Device and method for precise subcutaneous placement of a medical instrument

Claims

What is claimed is:

1. A system for monitoring medical instrument placement with respect to a reservoir in a body to ensure accurate positioning of an opening in an inserted end portion of said instrument at a preselected location with respect to reservoir, said system comprising:

electrical means positioned outside said body for providing an electrical power output;

signal generating means positioned outside said body connected with said electrical means for receiving said electrical power output to thereby supply output signals;

sensing means separate from connection with said instrument and adapted to receive said output signals from said signal generating means, said output signals being modified in accordance with the position of said instrument with respect to said reservoir, to thus utilize said signals to provide an electrical output indicative of at least a predetermined desired positioning of said inserted end portion of said instrument at said preselected location within said body;

signaling means connected with said sensing means to receive said electrical output therefrom and responsive thereto provide an electrically induced output signal; and

indicating means receiving said output signal from said signaling means and utilizing said output signal to provide an indication at least that said desired positioning of said inserted end portion of said instrument at said preselected location is then established.

2. The system of claim 1 wherein said inserted end portion of said instrument includes a metallic material, and wherein said sensing means includes an electrically inductive coil said output indicative of a predetermined desired position of said inserted end portion of said instrument being provided upon insertion of said end portion to attain a predetermined position with respect to said coil.

3. The system of claim 2 wherein said sensing means includes an oscillator and said coil is included in said oscillator, and wherein said signaling means includes signal modulation means for varying said output signal in response to said output from said sensing means.

4. The system of claim 1 wherein said indicating means includes microprocessor means for processing said electrically induced output signal from said signaling means.

5. The system of claim 1 wherein said instrument effects fluid delivery therethrough, wherein said body has reservoir means placed therein at said preselected location for one of receipt of said fluid through said opening in said inserted end portion of said instrument and maintaining said fluid therein for withdrawal of said fluid through said opening in said inserted end portion of said instrument, and wherein said reservoir means includes fluid passageway means for passage of said fluid between said reservoir means and said body.

6. The system of claim 1 wherein said inserted end portion of said instrument is made of electrically conductive material and wherein said sensing means includes first and second electrically conductive means, said sensing means providing said output indicative of said predetermined desired position of said inserted end portion of said instrument when said inserted end portion is in electrical contact with both said first and second conductive means.

7. The system of claim 1 wherein said sensing means provides outputs indicative of proximity of said inserted end portion of said instrument to said preselected location within said body.

8. A system for locating matter at a predetermined position within a body, which position is accessible through a medical instrumentality insertable into said body, said system comprising:

reservoir means positioned at said predetermined position within said body for receiving and maintaining said matter thereat;

first electronic means contiguous to said reservoir, said first electronic means including sensing means separate from connection with said medical instrumentality for sensing the position of said instrumentality relative to said reservoir means and signaling means connected with said sensing means for providing an electrical signal indicative at least of positioning of said instrumentality within said reservoir means;

second electronic means positioned outside said body, said second electronic means including signal processing means for sensing said electrical signal provided by said signaling means and indicating means for indicating to a user of said instrumentality said positioning of said instrumentality within said reservoir means responsive to said electrical signal sensed by said signal processing means; and

electrical signal generating means positioned outside said body for activating said first and second electronic means of said system.

9. The system of claim 8 wherein said signaling means includes means for providing a signal indicative of the proximity of said instrumentality to said reservoir means and wherein said indicating means of said second electronic means includes means for indicating to a user of said instrumentality said proximity of said instrumentality to said reservoir means.

10. The device of claim 8 wherein said sensing means is a proximity detector for sensing the positioning of said instrumentality relative to said reservoir means.

11. The device of claim 8 wherein said reservoir means includes a first section for receiving said instrumentality therethrough while remaining substantially impervious to passage of matter from said body therethrough, and a second section for storing said matter received through said instrumentality, said second section being adapted for metered delivery of said matter from said second section to said body.

12. A device for locating and establishing placement relative to a desired location in a body of a medical instrumentality insertable into said body for effecting fluid delivery to said desired location, said device comprising:

first means implanted within said body and contiguous to said desired location, said first means including first electronic sensing means for sensing inductance changes caused by positioning of said instrumentality inserted into said body relative to said desired location and signaling means for providing an electrically induced signal indicative of said inductance changes; and

second means movably positionable outside said body, said second means including second electronic sensing means for sensing the position of said first means relative to a location on said body suitable for insertion of said instrumentality and providing an electrical signal indicative thereof, signal receiving and processing means for receiving and processing said signals from said second electronic sensing means and said signaling means, and indicating means connected with said signal receiving and processing means for indicating to a user of said instrumentality when said instrumentality is suitably positioned for insertion and when said instrumentality is positioned at said desired location.

