Research Institute, National Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, Osaka 565, Japan

9. Intraventricular Artificial Heart (Iva-Heart) Sun Medical Technology Research Corp. 1-3-11 Suwa, Suwa, Nagano 392, Japan

10. New Developments of the Moving-Actuator Type Total Artificial Heart Byoung Goo Min Chairman and Professor, Department of Biomedical Engineering, Seoul National University Hospital, 28 Youngun­Dong, Chongno-Ku, Seoul 110-744, Korea

11. Linear Pulse Motor-Driven Total Artificial Heart System: Kuniko III Hajime Yamada Professor, Department of Electrical and Electronic Engineering, Faculty of Engineering, Shin shu University, 500 Wakasato, Nagano 380, Japan

12. The HeartMate Vented Electric Left Ventricular Assist System Thermo Cardiosystems Seidler Bernstein Inc. 215 First Street, Cambridge, MA 02142, USA

13. Tohoku University Pneumatically Driven Total Artificial Heart (TAH) and Totally Implantable Ventricular Assist System Using a Vibrating Flow Pump (VFP) Tomoyuki Yambe Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-cho, Aoba-ku, Sendai, Miyagi 980-77, Japan

501

502 Scientific Exhibitions

14. TOW NOK Component System III Heart Lung System, A VECOR AFFINITY Oxygenation Systems Tonokura Ika Kogyo Co. Ltd. 5-1-13 Hongo, Bunkyo-ku, Tokyo 113, Japan

15. New Concept of the Artificial Heart Kou Imachi Department of Biomedical Engineering, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan

Scientific Exhibitions

1. Pneumatic Driving Unit for Ventricular Assist and Intra-Aortic Balloon Pump (IABP) (Aisin Human Systems Co. Ltd.)

503

The CORART 104 is a multipurpose pulsation-type driving unit which can be applied to left and right ventricular assistance simultaneously and also to intra-aortic balloon pumping. The driving unit has a compressor, vacuum pump, and battery built in, and, furthermore, provides a remote controller and a back-up unit against an emergency. As a distinctive feature, air pressure is accurately controlled with a high-speed electromagnetic valve developed by Aisin Seiki Co. Ltd.

The CORART BPI, a new generation IABP, provides beat-to-beat optimization and automatic control for timing and volume of balloon inflation/deflation even in patients with severe tachyarrhythmias. With the sensored AISIN balloon catheter, the system is automatically driven by one-switch operation, and provides the potential for enhanced circulatory support to the sickest patients, reducing IABP staffing requirements in the coronary care unit.

Fig. 1. COR ART 104 Fig. 2. Back-up unit Fig. 3. CORART BPI (IABP drive unit) Fig. 4. Sensored IABP catheter

2 3

4

2

504

2. Baxter Novacor Wearable Electrical Left Ventricular Assist System (LV AS) (Baxter Limited)

Scientific Exhibitions

Following its first successful clinical application as a bridge to heart transplantation at Stanford University Medical Center in 1984, the Baxter Novacor LV AS has been used widely at more than 52 medical institutions throughout the United States, Europe, South America, and Japan. A total of 491 patients have received implantation of the device, and as of October 1996, the cumulative supporting period has exceeded 88 years . The longest supporting period (797 days) with the Novacor LV AS has been reported at Berlin German Heart Center in Germany, following which the patient was discharged. In 1992, conversion from the conventional console-type control system to the battery-powered wearable compact controller made it possible for the patients to move around freely, and thus has remarkably improved their quality of life. In 1994, the CE Mark for Europe was granted, which made sales of the device in Europe possible. In 1996, clinical investigation was started in Japan also.

The operating principle of the Baxter Novacor LV AS is simple. The pump sack is pressed by a pair of electromagnetic solenoids, and as the result the blood is ejected. Blood enters the pump freely by de-energizing, and thereby neutralizing, the solenoid. Ejection timing is achieved by synchronized counterpulsation to the natural heart.

