1
MEDICAL DEVICE FOR INSERTING A
GUIDE WIRE HAVING A RETRACTABLE
NEEDLE
FIELD OF INVENTION
The present invention relates to medical devices for inserting a guide wire into a patient. In a particular, the present invention relates to medical devices having a sharpened needle used for introducing a guide wire into a patient. The needle pierces the patient to provide vascular access, and the guide wire is then inserted into the patient through the needle. After use, the sharpened needle is protected against inadvertent contact. More specifically, after use, the needle is retracted so that the sharpened tip of the needle is enclosed within the device.
BACKGROUND
Various types of medical devices employed a needle for piercing the skin of a patient for diagnostic or therapeutic purposes. One such device is a device for introducing a guidewire into a patient. The guidewire is then used to guide a separate element such as an enlarged bore introducer sheath into the patient. Once the guidewire is properly positioned, the insertion device is withdrawn leaving the guidewire in place in the blood vessel. Handling of such medical devices after the needle is withdrawn from the patient can result in transmission of various pathogens, most notably human immune virus (HIV), due to in inadvertent needle stick to medical personnel.
SUMMARY OF THE INVENTION
In light of the foregoing, the present invention provides a method and apparatus for inserting a guide wire into a patient and rendering the device safe after use to prevent inadvertent contact with the contaminated needle. In accordance with one aspect of the invention, a medical device is provided that has a needle having a sharpened tip projecting forwardly from a housing. Prior to use a shield sheaths a portion of the needle so that the sharpened tip projects forwardly from the sheath. After use the sharpened tip is retracted into the shield. A biasing element biases the needle toward the retracted position, and a hub connected with the needle includes a guide for guiding a guide wire into the patient through the needle and a connector for attaching a fluid reservoir to the device.
The present invention also provides a medical device having a needle having a sharpened tip projecting forwardly from a housing. After use, the sharpened tip of the needle is shielded against inadvertent contact. A biasing element is operable to displace the sharpened tip of the needle into the shielded position. The device includes a connector for attaching a fluid collection device to the housing. The connector also includes a first port, and the device includes a second port in fluid communication with the needle. An adapter associated with the second port is configured for receiving and guiding a guide wire through the second port and into the needle.
The present invention also provides a method for inserting a guide wire into a patient using a needle-bearing medical device having first and second ports. According to the method, a needle is inserted into a patient and blood is aspirated through the first port. The needle is retracted so that the sharpened tip of the needle is shielded to protect against inadvertent contact. A guide wire is then inserted into the patient through the second port.
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The present invention also provides a method for inserting a guide wire into a patient using a needle-bearing medical device having a port. The needle is inserted into the patient and a fluid reservoir is attached to the port for collecting 5 blood from the patient. The fluid collection device is detached from the port and a guide wire is inserted into the patient through the device. The needle is retracted to shield the needle to prevent inadvertent contact with the contaminated needle.
1° Accordingly, when configured and used as described above, the present invention provides a safe and effective method for inserting a guide wire into a patient. In addition, the device is designed to improve manufacturing efficiencies thereby reducing the overall cost of the device.
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DESCRIPTION OF THE DRAWINGS
The foregoing summary as well as the following description will be better understood when read in conjunction with 20 the figures in which:
FIG. 1 is a cross-sectional view of a medical device having a retractable needle for inserting a guide wire;
FIG. 2 is a cross-sectional view of the medical device illustrated in FIG. 1, illustrating the needle in a retracted 25 position;
FIG. 3 is an enlarged fragmentary cross-sectional view of the portion designated A of the medical device illustrated in FIG. 2;
FIG. 4 is a cross-sectional view of an alternate embodi
30
ment of a medical device having a retractable needle for inserting a guide wire;
FIG. 5 is a cross-sectional view of the medical device illustrated in FIG. 4, illustrating the needle in a retracted 35 position;
FIG. 6 is a side view partially in section of the medical device illustrated in FIG. 5 in combination with a guide wire feeder, illustrating the device inserted into a patient; and
FIG. 7 is a side view partially in section of the medical 40 device illustrated in FIG. 5 in combination with a guide wire gripper, illustrating the device inserted into a patient.
DETAILED DESCRIPTION OF THE
PREFERRED EMBODIMENT
45
Referring now to the figures in general and to FIG. 1 specifically, a medical device for inserting a guide wire is designated generally 10. The device 10 includes a sharpened needle 65 for inserting the device vascularly. After the
5Q needle is inserted into the patient the needle may be retracted into the device 10 so that the sharpened tip of the needle is enclosed. A guide wire can then be inserted into the patient through the needle. After use, the device 10 is withdrawn with the needle safely shielded.