13. The device of claim 12 wherein said first and second means include cooperative electrical energizing means for energization of said first electronic sensing means, said signaling means, said second electronic sensing means, said signal receiving and processing means and said indicating means.

14. The device of claim 13 wherein said second electronic sensing means includes monitoring means for monitoring said cooperative energizing means, and wherein said location on said body suitable for insertion of said intrumentality is indicated by said indicating means when maximum energization of said first sensing means and said signaling means is sensed by said second sensing means.

15. The devide of claim 13 wherein said electrical signal indicative of said inductance changes is one of a radio signal and a signal indicative of a relative change of said energization corresponding to said positioning of said instrumentality with maximum relative change of said energization corresponding to placement of said instrumentality at said desired location.

16. The device of claim 15 wherein said first electronic sensing means includes induction means and oscillator means, and wherein said inductance changes are caused by positioning of said instrumentality relative to said induction means.

17. The device of claim 12 wherein said second means further includes microprocessor means connected to said receiving and processing means, and said indicating means.

18. A circulatory system accessing device for enabling repeated, precise placement of fluid in a body at a predetermined location through a metallic object capable of fluid delivery therethrough, said device comprising:

an implantable portion positionable in said body at said predetermined location;

an external portion positionable on the surface of said body including transmitting means for transmitting an electrically induced input signal;

chamber means in said implantable portion having a first section for receiving said metallic object therethrough while remaining substantially impervious to passage of matter from said body therethrough, a second section for storing said fluid delivered through said metallic object, and a passageway for delivery of said fluid from said second section to said circulatory system;

sensing means in said implantable portion adjacent said first section of said chamber means for sensing the position of said metallic object relative to said first section of said chamber means and establishment of said metallic object through said first section of said chamber means;

signaling means connected with said sensing means in said implantable portion for providing a signal indicative of said sensed relative position and said establishment of said metallic object through said first section of said chamber means;

input signal receiving means connected with said sensing means and said signaling means in said implantable portion for receiving said electrically induced input signal from said transmitting means of said external portion thereby activating and making operational said sensing means and said signal generating means of said implantable portion;

sensing means in said external portion for locating said implantable portion relative to a position on the surface of said body suitable for insertion of said metallic object and producing a signal indicative thereof;

signal receiving means in said external portion for receiving said signal indicative of said sensed relative position and achievement of placement of said metallic object from said signaling means of said implantable portion;

processing means connected with said sensing means and signal receiving means of said external portion and including indicator means for indicating to a user of said metallic object said position suitable for insertion, said sensed relative position of said metallic object to said first section of said chamber means and establishment of said metallic object through said first section of said chamber means; and

battery means connected with said transmitting means, said sensing means, said signal receiving means and said processing means of said external portion.

19. The device of claim 18 wherein said transmitting means of said external portion includes driver means with coil means connected thereto for generating a magnetic field.

20. The device of claim 19 wherein said input signal receiving means of said implantable portion includes coil means, rectifier means and capacitor means for receiving said operational input signal and producing a voltage for said sensing means, and regulator means to cause said voltage to remain constant.

21. The device of claim 20 wherein said sensing means of said implantable portion includes oscillator means connected to said regulator means and coil means connected to said oscillator means and adjacent said first section of said chamber means and configured for receipt of said metallic object therethrough whereby the frequency of said oscillator means is modulated by the relative position of said metallic object to said coil means.

22. The device of claim 21 wherein said signaling means of said implantable portion includes modulation means connected to said oscillator means and said power input signal receiving means whereby said frequency of said oscillator means modulates said signal received by said coil means of said power input signal receiving means.

23. The device of claim 22 wherein said signal receiving means of said external portion includes detection means for detecting said modulated loading of said coil means of said power input signal receiving means and producing a signal indicative thereof, amplifier means connected to said detection means for amplifying said signal indicative thereof, and comparator means connected with said amplifier means and said transmitting means of said external portion for providing an output to said processing means indicative of said modulated frequency from said sensing means of said implantable portion.