Fig. 1. Evolution of Novacor Left Ventricular Assist System (LVAS)

Fig. 2. Novacor wearable LV AS Fig. 3. Implantable blood pump Fig. 4. Uncovered blood pump

3

4

Scientific Exhibitions

3. DeBakey Ventricular Assist Device (VAD) (Baylor College of Medicine)

505

An implantable axial flow ventricular assist device has been under development as a joint project between the Baylor College of Medicine and NASA/Johnson Space Center. The components of the pump consist of a spinning inducer/impeller with a fixed flow straightener and diffuser residing within a flow tube. Magnets are installed in the impeller, and this impeller is rotated by the brushless motor stator. Computer Aided Design (CAD), Computer Aided Manufacturing (CAM), and Computer Aided Engineering (CAE) were aggressively applied for prototype fabrication and optimization. More than 50 configurations have been fabricated and tested. To date, the pump has been optimized in terms of hydraulic efficiency, hemolysis, and thrombosis. The pump requires less than 10 watts to deliver 5l/min against 100mmHg at 10000-11 000 rpm. A Normalized Index of Hemolysis of less than O.003mg/lOOI has been achieved. Several models have accomplished completely thrombus-free performance after 2 weeks' ex vivo implantation. Following the success of the ex vivo experi­ments, a series of in vivo experiments has been initiated aiming for 6 months' thrombus-free implantation.

flow SIr;ughlcnc:r

Flow -----i>

Fig. 1. DeBakey ventricular assist device (V AD). The small size (25 mm x 25 mm x 35mm) enables the device to be implanted in either a child's or an adult's chest cavity. The pump can provide 5l/min against 100mmHg with less than 10 watts of electri­cal power

Fig. 2. The schematic drawing of the DeBakey VAD. The flow is created by rotation of the impeller, which is supported by the flow straightener and flow diffuser. The magnets are installed in the inducer/impeller

Fig. 3. For the prototype, Computer Aided Design (CAD), Computer Aided Manufacturing (CAM), and Computer Aided Engineering (CAE) were aggressively applied. These technologies shortened the design cycle time and resulted in an optimized device. More than 50 configurations have been fabricated and tested

Fig. 4. Ex vivo implantation in calves. Several models have already achieved 2 weeks' implantation without thrombus formation in the pump. Following this success, a series of in vivo experiments have been initiated with the goal of 6-month, thrombus-free implantation

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506 Scientific Exhibitions

4. The Chang Heart Assist Device - An Inexpensive "Bridge" System (CHAD Research Laboratories)

Ventricular assist devices (V ADs) for "bridge to other therapy" are good candidates for lower-cost technologies, particularly in the areas of pump fabrication and valve and driver design. With the advent of less-expensive V ADs should come increasing willingness of clinicians to use these devices in cases where pharmacologic or intra-aortic balloon support is currently employed.

The Chang Heart Assist Device (CHAD) has been designed for ease of manufacture, and uses injection moulding for the rigid case and valve housings, and vacuum forming methods to produce the flexing diaphragm. All blood-contacting surfaces are solution-coated with a biocompatible polyurethane following assembly, to provide a continuous smooth layer. The blood pump incorporates integral valved conduits with ball occluders which provide good central flow characteristics to enhance the formation of a persistent "spiral vortex" within the pumping chamber.

A self-contained pneumatic driver has been designed which features a colour touch-screen interface. Multiple parameters are monitored by both main and backup microprocessors allowing fuzzy logic control of driving parameters and fault detection. This driver is made from stock components and is assembled onto a rigid chassis, which allows easy assembly and keeps all the components in tight and precise alignment whilst taking up all reaction forces.

Fig. 1. Self-contained driver unit with touch-screen user interface Fig. 2. Mechanical driver assembly featuring integral chassis Fig. 3. "Spiral vortex" ventricular assist device (V AD) concept with integral ball valves

Scientific Exhibitions

5. Eccentric Roller Type Artificial Heart (Hiroshima University)

507

Toward a completely implantable total artificial heart system, we have designed an eccentric roller type artificial heart. Blood chambers are made of silicone rubber and are toroidal in shape, and the actuator of the artificial heart is a drum-type eccentric roller, as shown in Fig. 1. The main characteristics of the artificial heart are that it discharges blood in pulsatile mode and that it requires no reversing of the motor. We tested the actuator with an overflow-type circulatory system of 100mmHg afterload. It worked at the roller speeds of 50, 100, and 150rpm producing outputs of 1.7, 3.7, and 5.4I/min, respectively, as shown in Fig. 2.

Silicone Trileaflet Valve for Artificial Hearts. Silicone trileaflet valves were developed for use in the artificial heart. The valves and the blood chamber are made en bloc

using a die caster. The blood chamber is placed in a casing and is driven by a pneumatic artificial heart driver, as shown in Fig. 3. In an overflow-type circulatory system, the maximal flow of 6.31/min was achieved at a rate of 80 bpm, as shown in Fig. 4. The pressure gradient across the silicone valves was slightly greater than that across the existing valves for clinical use. The device has worked well for eight weeks in the circulatory system.

