Use of a catheter and measuring device for measuring the motility and the peristaltic in tubular body parts by means of simultaneous measurement of a plurality of impedances

The invention relates to the use of a catheter in the form of a tube or cord made of an electrically non-conductive plastic, the similar to that described in US-A-4,706,688, arranged in the measuring area a plurality at a defined mutual distance, the plastic tube or plastic strand surrounding at least partially annular electrodes bears, whose signal leads or discharge lines are run inside the tube or rod or embedded in these. The invention further relates to a measuring device using such a catheter, the signals can be for evaluating motility and / or peristalsis win.

For the diagnosis of disease-related disorders of motility or peristalsis today are two fundamentally different process options available, namely<ul><li>a) the means of manometry Perfusionsmeßtechnik or by Halbleiterdruckaufnehmern and</li><li>b) imaging techniques that make use of either the radiographic representation or scintigraphy provided with contrast media content.</li></ul>

To a):

When manometry a change in pressure for characterizing the contraction processes is used in a narrow portion of the organ to be examined. The greatest distribution has experienced Perfusionsmeßtechnik in this type of measurement. The pressure change is determined that, at the outflow obstruction resulting in the catheter, which is flowed through by a constant flow of liquid through the contraction of the institution concerned, measured. Since, however, have to be used per channel hoses with an inner diameter of about 1 mm, a multi-catheter having up to eight channels is marginally acceptable with respect to its diameter yet. Another important disadvantage is that of a perfusion in organs liquid is introduced, which can impair the function of the measured organ substantially straight at a long-term measurement.

B):

Imaging methods are suitable in principle, to provide evidence of motility, for example, in the esophagus. The diagnosis in the intestinal area contrast is problematic because of the many overlaps. Moreover, must the high cost of the acquisition, the operation and not least also used for the evaluation of the images obtained in consideration.

The invention is based on the object, a method and relatively simple to implement measuring device for evaluation of motility and / or peristalsis in tubular, its contents transporting organs to create, which can be used universally and leads to reliable diagnostic results.

The invention provides for obtaining signals for evaluating motility and / or peristalsis in tubular, its contents transporting organs or for determining the dynamic resilience of tubular pipe organs by means of simultaneous multiple impedance measurement according to the invention the use of a defined in claim 1 catheter before.

Advantageous further developments of the inventive use of such a catheter are specified in further claims and are explained, inter alia, in the following description.

A measuring device for determining motility and / or peristalsis in tubular, its contents transporting organs using such a catheter is subject matter of claim 7 and further dependent claims.

The inventive use of such a catheter allows to obtain signals and data that are used in space and time to assess the nature of the motility and peristalsis, namely of stationary, propulsive, repulsive waves of contraction propagation, etc. The measuring process is based can, for the determination of characteristics, such. as the transit time and passage speed, the contraction frequency and the contraction frequency of individual organ sections are used.

The catheter is inserted for recording in an organ and fixed in a defined position against a longitudinal displacement. The used signals are generated by a<b>Simultaneous or quasi-simultaneous detection of the impedance of at least three to many channels</b> recovered, typically 32 or more channels are used.

Advantageous embodiments of the invention and further details of the same are explained in more detail with reference to the drawings in an exemplary embodiment. Show it:<dl id="dl0001"><dt>Fig. 1</dt><dd>the enlarged perspective view of Meßbereichabschnitts a tubular catheter; </dd><dt>FIG. 2</dt><dd>an enlarged fragmentary view in longitudinal section through a range of a catheter;</dd><dt>Fig. 3</dt><dd>illustrates a method for the simultaneous registration of the esophagus activity with a multiple measuring catheter in accordance with the invention using type;</dd><dt>Fig. 4</dt><dd>also illustrated in connection with Figure 3, a particular embodiment of a catheter.</dd><dt>Fig. 5</dt><dd>a schematic block diagram illustrating a test setup in accordance with the invention using a catheter; and</dd><dt>Fig. 6</dt><dd>various options for circuit-uniform distribution of individual measuring channels.</dd></dl>

The FIG. 1 can be a section of the measurement range of a tubular, preferably flexible catheter 1 recognize that consists of a tube of an electrically non-conductive plastic substantially. The materials used here for. Example, polyurethane, polyamide, polyethylene, polytetrafluoroethylene, polyvinyl chloride or silicone rubber, certain compounds.

