Abstract:
An improved needle for directional placement of the needle into or to a target area, such as a blood vessel or organ, for the purpose of performing an invasive procedure with a minimal amount of trauma to the target area. The needle comprises a connection hub, a needle shaft, and a flexible tip member connected to a distal end of the needle shaft to facilitate maneuvering the needle through tortuous passages within the body. The flexible tip member includes a blunt end that prevents or reduces trauma to tissues and vessels that are contacted with the distal portion of the needle during positioning of the needle. The invention further comprises a flexible-tipped needle having a balloon sealingly attached to a distal end of the spring tip member. The flexible-tipped balloon needle includes an inflatable balloon sealingly connected to the distal end of the flexible tip member. An alternate embodiment comprises a flexible-tipped needle having a balloon sealingly connected, via apertures in the needle shaft, to the bore within the needle shaft of the spring tip member. The invention also includes a flexible-tipped needle having an insulated needle shaft, an insulated flexible-tip member, a blunt conductive end and a conductive wire extending from said blunt conductive end to an apparatus for sending or receiving electromagnetic signals.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a divisional of application Ser. No. 08/925,523, filed Sep. 8, 1997, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an improved needle for directional and atraumatic placement of the needle into a vascular system or body tissue for the purpose of performing multiple invasive procedures. 
     2. State of the Art 
     Needles and needle systems are used extensively in a wide variety of procedures which are performed in various fields of medicine, such as cardiology, radiology, urology, interventional pain management, and internal medicine. The use of needles and needle systems in invasive procedures in various medical fields has become routine due, in part, to the ability of needles to pass through most tissues without causing significant destruction to the tissues. 
     Conventional hypodermic needles, such as those used with hypodermic syringes in the administration of intravenous fluids, are well known in the medical arts. Hypodermic needles such as these are usually used in conjunction with various types of disposable hypodermic syringes for administration of medications like antibiotics, narcotics, biologicals, and vitamins. Hypodermic needles are also utilized in a number of diagnostic and therapeutic procedures, such as aspiration, blood draws, and biopsies. As more fully described in conjunction with FIG. 1 below, hypodermic needles are typically made of metal, consist of a hub that locks to a tip of the hypodermic syringe by friction or through a locking mechanism (known as Luer-Lock™), and typically include a point (usually in the form of a beveled cutting edge) of varying diameter and length. 
     Another widely-used type of needle system includes a system that employs a catheter and guide member. Such needle systems generally include a small guide member (e.g., guide wire) which is used to guide a larger hollow catheter to a target area (e.g., a vessel, body cavity, tissue, or organ) within a human or animal body. In use, the guide member is directed to the proximity of the target area using a hollow cannula or needle. The cannula is inserted into the body and positioned with its distal end in contact with or adjacent to the target area within the body. The guide member is advanced through the cannula to the target area. The cannula is then removed and the catheter is advanced over the guide member and into or to the target area. The guide members of these intravascular catheterization systems typically consist of a rigid wire or rod and a flexible tip that enables the guide member to be directed around obstacles and through curved vessels without causing damage to tissues or body structures as the tip of the guide member is advanced into or to the target area of the body. The guide member is advanced to the desired location within the body through a cannula. The cannula is then removed and a catheter is advanced over the guide member to the target area within the body. 
     Intravascular catheterization systems, such as those described above, have proven useful and efficient for both therapeutic and diagnostic purposes. For example, intravascular catheterization therapies, such as angioplasty and atherectomy, have been developed and widely used to treat vascular diseases or other conditions that occlude or reduce the lumen size of portions of a patients vascular system. In particular, balloon angioplasty has proven to be a useful and commonly-used treatment for obstructive coronary diseases. Additionally, intravascular catheterization systems have been used to perform various diagnostic procedures, such as angiographies, blood flow measurements, and ultrasonic imaging. These intravascular diagnostic systems may be used in conjunction with the aforementioned therapeutic intravascular catheterization systems or may be used in conjunction with other invasive techniques, such as coronary surgery. 