Fig. I. Toroidal silicone blood chamber (left) and the eccen­tric roller squeezing the blood chamber (right)

Fig. 3. Cross-section of the silicone trileaflet valve (left) , valve-integrated blood chamber (center), and external view of the ventricular assist device (right)

Q) UI­- c: ::::1 . -C.E """':'"::3 0-o

iI'(p • • _ r~_u·. _ _ . ..-,-._ .·r_ ........ ~. ___ . __ -,. (a) 50rpm (b) lOOrpm (e) 150rpm

Fig. 2. Cardiac output (c. 0.) of the eccentric roller type artificial heart: upper, instantaneous flow rate; lower, mean flow rate

6.50-,--------------,

C 6.00-E ~ 5.50

~ 5.00 ;: o 4.50-iI

4.00

3.50+-----,.------.,----.-----i o 50 100 150 200

Driving rate (bpm)

Fig. 4. Relationship of flow rate and driving rate of the ventricular assist device

508

6. Totally Implantable Motor-Driven Assist Pump System (Hokkaido Tokai University)

Scientific Exhibitions

We have been developing a totally implantable motor-driven assist pump system that consists of a transcutaneous energy transmission system, a motor-driven assist pump, and a bidirectional optical telemetry system. The motor-driven assist pump consists of a brushless direct current motor driving a ball-screw and a pusher-plate-type blood pump. The ball screw converts high-speed bidirectional rotational motion of the motor into recti-linear movement of the pusher-plate.

Concurrently, we have also been developing polytetrafluoroethylene (PTFE)-coated ball-bearings to increase the endur­ance of the motor-driven assist pump. The goal of the PTFE-coated ball-bearings is two years' life in a humidity of 100% without any lubricant. The PTFE-coated ball-bearing system consists of stainless steel inner and outer rings, a stainless steel cage, and stainless steel balls. The raceways on both the rights and the cage are coated with PTFE (5 !lm) as a solid lubricant. For verification of its endurance, the PTFE-coated ball-bearing prototype has been tested in a bearing test system for 551 days (as of November 18, 1996). By monitoring results of the power of particular frequencies in sound and vibration signals from the ball-bearings, we have not detected any sign of deterioration of the bearings.

