Patent Publication Number: US-11382529-B2

Title: Electro-magnetic needle catheter insertion system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/154,362, filed on May 13, 2016, issued as U.S. Pat. No. 10,327,667 on Jun. 25, 2019, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     Aspects of the present disclosure relate to a device for magnetizing a tissue-penetrating medical device. 
     BACKGROUND 
     Emerging medical procedural guidance systems utilize a combination of ultrasound and magnetic technologies to visualize a patient&#39;s sub-dermal anatomy and to provide guidance for positioning an invasive medical device, for example, a needle, a stylet or a guidewire. The combination of ultrasound and magnetic methods allows for estimation of the position of the insertion device relative to the patient&#39;s anatomy, and thereby improves the likelihood of successfully accessing the vascular and completing the invasive procedure. 
     Ultrasound and magnetic procedural guidance system technology relies on the invasive device having a magnetic field source. One way to magnetize a portion of the invasive device prior to insertion is by using an externally applied magnetic field. For systems that apply an external magnetic field, the portion of the invasive device that is targeted for magnetization is the metal cannula of the invasive device, for example, the cannula of a needle. For this type of system, a separate device with integrated magnets is used to actively magnetize the needle just prior to the insertion procedure. 
     Systems that require the user to actively magnetize the metal cannula have certain limitations and inherent risks as this approach does not guarantee consistent magnetization given the reliance of the user to place the needle into the needle magnetizer and the variation of how this is done (i.e. depth, speed, centering, etc.). 
     Thus, there is a need for a system that passively and consistently magnetizes the needle while reducing or eliminating risks, such as needle tip damage and needle contamination. 
     SUMMARY 
     A first aspect of the disclosure pertains to a device for magnetizing a tissue-penetrating medical device. A first embodiment pertains to a device comprising a housing having a proximal portion and a distal portion, and a magnetic field generator contained within the distal portion of the housing to produce a magnetic field, and a tissue penetrating subassembly. In one or more embodiments, the device further comprises a power supply in electrical communication with the magnetic field generator, a switch in communication with the power supply to activate and deactivate the magnetic field generator. In one or more embodiments, the device utilizes a permanent magnet, and in such embodiments, a power supply may not be required 
     In one or more embodiments, the tissue penetrating subassembly includes a hub and a tissue penetrating medical device having a proximal end and a distal end. The hub is detachably connected to the distal portion of the housing and the proximal end of tissue penetrating medical device extends proximally from the hub such that the proximal end of the tissue penetrating medical device is exposed to the magnetic field and the distal end of the tissue penetrating medical device is magnetized upon exposure of the proximal end of the tissue penetrating medical device by the magnetic field. In one or more embodiments, the hub is detachably connected to the distal portion of the housing by a latch assembly. 
     In one or more embodiments, the housing further includes a controller in communication with the power supply and the magnetic field generator. The controller controls the magnitude of the magnetic field generated by the magnetic field generator. The magnetic field generated may be constant or variable, and the controller can control magnitude and variance of the magnetic field. 
     In one or more embodiments, the tissue-penetrating medical device may be a needle or stylet. In a specific embodiment, wherein the tissue penetrating medical device is a needle, the needle when magnetized can be used with a procedural guidance system including an ultrasound system which can be used to locate and project the position of the magnetized needle during an invasive medical procedure. 
     In one or more embodiments, the power supply is a direct current power supply, which may comprise a single battery or a plurality of batteries. In yet another embodiment, the power supply is an alternating current power supply. 
     In one or more embodiments, a flash chamber may be located within the hub of the tissue penetrating medical device. The flash chamber may include a vent plug which seals upon flow of blood into the flashback chamber. 
     In one or more embodiments, the distal end of the tissue penetrating device includes a notch to provide immediate confirmation of vessel entry at a point of insertion. 
     A second aspect of the disclosure pertains to a device for magnetizing a tissue-penetrating medical device having a catheter. In one or more embodiments, a device comprises a housing having a proximal portion and a distal portion, a magnetic field generator contained within the distal portion of the housing, a tissue penetrating subassembly including a catheter having a proximal end and a distal end, an introducer needle extending through the catheter, a catheter adapter having a distal end and a proximal end, an internal cavity, and a tip region having a distal opening having a circumference through which the catheter extends. In one or more embodiments, the catheter adapter is connected to the proximal end of the catheter. In one or more embodiments, a needle hub is connected to the proximal end of the introducer needle, the hub detachably connected to the distal portion of the housing. The proximal end of introducer needle extends proximally from the hub such that the proximal end of the introducer needle is exposed to the magnetic field and the distal end of the introducer needle is magnetized upon exposure of the proximal end of the introducer needle by the magnetic field. In one or more embodiments, the device further comprises a power supply in electrical communication with the magnetic field generator, a switch in communication with the power supply to activate and deactivate the magnetic field generator. In one or more embodiments, the device utilizes a permanent magnet, and in such embodiments, a power supply may not be required. 