     Due to the small size or position of the target area and the tortuous passages through the patient&#39;s vasculature, positioning of a catheter or needle to such target areas can be a difficult and time consuming task requiring considerable skill on the part of the health-care provider. Although currently-available intravascular catheters that employ a separate guide member provide advantages relating to placement, these catheters obtain this advantage at the expense of size and stability. Accordingly, there is a need for needles and needle systems that possess very small profiles and that can be positioned in narrow, tortuous regions of a vasculature or in a target area having critical dimensions in the body of an animal or person. 
     SUMMARY OF THE INVENTION 
     The present invention relates to an improved needle for directional placement of the needle into or to a target area, such as a blood vessel or organ, for the purpose of performing an invasive procedure with a minimal amount of trauma to the target area. The needle comprises a connection hub, a needle shaft, and a flexible tip member connected to a distal end of the needle shaft to facilitate maneuvering the needle through tortuous passages within the body. The flexible tip member includes a blunt end that prevents or reduces trauma to tissues and vessels that are contacted with the distal portion of the needle during positioning of the needle. 
     The invention further comprises a flexible-tipped needle having a balloon sealingly attached to a distal end of the flexible tip member. The flexible-tipped balloon needle includes an inflatable balloon sealingly connected to the distal end of the flexible tip member. The inflatable balloon has an interior portion that is in fluid communication with a first bore located within the hub and a second bore located within the needle shaft. The flexible-tipped balloon is intended for use in a number of procedures requiring dilatation of target areas within the body, such as a ureter for the evacuation of stones or blood vessels for treating hardening or blockage of the vessels. Alternatively, or in addition to the balloon connected to the distal end of the flexible tip member, the flexible-tipped needle can include a balloon that surrounds and is scalingly connected to the needle shaft. 
     The invention also includes a flexible-tipped needle having an insulated needle shaft, an insulated flexible-tip member, a blunt conductive end and a conductive wire extending from the blunt conductive end to an apparatus for sending or receiving electromagnetic signals. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     While the specification concludes with claims particularly pointing out and distinctly claiming that which is regarded as the present invention, the advantages of this invention can be more readily ascertained from the following description of the invention when read in conjunction with the accompanying drawings in which: 
     FIG. 1 is a side view of a prior art hypodermic needle, partly magnified to illustrate the configuration of a distal tip or end; 
     FIG. 2 is a side view of a spring tip needle made in accordance to the principles of the present invention and illustrates, in a partly-magnified view, the configuration of a flexible tip member attached to the shaft of the needle; 
     FIG. 3 is a cross-sectional view of the spring tip needle of the present invention, further illustrating the relative position of the spring tip needle in relation to a stylet and a guiding catheter which can be used in conjunction with the spring tip needle; 
     FIG. 4 is a side view of a second embodiment of the spring tip needle of the present invention which includes an inflatable balloon at a distal end of the flexible tip member; 
     FIG. 5 is a side view of a third embodiment of the spring tip needle of the present invention which includes an inflatable balloon disposed between the hub of the needle and the flexible tip member of the needle; 
     FIG. 6 is a side view of a fourth embodiment of the spring tip needle of the present invention which includes an inflatable balloon disposed between the hub of the needle and the flexible tip member of the needle and another inflatable balloon at a distal end of the flexible tip member; 
     FIG. 7 is a side view of a fifth embodiment of the spring tip needle of the present invention which includes a conductive tip for sending or receiving electromagnetic signals; and 
     FIG. 8 is a side view of a sixth embodiment of the spring tip needle of the present invention which includes a flexible tip; 
     FIG. 9 is a cross-sectional view of a seventh embodiment of the spring tip needle taken along lines  9 — 9  of FIG. 2 which includes an round shaped spring tip and needle shaft; 
     FIG. 10 is a cross-sectional view of an eighth embodiment of the spring tip needle which includes an oval shaped spring tip and needle shaft; 
     FIG. 11 is a side view of a ninth embodiment of the spring tip needle of the present invention which includes a flexible tip member having spaced apart coils; 
     FIG. 12 is an end view of a tenth embodiment of the flexible tip member of the spring tip needle which includes a sealing barrier at the distal end of the flexible tip member; and 
     FIG. 13 is a cross-sectional view of an eleventh embodiment of the spring tip needle of the present invention which includes a stylet that is curved at a distal end thereof. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates a representative prior art hypodermic needle or cannula  20  including a needle shaft  22 , a hub  24 , and a needle tip  26 . This prior art structure is shown in order to more fully describe the novelty of the present invention. The hub  24  is typically made of a plastic material and is shaped to lock to a syringe tip by friction or, alternatively, is shaped to interlock with a threaded syringe tip (as seen in Luer-Lock™ syringe systems). Attached to the hub  24  is the needle shaft  22 , which is made of any suitable metal or alloy, such as stainless steel or hyperchrome steel. The hub  24  can additionally include a “bead” or stop  32  at an end opposite the end used for attachment of the hub  24  to the syringe. 
