Technical Field

The present invention relates to a medical apparatus for the introduction of catheters into the human body for the processing of electrocardiographic data. Background Art

In the medical field, the use is known of special devices to detect the electrical activity behind heart function, both for diagnostic purposes and for simple purposes of heart activity monitoring.

Generally, such devices are provided with at least three electrodes to be positioned on the patient's body in order to detect the differences in potential which are created during cardiac activity.

The electrodes are positioned to form a triangle (Einthoven triangle) and are operatively linked to processing means adapted to graphically plot the pattern of the signal relating to the electrical activity of the heart over time.

The resulting pattern is known as electrocardiogram (ECG) and provides useful information on the patient's health condition, particularly related to health conditions tied to heart activity.

For each detection operation, three different ECG strips are obtained, these being the projection of the resulting cardiac activity on the three directions identified by the sides of the Einthoven triangle.

In particular, reference is made to the first derivation for the ECG strip relating to the right shoulder - left shoulder direction; to the second derivation for the ECG strip relating to the left inguinal - right shoulder direction; to the third derivation for the ECG strip relating to the left inguinal - left shoulder direction. By way of example, an ECG strip, referring to a cardiac cycle of a patient not subject to fibrillation, in first and second derivation, has the following major points:

wave P: this is the first section of the ECG which has a relative maximum point, conventionally positive with respect to the line, unlike zero potential difference defined as "isoelectric", and refers to the wave and originates in the sino-atrial node and points to the depolarization of the atria;

group QRS: this is a complex of three successive waves reflecting the progressive depolarization of the ventricles, with the depolarization wave passing from the atrium-ventricular node to the surface of the ventricles.

The Q wave is negative with respect to the isoelectric and corresponds to the depolarization of the interventricular septum; the wave R is positive and has the maximum adjustable peak and corresponds to the depolarization of the left ventricle apex; the wave S is negative and corresponds to the depolarization of the part of the ventricles in contact with the atria;

wave T: this has a positive relative maximum and corresponds to the phase of re-polarization of the ventricle cells.

In third derivation, the ECG strip shows differences in representation due to the variability of the vector representing electrical activity, with the wave T, for example, which is negative.

In any case, a distinction can be made between the same major points.

From an examination of the ECG strips, the medical staff is able to obtain information on the patient's health, or to obtain useful information of various types.

The use is in fact known of the devices described above, for the sake of simplicity called ECG devices, as support instruments in the implanting of central venous catheters (CVC), of totally implantable systems and of catheters for hemodialysis.

The CVC implant in fact envisages the insertion of the catheter into a blood vessel making it run along this until the ending part of the catheter itself is positioned at the cavoatrial junction.

The most commonly used technique, to date, envisages the use of an ECG device connected to the ending part of the catheter, the latter used as an electrode to detect the differences in potential, so as to "guide" the doctor in the positioning of the ending part itself.

As the ending part of the catheter is pushed towards the cavoatrial junction, the ECG strip undergoes changes due to the change in position of the electrode with respect to the catheter.

According to established practice, doctors make reference to changes in the height of the wave P, considering as point of arrival the positioning whereby the ECG strip shows the maximum value of such height.

In detail, the doctor inserts the catheter and pushes it with gradual and predefined forward movements towards the cavoatrial junction, observing the ECG strip for each forward movement.

On the basis of his/her experience, the doctor checks the pattern of the wave P and establishes the final position of the catheter.

Usually, when the wave P starts to decrease, or even shows an initial negative section, the doctor returns to the immediately preceding position, considering him/herself to be close to the cavoatrial junction.

This known technique has a number of drawbacks tied to the fact that most of the work is entrusted to the doctor' s experience.

The chosen final position may not be the ideal one, inasmuch as many factors accidentally influence the correct detection of the electrical activity of the heart. In order to address this type of drawback, proceeding is known with the aid of a radiographic control adapted to detect the position of the ending part of the catheter by X rays.

This solution too has a number of drawbacks tied to exposure to the X rays, known to be harmful for human health, and to the difficulty in controlling the position when the ending part of the catheter is covered by bone parts.

Description of the Invention

The main aim of the present invention is to provide a medical apparatus for the introduction of catheters into the human body which allows improving catheter implants.

One object of the present invention is to provide a medical apparatus for the introduction of catheters into the human body which allows an effective support for central venous catheter implants.

Another object of the present invention is to provide a medical apparatus for the introduction of catheters into the human body which permits improving the health and safety conditions of the patients undergoing central venous catheter implants.

Another object of the present invention is to provide a medical apparatus for the introduction of catheters into the human body which allows providing information on the operating conditions of the central venous catheters already implanted.

Another object of the present invention is to provide a medical apparatus for the introduction of catheters into the human body which allows to overcome the aforementioned drawbacks of the prior art within the ambit of a simple, rational, easy, efficient to use and cost-effective solution.

The aforementioned objects are achieved by the present medical apparatus for the introduction of catheters into the human body having the characteristics of claim 1.

