Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND APPARATUS FOR DUODENAL INTUBATION OF A PATIENT
BACKGROUND OF THE INVENTION
1. Field of the Invention: The present invention
relates to method and apparatus for duodenal intubation of a
patient for administering nutrition into the small intestine,
and, more particularly, to the selection and usage of permanent
magnets to establish a traction force useful to advance the
leading end of a catheter feeding tube along the stomach and
through the pylorus and distal duodenum of the small intestine.
2. Description of the Prior Art: In the course of
human illness there are many situations were the patient can not
or will not eat food in the traditional manner to obtain needed
nutrition which the patient must have or the healing process will
not occur. Nutrients can be supplied to the patient through the
use of a catheter. Modern science has developed numerous
nutrients suitable for administering intravenously to a patient
either peripherally in the arm or in some instances more
centrally into a large vein in the neck. These nutrients can
provide a high level of substance, even life saving for the
patient whose intestinal tract is dysfunctional. However,
problems can develop with intravenous introduction of the
nutrition. The piercing of the skin to provide access for the
small catheter to the vein, whether peripheral or central, also
forms a route for infection to enter the body. Complications
such as bleeding may occur and in instances where the catheter is
placed centrally, the possibility exists to puncture the lung
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during the procedure of placing the catheter. The nutrients
suitable for intravenous introduction have an extremely high cost
which coupled with the potential for infection and other
complications make it more desirable to supply the needed
nutrition to the intestinal tract.
A known method for introducing nutrition to the
intestinal tract is to supply the nutrition via a small tube
introduced through a naris of the nose along the oesophagus
through the stomach and beyond the pylorus into the duodenum of
the small intestines. In Figure 1 there is a pictorial
illustration of anatomical configuration of the stomach and
duodenum together common nomenclature identifying salient parts
for reference purposes. The introduction of nutrients from the
catheter to the duodenum adds to the patients immunity while the
nutrients facilitate healing. Moreover, feeding a patient
through the gut also prevents intestinal villi atrophy.
Maintaining the intestinal villi intact prevents the
translocation of bacteria from inside the gut of the patient to
his blood stream.
When a catheter tube is advanced through the nose into
the oesophagus and comes into the stomach, the tip of the
catheter is no longer constrained to a course of travel as it was
during movement along the nose and oesophagus. In contrast, the
stomach cavity is large in a direction transverse to the
direction of passage of bolus therein. Shown in Figure 2 are
three possible positions A, B and C for the leading part of a
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catheter D to assume upon entrance in the cavity of the stomach
E. The cavity of the stomach merely contains the catheter tip as
it is advanced but fails to constrain and guide for an intended
course of travel to the pylorus. The flexible elasticity of the
catheter usually allows a coiled configuration to be formed as
shown in Figure 3 as the catheter is advanced further into the
stomach. The leading part of the catheter D is most likely to
follow a return course of travel generally toward the oesophagus
but following a path along the internal wall of the greater
curvature of the body of the stomach. Continued introduction of
the catheter moves the tip portion into the fundus where it
executes a return course to the body of the stomach. It has been
found that only about 10% of the attempted catheter placements
using conventional placement techniques successfully negotiate
the necessary course of travel in the stomach to the pylorus and
thence to the duodenum. The incidence of successful placement of
the catheter was usually a matter of random luck.
A common site to locate a misplaced catheter inside the
stomach is at the fundus of the stomach. The anatomical
configuration of the stomach can range from what is described as
a hypotonic stomach to an atonic stomach. The variety to the
size and configuration serves only to complicate the intubation
of the patient. The tract of the catheter through the stomach
must be made to follow the general J-shaped curvature of the
stomach which becomes an extremely difficult procedure when the
sole means available to control the catheter is the manipulation
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of the catheter at the entrance site through the patient's nose.
Even after the stomach is traversed by the catheter tip, the tip
must be advanced beyond the pyloric sphincter and into the
duodenum before the introduction of nutrition since if the
pyloric sphincter is not traversed by the catheter, a patient
when lying flat and perhaps unconscious, might aspirate fluids
from the stomach through the oesophagus to the lungs, leading to
serious complications.