     The needle shaft  22  is attached to and in fluid communication with the hub  24  (or the bead  32 ) and is substantially rigid. Interior walls of the needle shaft  22  define a bore thercthrough to allow passage of fluid through the needle shaft  22 . Prior art needles are particularly characterized by their tips  26 , which typically consist of long, tapering reinforced points  28  and beveled edges  30  of varying degrees. This particular configuration of the tips  26  varies according to the intended use. For example, long-bevel or long-taper needles are usually used for administering local anesthesia, aspirating, and subcutaneous administration. Short-bevel needles are usually used for intravenous administration and transfusions. 
     In contrast to the prior art hypodermic needle  20  shown in FIG. 1, FIG. 2 illustrates a spring-tip needle  40  configured in accordance with a first embodiment of the present invention. For purposes of simplicity, structures and elements shared in common between the prior art device and various embodiments of the present invention will be numbered identically. The spring-tip needle  40  includes the hub  24  that is in fluid communication with the needle shaft  22 . Adjacent to the hub  24  is shown a stylet base  48 , which is attached to a stylet  52  (FIG. 3) that, when inserted, is disposed within the hub  24 , the needle shaft  22 , and a spring tip  42  of the spring-tip needle  40 . The spring-tip needle  40  can also include the bead  32 , which is interposed between and in fluid communication with the needle shaft  22  and the hub  24 . Unlike the prior art needle  20  of FIG. 1, the spring-tip needle  40  does not include the tip  26 , or the reinforced points  28  and beveled edges  30  therein. Also, unlike most conventional needles having a round shaft, the needle shaft  22  of the spring-tip needle  40  can alternately be oval in shape. 
     In place of the tip  26 , the spring-tip needle  40  includes the spring tip  42 , which is attached to and in fluid communication with the needle shaft  22 . The spring tip  42  serves to safely guide the spring-tip needle  40  through the tortuous passages of the vasculature or to a defined target area within the patient&#39;s body. The spring tip  42  can be attached to the needle shaft  22  by any suitable means (e.g., soldering, bonding, or molding). At a distal end of the spring tip  42  is a blunt end  44 . Blunt end  44  is preferably an open-ended extension of the spring tip  42  which provides fluid communication with the hub  24 , needle shaft  22 , and spring tip  42 . In such open-ended embodiments, blunt end  44  consists of a smooth-rimmed band or collar which allows for passage of the spring tip  42  in atraumatic fashion so that damage to tissue or vasculature does not occur. Alternatively, blunt end  44  can consist of a close-ended cap, which essentially blocks passage of fluids into or out of spring-tip needle  40 . In such a “capped” embodiment, the spring tip  42  can be made to have a spread between the individual coils therein so as to permit passage of fluid through the soils of the spring tip  42 . 
     As illustrated in FIG. 2, the external diameter or outer periphery of spring tip  42  is preferably equal to or less than the external diameter or outer periphery of the needle shaft  22 . The diameters of the needle shaft  22  and the spring tip  42  are of any desirable gauge. For most applications the diameters typically range from 12-gauge (large diameter) to 27-gauge, although larger and smaller dimensions are commonly used for special procedures. The length of the spring-tip needle  40  and the needle shaft  22  can be of any desirable length depending on the specific procedure being performed, but is usually a length in the range between ¼ to 9 inches for most intravenous administration procedures. 