Brief Description of the Drawings

Other characteristics and advantages of the present invention will become more evident from the description of a preferred, but not exclusive, embodiment of a medical apparatus for the introduction of catheters into the human body, illustrated by way of an indicative, but non-limiting example, in the attached drawings in which:

Figure 1 is a schematic general view of the medical apparatus according to the invention;

Figure 2 is a schematic view of a detail of a first embodiment of the medical apparatus according to the invention;

Figures 3 to 6 are schematic illustrations of the operation of a first embodiment of the apparatus according to the invention;

Figure 7 is a schematic view of a detail of a second embodiment of the medical apparatus according to the invention;

Figures 8 and 9 are schematic illustrations of the operation of a second embodiment of the apparatus according to the invention.

Embodiments of the Invention

With particular reference to these illustrations, reference numeral 1 globally indicates a medical apparatus for the introduction of catheters into the human body.

According to the invention, the apparatus 1 comprises an electrocardiogram device, for sake of simplicity indicated in the present treatise by the term ECG device and by reference numeral 2.

The ECG device 2 has at least three electrodes 3, positionable on a human body 4 for the detection of surface electrical potential data, that is electrical potential data which can be detected at the body surface.

Consistently with what has been written above, the ECG device 2 is adapted to provide at output a surface ECG strip in the form of a signal, for simplicity not illustrated in the figures, i.e. referred of potential differences detected on the body surface, which represent the module of a vector the direction and orientation of which are determined by the position of the electrodes.

The apparatus 1 also comprises at least one catheter element 5, schematically illustrated in the figures as a hollow tubular element.

The catheter element 5 has a distal ending part 6, illustrated in a simplified manner in the figures, positionable inside the human body 4.

The distal ending part 6 has an auxiliary electrode element 7 for the detection of intracavitary electrical potential data, i.e. referred to electrical potential data detectable within a cavity of the human body, particularly within a vein.

In this case, the auxiliary electrode element 7 is the catheter itself that, filled with water, acts as a water column.

The catheter element 5 is associated with the ECG device 2 for sending intracavitary data to the latter, with the ECG device which is adapted to provide at output at least one intracavitary ECG strip 8 in the form of a processable signal.

Such characteristic allows using the same ECG device 2 to obtain both surface ECG strips, and intracavitary ECG strips.

The surface ECG strips are obtained from data provided by the electrode elements 3, while the intracavitary ECG strips are obtained from the data provided by the auxiliary electrode 7 combined with the data provided by two other electrode elements 3.

In the present embodiments, the surface ECG strips and the intracavitary ECG strips refer to the "second derivation", but the same considerations can also be made for first and third derivation strips.

Advantageously, the apparatus comprises an electronic device 9 associated with the ECG device 2 to receive the intracavitary ECG strip 8 and the ECG strip. In particular, the electronic device 9 comprises a data processing module 10 adapted to process the intracavitary ECG strip 8, and possibly the other ECG strips, for obtaining usage information H.

Usage information H is adapted to provide instructions on the insertion of the catheter element 5 into the human body 4 and, along with all other information, data and parameters coming from the electronic device 9, is useful to medical staff during the insertion operations of the catheter element 5 into the human body 4.

In the present treatise, reference is made to a "medical operator" but other figures cannot be ruled out belonging to the medical staff.

For example, besides the data directly detectable by the ECG device, such as heart rate, usage information will be the data coming from the ECG strip printouts.

In particular, the usage information H is at least in part of the type of heights measured on the ECG strip.

Conveniently, the module comprises first processing means 11 associated with the ECG device 2 for the acquisition of at least the intracavitary ECG strip 8 so as to obtain recognition data Q, R, S, P, T, V, W, J which are adapted to provide analytical information on the ECG strip 8.

The recognition data Q, R, S, P, T, V, W, J are data deriving from an analysis of the signal of the intracavitary ECG strip 8 and permit locating particular values on the strip itself such as the relative maximums and minimums, or constant- height points.

To this purpose, the first processing means 11 comprise a first data processing unit 12 receiving at input the intracavitary ECG strip 8 to obtain first recognition data Q, R, S, P, T, V, W of maximum and minimum points referred to the same strip.

In the first data processing unit 12, the intracavitary ECG strip 8 is analyzed and the relative maximum and minimum points are recognized referred to a heart cycle and are indicated by the reference letters P, Q, R, S, T, V and W.

P, Q, R, S, T correspond to the maximum and minimum values of a typical ECG strip, while V and W correspond to the absolute maximum and absolute minimum values of the ECG strip analyzed in a heart cycle.

The first processing means 11 also comprise a second data processing unit 13 receiving at input the intracavitary ECG strip 8 and the first recognition data Q, R, S, P, T, V, W to obtain second recognition data J of points of an isoelectric line of the same strip.

In the second data processing unit, the signal of the intracavitary ECG strip 8 is analyzed, preferably, but not exclusively, in combination with the first recognition data Q, R, S, P, T, V, W and the isoelectric line is identified of the strip itself, i.e., the line whose points have a substantially identical electric potential value.

