Abstract
A system (10) for moving an intravascular medical device (85) in a vascular network (V) comprises a magnetic actuator (40), a controlling unit (50) and a controlling line driver (60). The controlling line driver (60) is adapted to hold and/or to release a controlling line (70) attached to the medical device (85) at different speeds. The magnetic actuator is adapted to generate a magnetic field (41) at a predetermined location in order to pull the medical device (85) in a pre-determined direction. The controlling unit (50) is adapted to balance at least three forces applied on the medical device (85) and to operate the magnetic actuator (40) and/or the controlling line driver (60).
Claims
1-17. (canceled)
18. A system for moving, in a vascular network, an intravascular medical device including a magnetic part in a head section and a controlling line in a back section, the system comprising: a magnetic actuator; a controlling unit; a controlling line driver; wherein the controlling line driver is adapted to hold and/or to release at different speeds the controlling line when the controlling line is attached to the controlling line driver, wherein the magnetic actuator is adapted to generate a magnetic field at a location in order to pull the medical device, and wherein the controlling unit is adapted to balance at least three forces applied on the medical device.
19. The system according to claim 18, wherein the controlling unit is adapted to balance at least four forces applied on the medical device.
20. The system according to claim 18, wherein the controlling unit is adapted to take into account a friction force induced by the controlling line with the blood vessel walls.
21. The system according to claim 18, wherein the controlling unit is adapted to balance the contact forces induced by the head section with the blood vessel walls.
22. The system according to claim 18, wherein the system comprises at least two magnetic actuators and wherein the controlling unit is adapted to control the at least two magnetic actuators.
23. The system according to claim 18, wherein the controlling unit has an interface for receiving intraoperative data from an imaging system, wherein the controlling unit is adapted to locate the position of the medical device.
24. The system according to claim 18, wherein the controlling unit is adapted to compute the forces based on trajectory data that are representative for a predetermined vascular path.
25. The system according to the claim 24, wherein the controlling unit has an interface for the user to enter the trajectory data.
26. The system according to claim 18, wherein the controlling unit is adapted to control the controlling line driver to slow down and/or to stop the displacement of the medical device when moving at least one magnetic actuator to a next position.
27. The system according to claim 18, wherein the controlling line driver comprises a force sensor.
28. The system according to claim 18, wherein the controlling line driver comprises at least one interface to trigger and/or power at least one function of the medical device.
29. The system according to claim 18, wherein the controlling line driver and/or the controlling line is embedded into a sterile feature.
30. The system according to claim 18, comprising multiple controlling line drivers, wherein the controlling unit is adapted to operate the magnetic actuator and the multiple controlling line drivers to control the navigation of multiple medical devices.
31. The system according to claim 18, further comprising means for controlling and/or reducing blood flow in a vessel.
32. The system according to claim 18, comprising at least two controlling line drivers wherein the controlling unit is adapted to independently control the at least two controlling line drivers.
33. A method of treating or diagnosing a patient, comprising the steps of introducing a medical device in a vessel of a patient; computing balanced forces applied on the medical device to create a resulting force able to move the medical device along a pre-determined path; operate at least one magnetic actuator to create at least one magnetic field at at least one pre-determined location; and adapting the releasing velocity of a controlling line attached to the medical device.
34. The method according to claim 33, comprising the further steps of stopping the medical device prior to a bifurcation.
Description
[0099] In the following, the invention is described in detail with reference to the following figures, showing:
[0100] FIG. 1a-1d: a first embodiment of a controlling line driver in use;
[0101] FIG. 2a-2b: a third embodiment of a controlling line driver;
[0102] FIG. 3a-3b: a fourth embodiment of a controlling line driver;
[0103] FIG. 4a-4b: a fifth embodiment of a controlling line driver;
[0104] FIG. 5: schematically a user interface of a controlling unit;
[0105] FIG. 6: a medical device being navigated in a vessel of a patient;
[0106] FIG. 7: a medical device being navigated in a vessel by a system for moving a medical device;
[0107] FIG. 8: a first embodiment of a system for moving a medical device;
[0108] FIG. 9: a second embodiment of a system for moving a medical device;
[0109] FIGS. 10a-10c: a schematic illustration of a magnetic actuator;
[0110] FIG. 11: a schematic illustration of multiple medical devices being moved in a vessel by a system for moving a medical device;
[0111] FIG. 12: a schematic illustration of the working principle of the actuation device.
