ULTRASOUND-PLACED PAIN MANAGEMENT SYSTEM AND METHOD WITH SUBCUTANEOUS CATHETER

Abstract

A catheter system includes a medication dispenser located external to a patient. A subcutaneous port is placed internally to the patient and receives a quantity of medication. The port can be filled from a syringe or medication dispensing system. An echogenic catheter can be placed in proximity to a patient's nerve or nerve center using a point-of-care ultrasound imaging system. A method of administering a nerve block or other medication subcutaneously to a patient includes the steps of placing a subcutaneous port using ultrasound imaging for guidance and administering pharmacologic agents via a catheter connected to the port. Alternative embodiment catheter systems include echogenic tips and a stylet to facilitate accurate placement.

Claims

1. A catheter system for administering medication to a patient, which system includes: a medication dispenser configured for placement externally to the patient and including a hypodermic needle; a medication port configured for receiving medication from said dispenser; said medication port configured for placement subcutaneously to the patient and fluidic connection to said medication dispenser; an echogenic catheter configured for fluidic connection to said medication port and terminating at a distal end internally to the patient; and a point-of-care ultrasound imaging system configured for monitoring placement of said echogenic catheter.

2. The catheter system according to claim 1, which includes: said catheter configured for terminating in proximity to a nerve center of the patient.

3. The catheter system according to claim 2, which includes: a medication control system connected to said medication dispenser and configured for selectively injecting medication to said catheter.

4. The catheter system according to claim 3, which includes: said medication control system configured for injecting medication in predetermined dosages.

5. The catheter system according to claim 4, which includes: said medication control system configured for injecting medication at predetermined time intervals.

6. The catheter system according to claim 5, which includes: said point-of-care ultrasound imaging system configured for imaging patients' neurology.

7. The catheter system according to claim 6, which includes: said point-of-care ultrasound imaging system configured for imaging said catheter and patient nerve or nerve centers in real time; and said point-of-care ultrasound imaging system configured for use in guiding said catheter for medication discharge in proximity to a patient nerve or nerve center.

8. The catheter system according to claim 1, which is configured for administering nerve block or other medications for treating nerve-related conditions.

9. A catheter system for administering medication to a patient, which system includes: a medication dispenser configured for placement externally to the patient; a medication port configured for placement subcutaneously to the patient; a needle configured for injecting medication into said port; tubing configured for connecting said medication dispenser and said needle; a catheter configured for fluidically connecting to said medication port and terminating at a distal end internally within the patient, said catheter including an infusion port configured for discharging medication internally within the patient; a medication control system connected to said medication dispenser and configured for selectively injecting medication to said catheter; said medication control system configured for injecting medication in predetermined dosages to said port; said medication control system configured for injecting medication at predetermined time intervals; a point-of-care ultrasound imaging system configured for placing said catheter; said point-of-care ultrasound imaging system configured for imaging patients' neurology; said point-of-care ultrasound imaging system configured for imaging said catheter and patient nerve centers in real time; said point-of-care ultrasound imaging system configured for use in guiding said catheter for medication discharge in proximity to a patient nerve center; and said catheter system configured for administering nerve block medications and other medications for treating nerve-related diseases.

10. The system according to claim 9 wherein said catheter includes an echogenic marker located in said catheter distal end.

11. The system according to claim 9 wherein said catheter includes: a solenoid coil located in said distal end of said catheter; said solenoid coil configured for connection to an electrical power source via electrical leads within said catheter; and an echogenic magnet reciprocably received in said solenoid coil and configured for ultrasonic detection and monitoring.

12. The system according to claim 9, which includes a quantity of electrorheological fluid encapsulated in said catheter distal end.

13. The system according to claim 9, which includes a quantity of magnetorheological fluid encapsulated in said catheter distal end.

14. The system according to claim 9, which includes a quantity of a phase change agent encapsulated in said catheter distal end.

15. The system according to claim 9, which includes a microelectromechanical system encapsulated in said catheter distal end.

