CN101361994B - Artificial heart blood pump that raises blood pressure step by step - Google Patents

Abstract

An artificial heart blood pump for increasing blood pressure step by step belongs to the technical field of biomedical engineering and relates to an artificial heart blood pump for increasing blood pressure. The artificial heart blood pump includes a drive stator and a rotor, and a drive power supply is provided by a controller connected to the drive stator. The drive stator composed of a ring coil is located in the interlayer formed by the cylindrical shell 13 and the tubular lumen 10; in the lumen 10 Contains the head guide vane 1 located at the front end of the inner cavity 10 supporting the rotor, the tail guide vane 8 located at the rear of the inner cavity 10, and the rotor located between the head guide vane 1 and the tail guide vane 8; it is characterized in that: the artificial heart The blood pump is divided into front and back two stages, the former stage is the first-stage blood pump; the latter stage is the second-stage blood pump; the first-stage blood pump and the second-stage blood pump are respectively driven by the controller. The blood first flows through the first-level blood pump to generate a blood pressure, and then through the second-level blood pump to generate another blood pressure. The two blood pressures can be superimposed to achieve the blood pressure required by the human body, which avoids the need for a single pump to increase blood pressure to achieve higher blood pressure. The problem of damage to red blood cells caused by impeller speed.

Description

Artificial heart blood pump that raises blood pressure step by step

technical field

The invention belongs to the technical field of biomedical engineering, and relates to an artificial heart blood pump for increasing blood pressure step by step.

Background technique

The artificial heart can be divided into two types according to the working principle of the blood pump: volumetric type and impeller type. A variety of impeller-type artificial hearts have been used clinically due to their relatively simple structure and small size, but at the same time, the problem of hemolysis has plagued the use of impeller blood pumps. At present, most impeller blood pumps are single-stage blood pumps. In the typical structure of this type of blood pump, there is only one set of blood pump units that compensate blood pressure and provide blood flow. Therefore, huge suction force is required to meet the requirements of blood pressure and blood flow rate. Require. For example, in the patent document US2006241335A1, the blood pump provides blood pressure and blood flow by an impeller, and the suction force at the front end is large, which may generate negative pressure, which will cause hemolysis to blood cells. In addition, the high shear force caused by the high rotational speed of the magnetic levitation rotor blood pump (application number 200710039971.7) is quite damaging to red blood cells, and the hemolytic performance problem caused by this cannot be overcome.

Contents of the invention

The purpose of the present invention is to provide a two-stage artificial heart blood pump to solve the problem of insufficient blood pressure difference under the premise of ensuring that the red blood cells are not destroyed.

In order to achieve the above object, the present invention adopts the following technical scheme: the artificial heart blood pump that increases blood pressure step by step includes a drive stator and a rotor, and the drive power is provided by a controller connected to the drive stator. The drive stator composed of a ring coil is located in a cylindrical In the interlayer formed by the casing 14 and the tubular inner cavity 10, one end of the casing 14 is sealed, and the other end is sealed by an annular end cover 11; The tail guide vane 8 at the rear of 10, and the rotor between the head guide vane 1 and the tail guide vane 8; wherein the rotor is an impeller; and the rear end of the inner cavity 10 is provided with a rectifying tail cone 9, characterized in that: The heart blood pump is divided into two stages: the front stage is a first-stage blood pump, including a first-stage impeller 3, and a first-stage drive stator 13; the latter stage is a second-stage blood pump, including a second-stage impeller 5, and a second-stage drive stator 12; Between the primary impeller 3 and the secondary impeller 5, there is an intermediate guide vane 4, which serves as the tail guide vane of the primary blood pump and serves as the head guide vane of the secondary blood pump, and is used to support the primary impeller 3 and the secondary impeller. The impeller 5; the primary drive stator 13 and the secondary drive stator 12 are respectively driven by the controller, and the power of the primary blood pump is guaranteed to be greater than that of the secondary blood pump.