55 Referring now to FIGS. 1 and 2, the device includes an elongated hollow barrel 20. The needle 65 projects forwardly from the barrel, with a shield 30 surrounding the length of the needle. The needle 65 is attached to a needle hub 40 disposed within the barrel 20. A spring 60 disposed
60 within the barrel biases the needle hub 40 and the attached needle 65 rearwardly toward a retracted position. A needle retainer 42 releasably retains the needle hub against the bias of the spring 60. A port at the rearward end of the device 10 provides access for a guide wire 68, so that the guide wire
65 can be threaded into the patient through the needle 65.
The medical professional using the device 10 can retract the needle by pressing a button 43, which disengages the
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needle retainer 42. The spring 60 then propels the needle 65 rearwardly so that the sharpened tip of the needle is enclosed within the shield 30. In this way, the contaminated needle 65 is protected against inadvertent contact.
The details of the device will now be explained in greater 5 detail. As shown in FIG. 1, the barrel is a generally cylindrical barrel having a hollow central bore. A locking aperture 22 in the sidewall of the barrel 20 is configured to cooperate with the needle retainer 42 as described further below. The rearward end of the barrel is generally open for receiving the 1° needle hub 40 and a connector hub 50. The forward end of the barrel 20 is generally closed, having a reduced diameter opening through which the needle 65 extends. Preferably, a seal 35, such as an O-ring forms a fluid seal between the reduced diameter opening and the needle 65 to prevent fluid :5 from leaking from the shield 30 into the barrel 20.
Apair of opposing axial slots 28 are formed in the interior surface of the barrel, adjacent the rearward end of the barrel. The slots 28 form a guide track that cooperates with the connector hub 50 to guide the needle 60 during retraction, as 20 is discussed further below. Additionally, the slots 28 cooperate with the connector hub 50 to prevent the button 43 from being twisted relative to the locking aperture 22 when a fluid collection device is attached to the device 10 as is discussed further below. Although the barrel 20 may be 25 formed as a single piece, in the present instance, the barrel is formed in two portions that are snap-fit together. Alternatively, the two portions can be connected by ultrasonic welding or adhesive.
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The barrel 20 further includes a flange 27 projecting radially inwardly from the interior surface of the barrel, intermediate the length of the barrel. The flange 27 forms a stop that cooperates with the needle hub 40 to limit rearward displacement of the needle hub, which in turn limits the 3J retraction of the needle.
Referring again to FIGS. 1 and 2, the details of the needle hub 40 are illustrated. The needle hub 40 is generally cylindrical having an internal bore for receiving the needle 65. Preferably, the needle retainer 42 is integrally formed 40 with the needle hub 40. The needle retainer includes an axially elongated radially deformable arm with a latch or button 43. The button 43 is configured to cooperate with the locking aperture 22 in the barrel, to releasably engage the needle hub 40 with the barrel 20. The forward end of the 45 needle hub 40 flares outwardly forming a circumferential flange 45 having an external diameter corresponding to the central bore 24 of the barrel. In this way, as the needle hub 40 is displaced rearwardly during retraction, the flange 45 slides along the interior bore to guide the needle hub. 50
The needle 65 is operable between a projecting position illustrated in FIG. 1 and a retracted position illustrated in FIG. 2. In the projecting position, the needle projects forwardly from the barrel so that the sharpened tip of the needle is exposed to pierce the patient and guide the shield 30 into 55 the patient. In the retracted position, the sharpened tip of the needle is disposed within the shield 30 to prevent inadvertent contact with the contaminated needle. The spring 60 biases the needle 65 rearwardly toward the retracted position. The needle retainer 42 releasably retains the needle 65 go in the projecting position against the bias of the spring 60.
The needle 65 extends through the central bore of the needle hub 40, and through the opening in the barrel tip 25 so that the sharpened tip of the needle projects forwardly from the barrel. The shield 30 is fixedly attached to the barrel 65 tip 25 so that the shield also projects forwardly from the barrel 20. More specifically, the forward end of the barrel 20
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forms a cavity or socket. A shield connector 32 is configured to cooperate with the cavity to fixedly attach the shield to the barrel. The shield connector 32 includes an internal bore approximately the same as the external diameter of the shield 30. The shield connector 32 forms an interference fit with the cavity on the barrel, which in turn provides an interference fit between the shield connector and the shield 30, thereby attaching the shield to the barrel. The depth in which the shield connector 32 is inserted into the cavity can be varied so that the length of the shield 30 overlapping the needle 65 can be varied. In this way the length of the needle 65 projecting forwardly from the shield can be controlled during manufacture.