16. The system according to claim 9, which includes a Piezoelectric micro-machined, ultrasonic transducer encapsulated in said catheter distal end.

17. A method of administering medication to a patient with ultrasound guidance, which includes the steps of: providing a medication dispenser and placing said medication dispenser externally to the patient; placing a medication port subcutaneously to the patient; injecting medication from said medication dispenser into said port; connecting a catheter to said medication port; placing an infusion port of said catheter internally in the patient; and infusing medication from said catheter medication port in said patient.

18. The method according to claim 17, which includes the additional step of placing said catheter discharge in proximity to a nerve or nerve center of the patient.

19. The method according to claim 18, which includes the additional step of providing a medication control system configured for selectively injecting medication to said catheter.

20. The method according to claim 19, which includes the additional steps of: configuring said medication control system for injecting medication in predetermined dosages; configuring said medication control system for injecting medication at predetermined time intervals; providing a point-of-care ultrasound imaging system configured for placing said catheter; configuring said point-of-care ultrasound imaging system for imaging patients' neurology; configuring said point-of-care ultrasound imaging system for imaging said catheter and said patient nerve or nerve centers in real time; configuring said point-of-care ultrasound imaging system for guiding said catheter for discharge of medications in proximity to a patient nerve center; configuring said catheter system for administering medications; monitoring said patient for adverse reactions to said medication; and signaling an adverse reaction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 a cross-sectional view of a catheter system embodying an aspect of the present invention, shown receiving a medication for transfusion in a patient.

[0032] FIG. 2 is a flowchart showing a pain management treatment protocol method embodying an aspect of the present invention.

[0033] FIG. 3 is a fragmentary, cross-sectional view of an alternative embodiment catheter tip with an echogenic marker.

[0034] FIG. 4 is a fragmentary, cross-sectional view of another alternative embodiment catheter tip with a solenoid and magnet assembly.

[0035] FIG. 5 is a fragmentary, cross-sectional view of another alternative embodiment catheter tip with magnetorheological or electrorheological fluid.

[0036] FIG. 6 is a fragmentary, cross-sectional view of another alternative embodiment catheter tip with a phase change agent.

[0037] FIG. 7 is a fragmentary, cross-sectional view of another alternative embodiment catheter tip with a micro-electronic mechanical system or a piezo-electronic micro-machined ultrasonic transducer.

[0038] FIG. 8 is a fragmentary, cross-sectional view of another alternative embodiment catheter with a braided sleeve and an echogenic tip.

[0039] FIG. 9 a cross-sectional view of another alternative embodiment with a bent-end placement stylet configured for manipulation to facilitate ultrasound visibility and accurate placement, shown being positioned in a patient.

[0040] FIG. 10 is an enlarged, fragmentary view of the bent-end stylet.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

I. Introduction and Environment

[0041] As required, detailed aspects of the present invention are disclosed herein, however, it is to be understood that the disclosed aspects are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art how to variously employ the present invention in virtually any appropriately detailed structure.

[0042] Certain terminology will be used in the following description for convenience in reference only and will not be limiting. For example, up, down, front, back, right and left refer to the invention as orientated in the view being referred to. The words, “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the aspect being described and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof and words of similar meaning. The definition of nerve designates peripheral nerves such as are commonly known, such as the saphenous, femoral, intercostal or radial nerves as well as numerous others. Nerve centers designate more proximal (e.g., closer to the central nervous system) nerve locations than peripheral nerves and include, but are not limited to, nerve roots, trunks, divisions, cords, and plexuses. Examples of these are the cervical roots, anterior division, lateral cord and the brachial plexus. Likewise, epidural or subarachnoid, as they are commonly referred to in the art, are an anatomic location that contains nerves, nerve roots and/or plexuses.