     Operation and use of the spring-tip needle  40  can best be described with reference to FIG. 3, which depicts a partially-magnified cross-sectional view of the spring-tip needle  40  of FIG.  2  and which further illustrates the guide wire or stylet  52  and a guiding cannula  56  that can be used in conjunction with the spring-tip needle  40 . For example, when access to a blood vessel is desired, the stylet  52  is inserted into and through the hub  24 , the needle shaft  22 , and the spring tip  42 . The stylet  52  can be made of any material, but preferably consists of a material that is “malleable,” that is, which is bendable yet sufficiently rigid to maintain a desired shape when the spring-tip needle  40  is steered through a patient&#39;s vascular system. Alternatively, the stylet  52  can be made of a rigid material having either a straight or curved configuration. It is contemplated that the hub  24 , needle shaft  22 , and spring tip  42  have a sufficiently large diameter and size to accommodate the stylet  52 . 
     In order to facilitate the introduction of the spring-tip needle  40  into an orifice or to aid in venipuncture, the guiding cannula  56  can be used. As shown in FIG. 3, the inner diameter of the guiding cannula  56  must be sufficiently large to accommodate the spring tip  42  and the needle shaft  22 , and should be sufficiently flexible to permit passage of a spring-tip needle that has a bent configuration, while retaining the bend. The guiding cannula  56  can be any suitable catheter typically used for accessing vasculature or for accessing any other target area, such as tissue or an organ. The guiding cannula  56  includes a tip  58  and a beveled edge  60  to facilitate insertion of the guiding cannula  56  into tissue or vasculature. Insertion of the guiding cannula  56  into the patient is preferably performed with the spring-tip needle  40  already inserted therein. Alternatively, the site of entry into the patient can be independently accessed with the guiding cannula  56  prior to the insertion of the spring-tip needle  40  therein. 
     After the guiding cannula  56  has been positioned in the target area (e.g., patient&#39;s vessel), the spring-tip needle  40  is advanced to the target area. For example, where access to a particular area of a patient&#39;s vasculature is desired, the spring-tip needle  40  is advanced through the guiding cannula  56  and into the blood vessel. If it is desired to rotate the spring-tip needle  40 , and in particular the spring tip  42 , into a particular portion of the vessel (e.g., such as an angled portion of the vessel), the bent stylet  52  can be rotated by maneuvering the stylet hub  48  to cause rotation of the spring tip  42  (or a distal extremity thereof). To assist in positioning of the spring-tip needle  40  within the patient&#39;s body, a distal portion of the stylet  52  or the spring tip  42  can be marked with a radiopaque substance, so that movement of the marked section can be observed under a viewing device (e.g., a fluoroscope). Once the intended procedure has been performed, the spring-tip needle  40  and guiding cannula  56  can be withdrawn, leaving the spring-tip needle  40  in place. 
     Alternatively, the aforementioned procedure can be carried out by advancing the spring-tip needle  40  to a target area through the guiding cannula  56 . Once the spring-tip needle  40  has reached a desired place, such as a blood vessel, the stylet  52  can be removed from within the spring-tip needle  40 . Because the spring tip  42  is no longer held in a particular configuration by the stylet  52 , the spring-tip needle  40  can be freely advanced through the vessel. Due to the combination of the blunt end  44  and the spring tip  42 , which together follow the contours of the pathways (i.e., vessels or cavities) of the body through which they travel, the spring-tip needle can be safely advanced through a curved vessel or target area without the typically-experienced tissue trauma. 
     FIG. 4 illustrates another embodiment of the spring-tip needle of the present invention. The spring-tip needle  68  of FIG. 4 is similar to the spring-tip needle  40  described thus far, except that spring-tip needle  68  further includes an inflatable balloon  70  attached to the distal end of the spring tip  42 . The balloon  70  (shown inflated) extends distally from the distal end  69  of the spring tip  42 . In its deflated state, the balloon  70  is substantially contained within the spring tip  42 . The balloon can be made of any suitable material, such as a polyolefin, which is expandable, non-toxic, and flexible. 
