CATHETER WITH DIRECTION ORIENTATION
A regional anesthesia catheter used with a guide, for example a cannula, has a distal portion integrally connected to its main portion by a junction portion that has a cross-sectional profile different from the distal and main portions, so as to predispose the distal portion of the catheter to move in a given direction when it is not constrained by the guide. The cross-sectional profile of the junction portion may be configured in a particular shape, or be constructed to have a flexibility that predisposes the distal portion to bend, curve or move toward a given direction. A number of portions of a catheter may be configured to bend at a predefined direction. Further, a catheter may be configured to have a cross sectional profile or a predefined flexibility along its entire length to cause the catheter to move in a predefined direction.
The present invention relates generally to catheters such as for example regional anesthesia catheters including epidural catheters that provide local anesthesia to a patient and more particularly to a catheter that has a built-in direction orientation that enhances the movement of the catheter to a particular location inside the patient.
BACKGROUND OF THE INVENTIONFor regional anesthesia, a cathether such as an epidural catheter is used to introduce anesthetic agents to the nerves for example at the spine of a patient. To place a catheter close to the nerve spinal column, an epidural needle such as a Tuohy needle is used by the anaesthesiologist. The Tuohy needle is inserted into the nerve sheath, alongside a nerve plexus of the patient. The Tuohy needle has a sharp distal end that has a beveled aperture, the sharp distal end adapted to readily pierce the nerve sheath at the spinal column of the patient. Once the anaesthesiologist believes that she has placed the epidural needle at the appropriate location in the patient, she would insert the catheter into the needle and move the catheter until its distal end extends out from the beveled end of the needle cannula. The catheter is usually marked along its length so that the anaesthesiologist knows approximately how much the distal end of the catheter extends beyond the distal tip of the needle cannula. The direction in which the catheter is moved inside the patient depends, to a large extent, on the insertion and placement of the needle cannula inside the patient by the anaesthesiologist and the skill of anaesthesiologist in maneuvering the catheter. Oftentimes, an anaesthesiologist, experienced or not, may have a difficult time maneuvering the distal end of the catheter to the desired location. As a result, a larger than necessary dose of anesthetic agent may be required to be delivered to the patient to locally anaesthetize the patient.
There is therefore a need to provide a catheter that can readily be maneuvered by the physician to a desired location inside a patient.
SUMMARY OF THE PRESENT INVENTIONTo assist a physician or an anaesthesiologist with the placement of a catheter for supplying local anesthetic to a patient, the catheter of the instant invention has at a portion proximate to its distal end, whereby anesthetic agent is output to a patient, a cross-sectional profile that predefines or predisposes the distal end of the catheter to be bent or headed to a given direction, once the catheter is no longer constrained by the guide or needle cannula wherethrough it passes. Conventionally, a catheter usually has a uniform circular cross sectional configuration throughout. For the instant invention, at least one portion of the catheter, preferably at a distance proximate to the distal end of the catheter, is configured to have a cross-section, which may or may not be circular, that predefines or predisposes the distal end of the catheter to move in a given direction. One of the cross-sectional profiles that may be used is an oval shaped configuration that causes, or predisposes, the catheter to be bent in the direction of the width of the greater cross-section width. Another sectional profile that may be used at the one portion of the catheter is C-shaped so that the distal end of the catheter is predisposed to bend toward the direction represented by the open mouth of the C.
In addition to having different cross-sectional profiles, the one portion that is configured to cause the distal end of the catheter to bend at a distal direction could have a different thickness at a section thereof so that, even though from the outside diameter the catheter may appear to be no different from the rest of the catheter, the inside diameter at the one portion is dimensioned to have thicker and thinner sections so that, once the one portion is outside of the needle cannula or guide, subject to additional movement, the catheter would tend to bend at a predefined orientation to a given direction, thereby enhancing the movement of the distal end of the catheter inside the patient.