     In one or more embodiments, the needle hub is detachably connected to the distal portion of the housing by a latch. 
     In one or more embodiments, a flash chamber may be located within the needle hub of the introducer needle. The flash chamber may include a vent plug which seals upon flow of blood into the flashback chamber. 
     In one or more embodiments, the introducer needle includes a notch to provide immediate confirmation of vessel entry at a point of insertion. 
     A fourth aspect of the disclosure pertains to a method for magnetizing a tissue-penetrating medical device comprising obtaining a tissue penetrating medical device having an elongated needle having a proximal end and a distal end. The elongated needle is disposed in a needle hub subassembly such that the proximal end of the elongated needle extends in a proximal direction from the hub and the distal end of the elongated needle extends in a distal direction from the hub towards a patient. The method includes obtaining a housing having a proximal portion and a distal portion wherein the housing includes a magnetic field generator contained within the distal portion of the housing. A power supply is in electrical communication with the magnetic field generator, and a switch is in communication with the power supply to activate and deactivate the magnetic field generator. The method further includes connecting the needle hub assembly to a distal portion of the housing such that the proximal end of the elongated needle is exposed to the magnetic field generator and depressing the switch in communication with a power supply to activate a magnetic field generator to magnetize the elongated needle. The method further includes positioning the distal end of the elongated needle adjacent to a desired point of vascular entry and inserting the magnetized elongated needle into a patient&#39;s vasculature. In one or more embodiments, the method further includes using an ultrasound imaging device to visualize the magnetized elongated needle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of an embodiment of a device for magnetizing a tissue-penetrating medical device of the present disclosure. 
         FIG. 2  shows a cross-sectional view of an embodiment of a device for magnetizing a tissue-penetrating medical device of the present disclosure. 
         FIG. 3  shows a perspective view of an embodiment of a device for magnetizing a tissue-penetrating medical device of the present disclosure wherein the housing is separated from the tissue penetrating subassembly. 
         FIG. 4  shows a perspective view of another embodiment of a device for magnetizing a tissue-penetrating medical device of the present disclosure including a catheter assembly. 
         FIG. 5  shows a cross-sectional view of the embodiment as shown in  FIG. 4  for magnetizing a tissue-penetrating medical device of the present disclosure. 
         FIG. 6  shows a perspective view of an embodiment of a device as shown in  FIG. 4  wherein the housing is separated from the tissue penetrating subassembly. 
         FIG. 7  shows a perspective view of yet another embodiment of a device for magnetizing a tissue-penetrating medical device of the present disclosure including a permanent magnet. 
         FIG. 8  shows a cross-sectional view of the embodiment as shown in  FIG. 7  of a device for magnetizing a tissue-penetrating medical device of the present disclosure. 
         FIG. 9  shows a perspective view of the embodiment as shown in  FIG. 7  of a device for magnetizing a tissue-penetrating medical device of the present disclosure wherein the housing is separated from the tissue penetrating subassembly. 
     
    
    
     DETAILED DESCRIPTION 
     Before describing several exemplary embodiments of the disclosure, it is to be understood that the description provided is not limited to the details of construction or process steps set forth in the following description. The devices described herein are capable of other embodiments and of being practiced or being carried out in various ways. 
     In this disclosure, a convention is followed wherein the distal end of the device is the end closest to a patient and the proximal end of the device is the end away from the patient and closest to a practitioner. 
     Aspects of the disclosure pertain to a device for magnetizing a tissue-penetrating medical device and for generating a magnetic field for a tissue penetrating medical device, such as a needle, in order to improve visualization during insertion into a vein using ultrasound imaging. One or more embodiments relate to a device comprising a disposable tissue penetrating medical device detachably connected to a reusable magnetic field generator contained within a distal portion of a housing to produce a magnetic field. According to one or more embodiments, the magnetic field generator can be reused numerous times to magnetize an unlimited number of tissue penetrating medical devices. While specific embodiments show an introducer needle used in combination with a catheter such as a peripheral intravenous catheter, it is understood that that devices described in this disclosure can be used on a variety of tissue-penetrating medical devices, including, but not limited to stylets, guidewires, spinal needles, epidural needles, hypodermic needles and introducer needles used with catheters. In one or more specific embodiments, the tissue-penetrating medical devices comprise a needle with a hollow cannula, which can be used to remove fluids from a patient or deliver fluids to a patient. According to one or more embodiments, systems and devices are provided which can passively and consistently magnetize tissue-penetrating medical devices. According to one or more embodiments, passive magnetization of tissue-penetrating medical devices can be accomplished without any additional or new clinical steps, a more consistent and predictable magnetic field can be provided. In one or more embodiments, magnetization can be accomplished with no additional risk of damage to the tissue-penetrating medical device, and the device and system does not introduce additional risk for contamination of the tissue-penetrating medical device. 