[0112] FIG. 13: a schematic illustration of the forces acting on a medical device.
[0113] FIGS. 14a-14c: schematically a medical device with three controlling lines.
[0114] FIGS. 15a-15c: schematically a medical device with two controlling lines.
[0115] FIG. 16a-16b: schematically a system including a medical device and an additional device to influence blood flow in a vessel.
[0116] FIG. 17a-17b: schematically an alternative system with a medical device and a device to influence blood flow in a vessel.
[0117] FIG. 18: schematically an alternative device to influence blood flow in a vessel.
[0118] FIG. 1a shows an embodiment of a controlling line driver 60. The controlling line driver 60 comprises and electric motor 62 For clarity, a connection to a controlling unit (see FIG. 9) is ommitted. It will be understood that the controlling unit may be connected to the controlling line driver 60 by any means known in the art, such as cables or wireless connections (such as Bluetooth, wireless LAN, infrared ports, or others). The controlling line driver 60 further comprises an axel 61 which is in operable connection with the electric motor 62. The axel is adapted to receive a controlling line 70, which can be rolled around the axel 61. Rotation of the axel 61 releases or pulls in the controlling line 70. The controlling line driver 60 further comprises a clamp 63. Here, the clamp 63 is shown in an open arrangement, allowing the controlling line 70 to move freely through the clamp. Thus, release, stop, or pull-in of the controlling line 70 is controlled only via the axel 61. Here, a medical device head section 80 is attached to the controlling line 70. The position of the medical device is controllable by the controlling line driver 60 and the axel 61 via movement of the controlling line 70.
[0119] FIG. 1b shows the controlling line driver 60 of FIG. 1a, wherein the clamp 63 is shown in closed configuration. Thus, the controlling line 70 can be stopped and held independently of movement of the axel 61. For example, the medical device 85 may temporarily be held and secured without using power for the electric motor 62. Closing the clamp 63 to hold the controlling line 70 may also be advantageous to secure the medical device 85 via the controlling line in case of a malfunction of the controlling line driver 60. The clamp 64 may, however, be used to stop and/or hold the controlling line 70 at any time and for any reason.
[0120] FIG. 1c shows the controlling line driver 60 of FIGS. 1a and 1b, wherein the controlling line 70 is released by rotation of the axel while the clamp 63 is closed. Thus, an accumulation 71 of controlling line forms within the controlling line driver 60 between the axel 61 and the clamp 63. Here, the clamp 63 is closed and the medical device 85 (via the controlling line 70) is held.
[0121] FIG. 1d shows the embodiment of FIGS. 1a-1c, wherein the clamp 63 is opened after the release of the controlling line within the controlling line driver 70 and the formation of an accumulation of controlling line as shown in FIG. 1c. Thus, the medical device 85 is allowed to flow substantially freely within a fluid such as blood until the controlling line 70 is extended as shown here. The method of operating a controlling line driver 60 as shown here is particularly advantageous to reduce tension in the controlling line 70 during navigation, for example if no bifurcations are to be navigated for a certain path. It will be understood that a force exerted on the medical device 85 by the controlling line 70 when navigated as shown in FIGS. 1c and 1d is temporarily substantially 0, and that a controlling unit (see FIG. 9) may balance the magnetic force with drag force accordingly.