The instant invention therefore relates to a catheter to be used with and passable through a guide for insertion to a patient. The catheter includes a tubing that has at least one portion having a cross-sectional profile that is configured to bend or orient the tubing in a given direction so that when the one portion of the tubing extends out of the guide, the tubing is predisposed to be routed or headed in a given direction.
The instant invention also relates to a combination of a hollow guide and a catheter passably fitted to and moveable along the guide. The catheter has a substantially circular cross-sectional profile along its entire length except for at least one portion between its distal and proximal ends. This one portion has a cross-sectional profile configured to predispose the distal end of the catheter toward a given direction so as to cause the catheter to move toward the given direction once the one portion of the catheter is no longer constrained by the guide.
The instant invention further relates to a catheter that has a distal portion connected to a main portion by a junction that has a cross-section that is different from the respective cross-sections of the main and distal portions. The distal portion, if unguided, points to and is movable along a first direction; and the main portion, if unguided, would point to and is movable along a second direction not in alignment with the first direction. The catheter is insertable into and movable along a hollow guide extending along a given axis. The junction that connects the distal portion with the main portion is configured to have a cross-sectional profile that causes the distal portion to bend or head toward the first direction once the distal portion and the junction are no longer confined within the guide after the catheter has been inserted to the guide and moved therealong.
The instant invention yet further relates to an apparatus that comprises a needle cannula and a regional anesthesia catheter such as an epidural catheter having a distal end and a proximal end. The catheter is movably fitted to the cannula with its distal end being inserted first into the first end of the cannula so that the catheter is movable along the cannula. The catheter has a substantially circular cross-section along its entire length except for at least one portion proximate to its distal end. This one portion has a non-circular cross-section configured to cause the distal end of the catheter to move in a direction predefined by the configuration of the one portion when the distal end and then the one portion of the catheter exit outside the cannula through its distal end.
The instant invention moreover relates to a method for introducing a catheter into a patient in which a hollow cannula is provided. The catheter has at least one portion between its distal and proximal ends that is configured to cause the distal end of the catheter to be predisposably moved toward a direction not in alignment with the cannula when the one portion is not confined within or constrained by the cannula. The cannula is inserted into the patient proximate to a location where anesthesia is desired. A catheter is inserted into and moved along the cannula. The distal end of the catheter is first inserted into the cannula. Thereafter, the catheter is continuously moved into the cannula until at least the one portion of the catheter is extended beyond the distal end of the cannula to predisposedly move the distal end of the catheter to the desired placement within the patient.
Another embodiment of the instant invention features a catheter such as for example a regional anesthesia catheter that has a cross sectional profile that extends longitudinally along the entire length of the catheter. The cross sectional profile is configured to cause the catheter to move in a predefined direction. In particular, the catheter of this embodiment comprises a tubing passable through a guide for insertion into a patient, the tubing having a given length and the cross sectional profile of the tubing along its entire length is configured to cause the catheter to bend, curve or move in a given direction.
The cross sectional profile of the catheter of the instant invention at the one portion as noted above or along the entire length of the catheter may be configured to be oval shaped or C shaped, or other non-circular shapes for example. The cross sectional profile may also be configured to be partially concaved inwards toward the center axis of the catheter or tubing, or may have a section of the wall where its thickness is different from that of the rest of the catheter.
It is therefore an objective of the instant invention to provide a catheter that is configured to be moved in a predisposed direction inside the patient.
The present invention will become apparent and the invention itself will be best understood with reference to the following description of the present invention taken in conjunction with the accompanying drawings, wherein:
With reference to
Although
Conventionally, a regional anesthesia catheter, such as for example the epidural catheter shown in the embodiment of
Cannula 4 is adapted to receive a catheter 10. Catheter 10, which has a distal end 12 and a proximal end 14, is inserted into cannula 4 via its distal end 12 to the opening (not shown) formed by cannula 4 at hub 8. Catheter 10 is moved so that its distal end 12 passes through cannula 4, exiting at the latter's distal tip 6. Catheter 10 may be manufactured from materials such as but not limited to: nylon including polyamides, Teflon, PVC, urethane, silicone and polyolefins such as polypropylene, polyethylene and polybutylene.
