Surgery – Diagnostic testing – Detecting nuclear – electromagnetic – or ultrasonic radiation
Reexamination Certificate
2000-11-21
2003-04-22
Smith, Ruth S. (Department: 3737)
Surgery
Diagnostic testing
Detecting nuclear, electromagnetic, or ultrasonic radiation
C604S048000, C604S500000, C604S514000, C604S093010, C604S285000
Reexamination Certificate
active
06553249
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a diagnostic method and a diagnostic means used in carrying out the method.
In certain circumstances it is desirable but difficult to prove the existence of a medicament in its surroundings in and on its way through the digestive apparatus.
Conventional methods use capsules, which are labeled with radioactive isotopes. This certainly facilitates the finding of the capsule, but it subjects the examined person to radiation, which should be avoided.
Another method tested, by means of magnetic resonance imaging (MRI), shows the existence of a tablet shown by a negative contrast agent (iron oxide+ barium) in the digestive apparatus, this tablet being shown as a black silhouette against a white background of the conventional liquid positive MRI-contrast agent Magnevist enteral.
This method has a drawback, since even if it is easy to visualize this black tablet in the ventricle (stomach) in a white sea of liquid contrast agent, this very contrast agent, when being transferred to the small intestine, apparently is mixed with other digestive liquids, which results in an uneven, streaked filling of the small intestine, the tablet also being dissolved too quickly. Thus, an indication of the existence of the tablet is not possible. Various efforts to make the positive contrast agent more paste-like have not yielded any satisfactory results. Examinations with Magnevist enteral and a negative contrast agent, i.e. an agent which is black in an MRI-display, require, that the stomach is purged before the examinations.
U.S. Pat. No. 3,939,259 teach how to fill a capsule with tablets and delay the release of medicaments by a layer of beeswax.
Barium sulphate and iron oxide in a water solution are used as negative contrast agents according to U.S. Pat. No. 5,323,760.
WO 94/03210 relates to oils, used as positive contrast agents.
Various useful and also advantageous details are individually known through these publications, but they are not combined in a particular way to speed up a diagnosis and make it more reliable, and so clear and simple that certain preparatory measures, such as purging, completely or partially can be dispensed with. Also no efforts apparently have been spent to develop a simple, variable construction, which is easy to adapt to various diagnostic requirements and desires. Also, it has not been found, that so far there has been a generally expressed desire to design a capsule having tracer functions and which can be charged with an optional module, which contains a substance to be examined.
The object of the present invention is to counteract and as far-reachingly as possible overcome the above-mentioned drawbacks. Additional objects comprise the development of the state of the art in this field in various respects.
These objects are achieved in accordance with the invention by designing a diagnostic method of the type described in the specification.
A negative MRI-contrast agent Abdoscan is on the market. This agent is mixed with water to a water solution, which, when it has been swallowed, becomes pudding-like in consistency in the digestive apparatus and fills e.g. the small intestine relatively uniformly, which substantially facilitates the finding of the white signal capsule in this uniform black sea of contrast agent. This is an obvious advantage compared to said liquid positive, i.e. white, contrast agents.
The following problem appeared; to develop a capsule, which through a positive contrast agent filling is clearly visible in a negative contrast agent and which only in the lower part of the digestive apparatus releases the substance to be examined and also is not toxic. This substance, i.e. the cargo portion, is allowed to be dissolved depending on its composition, which varies from substance to substance, in interaction with the biochemical environments in the body in various places along the movement path.
It has been found that certain deep-sea fish oil capsules on the market yield an excellent positive contrast in MRI, i.e. gives a white picture. Other natural or synthetic organic non-toxic substances may also be used.
However, such capsules are dissolved too quickly, i.e. already in the stomach and also, they have the negative property in the stomach of being lighter than water. Thus, they float on top of the contents of the stomach and do not reach the lower outlet of the stomach.
Consequently, two such capsules are wrapped in a mixture of iron oxide+ barium sulphate powder in an empty gelatin capsule and two deep-sea fish oil capsules are chosen, since the signal picture which only one capsule gives, may look like the body's own structures, e.g. fat. In case the MRl-picture shows the two Inner capsules In front of each other, only a bright white point is visible. In order to decide, whether this is the capsule, the next picture is taken with a 90° angle in relation to the previous one and then, In the same plane, two bright white points, having the same size, are visible, obviously a picture of the capsule and not one of the body's own structures. In principle or alternatively, if is possible to choose such an oblong and/or a rectangular and/or an oval, inner capsule shape that, when said pictures are taken from different angles always at least one picture is obtained, which clearly differs from more common own structures of the body. As far as possible, in order to avoid taking pictures from different angles with great reliability and speed are able to identify the position of the capsule, it is also possible to give the capsule an asymmetrical shape as regards its contents in such a way, that one capsule side or end always tends to sink first, because this side or end contains substances having a larger weight and density, respectively. Alternatively, a small air inclusion can serve the same purpose. An iron oxide is chosen due to the fact that this compound, because of its negative (black) MRI-picture, yields an increased contrast around the positive (white) picture, which substantially facilitates the determination of its position. Barium sulphate is added because this compound substantially facilitates the displacement of the capsule through the force of gravity through the stomach and into the small intestine during the time when the patient, between the picture takings, is up and moves about. Tests without barium sulphate have shown that the capsule then is too light-weight, flows on top of the contents in the stomach and does not reach the small intestine within several house. Also, barium sulphate has a negative contrast effect, i.e. it gives a black picture in MRI.
Alternatively it is possible to put the signal substance in e.g. a gelatin capsule, which is wrapped up in a shell, which consists of a mixture of solid paraffin and barium sulphate.
It was found, that this functioned properly. An excellent contrast is seen between the two white oil capsules and the mixture of iron oxide and barium sulphate with its negative (black) MRI-picture and between the positive substance and the signal-negative shell respectively, which latter consists of paraffin plus barium sulphate.
In the human body there are no structures, which yield such a similar signal pattern in MRI, which substantially facilitates the finding of the capsule.
Also, the capsule is now so heavy, that it finds its way by itself to the lower outlet of the stomach.
With regards to the dissolution which is too quick, beeswax does not melt or is not dissolved at body temperatures. Thus, the dry gelatin capsule is provided on its outer side with liquid beeswax and has let the beeswax cool. The capsule is still sufficiently heavy to sink, thanks to the included barium. However, thanks to the beeswax, it has not even been dissolved when it reaches the anal opening, which is perfect from the point of view that it then also is not able to influence the examination of the substance, which is to be examined. Instead of beeswax, it is possible to use a layer, which consists of a mixture of solid paraffin (paraffinum solidum) a
Davis & Bujold P.L.L.C.
Smith Ruth S.
LandOfFree
Diagnostic method and diagnostic means used in delivering a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Diagnostic method and diagnostic means used in delivering a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Diagnostic method and diagnostic means used in delivering a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3087344