     Referring now to  FIG. 1 , one aspect of the disclosure pertains to pertains to a device  10  comprising a housing  20  having a proximal portion  21  and a distal portion  22 , a magnetic field generator  30  contained within the distal portion  22  of the housing  20  to produce a magnetic field, a power supply  40  in electrical communication with the magnetic field generator  30 ; a power switch  50  in communication with the power supply  40  to activate and deactivate the magnetic field generator  30 ; and a tissue penetrating subassembly  60 . 
     The tissue penetrating subassembly  60  includes a hub  70  and a tissue penetrating medical device  80  having a proximal end  81  and a distal end  82 . The hub  70  may be detachably connected to the distal portion of the housing  20 . The proximal end  81  of the tissue penetrating medical device  80  extends proximally from the hub  70  such that the proximal end  81  of the tissue penetrating medical device is exposed to the magnetic field and the distal end  82  of the tissue penetrating medical device is magnetized upon exposure of the proximal end  81  of the tissue penetrating medical device  80  by the magnetic field. 
     In one or more embodiments, the magnetic field generator  30  further includes a coil  31  that is electrically energized by the magnetic field generator  30  to produce a magnetic field in and around the tissue penetrating medical device  80 . 
     Housing  20  includes a grip  23  and encloses a coil  31  of the magnetic field generator  30 , controller  90 , power supply  40  and latch assembly  110 . Grip  23  is the portion of the housing  20  that the clinician would typically hold during insertion of the tissue penetrating medical device  80  into a patient. In one or more embodiments, housing  20  is removably connected to a tissue penetrating medical device  80 . In one or more embodiments, the tissue penetrating medical device  80  is disposable. 
     Housing  20  further includes a power switch  50  which is in communication with the power supply  40  to activate and deactivate the magnetic field generator  30  that induces the flow of current to the coil  31  from the power supply  40  to magnetize the tissue penetrating medical device  80 . The ability to selectively activate the flow of current from the power supply  40  to the coil  31  during active use allows for the preservation of the power supply  40 . 
     In one or more embodiments, the power supply  40  comprises a direct current power supply, which may include one or more batteries  102 . In yet another embodiment of the present disclosure, power switch  50  may be in the form of a side-push power button located on the side of device  10 , potentially molded into the side of the housing  20  as shown in  FIG. 1 . Alternatively, power switch  50  may be in the form of a top or top-mounted button (not shown) into the housing  20  or grip  23  of device  10 , the device can be activated by pressing power button to magnetize the tissue penetrating medical device  80 . The power switch  50  can be configured in a variety of ways, such as a rocker switch, a sliding switch, a toggle switch, or a rotary switch. After activating the device  10  by contacting the power switch  50  to magnetize the needle, the needle can be inserted into a skin surface of a patient. In one or more embodiments, the tissue penetrating medical device  80  may be a needle and/or catheter, wherein the needle and catheter can be inserted into a skin surface after activating the device by depressing the power switch  50  to magnetize the needle. 
     The power supply  40  may be in the range of 5 to 20 volts. Power supply  40  may comprise any suitable device that is capable of supplying power to controller  90 , magnetic field generator  30  and coil  31  to fulfill its intended purpose. Some examples of suitable DC power supply include one or more batteries  102  or a capacitor. Batteries  102  may include a low-cost, commercially-available button-cell, hearing-aid, or watch type battery. In one or more embodiments, power supply  40  is a DC battery or capacitor that is contained within housing  20 . By way of illustration,  FIG. 1  shows one embodiment in which the power supply  40  comprises one or more batteries  102  to supply power to the controller  90 , magnetic field generator  30  and coil  31 . Controller  90  may include one or more printed circuit boards  91 . In one or more embodiments, the proximal portion  21  of the housing  20  includes a battery access lid  103  to allow access to batteries  102 . 
     In yet another embodiment, the power supply comprises an alternating current (“AC”) power supply. An example of a suitable AC power supply is a suitable connection (e.g., a plug, transformer, and/or another suitable component) to a power grid, such as a municipal power supply. In one or more embodiments, the power supply is a power cord (not shown) attached to the proximal portion of the housing. 