[0122] FIG. 2a shows a controlling line driver 60 that is substantially similar to the controlling line driver of FIGS. 1a-1c. However, in the present embodiment, no clamp (see FIG. 1a) is arranged. Thus, the velocity of the controlling line 70 may directly controlled by the axel 61. The medical device head section 80, when attached to the controlling line 70, thus moves at a maximum velocity controlled by the velocity of the controlling line 70 and the release velocity of the controlling line driver 70. Typically, a user may decide to navigate the medical device 85 at a velocity lower than the velocity of a blood flow surrounding that medical device. In such a case, the velocity of the medical device substantially corresponds to the release velocity of the controlling line 70 determined by the rotation speed of the axel and the electric motor 62. Thus, a controlling unit (see e.g. FIG. 9) may be employed to control the movement of the medical device 85 via control of the electric motor 62. It will be understood, however, that a user may also choose to release, via the controlling unit, the controlling line 70 at a faster speed than the velocity of the blood flow in order to move the medical device head section 80 at substantially the velocity of the blood flow.
[0123] FIG. 2b shows the embodiment of FIG. 2a wherein the controlling line has been released further and the medical device 85 has moved downstream accordingly.
[0124] FIG. 3a shows a further embodiment of a controlling line driver 60. The embodiment shown here is similar to the embodiments shown in FIGS. 1-1d and FIGS. 2a-2b. In the present embodiment, the controlling line driver further comprises a force sensor 64 adapted to detect a pull force exerted on the controlling line and/or the medical device head section 80. When the medical device 85 is only surrounded by blood, for example, and has not encountered any obstacles, the medical device is typically substantially propelled by the drag force exerted by the blood, wherein the controlling line 70 may slow the medical device 85 down. Thus, the pull force measured by the force sensor 64 may provide a correlation with a drag force by the blood flow. It may thus be possible to calculate a drag force based on the release velocity of the controlling line 70 and the force measured by the force sensor 64.
[0125] FIG. 3b shows the embodiment of FIG. 3a, wherein the medical device 85 has encountered an obstacle, here a thrombus 101. Thus, the movement of the medical device is slowed down, and a tension in the controlling line 70 is decreased. The force sensor 64 thus measures a lower force. On one hand, this allows to balance other forces as disclosed herein, for example to increase or decrease a magnetic force and/or the release velocity of the controlling line 70 accordingly. On the other hand, it may also be possible to detect obstacles 101 by analysis of the force data provided by the force sensor 164.
[0126] Additionally or alternatively, optical sensors may be used to monitor bending and/or a change in diameter and/or crosssectional area or shape of the controlling line 70, which may in turn be used to calculate a force acting on the controlling line 70 and/or the medical device head section 80.
[0127] FIG. 4a shows a further embodiment of a controlling line driver which is similar to the embodiments of FIGS. 1a-1d, FIGS. 2a-2b, and FIGS. 3a-3b. Here, the controlling line driver 60 further comprises a trigger 65 adapted to trigger a function of the medical device head section 80 (and/or the medical device 85). Specifically, the trigger 65 may comprise optical fibers, fluid transmission tubes for liquids or gases, electrically conductive fibers or wires, or wireless signal transmission means.
[0128] FIG. 4b shows the controlling line driver after the trigger 65 has stimulated the medical device 85 may perform an action 81, or example a release of a drug, mechanical removal, cutting, obliteration, heating, cooling, release of an adhesive, and/or inducement of thrombosis.
[0129] FIG. 5 shows a user interface 90 for a controlling unit (see FIG. 9). The user interface 90 has multiple screens 91, 92, 93, 94 showing treatment and/or navigation characteristics. Here, the interface 90 comprises a first screen 91 that shows a patients' vasculature V. The first screen 91 is configured as a touch screen and allows a user to define a target area G and/or a preferred trajectory T. Here, the target G was defined and the controlling unit has calculated automatically an optimal trajectory T. The trajectory is saved as data in a memory (not shown). A second subscreen 92 shows the vasculature with the position of the medical device 85. A third subscreen 93 shows controlling line driver parameters and provides an input interface by being configured as a touchscreen. When controlled automatically, the third subscreen may display actual values such as a rotation velocity, a device velocity and/or stimuli activation (see FIGS. 4a-4b). A user may, however, also set certain device velocity, wherein the controlling unit may determine other parameters (such as release velocity of the controlling line, magnetic forces, etc.) automatically to reach the desired value set by the user. A fourth subscreen 94 displays parameters of a magnetic actuator (see FIGS. 10a-10c and FIG. 11). Similar to the third subscreen, actual values may be displayed such that a user may monitor them. A user may also set certain values, if desired. Preferred values that can be displayed and/or set via the fourth subscreen are position and orientation in x-, y- and z-directions in space, displacement velocity of the magnetic actuator, and/or distance of the magnetic actuator to a patient. It will be understood that other parameters may be displayed or set in addition or as an alternative.
