Patent Application
20140180028
Cardiovascular disease frequently arises from the accumulation of atheroma material on inner walls of vascular lumens, particularly arterial lumens of the coronary and other vasculature, resulting in a condition known as atherosclerosis. Atherosclerosis occurs naturally as a result of aging, but it may also be aggravated by factors such as diet, hypertension, heredity, and vascular injury. Atheroma and other vascular deposits restrict blood flow and can cause ischemia that, in acute cases, can result in myocardial infarction. Atheroma deposits can have widely varying properties, with some deposits being relatively soft and others being fibrous and/or calcified. In the latter case, the deposits are frequently referred to as plaque. Depending on the level of atheroma deposits which occlude the vessel, the diseased vessel is often called partially-occluded or total occluded vessel.
Treatment of cardiovascular disease often requires introduction of interventional and imaging catheters into the delicate vasculature. Prior to catheter introduction, a guidewire is typically inserted into the vessel-to-be-treated and then the catheter is moved over the guidewire to the location of the atheroma. In order to drive the guidewire the vessel-to-be-treated within vasculature, some guidewires have shapeable-flexible tips that may be pre-bent ex vivo by a physician into a shape that allows guidewire access into most lesions. However, the physician is often forced, during the procedure, to remove the guidewire and re-shape the tip to allow the guidewire to pass through specific tortuosities within the vasculature.
In addition, it is often desirable to take pressure and flow measurements within the vessel occluded by the atheroma. Previous techniques required introducing a catheter with pressure and flow sensors into the vessel. However, catheters are often too large in diameter to reach the vessel of interest or their size interferes with blood flow resulting in inaccurate pressure and flow measurements. In order to improve and streamline procedures, guidewires, which have significantly smaller diameters than catheters, have been designed to include miniature pressure and flow sensors near the distal tip of the guidewires. These guidewire are less disruptive to blood flow and are able to provide more accurate pressure and flow reading. However, the tips of the combo flow/pressure guidewires are often designed with more rigidity (i.e. less flexible and bendable) to avoid disruption of the sensor signal connections that run from the sensors to a proximal electrical hub. Because of this rigidity, the physician is often unable to maneuver the guidewire within the vessel such that the sensors on the guidewire tip are optimally positioned within the vessel to provide the most accurate measurements.
The invention recognizes that while the pre-bent shaped tips of current guidewires may sometimes allow an operator to pass a tortuous segment of a vessel, the pre-bent shape is not always the optimal tip shape for the guidewire once past the tortuous segment. For example, a pre-bent tip shape to maneuver a tortuous segment is not the best tip shape for allowing the guidewire to push through an obstructed vessel. In addition, the pre-bent tip shape may risk vessel perforation in vessels with smaller diameters. Moreover, current techniques often require that the physician, during the procedure, remove the guidewire in order to re-adjust the tip shape.
The present invention solves those problems by providing a guidewire with an adjustable tip that allows an operator to control the adjustment of the tip while the guidewire is disposed within the vasculature. The ability to adjust the tip in vivo greatly reduces procedure time in a complex tortuous anatomy and allows the operator to adjust the tip of the guidewire to fit the current procedural need for the tip within the vasculature. For example, the guidewire tip of the invention can be adjusted in vivo for the appropriate shape required to, for example, maneuver around a tortuous vessel segment, to remove an obstruction within a vessel, to pass through a small diameter vessel, and to minimize vessel puncture.
Of particular importance, devices of the invention provide for an adjustable guidewire tip that includes one or more sensors for monitoring the vessel environment. Unlike previous pressure/flow guidewires that require a rigid tip, the device of the invention is configured to have an adjustable tip without disrupting the sensor signal connections. Adjustable tips for sensing guidewires are especially desirable because often the guidewire tip needs to be adjusted in order to position the sensors within the vessel to obtain the most accurate measurements for, e.g., pressure and flow.
In certain aspects, the adjustable guidewire of the invention includes an elongate member and a core member extending through a lumen of the elongate member. The elongate member includes a distal portion and defines a longitudinal axis. The distal portion of the elongate member includes a coil segment, and at least a portion of the coil segment is compressible from a relaxed state, in which the coil segment aligns with the longitudinal axis, to a compressed state, in which the coil segment moves in a direction away from the longitudinal axis. The core member extends through the lumen of the elongate member and is coupled to the distal portion of the elongate member at a point on the distal portion. Typically, the core member couples to a distal tip of the distal portion. Because the core member is coupled to a distal portion of the elongate member, the elongate member can translate with respect to the core member. As a result, movement of the elongate member translates the elongate member relative to the core member and compresses the coil segment of the distal portion from the relaxed state to the compressed state. This compression causes the distal portion to bend relative to the longitudinal axis, and thereby adjusts the distal portion.