In
When confined within a hollow guide, such as for example needle cannula 4, both the distal portion 13 and the main portion 15 of the catheter, being constrained by the cannula, are in alignment along the longitudinal axis defined by the needle cannula. However, when not confined or constrained, distal portion 13 of catheter 10 of the instant invention is not in alignment with its main portion 15, as portion 16 is configured to predisposedly position distal portion 13 out of alignment with main portion 15 of the catheter 10. Portion 16 of catheter 10 may also be configured to have a given flexibility that allows distal portion 13 and main portion 15 of catheter 10 to align along substantially the same longitudinal axis, so long as distal end 12 of catheter 10 does not come into contact with any obstruction. In other words, portion 16 may be configured to flexibly bend in a predisposed direction relative to main portion 15 of catheter 10 when distal portion 13 encounters an obstruction. Although shown as being only a part of catheter 10, portion 16 may in some iterations include the entire catheter.
As noted above, portion 16 of catheter 10 is configured to have a cross-sectional profile that is different from the rest of the catheter. For the
In the event that obstruction is encountered, distal end 12 would bend in either direction 18a or direction 18b, depending on the orientation of the catheter, and the flexibility of the catheter at portion 16. Portion 16 of the catheter, which may be made from polyamide, may have a different thickness than that of the rest of the catheter. The difference in thickness may be effected during the extrusion process by stretching portion 16 more than the rest of the catheter. To effect an oval shape, portion 26 may be compressed by an appropriate tool after the catheter has been extruded or during extrusion. In any event, to effect the predisposed bending of the distal end 12 of the catheter relative to the remaining portion of the catheter, portion 16 may have a length from approximately 3 mm to 15 cm, depending on the length of the catheter.
In operation, a physician is provided with a hollow guide, such as needle cannula 4. The cannula is inserted into the patient proximate to a desired location where the catheter is to be placed. The catheter, and more particularly the distal end of the catheter, is inserted into the needle cannula and moved therealong, so that distal portion 13, portion 16, and main portion 15 of catheter 10 are confined within the cannula and are therefore in alignment along the longitudinal axis of the cannula. The catheter is moved further until distal end 12, and then portion 16, exit distal tip 6 of cannula 4. The orientation of distal end 12 of catheter 10, relative to cannula 4, is rotatably adjusted or oriented by the physician prior to her inserting the catheter into the cannula so that the distal end of the catheter would exit from the distal tip of the cannula in the direction of the desired location in the patient.
For the catheter 34 of the
Although the catheter of the instant invention has been described thus far as used for supplying an anesthetic agent to a patient, it should be noted that other treatment agents may also be supplied via the inventive catheter. Such other treatment agents may include for example electrical energy, radio frequency (RF), microwave and ultrasound waves that may be transmitted by the catheter. In the case of electrical energy, it is envisioned that the catheter may be imbedded with an electrical conductive material such as carbon or includes a wire extending along its length.
It should be appreciated that the present invention is subject to many variations, modifications and changes in detail. Thus, it is the intention of the inventor that all matters described throughout this specification and shown in the accompanying drawings be interpreted as illustrative only and not in a limiting sense. Accordingly, it is intended that the invention be limited only by the spirit and scope of the hereto appended claims.
Claims
1-20. (canceled)
21. A method of introducing a catheter into a patient, comprising the steps of:
- a) providing a hollow cannula having a proximal end and a distal end;
- b) providing a catheter insertable into and movable along said cannula, said catheter having at least one portion between its distal and proximal ends configured to cause the distal end of said catheter to be predisposedly moved toward a direction not in alignment with said cannula when said one portion is not confined within said cannula;
- c) inserting said cannula into the patient proximate to a desired location where said catheter is to be located in the patient;
- d) inserting said catheter into said cannula by first inserting the distal end of said catheter into said cannula; and
- e) continuing to move said catheter into said cannula until at least said one portion of said catheter extends beyond the distal end of said cannula to move the distal end of said catheter to the desired location within the patient.