[0130] FIG. 6 shows a concept wherein a medical device 85 is moved in a vessel V in order to reach a target area G. Here, a blood drag force F2 and a magnetic force F1 act on the medical device. Thus, although the medical device 85 is moved generally in the direction of the magnetic force F1, the drag force F2 is strong enough to move the medical device to a second position 82 and subsequently to a third position which correspond to a vessel branch away from the target.
[0131] FIG. 7 shows a medical device 85 which is navigated by a system according to the invention. The medical device head section 80 is attached to a controlling line 70 which provides a third force F3 to the medical device, in addition the blood drag force F2 and the magnetic force F1. Because the system detects the drag force F2 (see, for example, FIGS. 3a-3b), the system may, via the controlling unit (see FIG. 9) balance and set the pullback force F3 and the magnetic force F1 such that the total force acting on the medical device 85 moves the medical device to a second position 82 and subsequently to a third position 83 in the direction of a target area G.
[0132] FIG. 8 shows a system 10 according to the invention. The system comprises controlling unit 50, which is in operable connection with a magnetic actuator 40 and a controlling line driver 60. The controlling line driver 60 may, for example, be any controlling line driver 60 shown and described herein, and is connected to a controlling line 70. The controlling line 70 is inserted into a vessel of a patient P and holds a medical device head section 80. Here, the medical device 85 is guided to a head of the patient to treat a vessel in the brain.
[0133] FIG. 9 shows a system 10 according to the invention which is similar to the system of FIG. 8. In addition, the system shown here further comprises an imaging system 11. The imaging system may in particular be an ultrasound imaging system, a Doppler ultrasound imaging system, a fluoroscope, PET scanner, CT scanner, MRI system, or any other imaging system known in the art.
[0134] FIGS. 10a-10c schematically show different magnetic actuators 40 that may be used with any of the systems 10 described herein. The magnetic actuators 40 shown here comprise electromagnets. By means of the controlling unit (see FIGS. 8 and 9), the characteristics of the magnetic field 41 in order to create a magnetic force acting on the medical device at its position.
[0135] FIG. 10a shows the magnetic actuator 40, wherein the controlling unit controls the power and direction of electricity such that the strength of the magnetic field 41, here illustrated by the density and number of lines 41, is moderate. The magnetic field is oriented from up to down (symbolized by arrows) and may have a strength of up to 75 Millitesla. It will be understood that the magnetic field strength values shown herein are of exemplary nature and may of course be configured to any value, in particular values lower than the ones shown here.
[0136] FIG. 10b shows the magnetic actuator 40 of FIG. 10a, wherein the controlling unit is controlling the electromagnet such that the magnetic field strength is set to higher value, as compared to the embodiment of FIG. 10a, of 150 Millitesla (illustrated by the higher density of lines 8). The magnetic field direction is set from down to up.
[0137] FIG. 10c, shows the magnetic actuator 40 of FIGS. 10a and 10b is controlled by the controlling unit such that the magnetic field 41 has a strength of 75 millitesla and the direction of the magnetic field is oriented from down to up, i.e. in the same direction compared to FIG. 10b and opposite direction compared to FIG. 10a.