In order to avoid excessive suction for blood circulation, the power of the primary blood pump is required to be greater than that of the secondary blood pump. In the present invention, the coil turns of the primary drive stator 13 are greater than the coil turns of the secondary drive stator 12 , and the length of the primary impeller 3 is greater than that of the secondary impeller 5 . In this way, when the controller provides the same control signal to the two coils driving the stators, the power of the primary blood pump will be greater than that of the secondary blood pump, which can simplify the device.

The first-stage impeller 3 and the second-stage impeller 5 of the artificial blood pump are set on the fixed shaft 7 fixed on the central axis of the head guide vane 1, the middle guide vane 4 and the tail guide vane 8 through the first-stage bearing 2 and the second-stage bearing 6 respectively. superior. And the first-stage impeller 3 and the second-stage impeller 5 as well as the middle guide vane 4 and the tail guide vane 8 adopt spiral blades, and the spiral direction of the first-stage impeller 3 and the second-stage impeller 5 is the same as that of the middle guide vane 4 and the tail guide vane 8 on the contrary.

Similar to the primary blood pump and the secondary blood pump, the artificial heart blood pump can be provided with a multi-stage blood pump with more than two stages.

The beneficial effects of the present invention are: 1) Due to the adoption of two or more blood pump schemes, the blood pressure pressure difference between the inlet and the inlet of the blood pump can reach a value that meets the requirements of the human body without increasing the rotational speed of the rotor, avoiding the need for rotor Damage to red blood cells caused by excessive rotational speed. 2) A fixed shaft is adopted, and the impeller rotates on the fixed shaft. Experiments have proved that this is beneficial to reduce the resistance of the pump.

Description of drawings

Fig. 1 is the structural representation of the artificial heart blood pump that increases blood pressure step by step in the present invention

In the figure: 1. Head guide vane, 2. Primary bearing, 3. Primary impeller, 4. Middle guide vane, 5. Secondary impeller, 6. Secondary bearing, 7. Fixed shaft, 8. Tail guide vane, 9. Rectifier tail cone, 10. Inner cavity, 11. End cover, 12. Secondary drive stator, 13. Primary drive stator, 14. Shell.

Detailed ways

As shown in FIG. 1 , the artificial heart blood pump for increasing blood pressure step by step disclosed by the present invention mainly includes two parts: a casing 14 and an inner cavity 10 , both of which are cylindrical and made of medical titanium alloy TC4. The outer shell 14 is placed outside the inner shell to form an interlayer, and the stator coil is placed in the interlayer; one end of the outer shell 14 is sealed and connected with the inner cavity 10 by an annular side plate, and the other end is sealed and connected with the inner cavity 10 by an annular end cover 11 . In the inner cavity 10, the head guide vane 1, the first-stage impeller 3, the middle guide vane 4, the second-stage impeller 5, the tail guide vane 8, and the rectifying tail cone 9 are placed in sequence; the head guide vane 1, the middle guide vane 4, and the tail guide vane 8 Fixed with the inner cavity wall; a fixed shaft 7 is fixed on the axis of the head guide vane 1 and the middle guide vane 4, the middle guide vane 4 and the tail guide vane 8, and the first-stage impeller 3 and the second-stage impeller 5 respectively pass through the first-stage Bearing 2 and secondary bearing 6 are sleeved on the fixed shaft 7. The blades of the head guide vane 1 are 2-4 pieces, adopting straight blades along the direction of the inner cavity; ), the helical direction of the first-stage impeller 3 and the second-stage impeller 5 is opposite to that of the middle guide vane 4 and the tail guide vane 8 . The tail end of the cavity 10 is a rectifying tail cone 9 , and the rectifying tail cone 9 is fixed on the tail guide vane 8 .

The first-stage impeller 3 and the second-stage impeller 5 are evenly embedded with permanent magnets in a conventional manner, and when the stator coil is connected to the controller, it interacts with the electrode stator to make the impeller rotate. The first-stage impeller 3 and the second-stage impeller 5 are made of medical titanium alloy TC4 material, the diameter of the fixed shaft 7 is less than half of the diameter of the impeller itself, and the thickness of the blade in the impeller is not more than 1 mm. The stator coil is a three-phase coil, and the controller has a three-phase current-type PWM control function.