24. The device of claim 23 wherein said sensing means of said external portion includes current monitoring means connected to said battery means, said transmitting means and said signal receiving means of said external portion whereby the overall current of said external portion is monitored and an output indicative of said overall current is provided to said processing means.

25. The device of claim 18 wherein said indicator means of said processing means provides at least one of a visual indication of said sensed relative position of said metallic object to said first section of said chamber means and positioning of said metallic object through said first section of said chamber means and an audible indication of disestablishment of said metallic object through said first section of said chamber means subsequent to said establishment thereof.

26. The device of claim 18 where said first section of said chamber means is a septum and wherein said third section of said chamber means is a catheter.

27. A method of monitoring placement of a medical instrument within a body to insure accurate positioning of an opening in the inserted end portion of said instrument relative to a predetermined desired location in said body comprising:

utilizing an electrical power output to generate a first signal from a first position outside said body;

inserting said end portion of said instrument into said body at a position on the surface of said body adjacent said predetermined desired location in said body;

moving said inserted end portion of said instrument toward said predetermined desired location;

receiving said first signal at a second position separate from connection with said instrument and utilizing said first signal to sense when said inserted end portion arrives at said predetermined desired location;

providing an electrical output indicative at least of positioning of said opening in said inserted end portion of said instrument at said predetermined desired location;

utilizing said electrical output indicative at least of positioning to provide an electrically induced output signal; and

utilizing said electrically induced output signal to indicate to a user establishment of said desired placement of said opening in said inserted end portion of said instrument at said predetermined desired location.

28. The method of claim 27 including the step of sensing the relative proximity of said inserted end portion of said instrument to said predetermined desired location while said inserted end portion is being moved toward said predetermined desired location and indicating said relative proximity to said user.

29. A method for directing insertion of a metallic object having an open end portion into a body for achievment of desired placement of a fluid therethrough at a predetermined location in said body comprising:

positioning a reservoir at said predetermined location in said body;

providing an electrical power output outside of said body;

utilizing said electrical power output to generate a first signal from a position outside said body;

utilizing said first signal to sense the location of said reservoir relative to a position on the surface of said body suitable for insertion of said metallic object and indicating said position suitable for insertion to a user of said metallic object;

inserting said open end portion of said metallic object into said body at said suitable position;

moving said open end portion of said metallic object toward said reservoir;

receiving said first signal at a position inside said body and utilizing said first signal to sense movement of said open end portion of said metallic object into said reservoir;

providing an electrical output indicative at least of movement of said open end portion of said metallic object into said reservoir;

utilizing said electrical output indicative at least of movement to provide an electrically induced output signal;

utilizing said electrically induced output signal to indicate to a user establishment of the desired placement of said open end portion of said metallic object within said reservoir; and

effecting fluid delivery through said metallic object to said reservoir while said desired placement of said open end of said metallic object within said reservoir is maintained.

30. The method of claim 29 including the step of sensing the proximity of said inserted open end portion to said reservoir while said inserted open end portion is being moved toward said reservoir and indicating said proximity to said user.

FIELD OF THE INVENTION

This invention relates to a device and method for the placement of a medical instrument in a body and, more particularly, relates to a device and method for precise placement at a predetermined subcutaneous location of a medical instrumentality insertable into a body and capable of fluid delivery therethrough.

BACKGROUND OF THE INVENTION

Detecting devices for detecting the proximity of metallic objects relative to a selected position are well known and various devices have been heretofore suggested and/or utilized. Examples of such devices can be found in U.S. Pat. Nos. 3,350,660, 3,744,044, 3,889,249, 3,935,542, 4,004,234 and 4,502,042.

Implantable injection cites for receipt or withdrawal of fluids within the human body through a needle are also known and such devices have heretofore been suggested and/or utilized for allowing body cavity access over relatively long terms without unduly limiting the activities and/or movement of a patient (see, for example, U.S. Pat. Nos. 4,160,454 and 4,543,088).

Various sensing devices have also been heretofore suggested and/or utilized in association with stabbing or puncturing medical devices for sensing various parameters of patient penetration by an implement, for example depth of penetration and completion of cavity wall puncture. Examples of such devices are shown in U.S. Pat. Nos. 4,299,230 and 4,535,773.