The tip of the catheter can be advanced along the
stomach by peristaltic movement. Such movement may require three
to five days and sometimes medication is necessary to irritate
the stomach to increase the peristaltic movement. Serial X-rays,
sometimes at twelve hour intervals, are necessary to verify the
peristaltic movement of the catheter from the stomach through the
pylorus to the duodenum. Not only is the patient exposed to
frequent radiation of the incidence of X-rays, but also the time
delay and added costs for the care and transporting the
critically ill patient to a fluoroscope department or bring X-ray
equipment to the patient are all undesirable.
The use of magnet flux in the placement of catheters
and for a variety of purposes at a desired location is known in
the art which includes the disclosures by United States Patent
No. 3,043,309 to McCarthy; Patent No. 3,358,676 to Frei, et al.;
Patent No.3,674,014 to Tillander; Patent No. 3,794,041 to
Frei et al.; Patent l~o. 3,847,157 to Caillouette, et al.; Patent
No. 3,961,632 to Moossun; Patent No. 4,077,412 to Moossun; and
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Patent No. 4,809,713 to Grayzel. The McCarty patent no.
3,043,309 issued July 10, 1962 describes the use of a localized
magnetic field generated by an electrical magnet to manipulate a
suction tube with a magnetic member at its tip through an
intestinal obstruction under fluoroscopic visualization of the
magnetic member. The use of an electromagnet is seen as
essential because of the needed on/off control to allow turning
it off while fluoroscopy radiation is used. Otherwise, the
magnetic field generated by the electromagnet will distort any
picture on the fluoroscopy screen or X-ray plate. The electrical
magnet with its small pole surface area of about 1 1/4 square
inches supply only a very localized depth of penetrating flux,
thereby necessitating the use of fluoroscopy to capture the
targeted magnetic member of the tube, all represent complex
disadvantages. Moreover, the use of very strong electrical
current in the order of 40 amperes through the coils of the
electrical magnet wh:Lch is applied to the patient represent an
unwarranted risk and hazard. The remaining patents show a
variety of instructions for the inclusions of a magnet in a
catheter. The Frei Patent 3,794,041 shows beads of magnetic
material inserted in a body part with the catheter for moving the
body part using an external magnet. The Caillouette Patent
3,847,157 shows the use of a magnetic indicator in a medico-
surgical tube used to identify the location of the tube. The
Tillander Patent 3,6~4,014 shows a tip portion of a catheter made
of tandemly arranged magnetic sections with ball shaped ends so
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.
that the sections can deflect with respect to each other for
guidance of the catheter tip. The Moossun Patent 4,077,412 shows
a trans-abdominal stomach catheter of the Foley type used to
direct the placement of the catheter by way of an external
puncture from the outside of the abdomen through the stomach
wall. The Frei et al, Patent 3,358,676 shows the use of magnets
and for remotely controlling propulsion of a magnet through a
duct of a human being to perform a function upon activation such
as to effect a release of drugs at a predetermined location. The
Grayzel Patent 4,908,713 shows the use of a catheter for use for
electrically pacing or excitation of the heart.
The need therefore exists to provide a method and
apparatus for duodenal intubation of a patient to provide
nutrition to the digestive tract beyond the stomach which will
overcome the shortcomings and disadvantages of known intubation
procedures.
It is an ob~ect of the present invention to provide a
method and apparatus for duodenal intubation of a patient for
duodenal intubation of a patient using an external hand-held
permanent magnet having a pole face approximating the anatomic
width of the stomach of the patient which can be moved about the
abdomen of a patient to establish a flux coupling with a
permanent magnet in the tip of a catheter of a magnitude
sufficient to impart a traction force to the catheter for
advancement along the stomach through the pylorus to the
duodenum.
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..
