The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the present invention.
With reference to
Needle cannula 14 includes a rigid shaft 30 with its proximal end 32 supported by needle hub 34 which may be or couple to a flash chamber. The needle shaft 30 terminates in a distal sharp tip 36 defined by a bevel 38 which starts at heel 40.
As shown in
After insertion of catheter tube 22, the medical practitioner (not shown) will withdraw needle cannula 14 in the direction of arrow A (
In accordance with the principles of the present invention, it is desired that the medical practitioner be able to stop withdrawal of needle cannula 14 before reaching the second position, so as to stop in a third position of needle cannula 14 in which needle shaft 30 has been withdrawn from a distal portion 42 of catheter tube 22 while a portion 44 of shaft 30 proximal of heel 40 remains within a proximal portion 46 of tube 22. In this third position of needle cannula 14, the distal portion 42 is now free to flex for final placement of tube end 24 within the bodily space (not shown), yet there is still an impediment to fluid leakage through tube 22 into hub 16. To allow the medical practitioner to reliably move needle cannula 14 from the first position to the third position without going past the third position into the second position, a marker 50 is associated with shaft 30 in an area 52 thereof sufficiently proximal of heel 40 so as to position marker 50 within catheter 12, and advantageously within tube 22 as shown in
In the catheter insertion device 10 of in
The visual marker 50 may be associated with shaft 30 by applying a visually perceptible material such as ink to the surface 54 of shaft 30 at or up to area 52, or by a visually perceptible surface affect at or up to area 52 such as grinding, filing, etching, knurling, or otherwise altering the visually perceptible appearance of surface 54.
In use, catheter 12 is inserted into a bodily space (not shown) with needle cannula 14 in the first position. Once inserted, needle cannula 14 is withdrawn until at least some portion of marker 50 is seen proximal of hub 16, at which time needle cannula 14 is in the third position. Withdrawal of needle cannula 14 is stopped, allowing catheter distal portion 42 and/or tube end 24 to be finally positioned in the bodily space. Thereafter, needle cannula 14 may be withdrawn to the second position and removed from catheter 12 for subsequent medical use of catheter 12.
With reference to
Needle cannula 74 includes a rigid shaft 90 with its proximal end 92 supported by needle hub 94 which may be or couple to a flash chamber. The needle shaft 90 terminates in a distal sharp tip 96 defined by a bevel 98 which starts at heel 100.
Situated within hub 76, distal of opening 78 and proximal of eyelet 86, is a safety device 110 in the form of a clip. The structure and operation of clip 110, and its cooperation with hub 76 and needle cannula 74, will not be detailed here as they are explained in Bialecki U.S. Pat. No. 6,652,486, the disclosure of which is incorporated herein by reference in its entirety.
As shown in
After insertion of catheter tube 82, the medical practitioner (not shown) will withdraw needle cannula 74 in the direction of arrow A (
In accordance with the principles of the present invention, it is desired that the medical practitioner be able to stop withdrawal of needle cannula 74 before reaching the second position, so as to stop in a third position of needle cannula 74 in which needle shaft 90 has been withdrawn from a distal portion 130 of catheter tube 82 while a portion 132 of shaft 90 proximal of heel 100 remains within a proximal portion 134 of tube 82. In this third position of needle cannula 74, portions 116, 118 are still resiliently urged against surface 120 of shaft 90. Also in this third position of needle cannula 74, the distal portion 130 of tube 82 is now free to flex for final placement of tube end 84 within the bodily space (not shown), yet there is still an impediment to fluid leakage through tube 82 into hub 76. To allow the medical practitioner to reliably move needle cannula 74 from the first position to the third position without going past the third position into the second position, one or both of a first marker 140 and a second marker 142 are associated with shaft 90 in respective areas 144 and 146 thereof which are each sufficiently proximal of heel 100 so as to be within catheter 72, and advantageously within tube 82 as shown in
Tube 82 of catheter 72 extends a distance L1 from hub distal end 80 to tube distal end 84. Hub 76 has a length L2 between proximal opening 78 and distal end 80, with length L2 being long enough to normally enclose clip 110 in the first position of needle cannula 74. Clip 110 is typically held within hub 76 such that at least one of portions 116, 118 is spaced proximally of the distal end 80 of hub 76 by a distance L4. Areas 144 and 146 are proximally spaced from heel 100 a respective distance L3V and L3T which, in accordance with the principles of the present invention, are in respective relationships to L1, L2 and/or L4. To that end, L3V is advantageously greater than L2 and less than the sum of L1 plus L2. For many catheters 72, L3V is more advantageously less than L1, but for short catheters, may be more advantageously greater than L1. Similarly, L3T is advantageously greater than L4 and less than the sum of L1 plus L4, and more advantageously less than L1. The foregoing advantageously places at least marker 142 within catheter tube 82, and places marker 140 within catheter 72 and possibly within tube 82, in the first position of needle cannula 74, and such that they are exposed beyond at least catheter tube 82, with marker 140 further being exposed beyond hub 76, in the third position of needle cannula 74.
