WO2021158141A1

WO2021158141A1 - Controlling blood flow in rotary pumps in mechanical circulatory support systems

Info

Publication number: WO2021158141A1
Application number: PCT/RU2020/000597
Authority: WO
Inventors: Георгий Пинкусович ИТКИН; Аркадий Павлович КУЛЕШОВ; Александр Сергеевич БУЧНЕВ; Александр Александрович ДРОБЫШЕВ; Михаил Сергеевич НОСОВ
Priority date: 2020-01-29
Filing date: 2020-11-11
Publication date: 2021-08-12

Abstract

The invention relates to medical technology, and more particularly to extracorporeal and implantable mechanical circulatory support (MCS) devices. Proposed is an MCS system comprising a rotary pump with a pump control unit, a pump inlet line for connection to the left ventricle of the heart and a pump outlet line for connection to the aorta via a vascular prosthesis. The pump inlet line contains a flow resistance that allows full opening of the lumen of the inlet line in the systole phase of the cardiac cycle and a reduction of the lumen of the inlet line in the diastole phase of the cardiac cycle. Proposed is an MCS method in which the proposed MCS system is used outside or inside the body in copulsation with the patient's heart. The proposed device can be used in artificial blood circulation machines, extracorporeal membrane oxygenation machines and biventricular heart bypass systems. The technical result consists in creating a physiologically pulsatile flow and pressure in the aorta and the pulmonary artery with the impeller of the pump rotating at a constant set speed, improving the fluid dynamics inside the pump, and minimizing blood trauma by reducing the area of contact between the blood and the foreign surface of an MCS.

Description

BLOOD FLOW CONTROL OF ROTARY PUMPS IN MECHANICAL SUPPORT OF BLOOD CIRCULATION

FIELD OF TECHNOLOGY

This invention relates to medical technology, in particular to extracorporeal and implantable mechanical circulatory support (BMC) devices based on the use of rotary pumps (PH) or non-pulsating flow pumps (NNP), can be used when conducting an auxiliary circulation. The invention also relates to heart-lung machines (AIC) and extracorporeal membrane oxygenation (ECMO, can be used) both for cardiopulmonary bypass during cardiac surgery and for auxiliary circulation to restore the myocardium in case of congestive heart failure.

LEVEL OF TECHNOLOGY

The IPC method with the use of NNP, built on the principle of centrifugal and axial devices, has taken the leading direction (94%) in the world clinical practice for the treatment of patients with terminal heart failure (TSF). This is due to the significant advantages of these pumps in comparison with pulsating pumps, due primarily to their small size, high energy efficiency, greater reliability and service life.

At the same time, with rather optimistic forecasts for the use of this technology, the extensive clinical practice of using NNP has revealed a number of shortcomings that require revision of the strategy for their management. In almost all clinical BMD systems built on the basis of implantable NNP, the main control strategy is based on maintaining the pump rotor speed set by the operator. In this case, a low pulsation flow is formed at the pump outlet.

Numerous clinical studies have shown that an increase in pump speed is accompanied by nonsurgical bleeding, heart valve abnormalities and a decrease in myocardial unloading in comparison with the results of pulsating pumps. It is known that a sufficient, adequate unloading of the myocardium is the main factor in the restoration of the contractile ability of the own myocardium.

The use of VNP in the mode of increased pump rotor speed is necessary to maintain systemic circulation, but often leads to a vacuum at the pump inlet, which can cause tissue damage in the area of the inlet cannula, displacement of the interventricular septum, impairment of right ventricular function, arrhythmia, cardiac ischemia and hemolysis.

On the other hand, when the lower limit of the speed of rotation of the RNP rotor is reached, a mode is established in which conditions of regurgitation of blood flow from the aorta to the left ventricle occur in the diastolic phase. This regime creates unfavorable conditions for filling the right ventricle and, ultimately, leads to right ventricular failure. Another negative phenomenon associated with the use of NNP is the likelihood of developing aortic valve insufficiency. The work of NNP establishes a high transvalvular gradient, which affects the structure of cells and leads to the formation of adhesions, incomplete opening and thrombosis of the aortic valve (AK).

To solve this complex of problems, a concept was proposed for converting the mode of specified constant NNP revolutions into a mode of generating pulsating impulses synchronized with the work of one's own heart. (Pirbodaghi T, Asgari S. Cotter C. Physiologic and hematologic concerns of rotary blood pumps: what needs to be improved? // Heart Fail Rev 2014; 19: 259-266; Rotary pumps and diminished pulsatility: do we need a pulse? ASAIO J. 2013 Jul-Aug; 59 (4): 355-66; Kishimoto S, Date K, Arakawa M, Takewa Y, Nishimura T, Tsukiya T et al. Influence of a novel electrocardiogram-synchronized rotational-speed-change system of an implantable continuous-flow left ventricular assist device (EVAHEART) on hemolytic performance. J Artif Organs. 2014; 17 (4): 373-3770).

The implementation of this concept in known systems is based on providing a pulsating mode due to modulation of the NNR rate.

A device (US 7850594, B2) is known, which contains an NNP with a drive that provides a pulsating pump mode synchronously with the work of the heart. Moreover, the cardiac cycle is determined from the back EMF ripple index of the driving contactless DC motor.

A device is known (WO 2009150893, A1), which consists of a detector for reference signals of the cardiac cycle and an NNP control unit that regulates the speed of the pump, synchronously with the cardiac cycle.

An implanted NNP is described, connected to the body according to the "left ventricle - aorta" scheme (US 2017080138, A1). The device includes a pump drive and a sensor for electrophysiological signals such as an electrocardiogram. At the same time, the sensor is connected to the pump drive for cardiosynchronized control of it in the copulsation and counterpulsation modes. Obtaining the parameters of the cardiac cycle in this case is based on the averaging of two or more cardiac cycles.

Described are other IPC systems using NNP with cardiosynchronized modulation of the impeller rotation speed (US 9579435, B2, US 9345824, B2, US 8864644, B2). These systems contain an auxiliary VNP connected according to the "ventricle-artery" scheme. The devices include a drive that periodically changes the rotation speed the pump rotor using signals received from the electrocardiogram sensor for synchronization with the cardiac cycle.

The main disadvantage of the devices described above is the periodic change in the speed of rotation of the pump impeller, synchronized with the frequency of the cardiac cycle, which can lead to an increase in shear stresses in the blood flow and, accordingly, to blood trauma.

Another disadvantage of these devices is the inertia of the motor-pump system, which limits the receipt of a given amplitude of flow and pressure in the systolic phase and leads to a phase shift of the pump ejection relative to the cardiac cycle, which significantly reduces the effect of generating a pulsating flow (S Bozkurt, van de Vosse FN, Ruten MCM Enhancement of Arterial Pressure Pulsatility by Controlling Continuous-Flow Left Ventricular Assist Device Flow Rate in Mock Circulatory System. J. Med. Biol. Eng. (2016) 36: 308-31). In addition, these devices require significant material and technical costs to improve the pumps and control units of existing IPC systems using NNP (axial and centrifugal pumps).