[0138] FIG. 11 shows an exemplary embodiment of a system 10 according to the invention. The system comprises a controlling unit 50 which is in operable connection with three magnetic actuators, 42, 43, 44 and four controlling line drivers 60, 60′, 60″, 60′″. Each controlling line driver 60, 60′, 60″, 60′″ is connected to one controlling line 70, 70′, 70″, 70′″ each. Each controlling line 70, 70′, 70″, 70′″ is in turn attached to a medical device head section 80, 80′, 80″, 80′″. The controlling unit 50 is adapted to operate on several bifurcations B1, B2. Here, the vessel V is a carotid and comprises two bifurcations B1, B2 that into several branches V1, V1′, V1″, V2′, V2″. The four medical device head sections 80, 80′, 80″, 80′″ each comprise a magnetic microparticle 84 for interaction with a magnetic field 41′, 41″, 41′″. Two magnetic actuators 42, 44 are arranged such that they each create a magnetic field 41″, 41′″ with predefined characteristics at the first bifurcation B1. Here, the magnetic actuator 41 creates a magnetic field 41″ that pushes the medical devices the branch V1′. By contrast, the magnetic actuator 44 creates a magnetic field 41′″ that accelerates the moving elements into the branch V1″. However, the magnetic actuators 42, 44 are configured to only create relatively weak magnetic field. By slowing down the medical device head sections 80, 80′, 80″, 80′″ to a velocity lower than the blood flow velocity by means of the controlling line drivers 60, 60″, 60′″ and the controlling lines 70, 70′, 70″, 70′″, the magnetic fields 41″, 41′″ are nevertheless sufficient to guide the medical devices toward the branch V1″. The controlling unit 50 calculates the maximum velocity of the medical device head sections 80, 80′, 80″, 80′″ such that the magnetic force exerted by the magnetic actuators 42, 44 is sufficient for guiding and controls the controlling line drivers 70, 70′, 70″, accordingly, such that the controlling lines are released at a corresponding speed. At the second bifurcation B2, another magnetic actuator 43 creates a magnetic field 41′ that is adapted to move the medical device head sections 80, 80′, 80″, toward the branch V2′ and away from the branch V2″. The system 10 shown here enables to navigate medical device head sections 80, 80′, 80″, 80′″ along a path that is complex and would not be accessible by passive moving and/or magnetic guiding with two forces as known in the art.
[0139] FIG. 12 schematically shows a possible working principle of a controlling unit according to the invention when it comprises a feedback loop. A part of the body of a patient P is imaged by an imaging unit 11. The controlling unit 50 is adapted to analyze the images, for example to determine the position of the moving element with respect to a bifurcation. Based on that information, the controlling unit 50 controls the magnetic field and/or the controlling line, in particular by moving and/or powering a magnetic actuator and/or controlling the controlling line driver, such as to guide the medical device depending on a desired trajectory. This process can be repeated multiple times if necessary.
[0140] FIG. 13 schematically illustrates a force balancing model which may be used to with a device and system according to the invention. A medical device 85 is shown in a vessel including a controlling line 70. The forces acting on the medical device 85 are: [0141] Hydrodynamic force F.sub.d [0142] Gravitational force F.sub.g [0143] Adhesion force F.sub.adh [0144] Friction force F.sub.f [0145] Normal contact force on the surface F. [0146] Magnetic force F.sub.ext [0147] Force F.sub.line exerted by the controlling line 70
[0148] The hydrodynamic force F.sub.d, the gravitational force F.sub.g, and the adhesion force F.sub.adh, Friction force F.sub.f and the normal contact force on the surface F.sub.n are forces that occur inherently when a medical device 85 is immersed in a blood stream. The magnetic force F.sub.ext and the force F.sub.line exerted by the controlling line 70 are artificially exerted and controlled by the system according to the invention.
[0149] The combination of the different forces described above determines the speed vector (orientation & intensity) and therefore the movement of the medical device 85 in the vessel V.
[0150] The motion of the medical device 85 may be described using the following equation (where m is the mass of the medical device and v.sub.r its velocity):
[00001]
[0151] The purpose of the force balancing is to determine necessary forces to be exerted by the system that, combined with the naturally occurring forces will generate a speed vector suitable to move the medical device 85 along a pre-determined trajectory.
[0152] In particular, the force balancing as described above allows to stop, to pull back, to take a bifurcation and/or to steer the medical device 85 in a vessel with reduced flow.
[0153] The different forces can be pre-determined, estimated, measured directly, measured indirectly, or neglected.