It is a further object of the present invention to
provide a method and apparatus for duodenal intubation of a
patient through the use of a permanent magnet having a physical
size which can be grasped between the out-stretched fingers of a
person's hand and provide a magnetic pole face sufficiently large
that flux lines will permeate the abdomen of the patient and form
a flux coupling with a magnet in the tip of an intubation
catheter and impart a traction force thereto while resident in
the stomach of a patient.
SUMMARY OF THE INVENTION
More particularly, according to the present invention,
there is provided a method for intubating a patient to introduce
nutrition to the digestive tract beyond the stomach, the method
including the steps of selecting an elongated flexible radio
opaque catheter having a catheter permanent magnet in a distal
end portion which is remote to an access channel communicating
with a fluid conductive lumen of the catheter, introducing the
distal end of the catheter through the stomach to the duodenum of
the patient, arranging an external permanent magnet on the
patient's abdomen to form a magnetic guidance path between the
oesophagus and the pyloric part of a patient's stomach, the
magnetic guidance path consisting of a field of magnetic flux
enveloping the lesser curvature of the stomach, and imparting a
traction force to the distal end portion of the catheter through
a flux couple between the magnetic flux of the catheter permanent
magnet and the magnetic flux enveloping the lesser curvature of
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the stomach to advance the catheter tip along the magnetic
guidance tract.
The present invention further provides an apparatus to
intubate the gastrointestinal track of a patient to introduce
nutrition into the small intestine, the apparatus including the
combination of an elongated flexible catheter having a permanent
magnet at a distal end portion thereof, the catheter having an
access channel extending to a lumen for conducting a nutrient to
an eyelet communicating with the lumen at the distal end of the
catheter upstream of the magnet, and an external permanent magnet
having magnetic pole faces on a body of magnetic material
defining a flux density of such character for forming a magnetic
guidance path by permeating body tissue of the abdomen and
defining by the field of magnetic flux enveloping the lesser
curvature of the stomach, the field of magnetic flux being
sufficiently dense to impart a traction force to the distal end
portion of the catheter through a flux couple between the
magnetic flux of the catheter permanent magnet and the magnetic
flux of the external permeate magnet.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more fully understood
when the following description is read in light of the
accompanying drawings in which:
Figure 1 is a schematic illustration of anatomical
configuration of the stomach and duodenum together common
nomenclature identifying salient parts for reference purposes;
2l6asl2
Figure 2 is a schematic illustration of three
alternative tracts by the tip portion of the catheter entering
the body of the stomach according to conventional prior art
practices;
Figure 3 is a schematic illustration of a typical
undesired coil like tract of a catheter in the stomach commonly
occurring according to a conventional prior art practice;
Figure 4 is a plan view partly in section of a catheter
embodying magnetic means in the distal tip thereof to facilitate
the placement of the catheter according to the present invention;
Figure 5 is sectional view of a hand held permanent
magnet used for applying a traction force to the catheter for
placement in the duodenum;
Figure 6 is an illustration showing the path of the
catheter within anatomical quadrants during passage through the
stomach to the distal duodenum according to the present
invention;
Figure 7 is a schematic illustration identifying pH
levels of various sites in the stomach and duodenum;
Figure 8 is a schematic illustration of the flux
coupling between the hand held a permanent magnet and the
catheter permanent magnet through body tissue separating the
abdominal and stomach walls during intubating a patient according
to the present invention; and
Figures 9A-9C are illustrations of the sequence of
advancement by a catheter tip through the stomach beyond the
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pylorus to the distal duodenum by the positioning of the hand-
held magnet relative to permanent catheter magnet to establish a
traction force upon the catheter tip.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In Figure 4 there is illustrated a feeding tube
catheter 10 embodying a modified construction according to the
present invention by the inclusion of a cylinder shaped permanent
magnet 12, preferably a magnet composition of neodymium, iron,
boron and dysprosium as the supply source for magnetic flux.
Such a magnet composition was chosen for the preferred embodiment
because of the large field of magnetic flux enveloping the magnet
between the magnetic poles.