As a prototype of a system for mechanical support of blood circulation, we have chosen a device and a method for generating a pulsating blood flow NNP, presented in patent RU 2665 178 C1.

The proposed MPC system includes at least one NNP pump with a control unit that maintains a constant rotation frequency of the pump impeller, as well as a controlled blood recirculation channel connected parallel to the inlet and outlet pipelines of the pump with a controlled valve. The valve is connected to its own control unit, which receives signals from the cardiac synchronization unit. The valve performs the function of regulating the blood flow, which consists in partial or complete overlap, as well as opening the lumen of the blood recirculation channel in accordance with the phases of the cardiac cycle, both in the copulsation mode and in the counterpulsation with the patient's heart.

Despite the efficiency of this system in terms of generating a pulsating flow, its main disadvantage is the need to introduce a recirculation loop, which additionally increases the contact area of blood with a foreign surface. A controlled valve installed in the recirculation channel, when closed, requires a relatively large power to operate and maintain a given gap at a relatively high arterial pressure in the systole phase of the heart ventricle, which makes the use of this system in long-term implantable pumps limited.

Many factors influence the results of operations using AIC and ECMO, especially in pediatric patients with congenital heart defects. The advantage of pulsatile over non-pulsatile perfusion is one such factor that is still widely discussed among researchers, perfusionists and surgeons (Agati S, Ciccarello G, Salvo D, et al: Pulsatile ECMO as bridge to recovery and cardiac transplantation in pediatric population: A comparative study. J Heart Lung Transplant 2007; 26: 8).

In particular, the benefits of pulsatile perfusion in pediatric patients are to increase blood flow to vital organs, improve recovery of vital organs and reduce postoperative complications (Ungar A. Pulsatile Versus Nonpulsatile cardiopulmonary bypass procedures in neonates and infants: From clinical bench to practice. ASAIO 2005; 51: 6-10).

Currently, the literature provides fairly positive data obtained as a result of pulsed perfusion in children and adults, as well as in experimental animal models.

For a comparative assessment of non-pulsating and pulsating flow from the point of view of comparing the physiological effects of these modes in 1966 Shepard et al. (Shepard RB, Simpson DC, Sharp JF: Energy equivalent pressure. Arch Surg 1966; 93: 730-74) proposed an index of energy equivalent pressure (EED), which accurately estimates hemodynamic energy, which is defined as the ratio between hemodynamic work pressure and volume of blood pumped over the same period of time.

EED = (fpdt) / (fdt), where fpdt is the hemodynamic work on pressure, fdt is the volume of pumped blood.

At the same time, it has been shown that the pulsating flow, which creates a higher level of hemodynamic energy, can better support microcirculation and cellular metabolism, contributing to the restoration of vital organs after using APC and ECMO (Undar A, Masai T, Beyer EA, Goddard-Finegold J, et al: Pediatric physiologic pulsatile pump enhances cerebral and renal blood flow during and after cardiopulmonary bypass Artif Org 2002; 26: 919-923). In addition, pulsatile perfusion is believed to have a positive effect on the recovery process by decreasing the systemic inflammatory response syndrome and reducing the length of hospital stay. (Alkan T, Akc evin A, Undar A, et al: Benefits of pulsatile perfusion on vital organ recovery during and after pediatric open-heart surgery. ASAIO J, 2005; 3: 651-654). Various methods have been proposed to simulate natural pulsating blood flow in APC and ECMO, but none of them has been found satisfactory so far. However, there has been a lot of research into the development of pulsating systems for cardiopulmonary bypass.

There is a known device (US 7850594, B2), which contains an NNP with a drive that provides a pulsating pump mode due to periodic changes by the controller of the speed of rotation of the impeller. However, to implement this mode in the agro-industrial complex, which mainly use roller pumps due to the inertia of the impeller, a sinusoidal signal is formed at the output, which differs from the natural pulsation.

As a prototype of a device for controlling blood flow in cardiopulmonary bypass devices, we have chosen a device (RU 2665180), in which a pulsating blood flow in the AIC and ECMO is created due to the inclusion of a channel of regulated blood circulation in parallel with the NNP. The latter is equipped with a valve that is connected to the control unit to generate a pulsating flow at the outlet of the NNP. The valve performs the function of regulating the blood flow, which consists in partially or completely blocking, as well as opening the lumen of the blood recirculation channel.

The disadvantage of this device is the need to introduce an additional recirculation loop, which increases the contact area of blood with a foreign surface. A controlled clanan installed in the recirculation channel when closing requires a relatively large power to operate and maintain a given gap at a high pressure at the outlet of the pump-recirculation line system, which does not allow minimizing the control system and power supply to the valve. In addition, the blood flow in the recirculation loop does not participate in the oxygenation process, which leads to the need to increase the total volume of blood pumped by the pump and, as a result, can lead to additional blood trauma.

IPC technology using NNP, built on the principle of centrifugal, axial and roller devices, is successfully used in isolated left ventricular failure with a high percentage of patient survival (85% in the first year of implantation).

However, in more than 30% of cases, patients with TSF have bilateral heart failure and the survival rate of these patients is much lower. Therefore, the solution to this problem consists either in biventricular bypass of the heart (BFB), or in the implantation of an artificial heart (IC) (Sunagawa G, Horvath D J., Karimo JH, Moazami N. et al. Future Prospects for the Total Artificial Heart // J Expert Review of Medical Device. 2016. pp: l-29).

Currently, in clinical practice, the only pulsating NS device is the SynCardia TAN (CardioWest Inc), which is two pulsating implantable artificial heart ventricles with external electric pneumatic drives and a power supply system. The widespread introduction of this technology in clinical practice was limited by the same drawbacks, which put into the background the system of mechanical support of blood circulation using volumetric pulsating pumps: lower reliability and resource, relatively large dimensions of the IC, which did not allow the creation of a fully implantable IC system.

The clinical use of the Abiocor ™ TAN (Abiomed Inc) implantable electromechanical pulsating IC has been limited to a few cases. One of the reasons for this was the high cost of the system and the relatively low reliability and resource. Therefore, in recent years, the attention of IC developers has been directed to the use of NNPs, due to their advantages over pulsating flow pumps. In this case, the right and left NNP could be located in the same housing and driven from one contactless DC motor. Equally important is the lower cost of such an IP.

The first applications as an implantable IS of two NNPs, which worked in a non-pulsating mode, creating a non-physiological non-pulsating flow in the body, also did not receive clinical implementation.

Known device IS (US2014172087 A1) of the centrifugal type, the rotor of the electric motor which rotates two impellers to supply blood to the large and small circle of blood circulation.

Known device IS (US 2013331934 A1) of the centrifugal type. The device has an impeller on one side of the impeller and, accordingly, the impeller on the other side of the impeller. This invention describes a system control method and impeller design for the left and right channels, taking into account the differences in peripheral resistance of the systemic and pulmonary circulation.

Known device IC (US 9192702 B2), which discloses the technology of IC control using an embedded microcontroller, which regulates the speed of the motor in response to hemodynamic changes in blood pressure during physical activity of the patient.