22. Method of claim 21, further comprising the step of:
- orientating said one portion of said catheter relative to the cannula so that the distal end of said catheter is effected to move toward said direction when said one portion of said catheter is not confined by said cannula.
23-41. (canceled)
42. Method of claim 21, wherein the step (b) further comprises the step of:
- forming said catheter from a tubing having a circular cross sectional profile except at said one portion.
43. Method of claim 21, wherein the step (b) further comprises the step of:
- configuring the cross sectional profile of said one portion of said catheter to be oval shaped.
44. Method of claim 21, wherein the step (b) further comprises the step of:
- providing said one portion of said catheter to be approximately 3 mm to 15 cm in length proximate to a distal end of said catheter.
45. Method of claim 21, wherein said cannula comprises an epidural needle, the method further comprising the step of:
- inserting the epidural needle into the spine of the patient.
46. Method of claim 21, wherein the step (b) further comprises the step of:
- configuring at least one section of said one portion of said catheter to have a wall thickness less than that of the rest of said tubing.
47. Method of claim 21, wherein the step (b) further comprises the step of:
- configuring said one portion of said catheter to have a flexibility that is different from that of the rest of said catheter.
45. Method of claim 21, wherein said catheter comprises a regional anesthesia catheter, the method further comprising the step of:
- applying an anesthetic or other treatment agent to the desired location within the patient.
46. A method of manufacturing a catheter to be used with and passable through a guide for insertion into a patient, comprising the steps of:
- forming a plastic tubing;
- configuring said tubing to have a cross sectional profile that causes the tubing to have a naturally biased orientation in a given direction when said one portion of said tubing extends out of said guide, said tubing being routed in said given direction.
47. Method of claim 46, wherein the configuring step comprises configuring the cross sectional profile of said tubing to be oval shaped.
48. Method of claim 46, wherein the configuring step comprises configuring the cross sectional profile of said tubing to be C shaped.
49. Method of claim 46, wherein the configuring step comprises configuring the cross sectional profile of said tubing to be partially concaved inwards toward the center axis of said tubing.
50. Method of claim 46, wherein the configuring step comprises configuring the cross sectional profile of said tubing to be non-circular.
51. A method of directing a distal end of a tubing to move in a given direction, comprising the steps of:
- (a) providing a tubing having a distal portion connected to a main portion by a junction that has a cross section different from the respective cross sections of said main and distal portions;
- (b) configuring said junction to have a cross sectional profile that causes said distal portion to point to and movable along a first direction and said main portion to point to and move along a second direction not in alignment with said first direction if said tubing is unguided;
- (c) positioning a hollow guide relative to said given direction; and
- (d) inserting said tubing into and moving said tubing along said guide;
- wherein when said distal portion and said junction are no longer confined within said guide, the distal end of said distal portion is caused to move in said given direction.
52. Method of claim 51, wherein said guide comprises a cannula and said tubing comprises a regional anesthesia catheter, the method further comprising the steps of:
- positioning said cannula relative to a desired location within the patient; and
- inserting said catheter into and moving said catheter along said cannula to position the distal end of the catheter proximate to said desired location so that an anesthetic may be applied directly to said desired location of the patient.
53. Method of claim 51, wherein said tubing is a catheter and said guide is a cannula, wherein the step (b) comprises the steps of:
- configuring said catheter to have a substantially circular cross section along its entire length except at said junction; and
- configuring said junction to have a non-circular cross section configured to cause the distal portion of said catheter to move in a direction when the distal portion when not confined.
Type: Application
Filed: May 23, 2013
Publication Date: Nov 14, 2013
Inventor: David Jason Tucker (Walpole, NH)
Application Number: 13/900,584
International Classification: A61M 25/06 (20060101);