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RUBBER MAGNET

BLOOD PUMP

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STATOR

~~~~ll- MAGNET RING

BALL-SCREW

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Fig.2. Motor-driven assist pump, implantable con­troller, and its compliance chamber. The motor­driven assist pump displaces a volume of 350ml and weighs 790 g. The pump stroke volume is 65 ml

Fig. 1. Cross-sectional drawing of the motor-driven assist pump

o 2 3 4 5 em

Fig. 3. Polytetrafluoroethylene (PTFE)-coated ball-bearing system

Stainless Steel+ PTFE Coating

Outer Ring

Cage

Ball

Basic Dynamic Load Capacity 77kgf

Basic Static Load Rating 100kgf

Number of Balis 24

StaInless Sleel Ball

Stainless Sleel PTFE CoatIng

e---- ------ 4 ------ -

i . N ." .- .+-- M N

i e e 1 _______ _

-----------Basic Dynamic Load Capacity 68kgf

Basic Static Load Rating 94kgf

Number of Balis 21

Fig. 4. Constitution of PTFE-coated ball-bearing system. The raceways are coated with PTFE as a solid lubricant. Units are mm

Scientific Exhibitions

7. Centrifugal Pump with a Magnetically Suspended Impeller: Kyoto - NTN Pump (Kyoto University and NTN Corporation)

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A centrifugal pump with a magnetically suspended impeller has been developed in Kyoto University in collaboration with NTN Corporation. The pump is composed of three parts: a motor unit, a pump housing, and a magnetic bearing. The pump housing has an impeller inside that pumps blood flow in and out. The rotor of the motor and the corresponding impeller have 24 pairs of permanent magnets that produce magnetic attraction. On the opposite side of the impeller, electromagnets produce contrary magnetic force against the permanent magnets so as to float the impeller inside the casing. The magnetic bearing contains three electromagnets and gap sensors which detect the distance between the impeller and the electromag­nets so that any instability of the impeller can be actively controlled. The hemolysis test showed that this pump was better than the Biomedicus pump with respect to destruction of blood components. Chronic animal experiments are in progress using sheep in which the pumps have been extracorporeally placed. To date, seven sheep have undergone implantation of the pumps and the longest survival was 46 days. The pump flow rates during the experiment were 2.S-S.01/min under a pressure head of 100-140mmHg. The implantable version of the Kyoto-NTN pump is a promising device for long-term clinical use.

Fig. 1. Overview of a :urrent version of the Kyoto-NTN pump. The :mmp is designed as an Implantable left ventricu­ar assist system

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\ !., !! .. ,II, II, .'1"1"::

Fig. 2. Components of the Kyoto-NTN pump

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Fig. 3. Cross-sectional view and blueprint of the pump

Fig. 4. Chronic animal experiment using sheep

510 Scientific Exhibitions

8. Artificial Hearts Developed at the National Cardiovascular Center, Osaka, Japan (National Cardiovascular Center)

Two types of electric artificial heart have been developed for long-term use at the National Cardiovascular Center, Osaka, Japan. One is a centrifugal pump (NCVC-2) with a unique structure for chronic support. The pump is driven by magnetic coupling and has no shaft for rotation, no seal around the rotating part, and a balancing hole at the center of the impeller and the thrust bearing. The pump ran for more than a year as a left heart bypass in a chronic animal experiment.

The second device is a totally implantable electrohydraulic (EH) artificial heart. The components of the system are diaphragm-type ventricles, an intracorporeal and separately placed regenerative pump as an EH actuator, flexible stainless steel tubes to connect these two parts, an externally coupled transcutaneous energy transfer system, a transcutaneous optical telemetry system, an internal battery, and an internal control-drive unit. This device is now being tested in a chronic animal experiment.

Fig. 2. A totally implantable electrohydraulic (EH) artificial heart system 1. EH blood pumps: implantable in 50-70kg animals

Fig. 1. NCVC-2 type centrifu­gal pump for long-term use

- Pump output performance: up to 81/min driven with transcutaneous energy transfer (TET) system - Efficiency: 10% at 61/min of cardiac output (within 4°C temperature rise)

2. TET system: 80% d.c.-d.c. efficiency in a chronic animal experiment - Internal rectifier: 74 x 55 x 20mm - External switching circuit: 59 x 80 x 31mm

3. Transcutaneous optical telemetry (TOT) system: stable positioning and generous allowance of sensor displacement 4. Internal battery: 120ml and 280g (Li ion battery) 5. Internal control drive unit: 70 x 70 x 20mm

Scientific Exhibitions 511