     As shown in  FIG. 1 , the device comprises one or more electrical components, including wiring, which are configured to electrically connect the power supply  400 , controller  90  and coil  31 . In one or more embodiments, controller  90  can include one or more printed circuit boards. 
     In one or more embodiments, the tissue penetrating subassembly  60  includes a hub  70  and a tissue penetrating medical device  80  having a proximal end  81  and a distal end  82 . Hub  70  is detachably connected to the distal portion  22  of the housing  20  and the proximal end  81  of tissue penetrating medical device  80  extends proximally from the hub  70  such that the proximal end  81  of the tissue penetrating medical device is exposed to the magnetic field and the distal end  82  of the tissue penetrating medical device  80  is magnetized upon exposure of the proximal end  81  of the tissue penetrating medical device  80  by the magnetic field. 
     In one or more embodiments, the tissue penetrating medical device  80  may be a needle. Herein the term “needle” will include standard needles, such as hypodermic needles, spinal needles, epidural needles, introducer needles used with catheters and other like devices that may be used to access an anatomical structure near the outer surface of a body and/or deliver a fluid thereto. In one or more embodiments, the needle has a hollow cannula that can withdraw fluids from or deliver fluids to a patient. 
     In a specific embodiment, the tissue penetrating medical device  80  may be in form of a needle. The needle when magnetized can be used with a procedural guidance system including an ultrasound detector which can locate and project the position of the needle during an invasive medical procedure. In one or more embodiments, the tissue penetrating device may be needle with a hollow cannula. The needle with the hollow cannula can comprise virtually any rigid tube that includes a sharpened distal tip and which is configured to puncture a patient&#39;s body, to access an intended space, and to withdraw or to introduce a material (e.g., a fluid) from or into the intended space. A suitable cannula may include an introducer needle for use in an IV catheter assembly (e.g., an over-the-needle peripheral IV catheter assembly), a venous needle, and an arterial needle. 
     The tissue penetrating medical device  80  is made of a magnetizable metallic material. In one or more embodiments, the magnetizable metallic material may be stainless steel or similar materials. 
     In one or more embodiments, the tissue penetrating medical device  80  includes a solid body that extends from the distal end  82  to the proximal end  81 . In one or more embodiments, the tissue penetrating medical device  80  further includes an interior lumen that extends through the tissue penetrating medical device  80  from the distal end  82  to the proximal end  81 . Tissue penetrating medical device  80  may include a beveled tip  83  formed in the distal end of the tissue penetrating medical device  80  to facilitate entry into a body. In some embodiments, coil  31  extends only over the proximal end of the tissue penetrating medical device  80 . Alternatively, in some embodiments, coil  31  extends over the entire shaft of tissue penetrating medical device  80  excluding only a beveled tip  83  at the distal end  82 . 
     When magnetized, tissue penetrating medical device  80  can be used with a procedural guidance system including one or more ultrasound detectors to locate and project the position of the needle during an invasive medical procedure. 
     In one or more embodiments, as shown in  FIGS. 2 and 3 , the tissue penetrating medical device  80  may be a needle that extends both in the distal and proximal direction from hub  70  of the tissue penetrating medical device  80 . The elongated needle must be long enough to be enveloped within the coil, which, when energized, will generate a magnetic field surrounding the needle, thus magnetizing the needle. In the embodiment shown in  FIG. 3 , the tissue penetrating medical device  80  may be discarded after a single use. In contrast, the housing  20  may be reused many times with many different needles. Additionally, because the housing  20  is not discarded after a single use, the housing  20  may comprise more expensive components, including one or more printed circuit boards, magnetic field generator and power supply. 
     In one or more embodiments, a latch  100  mechanically connects the hub  70  to the distal portion  22  of the housing  20  and the proximal end  81  of tissue penetrating medical device  80 . As shown in  FIG. 2 , tissue penetrating medical device  80  may be in the form of an elongated needle extends proximally from the hub to fully penetrate coil  31 . 
     In one or more embodiments, latch button  110  is a means of disengaging the latch  100  in order to remove the tissue penetrating medical device from the housing. The latch button  110 , when pressed, actuates a latch  100  allowing the hub  70  of the tissue penetrating medical device  80  to be released from a hub retention element of the housing. In one or more embodiments, the latch  100  can be configured to secure the tissue penetrating subassembly  60  to the housing  20 , such that pressing the latch button  110  permits removal of the tissue penetrating medical device  80  from housing  20 . In one or more embodiments, latch button  110  can engage one or more detents on the housing such that the tissue penetrating medical device  80  cannot be removed from the housing  20  if the latch button  110  is in a first position, and can be removed when the latch button is in a second position.  FIG. 2  illustrates a latch  100  engaging a slot in the base of the hub  70  to prevent inadvertent separation of the tissue penetrating subassembly  60  from the housing  20 . In one or more embodiments, the latch button  110  may be included on housing  20 . In one or more embodiments, the latch button may include alignment pins to engage the needle hub. In one or more embodiments, the latch button is configured to be pushed downward into the device, and comprises guide slots for engaging and releasing the needle hub. 