Known device IC (US 8870951 B1), which provides automatic regulation of blood flows for the left and right pumps and maintaining a pressure balance by minimizing pressure gradients using high sensitivity of blood flow to pressure in the NNP.

Described are other NNP systems that can be used for ICs with modulation of the impeller rotation speed (US 2011178361 A1, US 9579435 B2, US 9345824 B2).

The disadvantages of pumps with modulation of the impeller rotation speed are associated with the fact that the amplitude of the generated flow pulses is limited due to the inertia of the drive. In addition, the variable rotor speed of the pumps increases the in-pump shear stress, which increases the likelihood of injury to the blood in the pump. In addition, for use in these systems as ICs of NNP designs previously developed for left ventricular bypass, a significant reworking of pump control units is required.

As a prototype of the IC we have chosen the IC, which is described in RU 2665179. The known IC contains the left and right NNP, each of which is connected with the pump control unit, which ensures the maintenance of a given constant rotation speed of the pump impeller. To each of the pumps, parallel to the inlet and outlet lines, a channel of controlled blood circulation is connected with the help of tees, containing a valve connected to the block control, including a block for setting the frequency and duty cycle. The valve control unit, by means of a hydraulic resistance, has the ability to independently regulate the blood flow in each recirculation channel, with the possibility of partially closing and opening its lumen.

Despite the efficiency of this system in terms of generating a pulsating flow, its main disadvantage is the need to introduce an additional recirculation loop with inlet and outlet tees, which increases the contact area of blood with a foreign surface and can be an additional source of thrombus formation and blood trauma. In addition, the blood flow in the recirculation loop does not participate in the total circulation of blood circulation, which leads to the need to increase the total volume of blood pumped by the pump and, as a result, can lead to additional blood trauma. A controlled valve installed in the recirculation channel, when closed, requires a relatively large power to operate and maintain a given gap under conditions of relatively high blood pressure, which, together with the introduction of additional recirculation circuits into the design, limits the possibility of creating an implantable IC system based on this design.

The optimistic picture of the treatment of patients with TSF, however, is overshadowed by a rather unfavorable prognosis for the use of left ventricular bypass systems in patients with concomitant right ventricular failure (more than 30%), which significantly affects the results of this method and requires the use of biofeedback methods.

The development of methods and means of biofeedback is directly related to work in the development of methods and means of OLVT

Devices that can be used to provide biofeedback include: 1. Implantable pump for LV and extracorporeal pump for right ventricular bypass (RV);

2. Extracorporeal biofeedback systems based on volumetric pulsating pumps;

3. Implantable biofeedback systems based on research institutes.

Currently, in clinical practice, the extracorporeal biofeedback system EXCOR (Berlin Heart AEG, Germany) is mainly used, representing two pulsating flow pumps (NLP) with a pneumatic drive. Considering the instability of the heart rate in bilateral heart failure, the system does not provide for the cardiosynchronization mode. The widespread introduction of this system into clinical practice was limited due to the relatively low reliability and a large percentage of strokes caused by pump thrombosis. Despite these inherent NIN disadvantages, this system is currently the only one approved for clinical use in the United States in young children with TSF.

With the introduction into clinical practice of new miniature pumps and, in particular, centrifugal pumps HeartWare HVAD, CoreAide, it became possible to implant them in older children. However, the use of these pumps was limited to individual cases due to thrombosis of the right pump, which is associated with the low-pulsating nature of the flow of these pumps. Nevertheless, in recent years, implantable NNPs have begun to be developed both for an artificial heart and for biofeedback.

Known device (US 2014172087 A1) of the centrifugal type, in which the rotor of the electric motor rotates two impellers to supply blood to the large and small circle of blood circulation.

Known device (US 2013331934 A1) of the centrifugal type, which has an impeller on one side of the impeller and, accordingly, an impeller with the other side of the impeller. This invention describes a method for controlling the system, as well as the design of the impeller for the left and right channels, taking into account the fact that the peripheral resistance of the systemic and pulmonary circulation is significantly different.

Known device (US 8870951 B1), which provides automatic regulation of the blood flow for the left and right pumps, as well as maintaining the pressure balance by minimizing pressure gradients using the high sensitivity of the NNP to changes in blood flow and pressure.

Described and other NNP systems that can be used for biofeedback, which are based on the principle of modulation of the speed of rotation of the impeller (US 2011178361 A1, US 9579435 B2, US 9345824 B2). The disadvantage of pumps with modulation of the impeller rotation speed is the inertia of the drive, which does not allow obtaining a given amplitude of flow pulses. In addition, the variable rotor speed of the pumps increases the intra-pump shear stresses, resulting in increased trauma to the blood.

As a prototype of the BFB device and method, we have chosen the BFB device and method described in the article by Krabatsch T, Potapov E, Stepanenko A, Schweiger M, Kukucka M et al. Circulation. : Biventricular circulatory support with two miniaturized implantable assist devices. Circulation 2011 124 (11) Suppl: S 179 - S 186.

The biofeedback system is based on the connection of the left and right HVAD centrifugal type (Heart Ware HVAD) according to the scheme: left ventricle - aorta and right ventricle - pulmonary artery. The control unit for each pump regulates the rotation speed of the impeller of each pump. The main disadvantage of this system is the non-pulsating blood flow at the outlet of the right and left pump, which negatively affects organ microcirculation. The absence of intra-pump pulsation increases the likelihood of thrombus formation in the pumps. In addition, since the pulmonary arterial resistance of the pulmonary circulation is approximately 6 times less than the arterial resistance of the large circle, for these pumps, the performance of which is calculated for use in LV LV systems, in order to maintain a relatively high rotor speed of the pump and reduce the likelihood of thrombosis when using the pump in the OPZh system, an additional hydraulic resistance is installed in series with the right pump. At the same time, the energy consumption for the operation of the right pump is practically equal to the energy consumption of the left pump, which ultimately leads to an increase in the total energy consumption of the biofeedback system and a reduction in the battery life of the system.

SUMMARY OF THE INVENTION

The MPC system is proposed, which includes an NNP with a pump control unit that maintains a constant rotation speed of the pump impeller, an inlet line of the pump for connection to the left ventricle of the heart and an outlet line of the pump for connection to the aorta through a vascular prosthesis. The input line of the pump contains hydraulic resistance, which ensures full opening of the lumen of the input line in the systolic phase of the cardiac cycle and a decrease in the lumen of the input line in the diastolic phase of the cardiac cycle at a given constant speed of rotation of the pump impeller.

In the passive version of the system, the hydraulic resistance is made in the form of a direct-acting mechanical valve.

In the active version of the system, a hydraulic resistance with a drive (or an actuator) is used.

The actuator can be used electromechanical, or electro-pneumatic, or electro-hydraulic drive. The actuator drive can be connected to a drive control unit containing a cardiosynchronization unit connected to an ECG recording unit.

The cardiosynchronization unit can be connected to the pump control unit with the possibility of receiving signals of the back electromotive force of the pump control unit.

Also proposed is the MPC method, in which the proposed MPC system is used extracorporeally or intracorporeally, in the mode of co-pulsation with the patient's heart, connecting the pump input line to the left ventricle of the heart, and the pump output line through the vascular prosthesis to the aorta.