II. Ultrasound-Guided Catheter System 2

[0043] A catheter system 2 embodying an aspect of the present invention is shown in FIG. 1 and generally includes an implantable port 4 connected to a catheter 6. The port 4 is preferably placed below the epidermis 10, and can be internally attached with sutures, surgical staples or some other attachment mechanism. The port 4 is preferably configured for receiving a quantity of a pharmacologic treatment, such as an anesthetic, a chemotherapy medication, etc. The port 4 can be constructed of ferrous or non-ferrous materials with a reservoir 5 and is designed for coupling with the catheter 6 via a coupler 7. The coupler 7 can be designed for repeated detachment from and attachment to the catheter 6 to facilitate replacement of the port 4 and catheter 6.

[0044] Additionally, it may be desired to temporarily detach the port 4 from the catheter 6 to inject pharmacologic agents into the catheter 6 to evaluate the placement of those medicines near nerves or nerve centers or evaluate function of the catheter 6. It may be desirable for the port 4 to be of smaller size in its height and diameter to allow for placement in a variety of anatomic locations to minimize discomfort and decrease the likelihood of skin ulceration due to pressure from outside the body to the skin over the port. The catheter 6 is fluidically connected to the port 4 and terminates in proximity to portions of the patient's nervous system to be anesthetized. Nerves and nerve centers 11 can be located using an ultrasound imaging procedure.

[0045] For placement of the catheter 6, a Tuohy needle, or some other suitable non-coring needle, is advanced under ultrasound guidance to a nerve or nerve center 11. The catheter is then advanced through the needle and the needle is withdrawn. In another embodiment, known as the Seldinger technique, a needle is advanced to the nerve or nerve center 11, a wire is advanced through the needle, the needle is withdrawn, and the catheter 6 is exchanged over the wire.

[0046] In another embodiment commonly used for catheter placement, a breakaway sheath and wire system accomplishes the same purpose.

[0047] The catheter 6 of the system 2 is located so that infusion ports 8 of the catheter 6 are near a nerve or nerve center 11, but the port portion of the system is located in an anatomic location that is convenient for access of injection as well as comfort of the patient. A path below the skin from the catheter to the port can be created by tunneling, as is well known in the art for the placement of ventriculoperitoneal shunts or spinal cord stimulators, if the desired location for the port is some distance from the catheter 6.

[0048] As an example, it may be necessary, as in the case of epidural placement of the catheter 6 in the midline of the back, for the port to be located on the patient's flank to prevent ulceration of the skin covering the port, for comfort of the patient and ease of injection. The catheter 6 can be trimmed to length so the distance from the infusion ports 8 of the catheter 6 to the port can be specifically tailored for each patient, allowing the port to be placed in an anatomic location convenient for injection and with adequate fascia layers for securing the port with sutures or other method, with its septum facing outward.

[0049] A syringe or other medication control system 12 is connected to tubing 16 terminating at a needle 18. Huber and other suitable non-coring needles can be used for injecting medications into the subcutaneous port 4. The needle 18 can also comprise a stylet, which can be curved. Various medication dispensing devices can be used with the catheter system 2 of the present invention. For example, in lieu of a manually-operated syringe, a motorized pump can be provided. Moreover, operation of the medication control system 12 can be automated with a programmable microprocessor 14 for cycling the operation of a motorized pump to dispense medication at predetermined intervals consistent with a predetermined treatment protocol. Medicine control systems such as described are currently available and commonly used in medical settings. Moreover, various medications can be selectively administered, including, without limitation, anesthetics, chemotherapy medications, growth factors, antibiotics, etc.

[0050] The port 4 can be accessed intermittently or continuously with a Huber or other non-coring needle 18. If used continuously, this needle 18 can be removed periodically, the skin 10 sterilized, and a new sterile needle 18 introduced to minimize infection risk.

[0051] FIG. 2 is a flowchart showing an example of a medication administration method embodying an aspect of the present invention. From a start 22, the method includes the steps of diagnosing the patient at 24 and devising a treatment plan at 26. At decision box 28, a procedure including a nerve block with a pain catheter can be considered. If negative (“NO”), other pain management can be chosen at 30. If positive (“YES”), the protocol continues to selection of medicines and type of block to be performed at 32 and selection of a delivery mechanism at 34. The treatment cycle (e.g., intermittent, continuous, etc.) is set at 36. Step 38 involves placing an ultrasound/alternative technology guided catheter system.

