METHOD FOR FORMING A BLOOD FLOW IN SURGICALLY RECONSTITUTED SEGMENTS OF THE BLOOD CIRCULATORY SYSTEM AND DEVICES FOR CARRYING OUT SAID METHOD

• US 20110152599A1
• Filed: 08/09/2007
• Published: 06/23/2011
• Est. Priority Date: 08/09/2007
• Status: Active Grant

• Current Assignee: Alexandr Yurievich Gorodkov, Gennady Iraklievich Kiknadze, Leo Antonovich Bokeriya
• Original Assignee: Alexandr Yurievich Gorodkov, Gennady Iraklievich Kiknadze, Leo Antonovich Bokeriya
• Inventors: Gorodkov, Alexandr Yurievich, Bokeriya, Leo Antonovich, Kiknadze, Gennady Iraklievich
• Granted Patent: US 8,123,670 B2
• Time in Patent Office: Days
• US Class Current: 600/16
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61F 2/2412 with soft flexible valve members, e.g. tissue valves shaped like natural valves check valves with flexible valve members in general F16K15/14
• CPC Class Codes: A61F 2002/068 Modifying the blood flow model, e.g. by diffuser or deflector
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0039 differing in diameter
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2206/16 Rotating swirling helical flow, e.g. by tangential inflows
• CPC Class Codes: A61M 60/148 in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices
• CPC Class Codes: A61M 60/178 drawing blood from a ventricle and returning the blood to the arterial system via a cannula external to the ventricle, e.g. left or right ventricular assist devices
• CPC Class Codes: A61M 60/196 replacing the entire heart, e.g. total artificial hearts [TAH]
• CPC Class Codes: A61M 60/523 using blood flow data, e.g. from blood flow transducers
• CPC Class Codes: A61M 60/894 Passive valves, i.e. valves actuated by the blood
• CPC Class Codes: G06T 17/00 Three dimensional [3D] modelling, e.g. data description of 3D objects
• CPC Class Codes: G06T 2210/41 Medical
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders

Abstract

The invention relates to clinical cardiology and cardiovascular surgery. The method for forming a blood flow in research stands and in surgically reconstructed segments of the blood circulation system comprises diagnosing the individual condition of a patient'"'"'s blood circulation system; measuring the blood flow velocity field in the heart chambers and great vessels; comparing the parameters measured against the physiological norm; determining parameters forming a swirled blood flow; and modeling an individual swirled blood current in the blood circulation system being diagnosed, the streamlined surfaces and guide elements of flow channels of the blood circulation system reconstructed being given shapes conforming to the flow lines of the restored normally swirled blood flow in accordance with formulas:

$\begin{array}{cc}Q\left(t\right)={\left[z+Z_0\left(t\right)\right]}^2& \left(1.1\right)\\ \varphi ={\varphi }_0+k\left(t\right)z& \left(1.2\right)\\ k\left(t\right)={\Gamma }_0\left(t\right)/4\pi Q\left(t\right)C_0\left(t\right)V_z=2C_0\left(t\right)zV_r=-C_0\left(t\right)rV_{\varphi }=\frac{{\Gamma }_0\left(t\right)}{2\pi r}\left\{1-\exp \left[\frac{-C_0\left(t\right)r^2}{2v}\right]\right\}& \left(1.3\right)\end{array}$

wherein: V_r, V_z, and V_φ are the radial, longitudinal, and tangential velocities of the swirled current; v is the kinematic viscosity of the medium; φ₀ is the initial swirling angle in relation to the flow axis normal; φ, z and r are current values of the angular, longitudinal, and radial coordinates along the flow line; and Q(t), Z₀(t), k(t), Γ₀(t), and C₀(t) are parameters of the swirled blood flow variable over time because of the non-stationary current and corresponding to the individual normal indicators for a physiologically swirled blood flow. The normal indicators are established by routine examination of a representative sample of patients having no changes in the cardiovascular system. A vessel prosthesis comprises a tube having an internal surface in contact with the blood flow provided with a pattern to swirl the blood flow in accordance with formulas (1.1 to 1.3) conforming to a specific localization of the segment being reconstructed. A cannula for para-corporeal perfusion devices comprises a flow channel having an internal surface that is provided with a longitudinal pattern to swirl the blood flow, the shape of the pattern being determined from formulas (1.1 to 1.3), relative to the specific localization of the point where the cannula is inserted into the vessel channel. A heart valve prosthesis comprises one or more shutoff elements arranged symmetrically in the center of a body of round and/or oval cross-section, the streamlined surfaces of the valve being provided with a pattern in accordance with formulas (1.1 to 1.3). A blood pump comprises a flow swirling unit, a flow channel, and valves at the inlet and outlet of the channel, the surface washed over by blood being provided with a relief variable over time in accordance with formulas (1.1 to 1.3). A swirling device comprises an end piece having a streamlined surface provided with guides in the form of ribs, grooves, or blades of a shape defined by formulas (1.1 to 1.3), the swirling angle of the guides relative to the flow axis being varied optionally an operator or by a special-purpose device for modeling different current conditions.