9. Intraventricular Artificial Heart (Iva-Heart) (Tokyo Women's Medical College, University of Pittsburgh, Waseda University, and Sun Medical Technology Research Corp.)

We have developed an intraventricular artificial heart. This device is an axial flow blood pump for use as an implantable left ventricular assist device (LVAD). The blood pump has a recirculating purge system with a mechanical seal. This is a break­through system, where purge fluid circulates within the pump and motor to minimize blood clotting and heat generation in the seal area of the pump rotary shaft. This purge system results in little leakage or clotting of blood during long-term use. Diamond-like carbon (DLC) coating is an original surface treatment method which has excellent antithrombogenicity.

The pump was implanted in a calf (168 days of support). It was inserted into the left ventricular (LV) cavity via the LV apex and the outlet cannula was passed antegrade across the aortic valve without any difficulty. Blood was withdrawn from the LV cavity through the inlet ports at the pump base, and discharged into the ascending aorta.

Pump function and hemodynamics remained stable throughout the experiment. No cardiac arrhythmias were detected, even during treadmill exercise tests. The plasma free hemoglobin level remained in an acceptable range (<10mg/dl). Post mortem examination did not reveal any interference between the pump and the mitral apparatus. No major thromboembolism was detected in the vital organs.

guide vane

- outlet cannula

impeller

inlet port

(

DC motor

Fig. 1. Schema of blood flow

blood pump

reservoir

Fig. 2. Schema of recirculating purge system

purge inflow

groove be ring guide vane Impeller

blood guide vane

blood

groove bearing outflow cannula

mechanical seal

purge outflow

Fig. 3. Schema of pump mechanism

Fig. 4. Iva-Heart (prototype no.9) Materials Pump body, impeller, pump casing: titanium alloy Outlet cannula: silicon Motor casing: polytetrafluoroethylene (PTFE) Surface treatment: diamond-like carbon (DLC)

coating Pump weight: 170 g Impeller diameter: 13.9mm Shaft sealing: mechanical seal Purge consumption <lO cm3/day

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3

512

10. New Developments of the Moving-Actuator Type Total Artificial Heart (Seoul National University)

Scientific Exhibitions

The electromechanical total artificial heart (TAH) developed in Seoul National University Hospital was verified as accept­able for human implantation through several successful animal experiments.

In the last two years (1994-1996), the TAH has been re-designed to be small (600-650cm3 total volume), and lightweight (approximately 950g), as well as improved to overcome the three practical problems that faced the animal experiments. First, we implemented modifications to the blood pump housing to resolve the problem of anatomical compatibility through the construction of a 3-dimensional model of the TAH, the human thoracic cavity, and the large vessels, from magnetic resonance imaging (MRI) and computed tomography studies. Secondly, the intraventricular surface of the blood sacs was modified with fibrinolytic and anti-infective surface treatments. Thirdly, the regulation mechanism of cardiac output (CO) was improved by analyzing the measured pressure of the interventricular volume space (IVP). This was very beneficial, to achieve CO regulation in response to the physiological demand as well as the prevention of atrial collapse due to suction. As an accurate indicator hemodynamic status, the IVP was used to predict the preload condition.

The three improvements will assist in the application of the newly developed implantable electromechanical artificial heart for long-term implantation.

Fig. 1. The moving-actuator type total artificial heart (T AH) Fig. 2. The redesigned electronics assembly for an implantable total artificial heart Fig. 3. The new blood pump. Solid model of the energy conver­tor and rack gear of the Korean TAH (upper left); outer case assembled to this model (upper right); two blood sacs for the left ventricle and right ventricle assembled in the correct position (lower left); and solid model of assembled Korean TAH (lower right)

For the relationship between the imbalanced pump output and interrentricular space pressure, refer to Fig. 3 in the chapter by 10, this volume.

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Scientific Exhibitions

11. Linear Pulse Motor-Driven Total Artificial Heart System: Kuniko III (Shinshu University)

513