     In one or more embodiments, as shown in  FIG. 2 , latch  100  may be mushroom-shaped and includes a cap portion and a stem portion. When the latch  100  is slotted between the cap and the base adjacent the stem portion, the housing is latched onto the base, as illustrated in  FIG. 2 . Latch  100  may frictionally engage one or more of the cap portion, stem portion and a portion of the base adjacent to the stem portion, in the latched state, as illustrated in  FIG. 2 . 
     Thereafter, when a user wishes to remove the tissue penetrating medical device  80  from the base that holds the tissue penetrating medical device, the user presses the latch button  110  so that the latch  100  becomes disengaged from the housing  20  allowing the tissue penetrating medical device  80  to be separated from the housing  20 . 
     In one or more embodiments, latch  100  may include a pair of levers, each having an arm. The levers are hinged to housing and the levers can be biased by depressing the latch button  110 . In order to connect the hub to the housing, the user aligns the hub to a corresponding slot in the housing and engages the arms of the levers by releases the latch button to lock the arms of the levers into the pockets and catches of the housing. In order to disconnect the hub  70  from the housing  20 , the user squeezes or depresses the latch button to release the levers of the hub from the pockets and catches of the housing. Thereafter, the user can lift the hub from the housing to separate the hub  70  from the housing  20 . 
     In one or more embodiments, the power switch  50  and latch button  110  may have finger bumps to aid the user in locating and using the respective buttons. 
     In one or more embodiments, the housing  20  further includes a controller  90  in communication with the power supply  40  and the magnetic field generator  30  which controls the magnitude of the magnetic field generated by the magnetic field generator  30 . The magnetic field generated may be constant or variable. In one or more embodiments, the controller  90  may include a printed circuit assembly that supplies and regulates power to the coil  31  and generates a magnetic field around the tissue penetrating medical device  80 . In one or more embodiments, controller  90  may also allow for additional functions, such as Bluetooth communication with other devices, lighting, and any additional electronic features that may be desired during operation of the device. 
     Magnetic field generator  30  is capable of producing a constant or variable electromagnetic field as desired to allow for the creation of an easily differentiable magnetic signature to improve detection of the tissue penetrating medical device  80  at a receiving image device (not shown). Device  10  has the potential of producing an enhanced magnetic signature by modifying the intensity and/or frequency of the magnetic field. 
     A magnetic signature may take the form of binary informational pulses that could be interpreted by a receiving imaging device. Once recognized, the image may be enhanced and the signal amplified in relation to the background fields, to create a clearer image of the needle tip. In one or more embodiments, the magnetic field generator has the potential to produce a magnetic field on demand. 
     In one or more embodiments, a flash chamber  120  may be located within the hub  70  and is in fluid communication with the tissue penetrating medical device  80  to allow blood to flow into the flash chamber to provide the user with confirmation of vasculature entry. The flash chamber  120  may include a vent plug  130  which seals upon flow of blood into the flashback chamber. 
     In one or more embodiments, a number of safety features can be provided to prevent needle stick injuries. In one or more embodiments, the device may further comprise safety devices such as a needle shield and a needle sheath which covers the needle (not shown). 
     In one or more embodiments, the needle assembly may also include a shield engaged with a portion of the housing. The shield is movable over the tissue penetrating device from a retracted position in which the distal end is exposed, to an extended position in which the distal end is shielded by at least a portion of the shield. At least a portion of the flash chamber is visible in the retracted position. 
     The shield may at least partially surround the distal end of the tissue penetrating device in the extended position. Optionally, the shield is substantially circumferentially disposed about at least a portion of the cannula, and transition of the shield from the retracted position to the extended position telescopes the shield over the cannula. In certain embodiments, the sidewall of the cannula defines an opening extending between the cannula interior and the flash chamber. 