The shield 30 is in the form of a relatively thin-walled cannula, overlying the needle 65 in telescoping relation. Specifically, the interior diameter of the shield is substantially the same as the external diameter of the needle 65. Preferably, the interior diameter of the shield 30 is the same as or several thousandths of an inch larger than the external diameter of the needle so that the needle 65 can readily slide within the shield.
As shown in FIG. 3, the forward end of the shield 30 tapers inwardly forming a thin wall with a feather edge, which provides a smooth transition between the forward end of the shield 30 and the needle 65. In this way, when the needle 65 is inserted into the patient's vein or artery, the overlying shield 30 is also readily inserted into the patient's vein or artery.
A stop limits the rearward travel of the needle hub 40 to limit the distance that the needle 65 is retracted. Specifically, the forward end of the needle hub flares outwardly forming an enlarged head 45. The enlarged head 45 engages the flange 27 on the interior of the barrel 20 when the needle is retracted. In this way, the engagement between the flange 27 and the enlarged head 45 limits the rearward displacement of the needle 65.
Preferably, prior to retraction, the axial distance between the flange 27 and the enlarged head 45 is less than the length of the shield 30 that projects forwardly from the barrel 20. More specifically, preferably the axial distance is less than half the length of the shield that projects forwardly from the barrel 20. It is further preferable that the axial distance be substantially less than one quarter the length of the shield that projects from the barrel. In this way, after retraction, the sharpened tip of the needle is enclosed within the shield 30, rather than being retracted into the barrel 20.
The device 10 further includes elements for impeding re-extension of the needle 65 after retraction, so that the contaminated sharpened tip of the needle is not exposed. Specifically, as shown in FIG. 2, the forward end of the actuator button 43 forms a shoulder that engages the rearward shoulder of the flange 27 on the interior of the barrel. As the needle 65 is retracted, the needle retainer 42 flexes radially outwardly when it is displaced into the larger diameter of the rearward half of the barrel. The rearward edge of the forward half of the barrel forms a lip that operates as a stop engaging the button to prevent the needle from being displaced axially forwardly.
A connector hub 50 attached to the needle hub 40 provides an access port for inserting a guide wire 68 through the device 10 and into the patient. The connector hub 50 includes a central bore in fluid communication with the needle 65. In the present instance, the rearward end of the needle 65 is connected with the connector hub 50.
The connector hub 50 has an open rearward end and preferably forms a connector in the form of a Luer fitting for
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attaching a medical device, such as a syringe or guide wire feeder as discussed further below. In addition, preferably a lock 56 is formed on the rearward end of the connector hub for locking the separate device to the connector hub. More specifically, preferably, the lock 56 is a threaded Luer lock 5 formed on the exterior of the connector hub.
In addition, a wire guide 52 is formed in the interior of the connector hub 50. The wire guide 52 is formed forward of the open end of the connector hub 50, and includes tapered walls, forming a generally frustoconical transition from the 1° open end of the connector hub to a small diameter opening adjacent to and coaxial with the rearward end of the needle. The wire guide 52 operates similar to a funnel, guiding the wire into the small diameter opening of the needle as the wire is inserted through the large opening at the rearward :5 end of the connector.
The connector hub 50 further includes a pair of opposing guide tabs 54 projecting radially outwardly into engagement with the guide tracks 28 formed in the interior of the barrel
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20. The guide tabs 54 cooperate with the guide tracks 28 to guide the needle 65 rearwardly during retraction. In addition, the guide tabs 54 and guide tracks 28 operate as a circumferential lock preventing torque applied to the connector hub from being transferred to the needle retainer 42.