[0052] Medication is administered at 42 and its efficacy is monitored at 44. Complications are monitored at 46 and can include, for example, infection, toxicity, etc. If a modified treatment plan is deemed necessary (“Yes” path from decision box 48), the protocol loops back to the treatment plan step 26. If “No,” the treatment terminates at 50.

III. First Alternative Embodiment Catheter System 102 with Echogenic Marker 104

[0053] In another embodiment or aspect of the present invention, shown in FIG. 3, an echogenic marker 104 that is discernable from anatomy is placed at the tip of a catheter 106 near infusion ports 108 in the wall of the catheter 106 as an aid in placement of the catheter system 102. The echogenic marker 104 can be comprised of biocompatible materials such as ceramics, polymethyl methacrylate (PMMA), titanium, stainless steel, or other suitable material. This echogenic structure can provide the medical professional with confirmation that the infusion ports 108 of the catheter system 102 are located in the desired location in relation to nerves or nerve centers 11.

IV. Second Alternative Embodiment Catheter System 202 with Solenoid

[0054] In another alternative embodiment or aspect of the present invention, shown in FIG. 4, a wire coil solenoid 220 is embedded in a catheter 206. Electrical conductors 222 (−) and 224 (+) are extended to a distal end 226 of the catheter 206. An echogenic magnet 228 is placed in the solenoid 220 and the system 202 is energized via a time-varying current producing oscillatory movement of the magnet 228 as a unique ultrasonic visual aid in placement of the catheter system 202. The system is energized by a nerve stimulator, as is commonly available in the medical setting, or a similar device suitable to produce the magnitude of electromagnetic field necessary to produce oscillatory movement.

[0055] Nerve stimulators can supply power in a regular on/off pattern per a predetermined frequency. As the solenoid 220 in the catheter is energized, the echogenic magnet 228 is induced to move due to electromagnetic energy. When the solenoid is de-energized, the magnet returns to its original position. This oscillatory movement can provide a unique visual identifier to the medical professional, thus confirming that infusion ports 208 of the catheter system 202 are located in the desired location in relation to nerves or nerve centers 11.

V. Third Alternative Embodiment Catheter System 302 with Electrorheological (ER) and

[0056] Magnetorheological (MR) Fluids

[0057] In a third alternative embodiment or aspect of the invention shown in FIG. 5, a catheter system 302 includes a quantity of ER or MR fluid 320 placed in a reservoir 321 in the catheter distal end 326. The catheter system 302 includes infusion ports 308. Negative and positive electrical conductors 322, 324 are extended to the catheter distal end 326 and energized by a nerve stimulator or similar suitable device for energizing the fluid 320 to induce a physical change, thereby making the catheter 306 more discernable when viewed with ultrasound. Likewise, a physical change in a MR fluid could be induced by creating a magnetic field by the use of a solenoid as described in the previous embodiment 202.

VI. Fourth Alternative Embodiment Catheter System 402 with Phase Change Agent

[0058] FIG. 6 shows a catheter system 402 comprising another alternative embodiment or aspect of the present invention with a phase change agent 420 contained within a reservoir 422 in a distal end 426 of a catheter 406 with infusion ports 408. Phase change agents, such as, but not limited to perfluorocarbons, have a boiling point near body temperature so that vaporization can be induced by the acoustic energy provided by the ultrasound probe producing expansion in volume. This volume change is visible via ultrasound. In another embodiment, phase change agents are encapsulated in the catheter system and induced by energy of the ultrasound probe to create a unique visual marker. When the ultrasound probe is removed, the phase change agent returns to the prior state.