     In one or more embodiments, as shown in  FIGS. 1 and 2 , the flash chamber  120  may be integrally formed within a portion of the hub  70  of the tissue penetrating medical device  80 . A porous vent may be disposed within the flash chamber such that the porous vent separates the flash chamber into a first chamber and a second chamber. The first chamber and the second chamber may be configured such that upon insertion of the distal end of the cannula into a patient, blood flows through the cannula and into the first chamber without sealing the porous vent. The flash chamber may include a vent mechanism in communication with an environment surrounding the needle assembly. The porous vent may include a plurality of pores for passage of blood from the first chamber to the second chamber. The vent mechanism may be a porous plug formed of a hydrophobic material, a one-way valve, or a porous plug formed of a hydrophilic material that swells on contact with blood. 
     In addition to flash chambers which may include a vent mechanism in communication with an external environment surrounding the needle assembly, it is also contemplated herein that a needle assembly may include a flash chamber having a vent plug which seals upon flow of blood into the flashback chamber, thereby inhibiting any pressurized air that may build up within the chamber, from moving in a reverse direction toward the inlet of the cannula. 
     In one or more embodiments, vent plug  130  allows air to escape from the flash chamber as it fills with blood. Once wetted, vent plug  130  becomes plugged as a result of exposure to blood. 
     In one or more embodiments, the distal end of the tissue penetrating medical device  80  includes a notch  140  to provide immediate confirmation of vessel entry at a point of insertion. 
     In one or more embodiments, the housing, hub, latch mechanism and safety device elements can be constructed of molded plastic materials, polycarbonate, thermoplastic polymers such as polyethylene terephthalate (PET and PETG), or similar materials. 
     A second aspect of the disclosure pertains to a device for magnetizing a tissue-penetrating medical device having a catheter. As shown in  FIG. 4 , in one or more embodiments, device  210  comprises a housing  220  having a proximal end  221  and a distal end  222 , a magnetic field generator  230  contained within the distal end  222  of housing  220 , a power supply  240  in electrical communication with the magnetic field generator  230 , a switch  250  in communication with the power supply  240  to activate and deactivate the magnetic field generator  230 , a tissue penetrating subassembly  260  including a catheter  261  having a proximal end  262  and a distal end  263 , an introducer needle  264  having a proximal end  265  and distal end  266  extending through the catheter  261 , a catheter adapter  267 , an internal cavity  268 , and a tip region  269  having a distal opening having a circumference through which the catheter extends, the catheter adapter  267  being connected to the proximal end  262  of the catheter, a hub  270  connected to the proximal end  265  of the introducer needle  264 , the hub  270  detachably connected to the distal end  222  of the housing  220 . The proximal end  265  of introducer needle  264  extends proximally from the hub  270  such that the proximal end  265  of the introducer needle is exposed to the magnetic field and the distal end  266  of the introducer needle is magnetized upon exposure of the proximal end  265  of the introducer needle  264  by the magnetic field. 
     The introducer needle  264  may have any component that is suitable for use with an IV catheter assembly. The introducer needle  264  is disposed within an internal cavity  268  of the catheter. The distal tip of the tissue penetrating device may comprise a standard bevel, a short bevel, a true short bevel, a bias grind point, a vet point, a lancet point, a deflected point (anti-coring), or another suitable known or novel needle point. The tissue penetrating medical device  80  may be any suitable length or any suitable gauge that allows it to be used for vascular access. 
     The tissue penetrating subassembly  260  may be made of a magnetizable metal including stainless steel needle. 
     In one or more embodiments, the device  210  may have a standard catheter hub or a blood control hub to connect a catheter  261  to the tissue penetrating subassembly  260 . In one or more embodiments, glue, press fitting or another bonding mechanism, such as solvent bonding, is used to secure the catheter  261  to the catheter adapter  267 . Standard catheter tubing or custom catheter tubing may be utilized. 
     In some embodiments, the hub  270  or catheter adapter  267  may be formed from a thermoplastic material, such as polyvinyl chloride, polyethylene, polycarbonate or polyurethane material. Catheter  261  generally comprises an intravenous catheter which includes a biocompatible material, such as a polymer or metallic material. In some embodiments, catheter  261  comprises a flexible polymer material, such as silicon rubber, latex, and/or various thermoplastic elastomers. Catheter  261  may further comprise a rigid polymer or metallic material, as may be desirable for an intended use. 
     The length and diameter of catheter  261  is generally determined by the application or use for which the intravenous catheter device is intended. Accordingly, one having skill in the art will appreciate that catheter may be modified or adjusted to include any size and dimensions as may be desired or necessary to facilitate a desired use. 
     In some embodiments, hub  270  comprises an aperture configured to house introducer needle  264  and the proximal end  262  of catheter  261 . Introducer needle  264  and the proximal end  262  of catheter  261  are fixedly secured to hub  270  such that the introducer needle, intravenous tubing, and catheter adapter  267  form a unitary structure. A fluid pathway or hollow body of introducer needle  264  may be in fluid communication with a fluid pathway of catheter  261 . 