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In this way, if a fluid collection device, such as a syringe, is attached to the connector hub 50 by threading the syringe onto the connector hub, the torque applied to the connector hub is not transferred to the needle retainer 42, which could cause the needle retainer to break or disengage the locking aperture 22. 30
In the present instance, the needle hub 40 and connector hub 50 have been described as two separate elements connected together. However, the two elements can alternatively be formed as a single element. 35
Retracting the needle into the shield rather than the barrel has several benefits. The overall length of the barrel can be reduced because the barrel need not be long enough to accommodate the retracted needle. In addition, the needle 65 provides support for the shield 30 to prevent the shield from 40 collapsing or buckling radially inwardly in response to external forces. For instance, the device 10 is used in conjunction with a guide wire. The guide wire is inserted vascularly into the patient through the needle 65. Prior to inserting the guide wire, and while the device 10 is inserted 45 in the patient, the medical professional may actuate retraction by depressing the button 43. The needle retainer 42 is thereby displaced radially inwardly out of engagement with the barrel, and the spring 60 displaces the needle 65 rearwardly into the retracted position. 50
As shown in FIG. 2, the needle remains within the shield 30 after retraction. The shield 30 can then be inserted further into the patient without risk of piercing or coring the vein or artery. Depending on the material used for the shield and the wall thickness of the shield, the shield may not have 55 sufficient columnar strength to overcome the resistance of inserting the length of the shield vascularly. In such instances, the needle provides additional rigidity so that the length of the shield can be inserted into the patient. After the length of the shield is inserted into the patient, the guide wire go is threaded into the patient through the retracted needle and the shield.
After use, the shield 30 shields the sharpened tip of the needle 65 against inadvertent contact. Preferably, the shield 30 is somewhat flexible. In addition, the shield is preferably 65 formed with sufficient column strength to prevent the shield 30 frown collapsing axially in response to an axial force
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after retraction. This columnar strength prevents the shield from readily buckling axially after retraction, which could expose the contaminated needle. In other words, the shield 30 is preferably laterally flexible, but is substantially axially incompressible. In the present instance the shield is formed of Teflon. However, a variety of other known plastic materials may be used to form the shield.
Configured in this way, the device 10 is preferably used to insert a guide wire as follows. The needle 65 and shield pierce the skin of a patient and the vein or artery of the patient. Upon inserting the needle vascularly, a flash of blood will flow through the device. The blood flash can be seen, indicating to the medical professional that a vein or artery has been pierced. A medical device, such as a syringe, is then attached to the connector hub 50 and an amount of blood is withdrawn from the patient to ensure that the needle is properly positioned within the patient's vein or artery. Alternatively, the syringe can be attached to the connector hub 50 prior to inserting the needle into the patient. If a syringe is used, the syringe plunger is withdrawn to form a vacuum that draws blood into the syringe barrel. Preferably, approximately 1-3 cc of blood are withdrawn to ensure that the needle is properly positioned.
After the blood is drawn, confirming that the needle 65 is properly positioned, the needle is retracted by depressing button 43. The spring then propels the needle 65 and needle hub 40 rearwardly so that the sharpened tip is shielded. The head 45 of the needle hub engages the flange 27 in the barrel 20 to stop the rearward displacement of the needle. The needle may be retracted so that the sharpened tip is disposed within the barrel. However, as discussed above, preferably, the needle tip is retracted into the shield 30. The shield and the shielded needle are then further inserted into the patient's vein or artery. Preferably, substantially the entire length of the shield is inserted into the patient.
After the shield 30 is inserted into the patient, the guide wire 68 is inserted into the patient. First, the syringe is detached from the connector hub 50. Blood may continue to flow through the connector hub 50 after the syringe is detached. The medical professional may control the flow of fluid by sealing the back end of the connector hub with his or her finger until he or she is ready to feed the guide wire. The guide wire 68 is then fed through the connector hub 50. The tapered surfaces of the wire guide 52 guides the guide wire 68 into the needle 65, so that feeding the wire through the connector hub 50 feeds the wire through the needle and shield 30, into the patient. Once the guide wire is inserted into the needle, the guide wire occludes most of the flow of blood through the device because the internal diameter of the needle is preferably substantially the same as the external diameter of the wire. After the guide wire is inserted into the patient, the device is withdrawn from the patient leaving the guide wire within the patient's vein or artery. Since the contaminated needle 65 is shielded, the device 10 can be safely disposed of without concern of an inadvertent needle stick.
Referring now to FIGS. 4-5, a second embodiment of a guide wire insertion device is designated generally 110. The second embodiment is similar to the first embodiment 10, except that the second embodiment includes a Y-shaped connecting hub 150 having two ports. The two ports allow the device to virtually eliminate blood leakage, thereby providing a "bloodless" procedure as discussed in greater detail below.
The device 110 includes a retractable needle 165 for inserting a guide wire 168. The two ports of the connecting
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