Claims

1. (canceled)

2. (canceled)

3. (canceled)

4. (canceled)

5. A vessel prosthesis comprising a tube having an internal surface that is provided with a pattern for swirling the blood flow in accordance with formulas:

6. The prosthesis as claimed in claim 5, wherein the internal surface thereof is provided with a relief consisting of areas of originally smooth surface alternating with curved areas in the form of depressions, each formed by quadric convex and concave surfaces joined along common tangents, a depression being joined to the originally smooth surface by convex surfaces producing slopes for which the originally smooth surface in the joint areas is a tangent.

7. The prosthesis as claimed in claim 6, wherein the tube is made of an elastic bio- and hemo-compatible material, for example, a woven synthetic fabric, that makes the shape of the flow section of the blood flow channel consistent with the normal blood flow parameters Q(t) and Z₀(t) along the vessel channel over the full cardiac cycle.

8. A cannula for para-corporeal perfusion devices comprising a flow channel having an internal surface that is provided with a longitudinal pattern for swirling the blood flow in accordance with formulas:

9. The cannula as claimed in claim 8, wherein the internal surface thereof is provided with a relief consisting of areas of originally smooth surface alternating with curved areas in the form of depressions, each formed by quadric convex and concave surfaces joined along common tangents, a depression being joined to the originally smooth surface by convex surfaces producing slopes for which the originally smooth surface in the joint areas is a tangent.

10. The cannula as claimed in claim 8, wherein at least a part of the channel is provided with guides in the form of ribs, or grooves, or blades at a swirling angle:

φ

=φ

₀+k(t)z

wherein;

φ

₀ is the initial swirling angle in relation to the flow axis normal;

φ and

z are current values of the angular and longitudinal coordinates along the flow line; and

k(t) is a parameter of a non-stationary swirled blood flow that corresponds to the individual normal indicators for a specific localization of the point where the cannula is inserted into the vessel channel.

11. The cannula as claimed in claim 8 made of an elastic material, wherein its flexibility results in consistency of the parameters Q(t) and Z₀(t) with the individual normal indicators along the flow channel at each moment of the cardiac cycle.

12. A heart valve prosthesis, comprising one or more shutoff elements arranged symmetrically at the center of a body of round and/or oval cross-section, the streamlined surfaces of the valve being provided with a pattern in accordance with formulas:

13. The prosthesis as claimed in claim 12, wherein the streamlined surface of the shutoff elements and body is provided with a relief consisting of areas of originally smooth surface alternating with curved areas in the form of depressions, each formed by quadric convex and concave surfaces joined along common tangents, a depression being joined to the originally smooth surface by convex surfaces producing slopes for which the originally smooth surface in the joint areas is a tangent.

14. A blood pump comprising a flow compression unit, a flow channel, and valves at the inlet and outlet of the channel, the surface washed over by blood being provided with a relief variable over time in accordance with formulas:

15. The pump as claimed in claim 14, wherein the surfaces washed over by blood are provided with a relief consisting of areas of originally smooth surface alternating with curved areas in the form of depressions, each formed by quadric convex and concave surfaces joined along common tangents, a depression being joined to the originally smooth surface by convex surfaces producing slopes for which the originally smooth surface in the joint areas is a tangent.

16. The pump as claimed in claim 14, further comprising on the outlet part of the streamlined surface of the flow channel guides in the form of ribs, or grooves, or blades at a swirling angle:

φ

=φ

₀+k(t)z,

wherein;

φ

₀ is the initial swirling angle in relation to the flow axis normal;

φ and

z are current values of the angular and longitudinal coordinates along the flow line; and

k_s(t) is a parameter of a swirled blood flow variable over time that corresponds to the normal indicator for the systolic flow.

17. The pump as claimed in claim 14, wherein the inlet part of the streamlined surface is provided with guides in the form of ribs, or grooves, or blades at a swirling angle:

φ

=φ

₀+k_d(t)z,

wherein;

φ

₀ is the initial swirling angle in relation to the flow axis normal;

φ and

z are current values of the angular and longitudinal coordinates along the flow line; and

k_d(t) is a parameter of a swirled blood flow variable over time that corresponds to the normal indicator for the diastolic flow.

18. A pump as claimed in claim 14, wherein the valves at the inlet or outlet thereof are heart valve prostheses;

the heart valve prosthesis comprising one or more shutoff elements arranged symmetrically at the center of a body of round and/or oval cross-section, the streamlined surfaces of the valve being provided with a pattern in accordance with formulas;

19. The pump as claimed in claim 14, wherein the cannulas and channels each comprise a flow channel having an internal surface that is provided with a longitudinal pattern for swirling the blood flow in accordance with formulas:

20. (canceled)

21. (canceled)