The distal portion of the adjustable guidewire may include one or more sensors. For example, the guidewire can include a pressure sensor (e.g. a crystalline semi-conductor sensor), a flow sensor (e.g an ultrasound transducer sensor), a temperature sensor, or combinations thereof. Preferably, the guidewire of the invention includes both a pressure sensor and a flow sensor on the distal portion. Pressure sensors are able to obtain pressure measurements and flow sensors are able to obtain blood velocity measurements within a blood vessel. The ability to measure and compare both the pressure and velocity flow significantly improves the diagnostic accuracy of ischemic testing.
Typically, the one or more sensors are positioned on the distal portion in a manner that causes the sensors move relative to the longitudinal axis along with the compressible distal portion. That is, the sensors are positioned to move along with the distal portion as the coil segment compresses from the relaxed state to the compressed state. In certain embodiments, the sensors are positioned in or coupled to a sensor housing. The sensor housing functions to contain and protect the sensors. The sensor housing can include an opening, and at least one sensor can be positioned in the opening.
In order to send and receive signals, the sensors of the guidewires may be coupled to one or more electrical connector wires. The one or more electrical connector wires extend through the elongate member and couple to an instrument via a connector. The configuration of the electrical connector wires within elongate member must not disrupt the sensor connection during tip adjustment. A preferred configuration of the electrical connector wires that prevents signal disruption includes embedding at least a portion of the electrical connector wires within the core member. The portions of the electrical connector wires that are not embedded can be connected to its respective sensor at the distal end.
The present invention generally relates to guidewires with adjustable tips that provide for a controlled bending of a distal portion of the guidewire. The guidewires of the invention allow an operator to manipulate an ex vivo proximal portion of a guidewire so that a distal portion of the guidewire disposed within a body lumen can be adjusted. The adjustable guidewires of the invention advantageously allow an operator to shape the distal portion of a guidewire during a procedure without having to remove the distal portion of the guidewire. Adjustable guidewires of the invention have a number of applications and advantages including, but no limited to, in vivo tip adjustment to maneuver a tortuous segment of a vessel, in vivo tip adjustment to a vessel having a small diameter, reduction in vessel perforation, in vivo tip adjustment to place sensors located on the distal portion in the best position within a vessel to obtain measurements, and in vivo tip adjustment to assist in vessel dissection.
The adjustable tip guidewires of the invention include non-sensing guidewires and sensing guidewires. In certain embodiments, an adjustable guidewire of the invention includes one or more sensors to obtain intraluminal measurements, such as pressure and flow measurements. In this embodiment, the adjustable guidewire of the invention allows the operator to adjust the tip to better position the sensors within the vessel. As described and illustrated hereinafter, the guidewire of the invention includes one or more sensors and sensor associated components. However, one could remove the sensors of the sensing guidewire to create a non-sensing adjustable guidewire.
The elongate body member 100 further includes an elongate shaft 116 operably coupled to the coil segment 112. The elongate shaft 116 defines a lumen extending from the proximal portion 102 to the distal portion 104. The coil segment 112 also defines a lumen extending therethrough. The core member or wire 150 extends through the lumens of the elongate shaft 116 and coil segment 112 and couples or is affixed to the distal portion 104 at a point on the distal portion 104 (see
The distal portion 104 of flexible elongate member 100 may include one or more coil segments 112. The coil segments 112 can vary in length along the elongate member 100. The coil segment 112 provides additional flexibility to the elongate member 100. Suitable materials for the coil segment 112 include stainless steels, radioopaque metals, platinum alloys, palladium alloys, and any other metals or alloys. The longer the length of the coil segment 112 is along the flexible elongate member 100 the greater the flexibility. In certain embodiments, the coil segment 112 is divided into to two regions, the tip coil and the proximal coil. The tip coil is a portion of the coil segment 112 closer to a distal tip 110 of the elongate member 100. The proximal coil 112 is a portion of the coil segment closer to the elongate shaft 116. The spacing between coils of the coil segment 112 can increase or decrease the flexibility of the coil segment 112. For example, a tightly wound coil, i.e. minimum spacing between coils, increases rigidity of the coil segment and a loosely wound coil, i.e. increased spacing between coils, increases flexibility of the coil segment.