VII. Fifth Alternative Embodiment Catheter System 502 with MEMS or pMUT

[0059] FIG. 7 shows a catheter system 502 embodying a fifth alternative embodiment or aspect of the present invention with a microelectromechanical system (MEMS) or a piezoelectric micro-machined ultrasonic transducer (pMUT) component 520. The component 520 is located in a closed, distal end 526 of a catheter 506 with infusion ports 508. Electrical conductors 522 (—) and 524 (+) are connected to a nerve stimulator, which can sequentially energize and deenergize the component 520 to achieve a desired result by varying the amplitude and frequency of the energizing signals.

[0060] The Microlectromechanical System (MEMS) catheter system 502 can be fabricated using semiconductor materials and incorporating mechanical components, sensors, actuators, and electronic elements with feature sizes ranging from a few millimeters to microns gauge. In another embodiment, MEMS can be incorporated in the catheter system and energized to induce a movement of a portion of the catheter system via an actuator that would be uniquely visible via ultrasound.

[0061] A distinct advantage of the herein described catheter system 502 is that the location of the port is immediately below the skin layer, minimizing distance to the external energy source, with the result of maximizing transfer efficiencies. The underside of the port, opposite of the septum, is geometrically suitable for placement of a receiving coil to be in parallel with a transmitting coil placed outside the skin. The coil that is embedded on the port can be connected to a conducting lead which is embedded in the catheter and terminating at the distal of end of the catheter in proximity to nerves or nerve centers and designed to conduct neuromodulation signals.

[0062] In another embodiment, ultrasonic energy transfer can be utilized to transcutaneously energy the catheter system. This utilizes the known piezoelectric effect that utilizes the conversion of ultrasonic energy to electrical energy. Ultrasonic transfer of energy allows longer power transmission distances and is free of electromagnetic interference. In this scheme, a piezoelectric transducer that is external to the skin layer faces a piezoelectric receiver embedded in the port and under the skin layer allowing transmission ultrasonic energy in either direction without penetrating the skin layer. Energy is transmitted through the skin layer via ultrasonic energy from the transducer to the receiver and is converted to electricity. Electrical energy can then be utilized to energize the other herein described embodiments.

VIII. Sixth Alternative Embodiment Catheter System 602 with Catheter Liner 604

[0063] FIG. 8 shows another embodiment catheter system 602 with a catheter liner 604 received in a catheter 606 including infusion ports 608. The liner 604 can comprise braided nickel titanium with a construction similar to medical, intravascular stents. A stainless-steel tip 612 is provided for echogenic visibility to facilitate placement.

IX. Seventh Alternative Embodiment Catheter System 702 with Stylet Locator 710

[0064] FIGS. 9 and 10 show another embodiment catheter system with a catheter 706 including a catheter end 707 and infusion ports 708. The catheter 706 can be configured for receiving a stylet 710, provided the passage of the catheter 706 has a sufficient internal diameter (ID). The stylet 710 includes a bent distal end 712 and a proximal end knob 714. As shown in FIG. 9, manually twirling the knob 714 causes a corresponding rotation of the stylet bent distal end 712, which facilitates ultrasound monitoring and accurate placement. In other words, a physician's “signature” manual manipulation of the stylet-catheter combination facilitates placement in proximity to a nerve center 11 for optimizing treatment effectiveness and patient outcomes.

X. Ultrasound-Placed Pain Management Methods with Subcutaneous Catheters

[0065] The ultrasound-placed pain management systems with subcutaneous catheters can be utilized for a variety of treatment protocols. Moreover, they are adaptable for a variety of medications. Automated systems, e.g., with programmable microprocessors, can be programmed for providing consistent, regular treatments as indicated. Moreover, patients' healing progress can be closely monitored and treatment protocols adjusted or terminated for achieving optimal patient outcomes.

XI. Conclusion

[0066] The catheter systems and methods of the present invention can be adapted to accommodate a variety of medical conditions and treatment protocols. For example, and without limitation, antibiotics for infection control and growth factors for promoting re-epithelialization can be introduced to a wound site.

[0067] It is to be understood that while certain embodiments and/or aspects of the invention have been shown and described, the invention is not limited thereto and encompasses various other embodiments and aspects.