     The balloon  70  is in fluid communication with the hub  24  and needle shaft  22  of the spring-tip needle  68 . Preferably, the balloon  70  is sealably connected to the distal end  69  of spring tip  42  by any suitable adhesive and sealing material, such as a cyanoacrylate or epoxy material. Such a configuration facilitates the use of the stylet  52 , if such use is desired, by allowing the stylet  52  and the balloon  70  to simultaneously extend through the needle shaft  22  and the spring tip  42 . Alternatively, the balloon  70  can be connected to an internal portion of the needle shaft  22  and positioned to extend through the inside of the spring tip  42 . 
     The balloon length will vary depending upon the size of the spring-tip needle  68 , which needle can have a length up to about two feet for most applications. Therefore, the length of the balloon  70  should be sufficient to permit fluid communication throughout the spring-tip needle  68  and extension beyond the distal end of the spring tip  42  following inflation of the balloon  70 . The balloon can be made and shaped to permit expansion of an exposed portion (that portion of the balloon  70  shown in FIG. 4) to any desirable diameter, which will naturally depend on the dimension of the area being dilated with the balloon. 
     In use, the spring-tip needle  68  is positioned at a desired location by following the technique described in conjunction with FIG.  3 . Once the spring tip  42  is positioned at a desired location, the balloon is inflated by activating an inflation/deflation device (not shown). The inflation/deflation device is used to inflate or deflate the balloon  70  at the distal end of the spring-tip needle  68 . The inflation/deflation device is sealably connected to the hub  24  or, alternatively, is connected to a mating member which is, in turn, connected to the hub  24 . Inflation of the balloon  70  causes radially directed stretching forces to be applied to the areas surrounding the balloon  70 . This technique can be applied to a number of procedures, such as, dilatation of a ureter for the evacuation of stones, dilatation of blood vessels for treating hardening or blockage of a vessel (e.g., angioplasty procedures), and dilatation of nerve areas to create a lesion in specific nerves. Use of the spring-tip needle  68  is only limited by the inventiveness of the health care practitioner. 
     Due to the small dimensions of the spring-tip needle  68 , more than one spring-tip needle  68  can be advanced and positioned to carry out the aforementioned procedures. For example, once the first spring-tip needle  68  has been placed in the appropriate position and the tissue plane has been established, a second spring-tip needle  68  can be passed to the same or an adjacent location. Additionally, where advantageous, dilatation of a target area can be accomplished by introducing a plurality of spring-tip needles  68  through multiple sites, such as by accessing a number of different merging blood vessels. 
     FIG. 5 illustrates an alternative embodiment of a spring-tip needle having an attached balloon. The spring-tip needle  78  of FIG. 5 is functionally similar to the spring tip needle  68  described in conjunction with FIG. 4, except that spring-tip needle  78  includes a balloon  90  that surrounds the needle shaft  22 , as opposed to having a balloon that is attached to the distal end of the spring tip  42 . The spring-tip needle  78  includes a blunt end  44  that consists of a close-ended cap, which essentially blocks passage of fluids into or out of spring-tip needle  78 . Specifically, a proximal end of the balloon  90  (shown inflated) is secured to the spring-tip needle  78  anywhere along the needle shaft  22 , preferably at a point distal to the hub  32 . A distal end of the balloon  90  is secured to a distal end  96  of the needle shaft  22 , preferably at a position adjacent the spring tip  42 , such as the junction  96 . 
     The interior of the balloon  90  is in fluid communication with the needle shaft  22  of the spring-tip needle  78  via one or more apertures  92  on the needle shaft  22 . The balloon ends are attached or secured to the needle shaft  22  by any suitable adhesive and sealing material, such as epoxy. The balloon length will vary depending upon the size of the spring-tip needle  68  and the desired area of balloon contact. 