In order to avoid excessive suction for blood circulation, the power of the primary blood pump is required to be greater than that of the secondary blood pump. Among the present invention, the number of coil turns of the first-level driving stator 13 is greater than the number of coil turns of the second-level driving stator 12, and the length of the first-level impeller 3 is greater than the length of the second-level impeller 5 accordingly. Like this, when the controller gives the two driving stators When the coils provide the same control signal, the power of the primary blood pump will be greater than that of the secondary blood pump, which can simplify the device. Of course, the controller can also provide different control signals for the coils of the primary drive stator 13 and the secondary drive stator 12, so that the power of the two blood pumps can be adjusted respectively.

When the device works, the blood first flows through the first-stage blood pump to generate a blood pressure, and then passes through the second-stage blood pump to generate another blood pressure. The superimposition of the two blood pressures can reach the blood pressure required by the human body. This avoids the problem of red blood cell damage caused by increasing the impeller speed to achieve higher blood pressure when the single-stage pump is working. In order to further reduce the damage to red blood cells, that is, to reduce the speed of the blood pump, more stages of blood pumps can be used to achieve the required blood pressure. The structure of the blood pumps at all levels is the same as that introduced above, and is controlled by the controller respectively.

Claims (6)

1. improve the artificial heart blood pump of blood pressure step by step, comprise and drive stator and rotor, provide driving power by the controller that is connected with the driving stator, the driving stator that loop coil constitutes is positioned at the interlayer of cylinder blanket (14) and tubular inner chamber (10) formation, the one end sealing of shell (14), the other end is sealed by annular end cap (11); Contain a guide vane (1) that is positioned at inner chamber (10) front end of support rotor in the inner chamber (10) and be positioned at the tail guide vane (8) at inner chamber (10) rear portion, and be positioned at the rotor between a guide vane (1) and the tail guide vane (8); Its rotor is an impeller; And be provided with rectification tail cone (9) in inner chamber (10) rear end, it is characterized in that: this artificial heart blood pump is divided into front and back stages, and prime is the one-level blood pump, comprises one-level impeller (3), one-level driving stator (13); The back level is the secondary blood pump, comprises sencond stage impeller (5), secondary drive stator (12); Between one-level impeller (3) and sencond stage impeller (5), be provided with middle guide vane (4),,, and be used to support one-level impeller (3) and sencond stage impeller (5) simultaneously as a guide vane of secondary blood pump as the tail guide vane of one-level blood pump; One-level drives stator (13) and secondary drive stator (12) is driven respectively by controller, and guarantees the power of the power of one-level blood pump greater than the secondary blood pump.

2. the artificial heart blood pump that improves blood pressure step by step according to claim 1, it is characterized in that: described one-level drives the coil turn of the coil turn of stator (13) greater than secondary drive stator (12), and the length of one-level impeller (3) is greater than the length of sencond stage impeller (5), and controller can be exported identical control signal and drive stator (13) and secondary drive stator (12) to one-level at this moment.

3. the artificial heart blood pump that improves blood pressure step by step according to claim 1 is characterized in that: described one-level impeller (3) is enclosed within on the fixed axis (7) that is fixed on a guide vane (1), middle guide vane (4) and tail guide vane (8) central axis by one-level bearing (2).

4. the artificial heart blood pump that improves blood pressure step by step according to claim 1 is characterized in that: described sencond stage impeller (5) is enclosed within on the fixed axis (7) that is fixed on a guide vane (1), middle guide vane (4) and tail guide vane (8) central axis by secondary bearing (6).

5. according to each described artificial heart blood pump that improves blood pressure step by step among the claim 1-4, it is characterized in that: described one-level impeller (3) and sencond stage impeller (5) and middle guide vane (4) and tail guide vane (8) adopt helical blade, and the hand of spiral of one-level impeller (3) and sencond stage impeller (5) is opposite with the hand of spiral of middle guide vane (4) and tail guide vane (8).

6. the artificial heart blood pump that improves blood pressure step by step according to claim 1 is characterized in that: the connected mode according to one-level blood pump and secondary blood pump, plural blood pump is coupled together, and form multistage blood pump.

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