In the IPC method, a mode of periodic reduction of resistance can be used, set for at least five cardiac cycles and with a duration of 0.5 to 1 minute.

The technical result achieved for the implementation of the present group of inventions consists in:

- creating a physiological pulsating flow and pressure in the aorta at a constant set speed of the pump impeller when bypassing the left ventricle of the heart;

- improvement of intra-pump hydrodynamics, minimization of blood trauma and areas of blood recirculation and stagnation, potentially dangerous for thrombus formation, due to the generation of a pulsating flow in the pump without changing the pump speed, as well as by reducing the area of contact of blood with a foreign surface of the IPC system;

- the versatility of the proposed IPC, in which a pump of any design can be used as a base NNP.

- the possibility of implementing this invention for both extracorporeal and implantable BMDs, including implantable BMDs for long-term use.

The peculiarity of these schemes for switching on passive or active hydraulic resistance in the inlet line of the pump is that the main energy for the work of this resistance is spent at the time of low diastolic pressure in the ventricles of the heart. Therefore, the energy intensity of the active controlled resistance is rather low, which makes it possible to significantly reduce its weight — overall and energy characteristics, as well as to implement the implantable version of the controlled resistance.

A device for controlling blood flow in a cardiopulmonary bypass apparatus is also proposed, including a rotary pump, an inlet line of the pump for connection to a venous reservoir and an outlet line for connection to an oxygenator. The inlet line of the pump contains an actuator made in the form of a hydraulic resistance with a drive. The latter is connected to a drive control unit, which provides pulsation with a given frequency and duty cycle of the blood flow entering through the oxygenator into the arterial line of the cardiopulmonary bypass system by partially blocking and completely opening the lumen of the pump inlet line.

A heart-lung machine can be used as a cardiopulmonary bypass apparatus.

The ECMO system can be used as a cardiopulmonary bypass apparatus, in which the drive control unit is connected to the cardiosynchronization unit connected to the ECG recording unit. The actuator of the ECMO system can be configured to regulate the blood flow in accordance with the phases of the cardiac cycle in the counterpulsation mode with the patient's heart. In this case, the actuator in the diastolic phase completely opens the lumen of the inlet line of the rotary pump, increasing the diastolic pressure in the arterial ECMO line, while providing an increase in coronary blood flow, and in the systolic phase, the actuator partially blocks the lumen of the input line, lowering the pressure in the arterial ECMO line, while providing reducing the load on the myocardium. The blood flow control device in the cardiopulmonary bypass apparatus may use an electromechanical or electro-pneumatic or electro-hydraulic drive.

Thus, at the inlet of the oxygenator and arterial line of the AIK and the ECMO apparatus, a physiological pulsating flow and pressure are formed at a constant speed of the rotor pump impeller.

The peculiarity of this system is that due to the installation of the hydraulic resistance of the actuator in the input line, the main energy for its operation is spent at a low input pressure of the venous reservoir, which makes it possible to reduce power supply and miniaturize the actuator for implementation, which in the long term makes it possible to use this invention to create portable ECMO system.

Thus, at the output of the rotary pump-actuator system in ECMO devices, a cardiosynchronized pulsating flow and pressure are formed in accordance with the phases of the cardiac cycle.

The technical result achieved by the implementation of the present invention consists in:

- creation of a physiological pulsating flow in the AIK and EKMO devices at a given speed of rotation of the pump impeller;

- prevention of blood trauma by reducing the area of its contact with a foreign surface in cardiopulmonary bypass devices;

- the versatility of the proposed device, in which a pump of any design can be used as a base NNP for AIK and EKMO;

- reducing energy consumption by minimizing the control system and power supply of the valve in blood flow control devices in cardiopulmonary bypass devices;

- simplifying the design of the pulsator in the blood flow control device in cardiopulmonary bypass devices; - reducing the size of the ECMO, the possibility of creating miniature portable ECMOs by reducing the size of the pulsator and reducing the energy consumption for its operation.

The peculiarity of this circuit for switching on the actuator in the inlet line of the rotary pump is that the main energy for the work of this resistance is spent at low pressure at the outlet of the venous reservoir. Therefore, energy consumption for the operation of the actuator is minimized, which makes it possible to significantly reduce its weight, overall and energy characteristics, which makes it possible to use this invention to create a portable ECMO system.

In addition, an artificial heart is proposed, containing a left and right NNP, each of which is connected with a pump control unit, which provides a given speed of rotation of the pump impeller constant. The input line of each pump contains an actuator made in the form of a hydraulic resistance with a drive connected to the drive control unit, which includes a unit for setting the frequency and duty cycle of the actuators. In this case, the drive control unit has the ability to regulate the blood flow at the outlet of each rotary pump, providing a pulsation of the blood flow due to the complete opening and partial blocking of the lumen of the inlet line.

Actuators can use electromechanical, electro-pneumatic or electro-hydraulic actuators.

Thus, the input line of each pump contains an actuator made in the form of a variable hydraulic resistance with a drive connected to the drive control unit.

The hydraulic resistance with the help of the actuator drive partially blocks or opens the lumen of the inlet lines of the left and right pumps. The drive control unit determines the frequency and duty cycle of the actuator drive and, accordingly, the frequency and duty cycle of blood flow pulses at the output of each pump.

Thus, a pulsating flow is generated at the output of the left and right rotary IC pump, which determines the pulse pressure in the aorta and pulmonary artery.

The peculiarity of the inclusion of actuators in the inlet lines of the pumps is that the main energy for the functioning of the actuator is spent at the moment of low pressure at the inlet of the left and right IS pumps (in the artificial atria). Therefore, the energy intensity of the active controlled resistance is rather low, which will significantly reduce its weight, dimensions and energy characteristics for the implementation of the implantable version of the IC.

- reducing the area of the foreign contact surface, potentially dangerous for thrombus formation and blood trauma, and simplifying the IC design;

- reducing the energy costs required for the functioning of the system, which allows, while simplifying the design of the IC pulsator, to reduce the weight and overall parameters for the implementation of a fully implantable IC;

- creation of a physiological pulsating flow and pressure in the aorta and pulmonary artery at a constant set speed of the impeller of the left and right IS pumps;

- improvement of the intra-pump hydrodynamics due to the generation of a pulsating flow in the right and left pumps of the IS without changing the speed of the pump rotor revolutions, which is especially critical for the right pump of the IS in terms of reducing the likelihood of thrombus formation in it.

- prevention of conditions for the appearance of a dangerous rarefaction mode and regurgitation in the diastolic phase at increased pump rotor speed; the possibility of implementing IS based on previously developed implantable structures of NNP, intended for left ventricular bypass.

A biofeedback system is also proposed, containing left and right NNP connected with the pump control unit. The pump control unit provides a constant speed of rotation of the impeller of each pump. The input line of each pump contains an actuator made in the form of a hydraulic resistance with a drive connected to the drive control unit. The latter includes a block for setting the frequency and duty cycle of the actuators. In this case, the drive control unit has the ability to regulate the blood flow at the outlet of each rotary pump by completely opening or partially blocking the lumen of the inlet line.