As is well known, the catheter 10 is about 45 inches
long and includes a radio opaque body portion 14 typically of a
diameter of about 3mm. At the distal end of the catheter there
is a radio opaque tip portion 16 adhered to the end part of the
body portion 14 and having an outside diameter typically of about
5mm. A lumen 18 in the body portion 14 forms a fluid conducting
relation with the internal cavity of the tip portion 16 which
contains eyelet apertures 20 at spaced apart locations along the
length of the tip portion for discharging and receiving fluids
including supplying nutrients in fluid form to the small
intestines of the patient after intubation. The magnet 12 has a
diameter of about 5mrl. and a length of about 6 mm. which produces
a slight bulge identified by reference numeral 22 when placed in
the distal end of the tip portion 16. The magnet can be inserted
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into the tip portion through an opening 24 in the end wall of the
tip portion. The magnetic polarity of the magnet is specifically
chosen such that the north pole faces the opening in the tip of
the tube which becomes a frame of reference for the orientation
of a large hand-held magnet externally of the patient's body, as
will be described in greater detail hereinafter. It is to be
understood that the foregoing dimensional relation of the
catheter tip portion and catheter magnet are only exemplary and
catheters that are either larger or smaller as to their
dimensional relation may be used to carry out the present
invention.
Extending along the entire length of the lumen is a
stylet 26 anchored in a cap 28. The stylet adds a desired degree
of stiffness and rigidity to the catheter to facilitate the
placement procedure. After placement of the catheter is
completed, the cap is used for extracting the stylet from the
catheter after which the lumen can be utilized for the supply of
nutrients for the patient. The cap 28 is fitted to a cavity
formed in a fixture 30 which is joined to the free end of the
catheter opposite the tip portion 16 and provided with an
additional duct section 32 having a removable closure cap 32A for
access when it is desired to introduce and withdraw fluids from
the lumen of the catheter. As will be explained in greater
detail hereinafter, a syringe can be fitted to the duct section
32 in a fluid tight manner per se well known in the art.
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In Figure 5 there is illustrated a preferred form of a
permanent magnet 34 which has a cylindrical sidewall between
oppositely directed pole faces 36 and 38. Pole face 36 is
selected to be the south pole and conveniently identified by the
suitable label as "P" to signify the patient's side. The magnet
34 is made of a composition including neodymium, iron, boron and
dysprosium and defines a physical size convenient to be grasped
between the outstretched fingers of a person to support and move
the magnet about a patient's body during the intubation
procedure. The magnet 34, according to the present invention, is
large as to its physical size, having a pole face with a diameter
of at least about 3 inches, preferably about 3-1/2 inches which
forms a surface area in excess of 9 square inches whereby the
pole face can be readily used to attain a stable attitude when
brought into a contacting relation with a patient's body. The
height of the magnet sidewall is at least about 4 inches, thus
defining a volume to the permanent magnet flux field in the order
of at least 36 cubic inches with at least 300 Gauss at 4 inches
distance. The mass and composition of magnetic material forming
the magnet are of such a character so as to thereby define a flux
field that is extensive and far reaching beyond the area
surrounding the volume of the magnet.
The magnet is protectively enveloped by a covering 34A
of elastic material that will form a thermal barrier when
contacting the patient's skin as well as protectively house the
magnet against the fracture and possible loss of chips or pieces
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of the magnet in the event of accidental impact with a foreign
object. The flux field in accordance with the present invention
can permeate the body tissue to the thickness of the order of 6
inches or greater about an area sufficient to completely envelope
the lesser curvature of the stomach. The density of the flux
field is sufficiently great to interact as a force coupled with
magnet 12 to establish and maintain a traction force to be
imparted to the catheter tip through movement of the hand held
permanent magnet.