     In one or more embodiments, a catheter adapter  267  may be provided having a proximal end, a distal end and a pathway extending therebetween. A catheter  261  may then be coupled to the distal end of the of a catheter adapter  267 , wherein the catheter  261  includes a lumen and a tip. Hub  270  is further provided for supporting introducer needle  264 . The introducer needle  264  generally includes a sharpened end, a base, and a hollow body extending therebetween. The base of the introducer needle is coupled to, and supported by the needle adapter. A section of intravenous tubing is further coupled to the needle adapter, wherein the needle adapter facilitates fluid communication between the hollow body of the introducer needle and a fluid pathway of the catheter. The introducer needle, needle adapter, and catheter are then slidably housed within the lumen of the catheter hub adapter. 
     In one or more embodiments, housing  220  includes a controller  290  in communication with the power supply  240  and the magnetic field generator  230  to control magnitude of the magnetic field generated by the magnetic field generator  230 . The controller  290  may include one or more printed circuit boards. The magnetic field generated may be constant or variable. 
     In one or more embodiments, the power supply  240  may be a plurality of batteries or an AC/DC cord attached to the proximal end of the housing. 
     In one or more embodiments, hub  270  is detachably connected to the distal end  222  of the housing  220  by a latch  300 , which is engaged and disengaged by latch button  310 . 
     In one or more embodiments, the device may include one or more vasculature entry confirmation mechanisms which can be varied in any suitable manner. In one or more embodiments, as shown in  FIG. 4 , a flash chamber  320  is located within the disposable portion of the tissue penetrating subassembly  260  to visually confirm that blood is flowing through the tissue penetrating subassembly  260  during insertion and to ascertain that the catheter  261  is in the patient&#39;s vein. In one or more embodiments, the introducer needle  264  may have a flashback feature to visualize flashback along the introducer needle before it is directly visible in the flash chamber  320 . In one or more embodiments, a notch  340  is located on the distal end of the introducer needle provides immediate confirmation of vessel entry at the point of insertion to improve first-stick success. Catheter  261  may include a notch through which blood can exit the inner lumen to provide flashback confirmation. For example, when using the device, medical personnel can visualize entry of the introducer needle tip into a target anatomical structure, such as a blood vessel. As blood begins to flow along the introducer needle, such as between an introducer needle and a catheter, the medical personnel can see the flashback as the blood enter into the flashback feature. In some embodiments, the flashback confirmation chamber comprises a flashback compartment that is configured to receive blood from the patient&#39;s vasculature and to allow the operator to visualize the blood. 
     Flash chamber  320  and notch  340  may be used with any suitable tissue penetrating device or system including any suitable catheter assembly. By way of illustration,  FIG. 4  shows that in a representative embodiment, the flash chamber  320  and notch  340  may be used with a catheter assembly comprising a catheter adapter and a catheter. 
     In some embodiments, at least a portion of the flashback compartment comprises a translucent or a transparent material that allows the operator to watch the chamber progressively fill with blood. The flashback confirmation chamber may comprise any component that allows (1) the operator to visualize blood filling the confirmation chamber once the cannula of the vascular access device punctures the patient&#39;s vasculature, (2) allows the operator to visualize a decrease (i.e., a cessation) of blood flow into the chamber if the distal tip of the cannula is pushed completely through the patient&#39;s blood vessel or the blood vessel is transfixed, and (3) allows the chamber to prolong the period of time in which the operator can observe active arterial flashback confirmation from the vascular access device. 
     The flashback compartment may be any shape that allows it to fulfill its intended purposes. For instance, the flashback compartment may be cylindrical, cuboidal, elongated cuboidal, elliptical, spherical, conical, spiral, irregular, tubular, polygonyl, conical, and/or any other suitable shape. By way of illustration,  FIG. 4  shows a representative embodiment in which the flashback compartment is cylindrical. 
     The confirmation chamber also comprises a vent. The vent can perform any suitable function, including allowing air to exit the flashback compartment as blood enters the catheter, extension tube, and/or flashback compartment. The vent, which is depicted in  FIG. 4 , may be disposed in any suitable location. By way of example,  FIG. 4  shows the vent can be disposed at the proximal end of the flash chamber. The vent may also comprise any component or characteristic that allows it to fulfill its intended purpose. 
     In one or more embodiments, a flash chamber may be located within the needle hub of the introducer needle. The flash chamber may include a vent plug  330  which seals upon flow of blood into the flashback chamber. 