While such devices now known have been found to be acceptable for some uses, such devices have not been heretofore suggested and/or have not been found to be fully suitable for assuring placement of, and maintenance of, a medical instrument at a desired location to dependably enable a fluid to be inserted into or withdrawn from a predetermined location, and improvements in such devices are deemed to be still useful and/or needed for such application.

SUMMARY OF THE INVENTION

This invention provides a device and method for enabling a user of a fluid delivery medical apparatus insertable into a body to dependably direct the apparatus to a predetermined subcutaneous location for delivery or withdrawal of fluid thereat.

It is an object of this invention to provide a device and method for precise placement of a medical instrument at a predetermined location in a body.

It is another object of this invention to provide a device for directing the placement of a metallic fluid delivery apparatus insertable into a body at a reservoir implanted in the body for fluid delivery thereat.

It is still another object of this invention to provide a device for precise placement of matter at a predetermined location in a body through a medical instrumentality insertable into the body employing a sensor positionable at the predetermined location for sensing the position of the instrumentality relative to the predetermined location, means for signaling the sensed position, and an indicator for receiving the signal and indicating that desired positioning of the instrumentality relative to the predetermined location is established.

It is yet another object of this invention to provide a device for the delivery of medicament to a reservoir implanted in a body through a medical instrumentality insertable into the body having a first sensor positioned contiguous to the reservoir and a second sensor positionable at the surface of the body, wherein the second sensor locates the first sensor relative to a position on the surface of the body suitable for insertion of the instrumentality, and the first sensor locates the instrumentality after insertion relative to the position of the reservoir.

It is still another object of this invention to provide a method of fluid delivery to a predetermined desired location in a body through a medical instrumentality insertable into the body.

It is yet another object of this invention to provide a method for directing insertion of a metallic object into a body for achievement of placement of fluid therethrough at a predetermined location for storage and distribution of the fluid in the body.

With these and other objects in view, which will become apparent to one skilled in the art as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts and method substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the herein disclosed invention are meant to be included as come within the scope of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate complete embodiments of the invention according to the best mode so far devised for the practical application of the principles thereof, and in which:

FIG. 1 is a perspective view of a first embodiment of the device of this invention for achieving precise subcutaneous placement of a medical instrument and specifically illustrating the relative positioning of the external and implantable portions of the device when utilized for insertion of a hypodermic needle within the body;

FIG. 2 is a perspective view of the implantable portion of the device shown in FIG. 1;

FIG. 3 is a sectional view taken through section lines 3--3 of FIG. 2;

FIG. 4 is a simplified electronic block diagram illustrating components of the internal portion of the device shown in FIGS. 1 through 3;

FIG. 5 is a simplified electronic block diagram illustrating components of the external portion of the device shown in FIG. 1;

FIG. 6 is a schematic illustration of the electronic circuitry within the implantable portion of the device shown in FIG. 2;

FIG. 7 is a schematic illustration of a portion of the electronic circuitry within the external portion of the device shown in FIG. 1, and particularly illustrating the current monitor and sensing portions thereof;

FIG. 8 is a schematic illustration of a second portion of the electronic circuitry within the external portion of the device shown in FIG. 1, and particularly illustrating the microprocessor, indicators, and optional access ports thereof;

FIG. 9 is a flow diagram illustrating typical operational control of the device shown in FIG. 1;

FIG. 10 is a side sectional view of a second embodiment of the device of this invention for precise subcutaneous placement of a medical instrument;

FIG. 11 is a block diagram illustrating the electronic circuitry of the second embodiment of the device shown in FIG. 10; and

FIG. 12 is a partial side elevational view of the implantable portion of a third embodiment of the device of this invention for precise subcutaneous placement of a medical instrument.

DESCRIPTION OF THE INVENTION

A system, or device, 19 for monitoring medical instrument placement within a body to ensure accurate positioning thereof is shown in FIG. 1. System 19 includes an implantable, or internal, portion 21 and an external portion 23 for locating and monitoring internal portion 21 during insertion of an instrument, for example hypodermic needle 25, into human body 27 (while needle 25 is shown it should be understood that system 19 is applicable with other instruments and that the instrument may be of metallic and/or other conductive material).

External portion 23 of system 19 includes hollow collar 30, having instrument access aperture 31 therethrough, and oppositely extending hollow shoulders 32 and 34. External portion 23 provides a housing for electronic circuitry as well as a mounting surface for the external portion 23 of system 19 on the skin of a patient so that the needed indicators and/or, switches utilized are made readily accessible.