In Figure 6 there is illustrated the portion of the
human anatomy involved in the intubation process for providing
nutrients to the small intestines, preferably the introduction of
nutrients to the distal duodenum of the small intestines thereby
preventing aspiration of fluids to the stomach. The tip portion
16 of the catheter 10 is preferably coated with a lubricant and
numbing agent and then the tip portion is introduced into the
naris 35 of the nose and advanced by the continued application of
a compressive force to the catheter forcing the tip portion back
to the backward portion of the patient's head and thence to the
oesophagus. As is common, the passageway of the oesophagus
affords ample guidance to the tip portion 16 whereupon it enters
the body portion of the stomach 38 at the lower portion of the
fundus. The movement of the catheter tip along the oesophagus
and into the body of the stomach occurs within the left upper
quadrant of the patient's body as indicated in Figure 6.
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To establish the site of the tip portion in the
stomach, a syringe is connected to duct section 28 the catheter
10 and operated to extract a specimen of fluid from the stomach.
Litmus paper is then brought into contact with a specimen of the
extracted fluid to establish a pH level which serves to identify
a region in the stomach where the catheter tip resides. It is
within the scope of the present invention to incorporate an
electrode for a pH meter in the catheter tip and connect it by
suitable wiring embedded in the material of the catheter wall to
a meter to thereby provide pH levels and eliminate the need for
extracting fluid samples during the procedure. In Figure 7 there
are demarkation lines separating regions wherein the pH level is
given. In the area of the fundus a highly acidic condition
exists in which the pH level of 3 will be detected and will turn
the litmus paper to red. The pH level undergoes general regional
changes as indicated in Figure 7 whereby a neutral pH level will
generally be found at the pyloric sphincter. In the duodenum, an
alkaline condition exists as will be detected by an increasing pH
level with a strong alkalinity condition being found in the
distal duodenum of the small intestines from where a specimen
sample will turn litmus paper dark green.
As can be seen from Figure 6, the stomach has a
generally J-shaped configuration extending with generally its
largest transverse anatomical size at about the cardiac orifice,
the entrance site to the stomach and then proceeding in the
direction at which the stomach functions to advance bolus, the
14
~160512
transverse dimension of the stomach narrows, and at an angular
notch 42 which is generally at the border between the left upper
quadrant, LUQ, and the right upper quadrant, RUQ. From the
annular notch 42 there commences a smaller transverse dimension
at the pyloric part 44 typically residing in the right upper
quadrant together with pyloric sphincter 45. The pyloric
sphincter, as is well known, is a muscular controlled closure
which will dilate as when a bolus comes into contact with the
sphincter. Beyond the sphincter, a bolus passes into the
duodenum portion 46 that extends to the right lower quadrant,
RLQ, and thence in a general horizontal direction into the left
lower quadrant, LLQ, where the distal duodenum 47 of the small
intestine is situated.
As is well known the generally J-shaped configuration
of the stomach is arranged with the longer limb of the "J" lying
to the left of the median plane and for the most part in the left
upper quadrant. The long axis of the stomach passes downwards,
forwards and then to the right and finally backwards and slightly
upwards. The shape and size of the stomach varies greatly as in
short, obese persons the stomach is high and transverse whereas
in tall persons the stomach is elongated. It is also known that
in a given patient the shape of the stomach depends on whether
the stomach is full or empty, the position of the body, and the
phase of respiration. At the cardiac orifice which is where the
oesophagus enters the stomach an acute angle is formed by the
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.
passage way tending to always misdirect the tip of the catheter
to the fundus rather than the body of the stomach.