According to certain embodiments, at least a portion of the coil segment 112 includes a compressible bendable portion that is configured to bend or move relative to the longitudinal axis x of the elongate member 100. The compressible portion of coil segment 112 includes increased coil spacing. In certain embodiments, the coil spacing of the compressible portion is sufficient to bend the coils from straight to approximately perpendicular to the longitudinal axis when the coils are compressed. In certain embodiments, the coil spacing of the compressible portion is greater than about 15% spacing (which is the spacing to coil ratio in the compressible region).
The coil segment 112 defines a lumen and the bendable portion of the coil segment 112 is compressible from a relaxed state, as shown in e.g.
In certain embodiments, the distal portion 104 of the flexible elongate member 100 includes a distal tip 110. The tip 110 may be rounded into a dome-like shape. This allows the guidewire to follow the curve of the vessel and is generally called an atraumatic tip. In certain embodiments, a sensor, such as an ultrasound transducer for measuring flow, is coupled to the distal tip 110. The core member 150 extending through a lumen of the flexible elongate member 100 may connect to an inner surface of the distal tip. In certain embodiments and as shown, a sensor housing 120 couples to and/or forms the distal tip 110 of the flexible elongate member 1000. Alternatively, the coil segment 112 can be coupled to the distal tip 110 of the flexible elongate member 100, as shown in
A sensor housing 120 may be positioned on the elongate member 100. The sensor housing 120 includes a housing body that defines a lumen. One or more cavities may be shaped into the walls of the sensor housing to form windows for sensors disposed or mounted therein. The sensor housing is preferably positioned between the coil segment 112 and the distal tip 110. In certain embodiments, the sensor housing 120 directly couples to the distal tip 110. In other embodiments, another coil segment may be between the sensor housing 120 and the distal tip 110. This additional coil segment provides for a softer, more flexible distal end. In this manner, the sensor housing 120 is sandwiched between coil segments. With this positioning, the sensor housing 120 moves along with the compressible bending portion of the coil segment when it is compressed from a relaxed state to the compressed state (See
The coil segment 112 may be coupled to the flexible elongate shaft 116, sensor housing 120, or distal tip 110 using any suitable design and/or manufacturing techniques. For example, the flexible elongate shaft may be coupled to the coil segment by solder or adhesive. In one embodiment, the ends of the coil segment are integrated into the connected ends of the elongate shaft 116 and sensor housing 120. For example, the elongate shaft and sensor housing may include cut-outs, such as the cut-outs 160 shown in
The proximal portion 102 of the elongate body 100 is the portion of the guidewire left outside a patient during a procedure for handling by the operator. The proximal portion 102 includes a gripping member 118 coupled to the elongate shaft 116 of the elongate body 100. The gripping member 118 allows a user to move the elongate shaft 116 towards the distal tip 110 relative to the core member 150. The gripping member 118 defines a lumen that receives a portion of the core member 150 there through. The gripping member 118 and the elongate shaft 116 are configured to slide in the distal and proximal directions relative to the core member 150, which remains fixed to a point on the distal portion 104 that is distal to the coil segment 112.
A proximal end of the core member 150 may be connected to a handle. The operator can hold the handle and slideably move the gripping member 118 and elongate shaft 116 over and along the core member 150. This embodiment is ideal for adjustable guidewires of the invention that do not include sensors. Alternatively and as shown, the proximal end of core member 150 can be removeably coupled to a connector housing 106. In addition to receiving the proximal end of the core member 150, the connector housing 106 may also removeably connect to and receive one or more electrical connection wires (not shown) that run the length of the elongate body 100 and connect to one or more sensors on the distal portion 102. This removable connection allows one to disconnect the guidewire from the connector housing 106 when placing a catheter over the guidewire and reconnect the guidewire thereafter to prove electrical communication to the sensors. The connector housing 106 may include one or more electrical connections that mate with the electrical conductor wires. In certain embodiments, at least a portion of the core member is operably associated with one or more electrical conductor wires. For example, the proximal end of the core wire 150 can form an electrical male connector 162 (as shown in
In certain embodiments, a proximal end of the elongate body 100 can be coupled to a torque element that causes rotation of the elongate body 100. In order to provide uniform rotation of the elongate body 100 (e.g. simultaneous rotation of the core member 150, coil segment 112, elongate shaft 116, ect.), the gripping member 118 may include a locking element that fixes the elongate shaft 116 relative to the core member 150. The locking element prevents unintended rotation of the elongate member 116 relative to the core member 150.