In the biofeedback system, electromechanical, electro-pneumatic or electro-hydraulic drives can be used.

A biofeedback method is also proposed, in which a patented biofeedback system is used. In this case, the input line of the left pump is connected to the left ventricle of the heart, and its output line to the aorta; the input line of the right pump is connected to the right ventricle of the heart, and its output line to the pulmonary artery.

Another method of biofeedback is proposed, in which the patented biofeedback system is used. For this, the input line of the left pump is connected to the left atrium, and its output line to the aorta, the input line of the right pump is connected to the right atrium, and its output line to the pulmonary artery.

Thus, a pulsating flow is generated at the output of the left and right rotary pumps of the biofeedback, which determines the pulse pressure in the aorta and pulmonary artery.

The peculiarity of the inclusion of actuators in the input lines of the pumps is that the main energy for the operation of the actuator is spent when low pressure at the inlet of the left and right pumps of the biofeedback system (in the atria), which helps to reduce energy consumption for the operation of active controlled resistance, which also makes it possible to significantly reduce its weight and overall characteristics for the implementation of the implantable version of biofeedback.

The technical result achieved by the implementation of the present group of inventions consists in:

- creation of a physiological pulsating flow and pressure in the aorta and pulmonary artery at a constant set speed of the impeller of the left and right biofeedback pumps;

- improvement of the intra-pump hydrodynamics due to the generation of a pulsating flow in the right and left pumps of the biofeedback without changing the speed of the pump rotor revolutions, which is especially important for the right-hand biofeedback pump from the point of view of reducing the likelihood of thrombus formation in it;

- the possibility of using previously developed NNPs intended for LV LV without the use of additional hydraulic resistance in the right pump, which creates the basis for creating a low-power implantable biofeedback system.

BRIEF DESCRIPTION OF DRAWINGS

The essence of the invention is illustrated in the figures, where figure 1 shows a diagram of the generation of a pulsating flow in the IPC systems in the mode of bypassing the left ventricle of the heart when installed in the input line of the NNP variable hydraulic resistance in the form of a mechanical valve, which is a passive element of direct action with full opening of the input line in systole of the heart and incomplete overlap of the input line, which reduces the amplitude of blood flow through the pump in the diastole of the heart; in fig. 2 shows a diagram of the generation of a pulsating flow in IPC systems. in the mode of bypassing the left ventricle of the heart when installing an actuator containing a variable hydraulic resistance and a drive in the input line of the NNP; in fig. 3 shows a diagram of pressures and flow rates obtained on a hydrodynamic bench when simulating heart failure and pump operation without a pulsator; in fig. 4 shows a diagram of pressures and flows obtained on a hydrodynamic stand, when simulating heart failure and the operation of a pump with a pneumatic pulsator; in fig. 5 shows a diagram of the generation of a pulsating flow in the AIK system using NNP when installed in the inlet line of an actuator pump - a hydraulic resistance with a drive connected to an electronic control unit that provides a given frequency and duty cycle of flow pulses and blood pressure at the output of the system; in fig. 6 shows a diagram of the generation of a pulsating flow in the ECMO apparatus in the cardiosynchronization mode with the use of NNP and an actuator built into the NNP input line, while the actuator drive is connected through the control unit to the cardiosynchronization unit, which receives signals from the ECG recording unit; in fig. 7 shows a diagram of pressures and flow rates in the arterial line of the AIK (ECMO), obtained on a hydrodynamic stand when the NNP operates in a non-pulsating mode; in fig. 8 shows a diagram of pressures and flow rates in the arterial line of the AIK (ECMO) obtained on a hydrodynamic stand using the claimed device providing a pulsating mode of operation; in fig. 9 shows a diagram of the proposed IC providing the generation of a pulsating flow in the left and right NNP IC; in fig. 10 shows a diagram of pressures and flow rates for the systemic and pulmonary circulation, obtained on a two-circle hydrodynamic stand, when the left and right NNP IS operate in non-pulsating mode without the NNP system - actuator (A); in fig. 11 shows a diagram of pressures and flow rates for the systemic and pulmonary circulation, obtained on a two-circle hydrodynamic stand, when the left and right NNP IS operate in a pulsating mode using the installation of the NNP - A system in the input line; in fig. 12 shows a diagram of the proposed biofeedback system, which provides the generation of a pulsating flow in the left and right NNP when connecting the right NNP according to the "right atrium - pulmonary artery" scheme and the left NNP according to the "left atrium - aorta"scheme; in fig. 13 shows a diagram of the proposed biofeedback system, which provides the generation of a pulsating flow in the left and right pump when connecting the right NNP according to the "right ventricle - pulmonary artery" scheme and the left NNP according to the "left ventricle - aorta"scheme; in fig. 14 shows a diagram of pressures and flow rates obtained on a two-circle hydrodynamic test bench when the left and right NNP of the biofeedback system operate in a non-pulsating mode; in fig. 15 shows a diagram of pressures and flow rates for the systemic and pulmonary circulation, obtained on a two-circle hydrodynamic stand, when the left and right NNP of the biofeedback system operate in a pulsating mode using the installation of the NNP-A system in the NNP inlet line.

The figures indicate the following positions: 1 - pump (NNP), 2 - hydraulic resistance, 3 - aorta, 4 - left ventricle of the heart, 5 - pump inlet line, 6 - pump outlet line, 7 - NNP control unit, 8 - actuator, 9 - actuator drive, 10 - actuator / actuator control unit, 11 - cardiosynchronization unit, 12 - ECG recording unit, 13 - oxygenator, 14 - left atrium, 15 - hydraulic resistance - direct-acting mechanical valve, right, 16 - right actuator drive, 17 - right actuator, 18 - right NNP, 19 - right pump input line, 20 - pulmonary artery, 21 - right atrium, 22 - the outlet line of the right pump, 23 - the right ventricle;

P _ao (P _ad) - pressure in the arterial line (mm Hg), P _lp - pressure in the left atrium (mm Hg), P _LV - pressure in the left ventricle (mm Hg), Q _H - flow rate NNP (l / min), Q _ao - flow rate in the artery / aorta (l / min); A - arterial line AIK (ECMO), B - venous line AIK (ECMO) of the cardiopulmonary bypass apparatus,

P _la - pressure in the pulmonary artery (mm Hg), Q _ia - flow rate in the pulmonary artery (l / min), P _pzh - pressure in the right ventricle (mm Hg), P _pp - pressure in the right atrium (mm Hg), () _la - flow rate in the pulmonary artery (l / min).

DISCLOSURE OF THE INVENTION

The patented device is designed in two versions.

Using the example of the connection diagram "left ventricle - aorta" shown in Fig. 1 and 2, we will consider the principle of generation of pulsed auxiliary circulation.

The circuit contains NNP 1 (axial or centrifugal) with a control unit 7, the left ventricle 4 of the heart and the aorta 3. In the first embodiment, FIG. 1, when connected to the left ventricle 4 of the heart NNP 1 in the input line 5, a variable hydraulic resistance 2 is set, made in the form of a direct-acting mechanical valve.