     A third aspect of the disclosure pertains to a device for magnetizing a tissue-penetrating medical device having a housing having one or more permanent magnets to which the needle tip is exposed and magnetized. In one or more embodiments, as shown in  FIG. 7 , the device  410  comprises a housing  420  having a proximal portion  421  and a distal portion  422 , one or more permanent magnets  430  contained within the distal portion  422  of housing  420  to produce a magnetic field, and a tissue penetrating subassembly  440  including a hub  450  and a tissue penetrating medical device  460  having a proximal end  461  and a distal end  462 , the hub  450  is detachably connected to the distal portion  422  of the housing  420  and the proximal end  461  of tissue penetrating medical device  460  extending proximally from the hub  450  such that the proximal end  461  of the tissue penetrating medical device is exposed to the magnetic field produced by one or more permanent magnets  430  contained within the distal portion  422  of housing  420  and the distal end  462  of the tissue penetrating medical device  460  is magnetized upon exposure of the proximal end  461  of the tissue penetrating medical device  460  by the magnetic field. In one or more embodiments the tissue penetrating medical device  460  is a needle, guidewire or stylet. As described above, the needle can be any type of needle, and in specific embodiments, the needle includes a hollow cannula which can be used for withdrawal or delivery of fluids to a patient. 
     In a specific embodiment, as shown in  FIG. 8 , the tissue penetrating medical device is a needle, which when magnetized can be used with a procedural guidance system to locate and project the position of the needle during an invasive medical procedure. 
     In one or more embodiments, as shown in  FIG. 9 , the hub  450  is detachably connected to the distal portion  422  of the housing  420  by a latch  470  operated by a latch button  471 . 
     In one or more embodiments, as shown in  FIG. 7 , a flash chamber  480  may located within the hub  450  of the tissue penetrating subassembly  440 . In one or more embodiments, the flash chamber includes a vent plug  481  which seals upon flow of blood into the flashback chamber. 
     In one or more embodiments, as shown in  FIG. 8 , the tissue penetrating medical device  460  includes a notch  490  to provide immediate confirmation of vessel entry at a point of insertion. 
     A fourth aspect of the disclosure pertains to a method for magnetizing a tissue-penetrating medical device comprising obtaining a tissue penetrating medical device having an elongated needle having a proximal end and a distal end, the elongated needle disposed in a needle hub subassembly such that the proximal end of the elongated needle extends in a proximal direction from the hub and the distal end of the elongated needle extends in a distal direction from the hub towards a patient. The method includes a user obtaining a housing having a proximal portion and a distal portion wherein the housing includes a magnetic field generator contained within the distal portion of the housing, a power supply in electrical communication with the magnetic field generator, and a switch in communication with the power supply to activate and deactivate the magnetic field generator. The user then connects the needle hub assembly to a distal portion of the housing such that the proximal end of the elongated needle is exposed to the magnetic field generated by the magnetic field generator. The switch in communication with a power supply is depressed to activate a magnetic field generator to magnetize the elongated needle. The user positions the distal end of the elongated needle adjacent to a desired point of vascular entry and the magnetized elongated needle is inserted into a patient&#39;s vasculature. In one or more embodiments, the method further includes using an ultrasound imaging device to visualize the magnetized elongated needle. 
     In practice, a user may use the distal point of the cannula to puncture the skin of a patient and force an over-the-needle peripheral IV catheter into a blood vessel. Once the needle has penetrated the blood vessel and blood flows into the cannula&#39;s lumen, a constant or variable magnetic field is produced. 
     The user attaches the tissue penetrating device to the base of the housing by pressing the tissue penetrating device down onto the base of the housing and snapping it in place. In this process, the latch resiliently deflects to allow the latch to pass over the catch. Subsequently, the latch returns to its un-deformed positions to prevent displacement of the tissue penetrating device from the housing. 
     After insertion of the needle/catheter into the patient&#39;s vein, the user can detach the needle hub from the housing by pressing the latch button. Once the latch has been disengaged from the slot, the hub having the tissue penetrating device may be removed from the housing, at which time the needle stick protection mechanism will activate. In addition, the introducer needle may also be retracted from the catheter. After use, the cannula may be extracted from the catheter hub, and the needle and cannula may be discarded. 
     Reference throughout this specification to “one embodiment,” “certain embodiments,” “one or more embodiments” or “an embodiment” means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. Thus, the appearances of the phrases such as “in one or more embodiments,” “in certain embodiments,” “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily referring to the same embodiment of the disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments. 
     Although the disclosure herein has provided a description with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the method and apparatus of the present disclosure without departing from the spirit and scope of the disclosure. Thus, it is intended that the present disclosure include modifications and variations that are within the scope of the appended claims and their equivalents.