     The balloon can be made and shaped to permit expansion of an exposed portion thereof to any desirable diameter and to a length covering up to the entire length of the needle shaft  22 . In use, positioning and inflation of spring-tip needle  78  can be accomplished by following the technique described in conjunction with FIG.  4 . Alternatively, the embodiments of FIGS. 4 and 5 can be combined to include two balloons, one surrounding the needle shaft  22  and the other attached to the distal end of the spring tip  42  (wherein blunt end  44  consists of an open-ended extension of the spring tip  42 ), as illustrated in FIG.  6 . 
     In FIG. 7 is shown yet another embodiment of the present invention used to provide electrical or radiofrequency stimulation to a target area. This alternate embodiment of the spring-tip needle  80  is structurally similar to the spring-tip needle  40  of FIG. 2, except that the needle shaft  72  and the spring tip  74  are insulated to the distal end of the spring tip  74 . The needle shaft and the spring tip  74  can be made of insulative materials or, alternatively, can be covered with a layer of insulative materials. Suitable insulative materials include any material known in the art having sufficient mechanical strength and good electrical and thermal insulating properties. 
     Conductive tip  76  is identical in shape and form to the blunt end  44  of FIG.  2  and is made of any material having good conductive characteristics, such as gold, copper, steel, and alloys thereof. The size of the conductive tip  76  varies according to use and the desired area of contact, most preferably ranging in size from about 2 mm to about 15 mm in length and from about 25 gauge to about 12 gauge in diameter. The conductive tip  76  is connected to an external energy source (e.g., an electromagnetic generator, such as an electrical, laser, or radiofrequency generator), which transfers energy from the generator through a conductive wire or, alternatively, through internal portions of the needle shaft  72  and spring tip  74  having insulated exteriors, and to the conductive tip  76 . Alternatively, where a larger area of contact is desired, only a portion of spring tip  74  can be made or covered with a layer of insulative materials so as to expand the area of conductivity beyond the conductive tip  76 . 
     In operation, the spring-tip needle  80  is positioned at a desired location by following the technique described in conjunction with FIG.  3 . Once the conductive tip  76  is positioned at or near a target site, the energy generator is activated to supply power via wires to the conductive tip  76 . In this fashion, target site tissue (e.g., heart tissue) is exposed to electrical or radiofrequency power to correct a particular problem (e.g., tachycardia or arrhythmia). The conductive tip  76  may alternatively or additionally include electrodes that are connected to external monitoring equipment, such as EKG machines or other monitoring and mapping equipment, to receive signals and data from the target area for various purposes, such as diagnosing electrical cardiac impulses. 
     FIG. 8 illustrates a modified embodiment of the spring-tip needle of FIG. 2, wherein a flexible tip  86  replaces the spring tip  42 . Like the spring tip  42  of FIG. 2, the flexible tip  86  of the instant flexible tip needle  84  includes an open-ended blunt end  88  at the terminal end thereof. The flexible tip  86  provides the same functional advantages of the spring tip  42 , but is made of a thermoplastic material, such as polyethylene, having the same flexibility and high strength characteristics. The flexible tip  86  is sealably connected to the distal end of the needle shaft  22  by any suitable means, such as by way of heat bonding or application of an adhesive material (e.g., a cyanoacrylate or epoxy material) therebetween. As previously described with reference to the spring tip  42  of FIG. 2, the flexible tip  86  can be configured and shaped in various desirable lengths, widths, and diameters. 
     While the invention has been described with reference to specific embodiments, the description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims. For example, the spring tip needle  40  of the present invention can be configured to have a round or oval cross section, as shown in FIGS. 9 and 10, respectively. Alternatively, the spring tip  42  of the spring tip needle  40  can be formed in such a manner that the adjacent coils  100  thereof are spaced apart so as to permit fluid flow through gaps  100  formed between coils  100 , as shown in FIG.  11 . Where fluid flow through the distal end of the spring tip  42  is undesirable, the spring tip  42  can include a sealing barrier  106  thereon, as shown in FIG. 12. A final exemplary modification can also include a curved stylet  108 , which is illustrated in FIG. 13, to facilitate placement of the spring tip needle  40  within a patient&#39;s vasculature.