In the second variant of the circuit in FIG. 2, when connected to the left ventricle 4 of the heart of NNP 1, an actuator 8 is installed in the input line 5, containing a variable hydraulic resistance 2 and an actuator drive 9. The control unit 10 of the actuator 8 must ensure full opening of the input line 5 in the systolic phase of the left ventricle of the heart 4 with an increase the amplitude of the systolic blood flow to the aorta in comparison with the pump operation in non-pulsating mode; and the specified hydraulic resistance in the diastolic phase of the heart, which provides a decrease in the amplitude of the diastolic volumetric blood flow at the NNP output. The actuator control unit 10 is connected to the cardiosynchronization unit 11, which receives signals from the ECG recording unit 12 or cardioverter pulses.

The cardiac synchronization unit 11 can be connected to the NNP control unit 7 to receive back EMF signals.

Outlet line 6 NNP through a vascular prosthesis is connected to aorta 3.

The operation of this IPC scheme is carried out as follows.

The input line 5 of the NNP 1 with the actuator 8 is connected to the left ventricle 4 of the heart, and the output cannula 6 is connected through the vascular prosthesis with the aorta 3. Accordingly, at the exit of the NNP 1 in the aorta 3 due to the change in the variable hydraulic resistance created by the actuator 8, a physiological pulsating flow and pressure. At the same time, due to an increase in blood flow in the systolic phase, NNP 1 more effectively reduces the afterload of the ventricle of the heart compared to the work of NNP in the standard non-pulsating mode, which is one of the main factors in myocardial recovery during auxiliary circulation.

In addition, the mode of operation of NNP 1 - actuator 8 with a minimum blood flow to diastole helps to eliminate dangerous modes associated with the occurrence of rarefaction at the inlet of NNP 1 and reverse regurgitation of blood from the artery to the ventricle. An additional advantage of this invention is to increase the intra-pumping blood pulsation, which is one of the most important factors in reducing the likelihood of thrombus formation in the pump cavities.

The control unit of the actuator 10 provides for a mode of periodic reduction of hydraulic resistance at intervals from 30 sec to 1 minute with a duration of at least 5 heart cycles. This mode is introduced to create conditions conducive to the periodic functioning of the aortic valve, in order to exclude the likelihood of developing its insufficiency. Thus, the mode of periodic opening of the input line is realized with an interval from 30 seconds to 1 minute, at least for five cardiac cycles.

In the actuator 8, an electromechanical, electro-pneumatic or electro-hydraulic drive can be used. The drive must provide a cardysynchronization mode in accordance with the phases of the cardiac cycle (systole / diastole). For the implementation of cardiosynchronization, both an electrocardiogram and cardioverter pulses or back EMF signals of the NNP drive system can be used.

The resulting effect of the system pump 1 - actuator 8 on the hydrodynamic stand is shown in the pressure diagrams (P _ao , P _lzh , P _lp ) and flow _{rates (Q ao} , Q _H ), in Fig. 3 and 4.

As can be seen from the diagrams, the pulse pressure in the aorta P _ao during the operation of the NNP 1-actuator 8 system is significantly higher than the pulse pressure in the aorta 3 than when the NNP 1 is operated without actuator 8.

In addition, as can be seen from the diagrams obtained, during the operation of the NNP system 1 - actuator 8, the intra-pump pulsation of the fluid flow is significantly higher compared to the operation of the NNP in the non-pulsating mode, due to which conditions are created in the NNP cavities to minimize stagnation and recirculation zones dangerous for the formation blood clots.

In this work, on a hydrodynamic stand, the conditions of operation of the MPC systems were reproduced when simulating heart failure for adult patients with a decrease in the systemic output of the simulated ventricle of the heart (VVS) from 5 l / min (normal) to 2.5 l / min. 6 tests were carried out using a ROTAFLOW pump (Maquet, Germany). Results of comparing the operation of the NNP in non-pulsating mode and in the mode of operation of the NNP system 1 - actuator 8 at modeling of heart failure obtained on the hydrodynamic stand are summarized in the table, where P _ao is the pressure in the aorta, AR _ao is the pulsation of aortic pressure, P _{lzh (sis) is the} systolic pressure in the IZhS, P _{lp (cf)} is the average pressure in the atrium, Q _{ao is the} average blood flow in the aorta.

table

As can be seen from the table, the pulsating pressure of AR _ao during the operation of the NNP1 with the actuator 8 increases in comparison with the work of the NNP in the non-pulsating mode by almost 3 times with the complete restoration of the systemic blood flow. In this case, the pressure in the systolic phase, the pressure in the left ventricular simulator decreases by 1, 4 times compared with the work of NNP 1 in a non-pulsating mode, which indicates an effective unloading of the left ventricle.

In another experiment on a hydrodynamic stand, the operating conditions of the IPC systems were reproduced when simulating heart failure when a hydraulic resistance 2 was installed in the input line 6 in the form of a direct-acting mechanical valve when the NNP 1 was operated with a given increased rotor speed, physiological pulsation of aortic pressure was obtained within 25- 30 mm Hg with an intra-pump pulsation of the flow - 6-8 l / min.

The patented device contains NNP 1, while in its input line 6, an actuator 8 is installed, containing a hydraulic resistance (HS) 2 and a HS actuator 9. The actuator control unit (BU) 10, connected to the HS actuator 9, provides a given frequency and duty cycle of contractions corresponding to the heart rate when working in AIK and when non-cardiosynchronized ECMO mode.

In another embodiment, when implementing the cardiosynchronous mode ECMO BU 10 is connected to the cardiosynchronizing unit 11 connected to the ECG 12 recording unit.

The operation of this device can be described as follows.

In the first variant of connecting the system NNP 1 -actuator 8 to the AIK and non-cardiosynchronized ECMO according to the "venous reservoir-oxygenator" scheme BU 10 of the actuator 8, connected to the drive 9, provides a given frequency and duty cycle of pulsations of blood flow and pressure corresponding to the heart rate due to changes in GS 2 , which is part of A 8, built into the input line 5 of the NNP 1, which changes the degree of its overlap, while increasing or decreasing the blood flow at the outlet of the NNP 1 (Fig. 5).

In the second version, when using a cardiosynchronized ECMO apparatus according to the "venous cannula - arterial cannula" scheme, the connection of the NNP1 - A 8 BU 10 system is connected by a drive 9 to the cardiosynchronization unit 11 and the ECG recording unit 12 (Fig. 6).

At the same time, due to the complete opening with the help of A8 of the lumen of the input line 5 NNP 1 in the phase of heart diastole, an increase in the amplitude of arterial pressure is provided, which creates conditions for an increase in coronary blood flow. In the systolic phase of the heart, due to the decrease in the lumen of the input line 5 of the NNP 1 with the help of A8, the blood flow at the exit of the NNP 1 decreases, lowering the pressure amplitude in the arterial line, reducing the afterload or the work of the left ventricle of the heart.

Thus, at the output of the NNP1 - A8 system, i.e. in the arterial line (A) pulsation and pressure close to physiological are formed without changing the speed of NNP1. This mode helps to minimize trauma to the blood corpuscles in comparison with the previously announced devices and to eliminate the rarefaction mode at the inlet of NNP1 with possible blood cavitation and the appearance of gas bubbles potentially dangerous for cerebral circulation.