The coil segment 120 of the elongate member 100 includes a compressible, bendable portion 210 as shown in, e.g.
As further shown in
In certain aspects, the distal portion 104 of the elongate member 100 includes one or more sensors 114. The sensors 114 provide a means to obtain intraluminal measurements within a body lumen and are connected to one or more electrical conductor wires 300, which transmit and receive signals from the sensors 114. For example, the guidewire of the invention can include a pressure sensor, a flow sensor, a temperature sensor or combinations thereof. Preferably, the guidewire is a combination guidewire that includes both a pressure sensor and a flow sensor. Pressure sensors can be used to measure pressure within the lumen and flow sensors can be used to measure the velocity of blood flow. Temperature sensors can measure the temperature of a lumen. A guidewire with both a pressure sensor and a flow sensor provides a desirable environment in which to calculate fractional flow reserve (FFR) using pressure readings, and coronary flow reserve (CFR) using flow readings.
The ability to measure and compare both the pressure and velocity flow and create an index of hyperemic steno sis resistance significantly improves the diagnostic accuracy of this ischemic testing. It has been shown that distal pressure and velocity measurements, particularly regarding the pressure drop-velocity relationship such as Fractional Flow reserve (FFR), Coronary flow reserve (CFR) and combined P-V curves, reveal information about the stenosis severity. For example, in use, the guidewire may be advanced to a location on the distal side of the stenosis. The pressure and flow velocity may then be measured at a first flow state. Then, the flow rate may be significantly increased, for example by the use of drugs such as adenosine, and the pressure and flow measured in this second, hyperemic, flow state. The pressure and flow relationships at these two flow states are then compared to assess the severity of the stenosis and provide improved guidance for any coronary interventions. The ability to take the pressure and flow measurements at the same location and same time with the combination tip sensor, improves the accuracy of these pressure-velocity loops and therefore improves the accuracy of the diagnostic information.
A pressure sensor allows one to obtain pressure measurements within a body lumen. A particular benefit of pressure sensors is that pressure sensors allow one to measure of FFR in vessel. FFR is a comparison of the pressure within a vessel at positions prior to the stenosis and after the stenosis. The level of FFR determines the significance of the stenosis, which allows physicians to more accurately identify clinically relevant stenosis. For example, an FFR measurement above 0.80 indicates normal coronary blood flow and a non-significant stenosis. Another benefit is that a physician can measure the pressure before and after an intraluminal intervention procedure to determine the impact of the procedure.
A pressure sensor can be mounted on the distal portion of a flexible elongate member. In certain embodiments, the pressure sensor is positioned distal to the compressible and bendable coil segment of the elongate member. This allows the pressure sensor to move along with the along coil segment as bended and away from the longitudinal axis. The pressure sensor can be formed of a crystal semiconductor material having a recess therein and forming a diaphragm bordered by a rim. A reinforcing member is bonded to the crystal and reinforces the rim of the crystal and has a cavity therein underlying the diaphragm and exposed to the diaphragm. A resistor having opposite ends is carried by the crystal and has a portion thereof overlying a portion of the diaphragm. Electrical conductor wires can be connected to opposite ends of the resistor and extend within the flexible elongate member to the proximal portion of the flexible elongate member. Additional details of suitable pressure sensors that may be used with devices of the invention are described in U.S. Pat. No. 6,106,476. U.S. Pat. No. 6,106,476 also describes suitable methods for mounting the pressure sensor 104 within a sensor housing.
In certain aspects, the guidewire of the invention includes a flow sensor. The flow sensor can be used to measure blood flow velocity within the vessel, which can be used to assess coronary flow reserve (CFR). The flow sensor can be, for example, an ultrasound transducer, a Doppler flow sensor or any other suitable flow sensor, disposed at or in close proximity to the distal tip of the guidewire. The ultrasound transducer may be any suitable transducer, and may be mounted in the distal end using any conventional method, including the manner described in U.S. Pat. No. 5,125,137, 6,551,250 and 5,873,835.
In certain embodiments, one or more electrical connection wires are coupled to one or more sensors. The electrical connection wires can include a conductive core made from a conductive material, such as copper, and an insulative coating, such as a polymide, fluoropolymer, or other insulative material. The electrical connection wires extend from one or more sensors located on the distal end of the guidewire, run down the length of the guidewire, and connect to a connector housing at a proximal end.
