Compression cardiac assist devices (CCAD) wrap around the epicardial surfaces or the aorta, assisting the weakened heart to restore its function. The advantage of avoiding the contact with patient bloods makes them a kind of important cardiac assist devices. This article reviews the current status and future challenges of compression cardiac assist devices.
Heart-Assist Devices ; trends

After introducing and comparing the most typical of axial-flow blood pumps in the world, this paper discusses the future development of axial blood flow pumps.
Equipment Design ; Heart Ventricles ; Heart-Assist Devices

This paper presents a design of non-blood contacting pneumatic ventricle assistance device, which consisted of several parts, such as dual-cavity cardiac assistance cup, ventricle assistance controller, computer, vacuum pump, and air compressor. And the performance of the non-blood contacting pneumatic ventricle assistance device on mock circulation loop is introduced, which is very close to the normal cardiac output.
Equipment Design ; Heart Ventricles ; Heart-Assist Devices

As an important means of treating heart failure (HF), cardiac assist device has been widely used in clinic. This paper reviews the application status, existing problems and future development trend of cardiac assist devices, including the classification of cardiac assist devices, representative research achievements and indications of the assist devices. It also summarizes the biomechanical indexes of the heart and the new approaches and methods for treating heart failure, as well as the hemodynamic studies of cardiac assist devices in recent years. The research findings provide references for further optimization of cardiac assist device structure and clinical application of the device.
Heart Failure ; Heart-Assist Devices ; Hemodynamics ; Humans

OBJECTIVETo develop an inflow cannula of left ventricular assist implanted by blood vessel.

METHODSThe maximum inflow and properties against folding of 8 sorts of cannulae were measured in mimic extracorporeal circulation appliances and canines.

RESULTSThe maximum flow of the cannula increased, as the inner diameter became greater (P < 0.01) compared with each group. The maximum flow rate was (1.82 +/- 0.03) L/min, (2.44 +/- 0.03) L/min, (3.02 +/- 0.04) L/min, (3.31 +/- 0.03) L/min respectively for polyvinyl cannulae with wall thickness of 0.5 mm (PV 0.5 cannula) and inner diameter of 3 mm, 4 mm, 5 mm, 6 mm; (1.83 +/- 0.03) L/min, (3.07 +/- 0.04) L/min respectively for the polyvinyl chloride cannula with wall thickness of 1.0 mm imbedded by spring wire (PVCSW 1.0) and inner diameter of 3 mm and 5 mm; (1.82 +/- 0.02) L/min, 1.84 +/- 0.02 L/min for strengthened polyvinyl cannula with wall thickness of 0.8 mm (SPV 0.8) and inner diameter of 3 mm and polyvinyl cannula with wall thickness of 1.0 mm (PV 1.0 cannula) of inner diameter of 3 mm. There was no remarked statistical difference in vitro maximum flow among the four cannulae of 3 mm inner diameter in vitro. PVCSW 1.0 was showed the best antifolding property, PV 1.0 cannula good and SPV 0.8 and PV 0.5 unsatisfactory in properties against fold. There was no significant statistical difference between in vivo and in vitro maximum flow for PVCSW 1.0 and PV 1.0 cannulae of 3 mm inner diameter. But for SPV 0.8 and PV 0.5 cannulae of 3 mm inner diameter, there was a significant difference between in vivo and in vitro.

CONCLUSIONSPV 0.5 cannula and SPV 0.8 cannula are not suitable to clinical use. PV 1.0 cannula can be used in clinics. PVCSW 1.0 cannula is fully qualified for inflow conduit of left ventricular assist in surgery.

This paper uses AVR16 SCM, programming to achieve the software of PWM (pulse width modulation) control of intelligent H bridge chip LMD18200 driver of high speed DC motor, makes special speed tablet, obtains speed signal of high speed for photocoupler PC817, through the A/D conversion and processing circuit, and realizes the LED LCD digital display speed scheme. The driver for the pediatric ventricular assist device has been used at the laboratory trial, has high performance and wide application prospect.
Child ; Heart-Assist Devices ; Humans ; Software

Magnetic bearing has no mechanical contact between the rotor and stator. And a rotary pump with magnetic bearing has therefore no mechanical wear and thrombosis due to bearing. The available magnetic bearings, however, are devised with electric magnets, need complicated control and remarkable energy consumption. Resultantly, it is difficult to apply an electric magnetic bearing to rotary pump without disturbing its simplicity, implantability and reliability. The authors have developed a levitated impeller pump merely with permanent magnets. The rotor is supported by permanent magnetic forces radially. On one side of the rotor, the impeller is fixed; and on the other side of the rotor, the driven magnets are mounted. Opposite to this driven magnets, a driving motor coil with iron corn magnets is fastened to the motor axis. Thereafter, the motor drives the rotor via a rotating magnetic field. By laboratory tests with saline, if the rotor stands still or rotates under 4,000 rpm, the rotor has one-point contact axially with the driving motor coil. The contacting point is located in the center of the rotor. As the rotating speed increases gradually to more than 4,000 rpm, the rotor will detache from the stator axially. Then the rotor will be fully levitated. Since the axial levitation is produced by hydraulic force and the driven magnets have a gyro-effect, the rotor rotates very steadly during levitation. As a left ventricular assist device, the pump works in a rotating speed range of 5,000-8,000 rpm, the levitation of the impeller hence is ensured by practical use of the pump.
Equipment Design ; Heart-Assist Devices ; Magnetics ; instrumentation

Since 1995, four different types of artificial heart pumps and artificial valvo-pumps have been developed in Jiangsu University of China. Three types of heart pumps and valvo-pumps have been applied in animal experiments in University Texas, Medical Branch, USA and in Zhenjiang No.1 People's Hospital of China. The recently-developed UJS-IV pump is a totally implantable trans-ventricular and cross-valvular pump for emergercy treatments.
Equipment Design ; Heart Valve Prosthesis ; Heart, Artificial ; Heart-Assist Devices

Heart failure is one kind of cardiovascular disease with high risk and high incidence. As an effective treatment of heart failure, artificial heart is gradually used in clinical treatment. Blood compatibility is an important parameter or index of artificial heart, and how to evaluate it through hemodynamic design and
Heart Failure ; Heart, Artificial ; Heart-Assist Devices ; Hemodynamics ; Hemolysis ; Humans

Right heart failure is a relatively common complication after left ventricular assist device (LVAD) implantation. Severe right heart failure can be managed by temporary right ventricular assist device (RVAD) implantation. However, trans-sternal RVAD insertion requires a subsequent third sternotomy for cannula removal. Herein, we present a case of RVAD insertion via a left anterior mini-thoracotomy after LVAD implantation in a patient with alcohol-induced cardiomyopathy.
Cardiomyopathies ; Catheters ; Heart Failure ; Heart-Assist Devices ; Humans ; Sternotomy ; Thoracotomy