We present the data obtained at the hydrodynamic stand, which confirms the possibility of implementing the declared purpose and achieving the specified technical result.

FIG. 7 shows a diagram of pressure and flow in the arterial line of the APC (ECMO), taken on a hydrodynamic stand when the NNP1 operates in a non-pulsating mode.

The resulting effect of the system NNP1 - A8 is shown in the diagram of pressure and flow in the arterial line (A) APC (ECMO) in Fig.8.

The flow curve also has a pronounced pulsation, which can have a positive effect when using the system in patients, both when performing open heart surgery with APC, and when used when ECMO is connected in conditions of congestive heart failure.

In this work, a Rotaflow centrifugal pump (Maquet AEG, Germany) was used at the hydrodynamic stand as NNP 1.

As can be seen from the diagram, the amplitude of the pulse pressure in the arterial line during the operation of the NNP 1 - A8 system is within physiological limits with an average flow rate of 4.8 l / min.

Thus, the invention can be used both in agro-industrial complex and in ECMO devices. In the latter case, the control unit of the actuator is connected to the cardiosynchronization unit 11, which receives signals from the ECG 12 recording unit. providing an increase in amplitude blood pressure in the diastole phase of the heart, realizing the counterpulsation mode and, thus, contributing to an increase in coronary blood flow. In the systolic phase of the heart, the actuator 8 partially overlaps the lumen of the input line 5, reducing blood flow and pressure at the output of NNP1 to oxygenator 13 and arterial line A. A decrease in systolic pressure in arterial line A will lead to a decrease in afterload on the left ventricle of the heart, which will contribute to recovery affected myocardium.

Using the example of the connection diagram of the left and right NNP shown in Fig. 9, we will consider the principle of pulse blood flow generation in IC.

The device being patented (Fig. 9) contains a left NNP 1 and a right NNP 18 (axial or centrifugal) with a pump control unit 7, which determines the set speed of rotation of the impeller of each pump. Actuators (A) 8 and 17, respectively, are installed in the input lines 5 of the left NNP1 and right NNP1 19. Each A contains: variable hydraulic resistance 2 and actuator 9 for the left channel IC and variable hydraulic resistance 15 and actuator 16 for the right channel IC. In this case, the drives 9 and 16 of each A are connected with a single drive control unit 10. The latter provides a given frequency and duty cycle of the output pulses of the flow and blood pressure at the output of the left and right channels of the IC.

To implement the IS mode, the input and output of the right NNP 18 are connected extracorporeally or intracorporeally according to the "artificial right atrium - pulmonary artery" scheme, and the left NNP 1 according to the "artificial left atrium - aorta" scheme.

The actuator drive control unit 10 provides full opening and partial overlap of the input lines 5 and 19, respectively, of the left NNP 1 and right NNP 18. Accordingly, at the output of the pumps, a pulse flow is formed and, consequently, a physiological pulse flow and pressure in the arterial reservoirs of a large and small circles of blood circulation.

The input line 5 of the left NNP 1 is connected to the left artificial atrium 14, and the input line 19 of the right NNP18 is connected to the right artificial atrium 21.

The output line 6 of the left NNP1 is connected to the aorta 3, and the output line 22 of the right NNP18 is connected to the pulmonary artery 20.

In the phase of generation of the increased amplitude of the output flow of the pumps (systole) A 8 and A 17 completely open the lumens of the input lines 5 and 19 of the left and right NNP, and in the phase of generation of a reduced amplitude of the output flow of the pumps (diastole) A 8 and A 17 partially overlap the lumens of the input highways.

Thus, the drive control unit A10 provides the set frequency and duration of the flow and pressure pulses for the left and right NNP 1 and NNP 18, respectively.

To confirm the possibility of realizing the declared purpose and achieving the specified technical result, we present the following experimental data obtained on a two-circle hydrodynamic stand.

As shown by studies on a hydrodynamic stand, the operation of the proposed IC using a system of two NNP-A creates conditions for the generation of a pulsating flow in the large and small circles of blood circulation.

For comparison, Fig. 10 shows a diagram of the pressures and flow rates of fluid in the large and small circles of blood circulation when the NLP is operating in a non-pulsating mode. The resulting effect of the operation of the IC system using the NNP-A systems is shown in the diagram (Fig. 11). As can be seen from this diagram, physiological pulsating pressure in the aorta of 111/76 mm Hg is created in simulators of the aorta and pulmonary artery. Art.) and pulmonary artery 19/13 mm Hg. Art.) with pulsating fluid flow in a large circle circulation A () _L = 6.9 L / min and AQ _n = 8.8 L / min in the pulmonary circulation, which contributes to the creation of conditions for intra-pump hydrodynamics, which prevents the formation of zones of stagnation and recirculation in the cavities of the left and right NNP.

Using the example of the connection diagram of the left and right NNP shown in Fig. 12, we will consider the principle of pulse flow generation in the biofeedback system.

The device being patented (Fig. 12) contains the left 1 and the right 18 NNP with the pump control unit 7, which determines the predetermined constant speed of rotation of the impeller of each pump. Actuators 8,17 are installed in the input lines 5 and 19, respectively, of the left 1 and right 18 NNP, each of which contains a variable hydraulic resistance 2, 15 with its own drive 9, 16, which are connected to the drive control unit 10. and the latter provides a given frequency and duty cycle output pulses of blood flow and pressure at the output of the left 1 NNP and right 18 NNP.

The drive control unit 10 provides full opening or partial closure of the input lines 5 and 19, respectively, left 1 NNP and right

18 NNP, adjusting the blood flow at the outlet of each pump.

In the first version, the input line 5 left 1 NNP and the input line

19 of the right 18 H1111 are connected, respectively, to the left 14 and right 21 atria, and the output lines 6 and 22 of the left 1 NNP and right 18 NNP are connected, respectively, to the aorta 3 and the pulmonary artery 20 (Fig. 12).

In the second version, the input line 5 of the left NNP and the input line 19 of the right NNP 18 are connected, respectively, to the left 4 and right 23 ventricles of the heart, and the output line 6 of the left NNP1 and the output line 19 of the right NNP 18 are connected, respectively, to the aorta 3 and the pulmonary arteries 20 (Fig. 13).

In the phase of generating an increased amplitude of the output flow of the pumps, actuators 8 and 17 completely open the gaps of the inlet lines 5 and 19 respectively, for 1 left NNP and right 18 NNP, and in the phase of generation of a reduced amplitude of the output flow of the pumps, the actuators 8 and 17 partially overlap the gaps of the inlet lines.

Thus, the control unit drives the actuators 10 provides a given frequency and duration of pulses of flow and blood pressure for the left 1 and right 18 NNP, respectively.