According to the present invention, a magnetic flux
- couple is established between the magnet 12 in the tip portion of
the catheter in the stomach and magnet 34 when placed upon the
abdomen of the patient. As shown in Figure 9A, the pole face 36,
designated as a south pole face, faces the patient and overlies
the duodenum at the juncture with the pyloric part of the
stomach. By arranging an external permanent magnet on the
patient's abdomen in this manner there is formed a magnetic
guidance path between the oesophagus and the pyloric part of a
patient's stomach. The guidance path is shown by a line in
Figure 9A and identified by reference numeral 50 has a boundary
formed by the lesser curvature of the stomach wall whereby the
flux field permeatinc~ the guidance path acts through the magnetic
couple to draw the catheter permanent magnet 12 toward the
angular notch and into the pyloric part of the stomach. The
traction force on the proximal pole of the magnet at the tip thus
imparted to the catheter tip may be supplemented by a force
imposed on the catheter tip due to continued advancing movement
of the catheter into the patient's body at the naris. Thus, it
can be seen that the field of magnetic flux is not only very
dense but covers a broad area which is sufficient to envelope the
lesser curvature area of the stomach. The flux field must have a
magnetic polarity in a direction to impart a traction force to
the distal end portion of the catheter by a magnetic flux couple
16
2160512
.~
and not a repulsive action which would serve to direct the
catheter tip in the wrong direction away from the pyloric part of
the stomach. During the course of travel by the catheter tip,
through the use of the magnetic guidance path 50, samplings of
fluid obtained from the stomach through the catheter by the use
of a syringe can be periodically tested with litmus paper to
confirm the progression of desired movement of the catheter tip
through the stomach by the progressive change from high acidic
toward neutral pH levels.
When it is confirmed by a fluid sample turning the
litmus paper red that the site of the catheter tip portion 16 is
in area 40 (Figure 6) at the bottom of the fundus, the force
couple relationship as best shown in Figure 8 exist between the
catheter tip portion 16 and the magnet 34. The magnetic force
couple traverses a boundary wall of the stomach 38 and the body
tissue separating the boundary wall from the surface of the
abdomen 48. The force couple between the flux of magnet 34 and
the flux of magnet 12 in their north-south pole relationship as
discussed hereinbefore is sufficient that the surprising
discovery was made that the position of the catheter tip could be
controlled while advanced within the stomach in the direction of
movement of a bolus. Magnet 34 imparts a traction force of a
magnitude necessary to produce a corresponding advancing movement
of the tip portion of the catheter. As explained previously, to
facilitate such movement of the catheter, a slight compressive
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force may be applied to the catheter at the naris in a direction
tending to advance the catheter to the stomach.
Returning to Figure 9A, as the catheter tip is advanced
along the pyloric part, the traction force is sufficient to draw
the catheter tip against the wall of the pyloric sphincter
thereby inducing dilation and penetration of the pyloric
sphincter. As shown in Figure 9B, when it is confirmed as by a
litmus paper test of a pH level of about 7 or slightly alkaline,
it will thereby indicate the catheter tip resides in the duodenum
whereupon the magnet 34 is rotated 90~ in a clockwise direction
and shifted laterall~ away from the stomach to the side of the
patient. The duodenum will be permeated by a dense field of
strong magnetic flux and thereby impart a steering force combined
with a traction force to the catheter tip, thus pulling the
catheter tip downwardly through the second part of the duodenum
to the terminus of the second part of the duodenum. A litmus
paper test from fluid samplings will indicate a strong alkaline
level whereupon the magnet 34 is rotated 180 to a position, as
shown in Figure 9C at the supra pubic area. The duodenum will be
penetrated again by a dense field of strong magnetic flux which
continues the established flux coupling resulting in the
application of the traction force to the catheter tip advancing
the catheter tip along the duodenum to the distal duodenum 47 of
the small intestine.
When in the distal duodenum, a fluid sampling can be
taken using the catheter which will turn litmus paper dark green
18
21 60~12
,
thus indicating a strong alkaline condition. Before the
introduction of nutrients to the distal duodenum of the small
intestines using the catheter, final confirmation of the site of
the catheter tip is to be made using X-Ray. Cap 28 is then used
to extract the stylet from the lumen of the catheter which will
then exhibit a marked increase to flexibility. Thereafter, as is
well known in the art an infusion set can be connected to the
duct in the fixture 30.
While the present invention has been described in
connection with the preferred embodiments of the various figures,
it is to be understood that other similar embodiments may be used
or modifications and additions may be made to the described
embodiment for performing the same function of the present
invention without deviating therefrom. Therefore, the present
invention should not be limited to any single embodiment, but
rather construed in breadth and scope in accordance with the
recitation of the appended claims.