In the catheter insertion device 70 of in
The visual marker 140 may be associated with area 144 by applying a visually perceptible material such as ink to the surface 120 of shaft 90 at or up to area 144 or by a visually perceptible surface affect at or up to area 144 by grinding, filing, etching, knurling, or otherwise altering the visually perceptible appearance of surface 120. Advantageously, marker 140 is not such as would create a noticeable tactile sensation as it passes along portions 116 and 118, and further advantageously does not create an outward projection large enough to prevent proximal withdrawal of needle cannula 74 through clip 110 to the second position or to cause release of clip 110. Tactile marker 142 may be a disruption of surface 120 in area 146 such as an outwardly directed (relative to surface 120) projection, an inwardly directed (relative to surface 120) recess or the like (such as a notch or gap, by way of example), or a roughening thereof, sufficient to interact with portion 116 and/or 118 to create a tactile feedback to the user (not shown) as marker 142 passes along the resiliently-urged portion(s). Advantageously, the disruption is an outwardly directed projection and may be associated with area 146 by crimping or coining surface 120 thereat, by way of example, although the extent of outward projection is advantageously not as large as that for disruption 122, so as not to prevent proximal withdrawal of needle cannula 74 through clip 110 into the second position or to cause release of clip 110. Where marker 142 is a roughening or an inwardly directed recess or the like (both not shown), it may be associated with area 146 by grinding, filing, etching, machining, or milling, by way of example, although marker 142 is advantageously not so far into surface 120 as to allow clip 110 to activate as marker 142 passes along portions 116 and 118. As may be seen in
Use of safety catheter insertion device 70 is similar to catheter insertion device 10, except that withdrawal of the needle cannula 74 may be stopped at the third position by either seeing some portion of visual marker 140 exposed beyond hub 76 and/or feeling a tactile sensation by tactile marker 142 exposed beyond tube 82 within hub 76 to pass along portion 116 and/or 118.
With reference to
Needle cannula 204 includes a rigid shaft 220 with its proximal end 222 supported by needle hub 224 which may be or couple to a flash chamber. The needle shaft 220 terminates in a distal sharp tip 226 defined by a bevel 228 which starts at heel 230. Extending proximally from catheter hub 206, and located between hubs 206 and 224, is a housing 234. Housing 234 may be coupled distally to catheter hub 206 by a duckbill mechanism as described in co-pending U.S. patent application Ser. No. 11/161,554, filed Aug. 8, 2005, the disclosure of which is incorporated herein by reference in its entirety. Housing 234 has a proximal end 238 and includes a safety device 240 in the form of a canting plate therein. The structure and operation of housing 234 and canting plate 240, and their cooperation with catheter hub 206 and needle cannula 204, will not be detailed here as they are explained in the aforementioned incorporated-by-reference co-pending U.S. patent application Ser. No. 11/161,554.