In some cases, in order to maintain the systemic release in conditions of TSN, it is necessary to increase the productivity of the NNP, which can lead to the closure of the aortic and pulmonary valves. In these conditions, with prolonged operation of the biofeedback system, there is a risk of developing insufficiency of the outlet heart valves. Therefore, in order to exclude the development of dysfunction of the aortic and pulmonary heart valves in the present biofeedback system, it can be possible to temporarily reduce the pump performance with a given period. The algorithm for applying this mode, including the frequency and duration of pump shutdown, can be set by the operator

To confirm the possibility of realizing the declared purpose and achieving the specified technical result, we present the following experimental data obtained on a two-circular hydrodynamic stand when connecting the input line of the left 1 NNP and right 18 NNP, respectively, to the left and right artificial ventricles of the heart, and the output lines of the left and right pumps, respectively connected to both aortic and pulmonary artery simulators.

Rotaflow centrifugal pumps (Maquet AEG, Germany) with a minute flow rate of 5 l / min were used as pumps on the hydrodynamic stand. In this case, the aortic and pulmonary reservoirs, imitating, respectively, the aorta and pulmonary artery, are containers filled with fluid with an air cushion. In this case, the air cushion determines the elasticity of the vessels (for the pulmonary artery simulator, the elasticity equal to 5.7 ml / mm Hg. Art. and for a simulated aorta 2 ml / mm Hg. Art.). Hydraulic resistances were used as peripheral resistance (for the pulmonary circulation 0.4 mm Hg / ml / s and for the systemic circulation 1.2 mm Hg / ml / s). The left and right atria were simulated by open reservoirs.

Thus, as shown by the studies on the hydrodynamic stand, the work of the proposed biofeedback with the use of the NNP-A system for the left and right pumps creates conditions for the generation of a pulsating flow in the systemic and pulmonary circulation.

The obtained comparative effect of the operation of the two biofeedback systems is shown in Fig. 14 a, b non-pulsating mode and Fig. 15 a, b pulsating mode.

As seen from the diagrams, FIG. 15 in the simulators of the aorta and pulmonary artery, physiological pulsating pressure of Rao is created - the pressure in the aorta is 111/76 (107) mm Hg. and Rla pulmonary artery pressure 27/13 (19) mm Hg. with pulsating fluid flow AQ _ao = 6.9 l / min and AQ _aa = 8.8 l / min. Accordingly, the intra-pump flow rate fluctuation for the left channel was 9 l / min and for the right channel 8.1 l / min, which contributes to the creation of conditions for intra-pump hydrodynamics, preventing the formation of stagnation and recirculation zones in the cavities of the left and right NNP.

For specialists in the field of medical technology, it should be obvious that the present invention can be made various modifications and changes without departing from the essence or scope of the claims, which are not reflected in the above embodiments of the invention.

Claims

CLAIM

1. A system of mechanical circulatory support, including a rotary pump with a pump control unit that maintains a constant rotation speed of the pump impeller, an inlet line of the pump for connection to the left ventricle of the heart and an outlet line of the pump for connection to the aorta through a vascular prosthesis; in this case, the input line of the pump contains hydraulic resistance, which ensures full opening of the lumen of the input line during the systolic phase of the cardiac cycle and a decrease in the lumen of the input line during the diastolic phase of the cardiac cycle.

2. The system of claim. 1, in which the hydraulic resistance is made in the form of a direct-acting mechanical valve.

3. The system of claim. 1, which uses a hydraulic resistance with a drive.

4. The system of claim 3, wherein an electromechanical or electro-pneumatic or electro-hydraulic drive is used.

5. The system according to claim 3, in which the hydraulic resistance drive is connected to the drive control unit containing the cardiac synchronization unit connected to the ECG recording unit.

6. The system of claim 5, wherein the cardiosynchronization unit is coupled to the pump control unit to receive back electromotive force signals from the pump control unit.

7. A method of mechanical support of blood circulation, in which the system according to any one of paragraphs. 1-6 are used extracorporeally or intracorporeally, in the mode of co-pulsation with the patient's heart, connecting the inlet line of the pump to the left ventricle of the heart, and the outlet line of the pump through the vascular prosthesis to the aorta.

8. The method of mechanical support of blood circulation according to claim 7, in which the mode of periodic decrease in resistance is set for at least five cardiac cycles and with a duration of 0.5 to 1 minute.

9. A device for controlling blood flow in a cardiopulmonary bypass apparatus, including a rotary pump, an inlet line of the pump for connecting to a venous reservoir and an outlet line for connecting to an oxygenator, while the inlet line of the pump contains an actuator made in the form of a hydraulic resistance with a drive connected with a drive control unit providing pulsation with a given frequency and duty cycle of the blood flow entering through the oxygenator into the arterial line of the cardiopulmonary bypass system, by partially blocking and completely opening the lumen of the pump inlet line.

10. A device according to claim 9, wherein a heart-lung machine is used as the cardiopulmonary bypass apparatus.

11. The device according to claim 9, where the ECMO system is used as a cardiopulmonary bypass apparatus, in which the drive control unit is connected to the cardiosynchronization unit connected to the ECG recording unit, and the actuator is configured to regulate the blood flow in accordance with the phases of the cardiac cycle in the counterpulsation mode with the patient's heart, while in the diastolic phase the actuator completely opens the lumen of the inlet line of the rotary pump, increasing the diastolic pressure in the arterial ECMO line, while providing an increase in coronary blood flow, and in the systolic phase, the actuator partially blocks the lumen of the input line, decreasing the pressure in arterial line ECMO, while ensuring a decrease in the load on the myocardium.

12. The device of claim 9, wherein an electromechanical or electro-pneumatic or electro-hydraulic actuator is used.

13. Artificial heart containing left and right rotary blood pumps, each of which is connected to a pump control unit, which provides a given speed of rotation of the pump impeller constant; the input line of each pump contains an actuator made in the form of a hydraulic resistance with a drive connected to the drive control unit, which includes a unit for setting the frequency and duty cycle of the actuators, while the drive control unit has the ability to regulate the blood flow at the outlet of each rotary pump, providing pulsation of the blood flow due to the complete opening and partial blocking of the lumen of the inlet line.

14. An artificial heart according to claim 13, wherein electromechanical, electro-pneumatic, or electro-hydraulic actuators are used.

15. System of biventricular bypass of the heart, containing left and right rotary blood pumps connected to the pump control unit, providing a given speed of rotation of the impeller of each pump constant, while the input line of each pump contains an actuator made in the form of a hydraulic resistance with a drive connected to a drive control unit, including a unit for setting the frequency and duty cycle of the actuators, while the drive control unit has the ability to regulate the blood flow at the outlet of each rotary pump by completely opening or partially blocking the lumen of the inlet line.

16. System for and. 15, which uses an electromechanical, electro-pneumatic or electro-hydraulic drive.

17. The method of biventricular bypass of the heart, which uses the system according to claim 15, connecting the input line of the left pump to the left ventricle of the heart, the output line of the left pump to the aorta; the inlet line of the right pump to the right ventricle of the heart, and the outlet line of the right pump to the pulmonary artery.

18. The method of biventricular bypass of the heart, which uses the system according to claim 15, connecting the input line of the left pump to the left atrium, the output line of the left pump to the aorta, the input line of the right pump to the right atrium, and the output line of the right pump to the pulmonary artery.