[0154] To illustrate the above, two exemplary calculations using the above model are shown. Two sizes of medical devices (1.2 mm and 0.6 mm) are modelled for two different bifurcations (internal carotid artery segment 1, hereinforth ICA1-R, to internal carotid artery segment 2, hereinforth ICA2; and ICA2 to anterior cerebral artery segment 1, hereinforth ACA1):
[0155] A medical device head section 80 with a size of 1.2 mm would need to be subjected to a magnetic force of 2.9.Math.10.sup.−6 N by a magnetic actuator having a volume of 400 cm 3 and which is placed at a distance of 45 cm to pass the ICA1-R to ICA2 bifurcation. To pass the ICA2 to ACA1 bifurcation, a force of 8.9.Math.10.sup.−5 N and a distance of 17 cm is necessary.
[0156] Similar calculations for a medical device head section 80 with a size of 0.6 mm yield 3.7.Math.10.sup.−6 N at a distance of 24 cm (ICA1-R to ICA2) and 5.4.Math.10.sup.−5 N at a distance of 10 cm (ICA2 to ACA1).
[0157] The equation shown above allows to estimate the acceleration (i.e. speed variation) of a medical device taking into the different forces acting on it.
[0158] Typically, all force acting on the device 80 are known except the force F.sub.line of the controlling line 70. Thus, the force balance equation may be solved by either one of two ways: [0159] estimate the force exerted by the controlling line 70 and compute the acceleration of the medical device 85 [0160] determine the acceleration of the medical device and compute the resulting force exerted by the controlling line 70.
[0161] There is an equivalence between the acceleration of the medical device head section 80 and the force exerted by the controlling line force 70. It is possible to determine force exerted by the controlling line 70 from the acceleration of the medical device 85 or to determine the acceleration of the medical device head section 80 from the force exerted by the controlling line 70.
[0162] For example, in one configuration of the system, the speed or the acceleration of the medical device can be controlled by controlling the speed at which the controlling line driver (not shown) releases the controlling line 70. The force exerted by the controlling line 70 can be determined from the speed/acceleration of the medical device.
[0163] FIGS. 14a-15b show different embodiments of medical device 85 with several controlling lines 70′, 70″, 70′″.
[0164] FIG. 14a shows an embodiment of a medical device 85 with three controlling lines 70′, 70″, 70′″. Each controlling line 70′, 70″, 70′″ is attached to a controlling line driver 60, 60′, 60″ and may be controlled independently. The controlling line drivers may be independent or integrated in one unit.
[0165] FIG. 14b shows the medical device 85 of FIG. 14a in a fluid stream (e.g. blood). Here, the medical device 85 is intended to flow substantially straight and with the fluid flow. Accordingly, all three controlling lines 70′, 70″, 70′″ exerted the same force on the medical device 80.
[0166] FIG. 14b shows the medical device 85 of FIGS. 13a-13b during a steering motion. Here, the controlling line 70′″ has been loosened while controlling lines 70′, 70″ still exert a force on the medical device head section 80. As a consequence, the medical device 85 is steered in the direction of controlling lines 70′, 70″.
[0167] In the shown embodiment, the medical device is attached to three controlling lines 70′, 70″, 70′″ that can be independently activated by the controlling line driver (not shown). By adjusting the tension of the different controlling lines, the system may modify the position of the medical device in the blood stream and may change the forces acting on it.
[0168] This control can help to balance the forces acting on the medical device 85 such as to orient the medical device toward the flow stream leading to the targeted artery.
[0169] The tension or the force on the different controlling lines 70′, 70″, 70′″ can be controlled by the release/rewind speed/movement of the different controlling lines.
[0170] FIG. 15a shows and alternative embodiment of a medical device which is similar to the embodiment of FIGS. 14a-14c. Here, only two controlling lines 70′, 70″ are attached to the medical device head section 80. Each controlling line 70′, 70″ is attached to a controlling line driver 60, 60′ and may be controlled independently.