A human body model equipped with a linear pulse motor-driven total artificial heart (linear TAH) system has been developed and dubbed "Kuniko III." She has a linear TAH, a mock circl,llatory system, a drive control unit, and a transcutaneous energy transmission (TET) system. The systemic and pulmonary circulation have been improved in this new system. The linear T AH consists of a linear pulse motor, two pusher plates, two sac-type blood pumps, and four Jellyfish valves. The volume of the linear TAH is 580ml. The linear TAH pumps out the blood by expanding and compressing the blood pumps according to the reciprocating motion of the pusher plates attached at the mover of the linear pulse motor. The TET system is made up of a d.c.-a.c. inverter, a transcutaneous transformer utilizing amorphous magnetic fiber, and an a.c.­d.c. converter. The TET system transmits the electric energy from a d.c. power supply outside of her body to the linear T AH within her body without piercing the skin. The excitation frequency to the transformer is 120kHz. The pumping rate of the linear T AH is displayed on an outside pumping rate meter through a photo coupler.

Fig.2. Constitution of Kuniko III. T AH, total artificial heart

Fig. 1. External view of Kuniko III

~~--------~ ~ ________ ~J ~~ ________________ ~ _________________ ~J Y ~

Out ide the body kin In ide the body (acrylate)

Fig. 3. Block diagram of the transcutaneous energy transmission system in Kuniko III

514 Scientific Exhibitions

12. The HeartMate Vented Electric Left Ventricular Assist System (Thermo Cardiosystems)

The HeartMate vented electric blood pump is an implantable device that takes over the pumping function of seriously damaged or diseased hearts. The system comprises an implantable left ventricular assist device (LV AD), along with external power and control electronics. In addition, the system's lightweight, belt-mounted controller gives patients complete mobility. The LV AD features a blood pump and an integrally coupled, high-efficiency electric motor. This motor produces one eject cycle during a single revolution. When the eject is complete, the motor halts, permitting the pump to be refilled by the left ventricle.

The pump's unique textured blood-contacting surfaces encourage the deposition of a tightly adhered fibrin/cellular matrix, rich in a variety of cells, including endothelial cells. The resulting pseudo-neointima reduces the need for anticoagulation and may reduce the risk of thromboembolic complications.

Thermo Cardiosystems is a leader in the research and development of implantable left ventricular assist systems. Our air­driven HeartMate is the only implantable heart-assist device approved in the United States for commercial sale, and our electric system is under clinical evaluation to sustain patients awaiting transplant, and as an alternative to medical therapy for nontransplant candidates.

System -Controller

Air Vent

~.

~ _. LVAD

'i l Skin Line

Fig. 1. The HeartMate vented electric blood pump in situ. L VAD, left ventricular assist device

a b

Fig. 3. a Sintered titanium microspheres and b Cardioftex polyurethane

Fig. 2. The LV AD's high-efficiency electric motor

Fig. 4. HeartMate patient able to resume activities of daily living

Scientific Exhibitions 515

13. Tohoku University Pneumatically Driven Total Artificial Heart (TAH) and Totally Implantable Ventricular Assist System Using a Vibrating Flow Pump (VFP) (Tohoku University)

A pneumatically driven T AH system was developed using a silicone ball valve in a sac-type artificial blood pump. It can be mounted into the thoracic cavity of the healthy adult goat and may be able to produce enough blood flow for the systemic circulation. The blood sac was improved to generate round shaped blood streamline on the basis of fluid science studies. An electromagnetic rotating ball pump was shown in one exhibition (Fig. 1). The rotating ball pump was for the extracorporeal circulation. A model totally implantable ventricular assist system using a vibrating flow pump (VFP) was shown in the other exhibition (Fig. 2). The VFP may be built as a small-sized artificial heart, because of its short stroke volume with high­frequency driving. This system was totally implantable and was driven by a transcutaneous energy transmission system (TETS). The TETS, developed at Tohoku University, was made from copper line with spokewise-placed cobalt amorphous fibers. Electromagnetic radiation from outside was shut out and energy transfer efficiency was increased by using this seal with amorphous fibers.

Fig. 1. Pneumatically driven total artificial heart (T AH) and rotary ball pump

Fig.2. Totally implantable ventricular assist system in which a vibrating flow pump (VFP) is used

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516 Scientific Exhibitions

14. TOW NOK Component System III Heart Lung System, AVECOR AFFINITY Oxygenation Systems (Tonokura Ika Kogyo Co. Ltd.)