As shown in
After insertion of catheter tube 212, the medical practitioner (not shown) will withdraw needle cannula 204 in the direction of arrow A (
In accordance with the principles of the present invention, it is desired that the medical practitioner be able to stop withdrawal of needle cannula 204 before reaching the second position, so as to stop in a third position of needle cannula 204 in which needle shaft 220 has been withdrawn from a distal portion 254 of catheter tube 212 while a portion 256 of shaft 220 proximal of heel 230 remains within a proximal portion 258 of tube 212. In this third position of needle cannula 204, plate 240 is still resiliently urged to lightly bear against shaft 220. Also, in this third position of needle cannula 204, the distal portion 254 of the tube 212 is now free to flex for final placement of tube end 214 within the bodily space (not shown), yet there is still an impediment to fluid leakage through tube 212 into hub 206. To allow the medical practitioner to reliably move needle cannula 204 from the first position to the third position without going past the third position into the second position, one or both of a first marker 260 and a second marker 262 are associated with shaft 220 in respective areas 264 and 266 thereof which are each sufficiently proximal of heel 230 so as to be within catheter 202, and advantageously within tube 212 as shown in
Tube 212 of catheter 202 extends a distance L1 from hub distal end 210 to tube distal end 214. Hub 206 and housing 234 have a combined length L2 between housing proximal end 238 and hub distal end 210, with hub 206 having a length L2H between proximal opening 208 and distal end 210 long enough for duckbill arms 242 to engage within hub 206 in the first position of needle cannula 204. Plate 240 is typically held within housing 234 such that through-hole 244 is spaced proximally of the distal end 210 of hub 206 by a distance L4. In accordance with the principles of the present invention, areas 264 and 266 are proximally spaced from heel 230 a respective distance L3V and L3T, which bear respective relationships to L1, L2, L2H and/or L4. To that end, L3V is advantageously greater than L2 and less than the sum of L1 plus L2, and more advantageously, less than L1 plus L2H. For many catheters, L3V may still more advantageously be less than L1, but for short catheters, may be greater than L1. Similarly, L3T is advantageously greater than L4 and less than the sum of L1 plus L4, and more advantageously less than L1. The foregoing advantageously places markers 260 and 262 within catheter 202, and possibly within catheter tube 212, in the first position of needle cannula 204, and such that they are exposed beyond at least catheter hub 206, with marker 262 further being exposed beyond housing 234, in the third position of needle cannula 204.
In the catheter insertion device 200 of in
The visual marker 260 may be associated with area 264 by applying a visually perceptible material such as ink to the surface 250 of shaft 220 at or up to area 264 or by a visually perceptible surface affect at or up to area 264 by grinding, filing, etching, knurling, or otherwise altering the visually perceptible appearance of surface 250. Advantageously, marker 260 is not such as would create a noticeable tactile sensation as it passes along any of edges 248, 252, and further advantageously does not create an outward projection large enough to prevent proximal withdrawal of needle cannula 204 through plate 240 to the second position. Tactile marker 262 may be a disruption of surface 250 in area 266 which results in either an outwardly directed (relative to surface 250) projection, of an inwardly directed (relative to surface 250) recess or the like (such as a notch or gap, by way of example), or a roughening of surface 250 sufficient to interact with edge(s) 248 (but advantageously not edge 252), to create a tactile feedback to the user (not shown) as marker 262 passes along edge(s) 248. Where the disruption is an outwardly directed projection (not shown), it may be associated with area 266 by crimping or coining surface 250 thereat, by way of example, although the extent of outward projection is advantageously not so large as to prevent proximal withdrawal of needle cannula 204 through plate 240 into the second position. Where marker 262 is a roughening of surface 250 or is an inwardly directed recess or the like, it may be associated with area 266 by grinding, filing, etching, machining, or milling, by way of example. Also, while tactile marker 262 is described herein as providing a tactile response in passing along edge(s) 248, marker 262 could instead be adapted to cooperate with edge 252 to produce the tactile response, meaning that associated area 266 would be more distal than that shown and L4 would be measured relative to edge 252 rather than through-hole 244.
Use of safety catheter insertion device 200 is similar to both catheter insertion devices 10 and 70, except that withdrawal of the needle cannula 204 may be stopped at the third position by either seeing some portion of visual marker 260 exposed beyond housing 234 and/or feeling a tactile sensation by tactile marker 262 exposed beyond hub 206 and within housing 234 to pass along edge(s) 248.
By virtue of the foregoing, there is thus provided a catheter insertion device which provides the medical practitioner with the ability to reliably withdraw the needle cannula sufficiently to free the distal portion of the tube to flex so as to facilitate final placement of the tube in the bodily space while maintaining at least a portion of the shaft proximal of the sharp tip within a proximal portion of the tube to continue to impede fluid leakage.
While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. For example, while separate visual and tactile markers are shown, there could be one marker to serve both as a visual marker and as a tactile marker. In many catheter insertion devices, the needle cannula is hollow and thus has a fluid lumen therethrough. The marker(s) of the present invention advantageously will not extend through the needle shaft surface so as to open a fluid path into the fluid lumen thereat. Otherwise, as the marker becomes exposed beyond the tube, an alternate leakage path would be created. Further, while the markers are shown as being wholly beyond the catheter, catheter tube, catheter hub or housing as the context admits, it will be appreciated that as used herein, a marker is “exposed beyond” even if only a portion thereof is beyond, while the rest is not, and that “exposed beyond” is a positional relationship not necessarily requiring that the marker be visible to the user. The invention in its broader aspects is, therefore, not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept.