U.S. patent number 3,786,810 [Application Number 05/126,439] was granted by the patent office on 1974-01-22 for placement apparatus for positioning an elongated element in a body lument.
This patent grant is currently assigned to Levoy's, Inc.. Invention is credited to Karl A. Pannier, Jr., Gordon S. Reynolds, James L. Sorenson.
United States Patent |
3,786,810 |
Pannier, Jr. , et
al. |
January 22, 1974 |
PLACEMENT APPARATUS FOR POSITIONING AN ELONGATED ELEMENT IN A BODY
LUMENT
Abstract
A placement apparatus or unit for positioning an elongated
element in a body lumen, and a method of using the same. The
elongated element may be a catheter, piezoelectric transducer means
carried in a catheter, a coaxial cable, or other sensing means,
which may or may not have a lumen therethrough, but which may be
connected to apparatus for indicating or recording central arterial
pulse wave-forms and other heart actions. The element is encased in
a sheath to which the proximal end of the element is removably
connected, and the element is advanced relatively to a needle into
a body lumen by pulling or pushing the sheath through an opening in
the needle hub. The method involves monitoring venous or arterial
pressure from the point of entry into a body lumen to the thoracic
cavity at or adjacent the heart.
Inventors: |
Pannier, Jr.; Karl A. (Salt
Lake City, UT), Reynolds; Gordon S. (Salt Lake City, UT),
Sorenson; James L. (Salt Lake City, UT) |
Assignee: |
Levoy's, Inc. (Salt Lake City,
UT)
|
Family
ID: |
22424840 |
Appl.
No.: |
05/126,439 |
Filed: |
March 22, 1971 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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885803 |
Dec 17, 1969 |
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Current U.S.
Class: |
604/158 |
Current CPC
Class: |
A61B
5/02 (20130101); A61M 25/0668 (20130101); A61M
25/013 (20130101); A61M 1/285 (20130101); A61M
2205/3348 (20130101) |
Current International
Class: |
A61B
5/02 (20060101); A61M 25/06 (20060101); A61M
25/01 (20060101); A61M 1/28 (20060101); A61m
031/00 () |
Field of
Search: |
;128/214.4,334C,348 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kamm; William E.
Attorney, Agent or Firm: Hill, Sherman, Meroni, Gross &
Simpson
Parent Case Text
CROSS-REFERENCE TO A RELATED APPLICATION
This application is a continuation-in-part of our pending
application entitled "Catheter Placement Unit," filed Dec. 17,
1969, Ser. No. 885,803, now abandoned and discloses and claims
subject matter disclosed in the aforesaid pending application, and
some additional subject matter.
Claims
The invention claimed is:
1. A placement unit embodying a needle and an elongated element
telescopically associated therewith for positioning the element in
a body lumen, wherein the improvement comprises:
a hollow hub in which a portion of the element is secured, and
a protective disruptible sheath around said element and removably
connected at one end to said hub,
the other end of said sheath being free and disposed adjacent said
needle,
means associated with said needle to disrupt said sheath for
removal from around said element during advancement of the sheath
to effect advancement of the element into a body lumen relatively
to said needle and disrupt means by pulling said sheath in
generally the advancing direction of the element, regardless of
length and flexibility of the sheath and element,
said disrupt means remaining spaced from the hub in a final
position of the hub relative to the disrupt means so that continued
pull in the same direction will effect removal of the sheath from
the hub.
2. The placement unit of claim 1, wherein said element is a
catheter.
3. The placement unit of claim 1, including means associated with
said needle to automatically release the connection between said
sheath and the hollow hub after the element is advanced.
4. The placement unit of claim 1, including a hollow hub secured
around the outer portion of said needle,
said needle hub having a slot therein through which the free end of
said sheath extends and the sheath is withdrawn as the element
advances.
5. The placement unit of claim 4, including interlocking means
carried by said hubs for coupling the hubs together after
advancement of the element.
6. The placement unit of claim 5, including means carried by one of
said hubs to automatically release the connection between the
sheath and element hub when the hubs are coupled.
7. The placement unit of claim 4, including means carried by the
needle hub to prevent retraction of the element relatively to the
needle after advancement of the element has started.
8. The placement unit of claim 1, including a hub on said
needle,
one of said hubs having a recess therein,
an annular shoulder in said recess, and
resilient fingers on the other said hub having means thereon to
enter said recess and latch behind said shoulder.
9. A placement unit embodying a needle and an elongated element
telescopically associated therewith for positioning the element in
a body lumen, wherein the improvement comprises:
a hollow hub in which a portion of the element is secured, and
a protective disruptible sheath around said element and removably
connected at one end to said hub,
the other end of said sheath being free and disposed adjacent said
needle,
means associated with said needle to disrupt said sheath for
removal from around said element,
whereby said element can be advanced into a body lumen relatively
to said needle by moving said sheath adjacent the free end thereof,
regardless of the length and flexibility of the sheath and
element,
said hub including a nipple,
said sheath being telescoped over said nipple,
a washer holding said sheath secured to said nipple when tilted and
releasing said sheath when disposed normal to the axis of the
element, and
means in said hub to retain said washer tilted during advancement
of the element.
10. A placement unit embodying a needle and an elongated element
telescopically associated therewith for positioning the element in
a body lumen, wherein the improvement comprises:
a hollow hub in which a portion of the element is secured, and
a protective disruptible sheath around said element and removably
connected at one end to said hub,
the other end of said sheath being free and disposed adjacent said
needle,
means associated with said needle to disrupt said sheath for
removal from around said element,
whereby said element can be advanced into a body lumen relatively
to said needle by moving said sheath adjacent the free end thereof,
regardless of the length and flexibility of the sheath and
element.
a floating taper in said element hub over which said sheath is
disposed and said taper diminishing in the direction of extension
of the sheath therefrom, and
a sleeve in said element hub carrying interlocking means and said
sheath being gripped between said taper and the inner edge of said
sleeve until the taper is pushed back by the blunt end of said
needle when said hubs are coupled.
11. In combination in a placement unit including an elongated
element to be positioned in a body lumen:
a hollow hub;
said element having an end portion thereof secured in said hub;
a protective disruptible sheath around said element and removably
connected at one end to said hub,
the other end of said sheath being free;
means adjacent the free end of said sheath to disrupt the same;
said means remaining outside of the body lumen and providing a
handhold relative to which the element and sheath can be
advanced;
whereby said element may be advanced through a previously
established cannulated entry into the body of a patient by moving
the free end portion of said sheath in generally the advancing
direction of the element and divergently relative to the element so
that the advancing sheath remains outside the body lumen as the
sheath progressively disrupts and diverts from the element while
advancing the element in the lumen;
said disrupt means remaining spaced from the hub in a final
position of the hub relative to the disrupt means so that continued
pulling in the same direction will effect removal of the sheath
from the hub.
12. The unit of claim 11, wherein said disrupt means comprise
a second hollow hub having a side opening through which the free
end of said sheath projects,
said element being advanced axially through said second hub as the
sheath is forced through said opening.
13. The unit of claim 12, including
cooperative means carried by said hubs for interlocking said hubs
together after advancement of the element and releasing the
connection between said sheath and element hub.
14. The unit of claim 12, including
a rigid tubular member disposed axially in said second hub through
which the element is advanced and which is positioned to disrupt
said sheath as the same is withdrawn.
15. A placement unit for positioning an elongated element in a body
lumen:
including a hollow hub;
an element having a portion thereof secured in said hub;
a protective disruptible sheath around said element and removably
connected at one end to said hub;
the other end of said sheath being free;
means adjacent the free end of said sheath to disrupt the same;
whereby said element may be advanced through a previously
established cannulated entry into the body of a patient by moving
the free portion of said sheath;
a nipple in said hub;
a floating washer around said nipple;
said sheath having its end portion disposed over said nipple and
through said washer, and
a stop member in said hub disposed to contact said washer at a
point adjacent the circumference thereof and tilt the washer to
exert a gripping action on the sheath when an advancing movement is
exerted on said sheath.
16. The unit of claim 15, including
a second hub through which the element is advanced and out of which
the sheath is withdrawn,
interengaging means carried by said hubs, and
means carried by said second hub to abut said washer and move it to
a position normal to said nipple and release said sheath when said
hubs are engaged.
17. A placement unit embodying a needle and an elongated element
telescopically associated therewith for positioning the element in
a body lumen, wherein the improvement comprises:
a hollow hub in which a portion of the element is secured, and
a protective disruptible sheath around said element and removably
connected at one end to said hub,
the other end of said sheath being free and disposed adjacent said
needle,
means associated with said needle to disrupt said sheath for
removal from around said element,
whereby said element can be advanced into a body lumen relatively
to said needle by moving said sheath adjacent the free end thereof,
regardless of the length and flexibility of the sheath and
element,
a nipple in said hub,
an elastic sleeve holding the end of said sheath on said
nipple,
said disrupt means comprising a hub on said needle, and
means carried by said needle hub to push said sleeve off said
sheath after the catheter is advanced.
Description
SUMMARY OF THE INVENTION
Heretofore, catheter placement units for advancing a catheter into
a body lumen have been developed so that the catheter may be
connected to an infusion system before the body puncture is made,
and then the catheter is advanced relatively to the needle through
a protective sheath having a longitudinal slit therein, whereby no
sterile field of operation is necessary. Such an arrangement may be
found in the W. H. Ring U. S. Letters Patent No. 3,185,152, issued
May 25, 1965. With such a placement unit, the protective sheath
must be substantially as long as the catheter, and the catheter was
advanced through the sheath by grasping a fitting secured to the
proximal end of the catheter and by means of which the catheter is
connected to the infusion system. That type of unit was highly
satisfactory for short or medium length catheters, but for
monitoring pressure in the thoracic cavity of a patient, a catheter
or other sensing means up to forty inches in length is necessary,
and for placing such an element in the body lumen, the hand of the
surgeon advancing the element was objectionably far away from the
hand holding the needle in place in the body of a patient. Most
physicians and surgeons, when advancing an element into a body
lumen, desire their hands to be closely adjacent the needle so that
the needle can adequately be held with one hand and the physician
has the "feel" to a greater extent than otherwise to determine if
the element is entering the body lumen in the proper manner. This
desirable feel is considerably augmented by the fact that the
element and the sheath move together. Such feel cannot be obtained
to the desired degree with a long element in a flexible sheath if
all the advancing is done from the end farthest from the needle,
and especially where the sheath remains stationary and the element
moves relatively to the sheath, as was the case heretofore.
In a Karl A. Pannier, Jr., U. S. Pat. No. 3,438,373, issued Apr.
15, 1969, there is shown locking means to prevent retraction of a
catheter relatively to a needle once advancement of the catheter
into a body lumen has begun. Such locking means are for the purpose
of avoiding the risk of cutting the catheter on the sharp end of
the needle. Further, it is now deemed desirable to monitor venous
or arterial pressure from the point of entrance of the catheter or
other element to the central or thoracic region during advancement
of the element, but such, insofar as we know, has not heretofore
been done.
The instant invention solves the problems mentioned above in the
provision of an element placement unit wherein the element may be
of any length desired and encased within a sterile sheath having a
longitudinal slit, with one end of the sheath indirectly and
removably connected to a proximal portion of the element and the
distal end slightly projecting through the opening in the hub of a
cannulated needle. The placement means are substantially the same,
whether the element is a catheter or other sensing means for
monitoring purposes. The element is advanced relatively to the
needle into a body lumen by pulling on the projecting end of the
sheath or by pushing the sheath adjacent the needle hub permitting
both hands of the operator to be closely adjacent the needle hub at
all times. Improved automatic locking means are provided to prevent
retraction of a catheter relatively to the needle after advancement
has begun, and also to maintain the sheath indirectly connected
with the proximal portion of an element until the element has been
fully advanced when the sheath is released for removal. The instant
placement unit may also be used to monitor venous or arterial
pressure, or both if two units are employed at the same time, from
the point of body entry of the element to the thoracic cavity while
the element is being advanced, and the method of so monitoring is
also a part of this invention.
Other objects, features and advantages of the present invention
will be readily apparent from the following detailed description of
certain preferred embodiments thereof when taken in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary central vertical sectional view through the
cannulated needle and its hub, and an element hub, the element and
sheath being eliminated for purposes of clarity;
FIG. 2 is a fragmentary vertical sectional view of the structure of
FIG. 1 but showing the element and sheath associated with that
structure, prior to full advance of the element;
FIG. 3 is also a central vertical sectional view of the structure
of FIG. 2 but with the element fully advanced and the two hubs
locked together;
FIG. 4 is a fragmentary central vertical sectional view of an
element placement unit of somewhat different construction but also
embodying principles of the instant invention;
FIG. 5 is a view similar to FIG. 4 but showing the element fully
advanced and the sheath released for removal;
FIG. 6 is a central vertical sectional view of an element placement
unit of still different construction but embodying principles of
this invention;
FIG. 7 is a view of the structure of FIG. 6 showing the elemet
fully advanced and the sheath released for removal;
FIG. 8 is a diagrammatic view illustrating our method of monitoring
venous pressure from the point of entry to the thoracic cavity;
FIG. 9 is a fragmentary diagrammatic view illustrating our method
of so monitoring arterial pressure;
FIG. 10 is a fragmentary vertical sectional view of an element
placement unit of substantially the same character as the righthand
portion of FIG. 4, greatly enlarged, but with which no catheter is
associated and the placement unit is utilized to advance a coaxial
cable directly into the body lumen;
FIG. 11 is a central vertical sectional view of the complemental
part of the placement portion shown in FIG. 10, this view being
substantially similar to the showing in FIG. 5;
FIG. 12 is a still further enlarged vertical sectional view taken
substantially as indicated by the line XII--XII of FIG. 10; and
FIG. 13 is a diagrammatic disclosure with parts eliminated of a
part of an advancing unit in which a different form of element is
disclosed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The instant invention may be made in substantially any size to
accommodate any desired length of element. FIGS. 1 to 7 of the
drawings, greatly exaggerated for purposes of clarity, disclose
placement units for positioning catheters in a body lumen. However,
the same general apparatus may be utilized for the placement of
other elongated elements, such as transducers, coaxial cables,
etc., for monitoring purposes, and to that end FIGS. 10 to 13
inclusive, even further enlarged, disclose substantially the same
apparatus with such sensing devices advanced directly into a
vein.
Looking at the first embodiment of the instant invention, seen in
FIGS. 1, 2 and 3, there is shown a catheter hub, generally
indicated by numeral 1, may, for convenience in molding, be made of
two initially separate pieces which are firmly secured together as
by adhesion, fusion, or in any other suitable manner. The hub
includes a generally cylindrical barrel 2 in which the passage
therethrough is reduced at the inner end of the barrel to provide
an interior annular shoulder 3. The hub also includes an adaptor 4
having an integral inwardly extending hollow nipple 5 in which the
proximal end of a catheter 6 is firmly anchored, as seen in FIGS. 2
and 3. The outer hollow portion of the adaptor forms a socket for
the reception of a catheter extension tube, diagrammatically shown
at 7 in FIGS. 2 and 3, which in turn may be connected to an
infusion system. Also, within the barrel 2 and around the nipple 5,
are locking means in the form of a floating washer 8 and a narrow
stop member 8a which causes a tilting of the washer to a proper
locking angle, as will later appear. The needle hub, generally
indicated by numeral 9, is securely attached to a hollow needle 10
having a sharp point 11 on the end that projects outside the hub.
The inner portion of the body 12 of the hub 9 is solid around the
shaft of the needle except for a slot 13 in the upper portion
thereof, this slot having an inclined bottom 14. The outer portion
of the body 12 is hollow as indicated at 15, and in this hollow is
another locking member in the form of a washer 16 disposed around
the blunt end portion of the needle shaft. A short cylinder 17 is
also inserted in the hollow 15 and secured firmly to the body 12 in
any suitable manner, this cylindrical portion having an oblique
inner end 18. The portion of the cylinder projecting outside the
hollow or cavity 15 is slotted as indicated at 19 to provide a
plurality of resilient latching fingers 20, four being shown in the
illustrated instance. Each finger 20 is provided with a locking
shoulder 21 thereon, the finger sloping outwardly to provide such
shoulder.
As seen best in FIGS. 2 and 3, the catheter 6 is encased in a
sheath 22 which maintains the catheter sterile during its placement
in the body of a patient. This sheath eliminates the need of any
sterile field of operation when the catheter is advanced into a
body lumen. The sheath is made of a relatively soft and flexible
plastic, such as extruded polyethylene, for example. The sheath is
provided with a slit 23 extending lengthwise thereof on the under
side, the resiliency of the sheath maintaining the slit closed
until it is forcibly opened when the sheath is removed. The
catheter 6, if used in a vein, could be polyvinyl chloride, or the
fluoroplastics such as polytetrofluoroethylene and fluorinated
ethylene-propylene. When used for monitoring arterial pressure,
polytetrofluoroethylene is usually preferred because the catheter
itself then will not pulsate along with the more powerful arterial
pulsations, since this material has properties allowing smaller
internal diameters for blood flow without clotting and thus permit
greater wall thickness, is easier to advance through a lumen
because of its lubricative characteristic, and an accurate reading
of the pressure may be obtained.
When the structure of FIG. 2 is assembled, the sheath is placed
over the catheter and entered into the catheter hub over the nipple
5 but through the aperture in the washer 8 and then retracted
slightly causing the washer to tilt, as shown in FIG. 2, abut the
stop 8a at one point and to the proper angle to lock the sheath to
the nipple of the catheter hub and indirectly to the catheter
adjacent the proximal end thereof. The other end of the sheath is
passed into the needle hub over a portion of the needle, the
catheter, of course, being entered into the needle until it
contacts the incline 14 and is pressed upwardly so that a small
portion of the sheath projects through the slot 13 in the needle
hub accessible to the fingers of the operator. The incline 13
facilitates disruption of the sheath at the slit 23 as the lower
side of the sheath contacts the needle. It will also be noted that
the sheath, when placed over the needle, passes through the
aperture in the washer 16 in the needle hub, and as long as the
washer is normal to the axis of the needle, as seen in FIGS. 2 and
3, the sheath may be pulled in a direction to advance the catheter
through the needle, but if any attempt is made to retract the
catheter after it is partially advanced, the washer 16 will assume
the oblique position seen in FIG. 1 and prevent any retraction of
the catheter, the sloping end 18 on the cylinder 17 facilitating
the tipping of the washer.
In operation, the instant invention is extremely efficacious. It is
simply necessary for the attending physician, surgeon, or other
operator to remove the placement unit from its sterile wrapping,
remove the customary needle guard, and by holding the needle hub,
make the body puncture, entering the needle into the desired body
lumen. Then, holding the needle hub in one hand, the catheter may
be advanced into the body lumen merely by pulling the catheter
sheath 22 outwardly through the slot 13 in the needle hub or by
pushing the sheath adjacent the needle hub. If the catheter is a
long one, it is a simple expedient to pull or push the sheath a few
inches at a time, slide the hand back and pull or push again,
thereby maintaining both the operator's hands immediately adjacent
the needle. Thus, the operator has the proper "feel" while
advancing the catheter, and the advancing operation is extremely
simple and positive owing to the structure and stability of the
parts of the placement unit, particularly as distinguished from
endeavoring to advance a catheter through a flimsy envelope. During
the operation, there can be no retraction of the catheter
relatively to the needle at any time because of the lock washer 16.
When the catheter is fully advanced, the latching fingers 20 on the
needle hub are entered into the catheter hub where the shoulders 21
automatically latch behind the shoulder 3 in the catheter hub
thereby firmly locking the two hubs together. The fingers 20 also
abut the locking washer 8 and move it to the position normal to the
axis of the catheter, as seen in FIG. 3, thereby releasing the
sheath from the nipple 5 and allowing complete removal and
discarding of the sheath, the stop 8a being sufficiently narrow to
be received in one of the slots 19 between adjacent fingers 20. The
needle withdrawn from the body puncture can be placed in a
protective guard and it and the connected hubs can readily be taped
to the body of the patient.
The structure of FIGS. 4 and 5 is illustrative of the fact that the
latching fingers may be carried by the catheter hub while the
barrel having the locking shoulder therein may be carried by the
needle hub. In this instance, there is a generally cylindrical
catheter hub 24 in which a cylindrical sleeve 25 is secured.
Integral with this sleeve and extending out of the hub are latching
fingers 26 of the same character above described. Extending inside
the sleeve 25 is a floating taper 27 over which the outer end of
the sheath 22 is expanded and a slight forward movement of the
taper causes a bind between the sheath and the inner end of the
sleeve 25, thereby removably anchoring the sheath to the taper. The
catheter 6 extends centrally into the taper and is firmly secured
thereto.
The needle hub carries a barrel 28 thereon having an annular
locking shoulder 29 therein. The other parts of the placement unit
are the same as above described in connection with FIGS. 1, 2 and
3.
The advancement of the catheter into a body lumen with the
placement unit of FIGS. 4 and 5 is the same as previously
described. When the catheter is fully advanced, the fingers 26 are
pressed into the barrel 28 and automatically locked behind the
shoulder 29, thus coupling the two hubs firmly together. At the
same time, the blunt end of the needle contacts the end of the
taper 27 and forces it outwardly sufficiently to release the
catheter sheath and permit its total withdrawal.
In FIGS. 6 and 7 we have shown a still different manner of
removably securing the proximal end of the catheter sheath 22 to
the nipple 5 in the catheter hub, the other parts of the placement
unit being the same as described in connection with FIGS. 1, 2 and
3. In this instance, the catheter sheath is connected to the nipple
5 by means of an elastic sleeve 30 which is partially stretched
over the outer end of the sheath, as seen in FIG. 6. The sleeve 30
may be made of any suitable material, such as a substance
containing polymeric silicones having the general property of
rubber. Such substance is commonly used in medical and surgical
prosthetic devices. After the catheter 6 has been advanced into a
body lumen in the manner above described and the two hubs joined
together as seen in FIG. 7, the sheath may be completely withdrawn
by virtue of the latching fingers 20 on the needle hub making
endwise contact with the elastic sleeve 30 and pushing it off the
sheath.
In FIGS. 8 and 9 we have illustrated the desirability and method of
utilizing the present invention for the purpose of monitoring
venous or arterial pressure, or both, if such seems to be
indicated. Of course, two element placement units would be utilized
if both venous and arterial pressure is monitored at the same time.
With the instant invention, the catheter or other sensing element
may be easily and accurately located in the central or thoracic
cavity at or adjacent the heart and monitoring may be obtained
during the placement of the element as well as thereafter.
Monitoring while the element is being placed aids materially in
accurately positioning the element and also gives the surgeon
valuable information as to the condition of the patient.
For monitoring venous pressure an arrangement such as
diagrammatically shown in FIG. 8 may well be utilized. A customary
hospital stand 31 may be positioned adjacent a patient 32, and a
manometer 33 may be mounted on the stand at such a level that the
zero point on the manometer is at the same level as the patient's
heart, as indicated by the dotted line 34. The manometer is
connected by way of a tube 35 leading to one arm of a Y fitting 36
to the leg of which the catheter extension tube 7 is connected.
Also suspended from the stand 31 is a container 37 for infusion
liquid and a tube 38 leads from that container to the other arm of
the Y fitting 36, flow through this tube being controlled by a
valve or clamp 39, and flow through any of the other tubes outside
the patient's body may be similarly controlled.
At the outset, the cathether is flushed out with sterile liquid,
such as infusion liquid, to eliminate sterilization residue and
air, as well as fill the catheter and associated tubing with
liquid. Flow of infusion liquid is then cut off and venipuncture is
made with the needle, frequently in the Basilic vein, or one
connecting therewith, in the arm. With the flow of infusion liquid
cut off, the liquid level in the manometer tube will drop until it
reaches a level equaling the back pressure created by the blood
pressure in the vein and the relationship of this new level to the
zeo mark on the manometer scale indicates the venous pressure.
Since the cardio vascular system pulsates with each heart beat,
there will be a pulsation of fluid level in the manometer and those
pulsations will vary as the catheter is advanced toward the
superior vena cava or other location within the chest which gives
the attending surgeon an indication of the venous pressure at each
location during advancement of the catheter from the peripheral
vein to the central vein, keeping the doctor fully aware of the
patient's condition, and aiding in the advancement of the catheter,
since a sudden drop or cessation of pulsations will indicate that
the catheter tip is obstructed or in contact with the wall of the
vein and adjustments may immediately be made before there is any
injury to the patient.
In the case of monitoring arterial pressure with a catheter when it
is to be advanced, one arm of the Y fitting 36 is connected by way
of a tube 40 to a pressure transducer 41 which transforms the fluid
impulses to electrical impulses, and by way of a line 42
establishes an impulse pattern on the screen of an oscilloscope 43.
The method of advancing the catheter is substantially the same as
that above described, flushing, filling with liquid, shutting off
any infusion flow, making an arterial puncture frequently in the
Radial artery in the arm, and advancing the catheter up to a point
near the heart. Arterial pressure will be noted all during the
advancement of the catheter in variations made apparent by the
amplitude of the oscilloscope pattern giving the attending surgeon
valuable patient information as well as aiding in the proper
positioning of the catheter.
If the element inserted in the body lumen is in the form of a
coaxial cable, a transducer, or some similar sensing device, it may
be directly connected to any suitable amplification means and
recording means for later usage on a computer, and the
oscilloscope, all in a known manner and utilizing available
equipment. Thereby a recording of the patient's condition may be
had and the various parameters may be obtained from the central
pulse contour. Thus, a record may be kept for future reference as
well as have the pulse contour visible to the attending physician
or surgeon to watch during an operation or while attending the
patient in other ways.
In either case, vein or artery, a skilled technician may accurately
place the catheter or element tip in its ultimate desired location
by watching either the pulsations in the manometer or the
variations in amplitude of the impulse wave on the oscilloscope
screen; or since the amount of sheath projecting from the needle
hub is of approximately the same length as that of the advanced
portion of the element, that projecting portion of the sheath may
be used to measure or determine the position of the element tip in
the body lumen. Insofar as we are aware, monitoring of venous or
arterial pressure from the point of body puncture to a point in the
thoracic cavity, during advancement of the element, was not
considered practical heretofore.
It should also be noted that for some usages the instant placement
unit, in any of its described embodiments, need not have a sharp
pointed cannulated needle extending outwardly from the needle hub,
although the needle hub would be retained in order to facilitate
stripping the sheath from the element. Such a structure would be
substantially the same as though a protruding portion of the needle
would be cut off at the point 44, as indicated in FIGS. 3, 5 and 7.
leaving a tubular portion of rigid material inside the hub through
which the element would be advanced and by means of which the
sheath would be stripped from the element. In use of the placement
unit without a pointed needle protruding from the hub 12, the hub
12 would be inserted into the exposed end of previously placed
means establishing a cannulated entry into the body of a patient.
The hub so held in one hand leaves the other hand free for pulling
or pushing upon the sheath and thus advancing the element while at
the same time removing the sheath. By way of examples, and not by
way of limitation, the unit without a pointed needle could be
utilized in conjunction with a Eustachian catheter for injecting
medicaments into the inner ear by way of Eustachian tube; also the
needleless unit could be used for dialysis within the peritoneal
cavity in conjunction with an already cannulated entry; and for
monitoring, the element could be advanced into a vein or artery
through a previously placed short catheter of sufficient diameter
to accommodate the element. Other uses of the unit without a
pointed needle will be apparent to those skilled in the art.
In FIGS. 10, 11 and 12 we have illustrated the instant placement
unit in operative association with a coaxial cable, generally
indicated by numeral 45, which cable may be advanced into a body
lumen instead of a catheter. In this instance, by way of example,
we have used the same needle hub arrangement as well as the hub 24
with a slight change in structure, as are shown in FIGS. 4 and 5,
although it will be understood that the structures of FIGS. 1 - 3
inclusive, and of FIGS. 6 and 7, may also be utilized for this
purpose. Accordingly, the same reference numerals for like parts as
were used in connection with FIGS. 4 and 5 are utilized in
connection with FIGS. 10, 11 and 12. The slight changes in hub 24
reside in a larger inside diameter for the floating taper 27, the
omission of the socket at the proximal end thereof, and the hub 24
itself is thickened at the proximal end and extends inwardly, as
indicated at 46 to intimately fit the diameter of the cable 45
extending therethrough, and a proximal portion of the cable is
secured to the part 46 of the hub in the region 47. Otherwise the
hub assemblies are the same as shown in FIGS. 4 and 5. The floating
washer 16 utilized in the needle hub assembly in FIGS. 4 and 5 has
been eliminated because there is little danger of the outer layer
of the coaxial cable 45 being injured by the needle point in the
event of a reverse movement of the cable relatively to the needle.
Of course, if the structure of the element being advanced into the
body lumen might be injured by the needle point, such a washer may
be utilized.
The coaxial cable 45, which has no open lumen therein, and which
per se does not form a part of this invention, is kept sterile
while being advanced into the body lumen by means of the above
described sheath 22 having the slit 23 in the lower portion
thereof, which slit, for purposes of clarity, is shown slightly
open in FIG. 12 but, as stated above, that opening will remain
closed until the slit is deliberately opened as the sheath is
removed through the needle assembly. The coaxial cable 45 comprises
a central conductive core 48 having a probe tip 48a, seen in FIG.
11. The core is surrounded by an inner insulation layer 49 which in
turn is surrounded by a conductive sleeve 50 which, in turn is
surrounded by an outer insulation layer 51. As seen best in FIG.
11, the conductive tube 50 terminates rearwardly of the probe tip
48a and the outer insulation layer 51 terminates a little
rearwardly of the conductive sleeve 50 whereby, when the cable
enters a body lumen, the body fluid such as blood will close a
circuit between the probe tip 48a and the conductive sleeve 50.
The coaxial cable is advanced into a body lumen in the same manner
as above described by either pulling or pushing upon the protective
sheath 22 adjacent the needle hub and when advancement is complete,
and the needle hub and hub 24, to which the proximal portion of the
cable is anchored, are locked together as above described the
needle will move back the floating taper and release the trailing
end of the sheath for complete removal. The portion of the cable 45
extending out of the hub 24 may be connected to an oscilloscope or
other indicating or recording means in a known manner to provide
the parameters of information desired, and the monitoring may be
accomplished from the time of entry into the body lumen of the
cable until it reaches its destination which may be at or near the
heart of the patient and, of course, thereafter as long as
desired.
In FIG. 13 we have diagrammatically illustrated a catheter 52 which
carries therein a sensing device in the form of a transducer,
generally indicated by the numeral 53 and which is of a known
construction. The catheter may be advanced into a body lumen by any
of the embodiments of the placing means herein described.
From the foregoing, it will be apparent that the placement
apparatus herein described in several embodiments may be used for
the purpose of positioning a catheter alone, a catheter carrying a
sensing device therein, or a sensing device alone, in a body
lumen.
Although various minor modifications might be suggested by those
versed in the art, it should be understood that we wish to embody
within the scope of the patent granted hereon all such
modifications as reasonably and properly come within the scope of
our contribution to the art.
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