As shown, shoulder 32 preferably includes battery access door 36 for access to battery 38 mounted within shoulder 32. Ports 40 may also be provided at shoulder 34 for data communication between the electronic circuitry of system 19 and a computer terminal and/or display. Indicators such as a beeper 42 and an LCD display 44 are provided at shoulder 34 for providing audible and visual indications of the position and status of needle 25 to a user of system 19. Off-on switch 45 is provided in shoulder 34, and push button switch 46 is provided at shoulder 32 for operational mode selection as discussed hereinafter.

Circuitry mounting surfaces, for example, mounting board 48 in shoulder 32 and coil spindle 50 in collar 30, are provided within external portion 23. External portion 23 may be releasably secured to the surface of body 27 in any conventional manner, for example, by adhesive tape 52.

As best shown in FIGS. 2 and 3, implantable portion 21 includes outer enclosure walls 60 which are preferably made of a nonpyrogenic plastic and/or metal material normally impermeable to fluid flow therethrough and substantially insusceptible to erosion due to proximity to body fluids and/or tissue. Septum 62 is provided over passageway 64 extending through throat 66 (which is formed from a nonconductive and nonpyrogenic material) for receipt of needle 25 through septum 62 while remaining substantially impervious to passage through the septum of contaminants from body 27. When implantable portion 21 is properly positioned in a body, septum 62 is facing and substantially parallel to the surface, or skin, of body 27 (as illustrated in FIG. 1).

Outer walls 60 of implantable portion 21 include side wall 68 and base 70. Side wall 60 includes upwardly extending annular shoulder 72 for mounting throat 66 and septum 62. All joints are formed to assure a substantial seal against entry or escape of matter through implantable portion 21 except for delivery or withdrawal of fluid through septum 62 using needle 25 (as illustrated in FIG. 1).

The interior of implantable portion 21 is divided into sealed compartments 75 and 77 by divider wall 79 which may, for example, be an integrally formed portion of side wall 68. Compartment 75, as defined by divider wall 79, is positioned below septum 62 and is a cylindrical reservoir configured to receive and maintain fluid therein (either body fluids for withdrawal from or, for example, medicament for delivery to, the body). Compartment 75 communicates through channel 81 (extending through side wall 68) with body 27, as shown in FIG. 1, and may include catheter 83 at side wall 68 for precise, placement in body 27 of medicament, or the like, metered (by choice of size for channel 81 and catheter 83) from compartment 75.

Compartment 77 houses electronic circuitry for sensing needle position and communicating with external portion 23, as more fully set forth hereinbelow. Compartment 77 may include therein, for example, coil bobbins 85 and 87 attached to base 70, and circuitry compartment 89 between base 70 and divider wall 79 for accommodating circuitry, coils and the like in compartment 77.

FIGS. 4 and 5 are block diagrams illustrating overall operation of the electronic circuitry maintained within implantable and external portions 21 and 23. As shown in FIG. 4, implantable portion 21 includes power input signal receiver 91, voltage regulator 92, oscillator 93 (including coil 94), and modulator 95. As illustrated in FIG. 5, current monitor 97 receives a +V voltage (for example, from battery 38, as indicated in FIG. 1), and external portion 23 also includes power transmitter 99, detector 101, tuned amplifier 103, comparator 105, microprocessor 107, and indicators 108.

As more fully detailed hereinafter, the +V voltage is coupled through current monitor 97 to transmitter 99 for transmission of a power input signal to implantable portion 21 (for example, a magnetic field). The power input signal is received by receiver 91 of implantable portion 21. Shunt voltage regulator 92, coupled with receiver 91, produces a constant voltage for oscillator 93. The frequency of oscillator 93 is capable of being modulated (i.e., varied) by insertion of needle 25 into coil 94. This modulation causes variance of the load at receiver 91 by modulation of regulator 92 through modulator 95. The load variation (in the 100 KHz range) at receiver 91 manifests itself as an amplitude modulation of the magnetic field established in the space between implantable portion 21 and external portion 23 with the magnetic field magnitude decreasing as the load increases.

The indication of loading of receiver 91, coupled to power transmitter 99 of external portion 23, is sensed by detector 101 (for example, an AM diode detector). The signal is amplified and conditioned by amplif