The latest version of our heart lung system, Compo, has made another step further to meet today and tomorrow's high demands of the operation room. Compo has been developed to be user-friendly as well as being friendly to the patient. Various messages can be displayed during the operation on a large screen liquid crystal display (LCD) monitor (option). With this monitor, the user can easily observe the necessary information. We have used our unique Q-shaped casing on the pump head. Our in-house experiment has confirmed that the Q-shaped casing has a far lower hemolysis level than the conventional U-shaped head casing. AVECOR Membrane Oxygenator AFFINITY The AFFINITY has been developed to meet all the demands for an oxygenator in today's cardiopulmonary bypass. A very high gas exchange performance with a small profile, a blood flow path with minimum blood shear and shunts, low pressure drop within the blood flow path; all of these features were made possible by using a highly sophisticated computational fluid dynamics program. The completely transparent housing employed for the product allows very high visibility of the blood flowing throughout the oxygenator. This high quality oxygenation system has an optional reservoir, both hardshell and a reservoir bag.

I'

Compo I

Fig. 1. Heart Lung System Compo III Fig. 2. Q-Shaped pump casing Fig. 3. AFFINITY Oxygenation System

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Scientific Exhibitions

15. New Concept of the Artificial Heart (The University of Tokyo)

517

The University of Tokyo has been developing an artificial heart (AH) since 1959. To date, many significant outcomes have been generated by out laboratory with new concepts in hardware and software. Typical new conceptual AH work includes development of the jellyfish valve, a polymer membrane valve, and the study of the lIR control method of the total artificial heart (TAH) in which the T AH goat itself controls cardiac output by changes in the total peripheral resistance. Using these technologies, we achieved the survival of a goat for 532 days with a pneumatically driven TAH in 1995. TAH research is now moving to ward a totally implantable TAH.

We exhibited two new conceptual AH systems, the undulation pump-TAH (UP-TAH) and the modified assist device (MAD). The UP-TAH is a very compact (75mm in diameter and SOmm long) TAH composed of two undulation pumps and two brushless DC motors. It could be implanted into the chest cavity of a goat weighing 42kg. The MAD is a percutaneously accessible ventricular assist device composed of a valveless single-port diaphragm-type pump and a cannula 6.5mm in diameter with a small inflow and outflow valve. It is driven pneumatically and can pump 2 to 3 Umin of pulsatile flow.

Fig. 2. The UP-TAH, the world's most compact TAH

Fig. 1. University of Tokyo exhibition booth Fig. 3. The MAD exhibited in a mock circulatory system

Key Word Index

lIR 34 1/R control method 313

Abiomed 217 Acoustic characterization 66 Acute animal experiment 21 Acute heart failure model 437 Acute myocardial infarction 217 Adaptive control 424 Adaptive pole assignment

method 424 Adaptive self-tuning proportional­

integral-derivative (PID) controller 59

Alternate ejection 8 Alumina ceramic 139 Angiogenesis 496 Antithrombogenicity 132 ARMA model 424 Arrhythmia 95 Arterial impedance 484 Arterial resonance 484 Artificial blood cells 482 Artificial heart 3,110,127,172,206,

295, 344, 370, 482 Artificial heart tests 487 Artificiallung 132, 148 Assist device 197 Assist device explantation 281 Assisted circulation 257 Atrial collapse 459 Atrial pressure 428 Autoantibodies 281 Axial flow ventricular assist

device 407 Azidophenyl functional group 467

Beta-cardiomyopathy 281 Bileaflet valve 353 Bioacceptance 103 Biocompatibility 361 Biointegration 103 Biomaterials 103 Biopassivation 103 Biventricular bypass system 445 Biventricular support 223 Bjork-Shiley tilting disc

prosthesis 348 Blood cell 471

Blood compatibility 118, 433 Blood pump 251 Blood-outside flow mode 382 Brain and spinal cord lesions 50 Bridge to transplant 217, 223 Bridge to transplantation 81,230,

235

Calcification 110 Calcified emboli 50 Cardiac assist 235, 248 Cardiac assistance 378 Cardiac output 331 Cardiac transplant 202 Cardiac valve prosthesis 110 CardioWest Total Artificial Heart

230 Cardiogenic shock 217,318 Cardiomyopathy 206, 210 Cardiomyoplasty 257, 496 Cardiopulmonary by-pass 464 Cell-biomaterial interactions 127 Central nervous system 34 Central venous pressure 313 Centrifugal blood pump 139, 401 Centrilobular necrosis 313 Chaos 308 Chaotic itineracy 308 Chronic heating 41 Circulatory support 476 Clinical evaluation 103 Closed impeller 401 Collagen III 281 Colored microsphere 437 Communications 370 Compliance 26 Complications 197 Composite biomaterial 152 Conductance 34 Contact angle 148 Contractility 269 Control 34 Control methods 370 Coronary blood flow 243 Counterpulsation 437 Creep rupture of polyacetal 348

DeBakey/NASA 407 Denervated heart 91

Design 417 Device surface temperature 41 Diagonal pump 441 Diastolic dimension 243 Direct drive 401 Dog 243 Durability testing 15 Dynamic cardiomyoplasty 243

Emax 378 Earthworm 471 Echocardiography 303 Efficiency 26, 344 Elderly 163 Electromechanical total artificial