[0171] FIG. 15b shows the medical device 85 in a blood stream flowing substantially with the blood stream. Both controlling lines 70′, 70″ exert substantially the same force on the medical device 85.
[0172] FIG. 15c shows the medical device 85 of 15b wherein the controlling line 70″ has been loosened such as to steer the medical 85 substantially as described in the context of FIG. 13c.
[0173] It will be understood that any number of controlling lines may be used depending on the intended application. The embodiments shown in FIGS. 14 and 15 with three and two controlling lines, respectively, are of exemplary nature.
[0174] In general, a higher number of controlling lines may be advantageous as it allows for more versatile and precise steering. By contrast, fewer controlling lines may allow for easier and cheaper manufacturing and easier operation of the medical device.
[0175] It is conceivable that one or more controlling lines are configured to be rotatable, in particular such as to rotate the medical device. Preferably, several or all controlling lines would be rotatable around the same axis.
[0176] Additionally or alternatively, at least two controlling lines may be configured as a spiral, in particular an elastic spiral. Thus, a rotation of the medical device may be induced by the controlling lines. The controlling lines, due to the spiral shape, may exert a torque on the medical device. A release mechanism may be used to release the spiraled controlling lines.
[0177] It is also conceivable that one or multiple lines are adapted to pick up and/or release a ballast. For example, a chamber may be adapted to be opened or closed via the controlling line. A ballast, for example saline, may be released by opening the closed chamber. It is also conceivable that the closed chamber contains gas or vacuum and opening it causes picking up of blood, thus increasing the weight of the medical device. In particular, a nitinol spring may be used to open and/or close the chamber. FIG. 16a shows a catheter device 100 used to deliver a medical device 85 to a general area to be treated. The medical device head section 80 is attached to a controlling line 70 and may be navigated by any means described herein.
[0178] FIG. 16b shows the catheter device of FIG. 16a. Here, a balloon 101 attached to the catheter device 100 and arranged at its distal end has been inflated such as to limit the blood flow through the vessel to be treated.
[0179] It will be understood that such a balloon may be used optionally with any of the medical devices 85 disclosed herein. Furthermore, additionally or alternatively, any other means to control and/or limit blood flow may be used, for example other inflatable means, drugs, patient orientation, and/or a contention system. A patient may be oriented appropriated and stabilized using a pillow, for example.
[0180] A contention system may in particular be understood as a system that is adapted to apply a pressure to a patient's skin. The pressure is adapted to compress an artery such as to modify blood flow, in particular reducing or stopping the blood flow.
[0181] FIG. 17a shows schematically a medical device navigating the Willis circle trough an internal carotid. In general, it may be challenging to navigate a medical device in the posterior communicating artery from the internal carotid as the blood flow is generally low in the posterior communicating artery due to incoming flow from the posterior cerebral artery.
[0182] FIG. 17b shows the medical device substantially in the same position as shown in FIG. 17a. In order to reduce to flow in the posterior cerebral artery and to increase the flow in the posterior communicating artery, a second medical device 100, which is configured here as a medical device substantially as described herein and additionally comprises an inflatable balloon 101, is introduced in the posterior cerebral artery to temporarily reduce the blood flow. It will be understood that the second medical device may additionally or alternatively comprise or be formed by a catheter device.
[0183] Blocking or decreasing the blood flow in the posterior cerebral artery can increase blood flow from the carotid artery to the posterior communicating artery and can facilitate the navigation of the medical device.
[0184] It will be understood that a system according to the invention may thus comprises a device for reducing or controlling blood flow which is integrated in the medical device 85 and/or catheter device 100 for delivery, or configured as a separate part of the system which may be deployed entirely independently from the medical device 85.
[0185] FIG. 18 shows an alternative embodiment of a device 110 to reduce and/or control blood flow configured as a neck contention device. The device 110 is configured to compress the carotids to reduce the blood flow therein. Here, the compression device 110 is configured as a flexible ring attachable around the neck of a patient. In the internal side, the ring is divided into flexible parts which are activatable to compress the tissue underneath it. For example, mechanical compression may be achieved by inflating a balloon or using a micro-actuator.