Any suitable arrangement of the electrical connection wires through the length of the elongate member can be used. The arrangement of electrical connection wires must provide for a stable connection from the proximal end of the guidewire to the distal end of the guidewires. In addition, the electrical connection wires must be flexible and/or have enough slack to bend and/or move with the adjustable distal portion without disrupting the sensor connection. In one embodiment, the electrical connections run next the core member within the lumen of the elongate member. In another embodiment, the electrical connection wires 300 are wrapped around the core member 150, as shown in
In yet another embodiment, the electrical connector wires 300 are embedded on the core member 150. For example, the electrical connection wires 300 are wrapped around the core member 150 (as shown in
As discussed, a proximal end of the electrical connection wires 300 connects to a connector housing, such as connector housing 106 in
The male connector mates with a female connector of the connector housing.
The connector housing, such as connector housing 106 in
In some embodiments, a user interacts with a visual interface to view images from the imaging system. Input from a user (e.g., parameters or a selection) are received by a processor in an electronic device. The selection can be rendered into a visible display. An exemplary system including an electronic device is illustrated in
Processors suitable for the execution of computer program include, by way of example, both general and special purpose microprocessors, and any one or more processor of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, (e.g., EPROM, EEPROM, solid state drive (SSD), and flash memory devices); magnetic disks, (e.g., internal hard disks or removable disks); magneto-optical disks; and optical disks (e.g., CD and DVD disks). The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.
To provide for interaction with a user, the subject matter described herein can be implemented on a computer having an I/O device, e.g., a CRT, LCD, LED, or projection device for displaying information to the user and an input or output device such as a keyboard and a pointing device, (e.g., a mouse or a trackball), by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well. For example, feedback provided to the user can be any form of sensory feedback, (e.g., visual feedback, auditory feedback, or tactile feedback), and input from the user can be received in any form, including acoustic, speech, or tactile input.
The subject matter described herein can be implemented in a computing system that includes a back-end component (e.g., a data server 413), a middleware component (e.g., an application server), or a front-end component (e.g., a client computer 449 having a graphical user interface 454 or a web browser through which a user can interact with an implementation of the subject matter described herein), or any combination of such back-end, middleware, and front-end components. The components of the system can be interconnected through network 409 by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include cell network (e.g., 3G or 4G), a local area network (LAN), and a wide area network (WAN), e.g., the Internet.
The subject matter described herein can be implemented as one or more computer program products, such as one or more computer programs tangibly embodied in an information carrier (e.g., in a non-transitory computer-readable medium) for execution by, or to control the operation of, data processing apparatus (e.g., a programmable processor, a computer, or multiple computers). A computer program (also known as a program, software, software application, app, macro, or code) can be written in any form of programming language, including compiled or interpreted languages (e.g., C, C++, Perl), and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. Systems and methods of the invention can include instructions written in any suitable programming language known in the art, including, without limitation, C, C++, Perl, Java, ActiveX, HTML5, Visual Basic, or JavaScript.
A computer program does not necessarily correspond to a file. A program can be stored in a portion of file 417 that holds other programs or data, in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub-programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network.
A file can be a digital file, for example, stored on a hard drive, SSD, CD, or other tangible, non-transitory medium. A file can be sent from one device to another over network 409 (e.g., as packets being sent from a server to a client, for example, through a Network Interface Card, modem, wireless card, or similar).
Writing a file according to the invention involves transforming a tangible, non-transitory computer-readable medium, for example, by adding, removing, or rearranging particles (e.g., with a net charge or dipole moment into patterns of magnetization by read/write heads), the patterns then representing new collocations of information about objective physical phenomena desired by, and useful to, the user. In some embodiments, writing involves a physical transformation of material in tangible, non-transitory computer readable media (e.g., with certain optical properties so that optical read/write devices can then read the new and useful collocation of information, e.g., burning a CD-ROM). In some embodiments, writing a file includes transforming a physical flash memory apparatus such as NAND flash memory device and storing information by transforming physical elements in an array of memory cells made from floating-gate transistors. Methods of writing a file are well-known in the art and, for example, can be invoked manually or automatically by a program or by a save command from software or a write command from a programming language.
References and citations to other documents, such as patents, patent applications, patent publications, journals, books, papers, web contents, have been made throughout this disclosure. All such documents are hereby incorporated herein by reference in their entirety for all purposes.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting on the invention described herein. Scope of the invention is thus indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
This application claims the benefit of and priority to U.S. Provisional Ser. No. 61/740,554, filed Dec. 21, 2012, which is incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61740554 | Dec 2012 | US |