heart 8 Endothelialization 127, 156 Epifluorescent video microscopy

118 Estimated maximum elastance 378 Extracorporeal membrane

oxygenation 190

Fatigue 248 Ferrofluids 482 Fibrin sealant 496 Finite element method 348 Flow regulation 459 Flow visualization tests 487 Fractal 308 Fractal dimension 374 Fracture and wear 348 Frequency 248 Fuzzy control 26 Fuzzy logic 459

Graphite 152

Heart 269 Heart assist device 437 Heart failure 172,257,441 Heart rate variability 374 Heart transplantation 81,91,197,

206, 223 HeartMate 163 Heat-induced angiogenesis 41 Hemoconcentrator 382

519

520

Hemodynamic power 323 Hemolysis 361 Hemosiderosis 313 Heparin bonding 132 Heparin-bonded materials 479 Heterotopic heart transplantation

95 Hollow fiber 382 Hypoperfusion 50

Idiopathic dilated cardiomyopathy 281

Imaging 464 Impeller pump 433 Implantable artificial hearts 41 Implantable assist device 337,

391 Implantable circulatory support 3 Implantable motor-driven left

ventricular assist device 445

Implantation into calves 396 In vitro strains 348 In vitro test 361 In vivo assessment 15 Inlet valve vortex generator 74 Internal organs 464 Interventricular pressure 59,428 Intra-aortic balloon pump 453 Intraventricular axial flow blood

pump 396 Ischemia-reperfusion

prevention 496 Ischemic heart disease 95

Jarvik 2000 Oxford System 172 Jellyfish valve 453

Kolomosov-Sinai (KS) entropy 308

Latissimus dorsi 243 Left ventricular assist device

(LV AD) 95, 163, 202, 223, 323, 374, 453

Left ventricular assist system 163, 303

Linear motor 21 Linear oscillatory actuator

(LOA) 417 Linear pulse motor 21 Long-term support 303 Low-temperature mechanical seal

337, 396 Lumbrokinase 467,471

Magnetic suspension 401 Magnetically suspended centrifugal

pump (MSCP) 391 Magnetically suspended motor 433

Mechanical assist device 81 Mechanical heart support 223 Mechanical heart valve 348 Mechanical reliability 433 Mechanical support 202 Microcirculation 318 Microembolus 361 Microphase separated structure

148 Microphone 66 Microporous structure 156 Mock test 21 Morbidity 476 Mortality 476 Motor current 459 Moving actuator 428 Moving actuator type total artificial

heart 59 MUltiple system organ failure 318 Multisystem organ failure 479 Multivariate analysis 476 Muscle damage 496 Muscle-driven 251 Myocardial O2 consumption 269

Neutrophil 464 Nonpulsatile circulation 295 Nonpulsatile flow 318 Nonthrombogenic coating material

148 Nontransplant 163 Norepinephrine 295 Novacor LV AD 206 Numerical model 361

Organ perfusion 441 Oscillating blood flow 484 Oxygen consumption 295 Oxygenator 382

Paediatric 190 Parameter optimization method

378 Pathological change 313 Patient selection 230 Penetrating micropores 156 Percutaneous access 453 Percutaneous cardiopulmonary

support (PCPS) 479 Permanent 163 Photochemical reaction 467 Planetary roller screw 8 Platelet 464 Platelet adhesion 118 Platelet antiaggregation effect

471 Pneumatic blood pump 445 Poly(BSMSIHEMA) block

copolymer 148 Polyethylene 139 Polyurethane 110, 118,467

Key Word Index

Polyurethane valve 8, 353 Polyurethane-polydimethylsiloxane

156 Postcardiotomy cardiogenic

shock 479 Postcardiotomy heart failure 476 Posttransplant exercise 91 Powder metallurgy 152 Pressure of interventricular volume

331 Pressure-volume relation 269 Profound heart failure 303 Prolonged extracorporeal membrane

oxygenation 132 Pulmonary hypertension 202 Pulsa tile flow 318 Pulsatile perfusion 323 Purification 471 Pusherplate blood pumps 8

Quality of life 210

Recovery of the heart 303 Reflection wave 484 Regional blood flow 437 Registry 190 Reliability 344 Remote monitoring 370 Replacement fibrosis 281 Roller screw linear actuator 251 Rotary blood pump 323, 337,

441

Sensorless preload and afterload detection 26

Sensorless system 391 Silicon coating 382 Silicone blood chamber 450 Silicone valve 450 Skeletal muscle 248 Skeletal muscle ventricle 257 Sound 66 Spray phase-inversion

technique 156 Surface modification 118 Sympathetic nerve 295 Sympathetic nerve activity 308

Thoratec V AD system 223 Thromboembolic complications

74 Thromboembolism 50 Thrombogenesis 361 Thrombus formation 110 Thrust characteristics 417 Time-frequency distribution 66 Titanium 152 Total artificial heart 21, 26, 34, 50,

66,235,313,331,417,424,428, 433,487

Key Word Index

Totally implantable 15 Totally implantable artificial

heart 401 Transcutaneous energy transfer 15,

344 Transplantation 172 Trileaflet valve 353, 450

Vacuum forming method 353

Valvular heart disease 95 Vascular resistance-based

control 424 Ventricle 269 Ventricular assist 344, 370, 459 Ventricular assist device 3, 15,

127,139,172,190,251,353, 450,487

Ventricular assist system (VAS) 391 Ventricular circulatory

assistance 217 Ventricular elastance 378 Vibrating flow pump 484

Waste heat dissipation 41 Water pressure 459 Wear debris 348 Wearable Novacor left ventricular

assist system 210

521