Around the outside of the tube 2 are about equally spaced, but not necessarily equally spaced sequence annular electrode 4 down, which can be as shown in FIG. 2 seen from a flat band material, and to the basic body of the catheter, that is with the tube 2, firmly adhering are connected. The edges of the electrodes 4 are rounded and constructed and embedded in the tube material that it can be no injury. As materials for the electrodes are metals, electrode materials of the second type and conductive plastics in question. Important characteristics of the electrodes 4 are their low impedance low polarization voltage in the upper electrode layer and their long term stability. Since an electrode 4 forms a transition to an electrolyte, it must to have these required properties, with a layer 9, z. B. silver-silver chloride, can be provided. The distance between the electrodes 4 can be made constant or according to a spatial pattern. Other variables in the area of ​​the electrodes are the width and the mutual distance between a pair of electrodes that is associated with a measuring channel in the impedance measurement. The width of the electrodes 4 can be formed differently; it depends on the diameter of the tube 2 and after to be measured applications.

The electrode leads extend in the interior of the hose 2, for example, a separate channel 14 that is separated by partition walls from further extending inside the hose individual channels 6 whose function will be explained later. On an inner contact point 8 a respective supply line 7 is connected to the associated electrode 4th

The catheter 1 may be provided with one or more lumens 5, taken at different locations through the body from the materials for analysis purposes or materials or liquids may be entered as a contrast medium or for functional stimulation. However, such a functional stimulation can be carried out not only by a liquid, but also electrically through the measuring electrodes 4 itself. In addition, the electrodes can be used for receiving electrical bio-signals.

The schematic diagram of FIG. 3 illustrates the simultaneous registration of the esophagus activity with a multiple measuring catheter. 1

A measuring channel is in this case (not shown) for measuring the series impedance or between an electrode on the catheter 1 and a central large-area electrode formed either between two electrodes 4 (E₁ / E₂ and E₂ / E₃ or E₃ / E₄) on the body.

The series impedance may, as FIG. 6 illustrates, either (a) sequentially, (b) a test basis or (c) are determined by the overlap.

In Fig. 3 is provided with MG denotes a reference channel, while the area marked by respective distance arrows sizes R₁, R₂, R₃ and R₄ indicate impedance changes in the channels 1, 2, 3 and 4. In the example shown, the signals R₁ to R₄ characterize a propulsive wave of contraction. From the terms of between two channels, the passage time or passage rate can be calculated in each investigated organ.

Fig. 4 illustrates further details of a modified embodiment of a catheter for use in the invention. The illustration shows that the catheter tube 2 is closed well rounded at the front end 3 and is connected with its running in the interior leads to a 7 plug 10th The diameter d may be up to a few mm. The catheter is flexible, however, the measurement part I_M may be the catheter 1 configured differently flexible or even rigid, for example by using ceramic materials. The length of the measuring part I_M and the leads I_Z may vary formed with up to several feet in length. Due to the tube interior of the catheter may temporarily, for example during the measurement, to be stiffened.

The catheter 1 is provided with a few (at least three) to many (eg., 32 or more) electrodes 4 (E₁, E₂, E₃, E₄, ...). The electrodes are connected via the leads 7 electrically connected to the connector 10 a Impedanzmeßanordnung 12 and connected to a display or recording device 18 and / or a signal processing unit 17 with an associated display device. An example embodiment of the assembly structure is illustrated in Fig. 5.

Except with the lumen 5 whose purpose and function has already been explained, the catheter 1 with one or more temperature sensors (not shown) may be provided along its longitudinal axis.

The catheter 1 may be in addition to the impedance measurement and simultaneously to recording EMG signals used to hasten the mechanical contraction of an organ.

Across the electrodes, the catheter also allows simultaneous functional electrical stimulation or irritation of the organ being examined.

In addition, other bio-signal converter 15 may in the measuring catheter for the simultaneous reception of electrical biosignals (z. B. EMG, ECG) with channel-wise provided amplifiers for signal separation or stimulation devices in any or all channels, z. B. current sources 16 for electrical stimulation or elements of the pressure receiving or for stimulation with a pressure balloon to be integrated.

In accordance with the invention using a measuring catheter of the type described can be the motility and Peristaltikabläufe in healthy as well as diseased organs, such. As in the esophagus, the intestine, the ureters, etc. to be recorded. The movement of the contents of these organs is oriented generally in one direction, although z. B. in the gut also occur many mixing processes and are known in which the contents back and be hertransportiert. For moving the contents of the contraction processes must be strictly synchronized. When loss or a total failure of the spontaneous activity already a small portion may cause malfunction of the entire organ. With the presented invention using a catheter and the measuring device can be the portions of the organ with a faulty function diagnose well.

In addition to use in the medical field and industrial use is possible, such. As to measure the dynamic resilience of tubular walls when applying a pulse pressure wave to determine the dynamic load on the walls. Thus, age-related changes of a tube wall be detected and cleared in time.