The difference in potential in these points of the ECG strip is not very appreciable, and consequently such points are substantially aligned along a straight line, conventionally called isoelectric line and indicated by the reference letter K.

The present embodiments require the first processing means 11 to be able to also acquire the surface ECG strip, and the signal printouts described for the intracavitary ECG strip 8 can be made in the same way for the surface strip as well.

Advantageously, the module 10 comprises second processing means 14 associated at least with the first processing means 11 for the acquisition and processing of at least the recognition data Q, R, S, P, T, V, W, J to obtain the usage information H.

The second processing means 14, therefore, acquire the information on points P, Q, R, S, T, V, W and on the isoelectric line K, and process them to obtain information useful to the medical operator, e.g., information related to the change in height values for intracavitary ECG strips 8 found for different positions of the distal ending part 6.

Conveniently, the electronic device 9 comprises at least one memory unit 15 associated at least with the module 10.

As shown in figure 2, the memory unit is connected to both the ECG device 2, and to the module 10 so as to allow storage of the ECG strips and of the data which are processed inside the module itself.

This way, therefore, the processed data and the usage information H can be recorded in order to obtain a historic record of the ECG strips and of the data related to them.

Conveniently, the electronic device 9 comprises at least one output unit 16 associated at least with the module 10 and adapted to provide at output usage information H or other data, such as the ECG strips, the data processed in the module 10 and other information stored in the memory unit 15.

As schematically shown in the illustrations, the output unit 16 is connectable to a screen so as to permit displaying the information H and the other data.

Such feature allows the medical operator to display all the information useful for inserting the catheter element 5 into the human body 4 of the patient on a simple monitor.

The output unit 16, furthermore, comprises connection means, not shown for the sake of simplicity, which allow transmitting the data and the information from the electronic device 9 to any one other destination unit such as, e.g., external peripheral units (USB pen drive, hard-disk and other similar solutions), networks for transmitting data via cable, transceiver devices for transmitting data through electromagnetic waves (wi-fi, bluetooth, radio).

The apparatus also comprises a user interface module 17, associated with the electronic device 9.

The user interface module 17 enables the medical operator, any other operator, to enter data and information directly in the electronic device 9, or to manage the processed data and information according to need.

Advantageously, the apparatus 1 comprises an ultrasound scanning device 18 associated with the electronic device 9 to obtain ultrasound scanned images. Usefully, the ultrasound device 18 is associated with the memory unit 15 to record and transmit ultrasound images.

This way, besides the information and data processed in the module 10, the operator can display, live or subsequently, ultrasound images showing the vein and the catheter element 5.

In a first embodiment, the first processing means 11 comprise an additional unit 19 for processing the first recognition data Q, R, S, P, T, V, W to obtain first input data Q, R, S and second input data P.

In particular, the first additional unit 19 processes the recognition data Q, R, S, P, T, U, V to identify the group Q, R, S (first input data) and to recognize the point P on the intracavitary ECG strip 8.

The second processing means 14, in this first embodiment, are associated with the additional unit 19 and with the second processing unit 13 for the acquisition and the processing of the second input data P and of the second recognition data J to obtain the aforementioned usage information H.

In this first embodiment, the processed usage information is the heights of the point P assessed with respect to the isoelectric line K and indicated by the letter H.

The usage information H, therefore, is at least in part of the type of heights of the point P assessed with respect to the isoelectric line K.

With the advancement of the catheter element 5, and therefore with the variation of the intracavitary ECG strip 8, the height of point P increases or decreases according to the position of the auxiliary electrode 7.

This information enables the operator to seek in a simple way the position in which H is maximum, i.e., the position corresponding to the position of the cavoatrial junction, indicated by the reference number 20.

In a second embodiment, the additional unit 19 is absent and the second processing means 14 are associated with the first processing unit 12 to receive the first recognition data Q, R, S, P, T, V, W, V, W, and with the second processing unit 13 to receive the second recognition data J.

The second configuration is particularly useful in case of ECG strips of patients with fibrillation under way, which means the "standard" pattern of the strip itself is lost.

In this case, the first recognition data processed are the points V and W, and the second recognition data J make reference to a condition in which it is hard to plot the isoelectric K.

In this second embodiment, the processed usage information H will be of the type of maximum heights evaluated between the absolute maximum point V and the minimum absolute point W of an intracavitary ECG strip 8 for a given cardiac cycle.

In this case too, the heights H will have a maximum value when the auxiliary electrode 7 finds itself at the cavoatrial junction 20.

The operation of the present invention is the following.

The electrodes 3 are arranged on the human body 4 in the positions usually adopted to operate the ECG device 2, permitting the detection of the surface ECG strips.

A medical operator starts the procedure for implanting the catheter element 5 by inserting this into a vein of the human body 4.

The auxiliary electrode 7 is connected to the ECG device 2 and so the intracavitary ECG strip 8 can be obtained.

The medical operator pushes the distal ending part 6 along the vein of the human body 4 which leads to the cavoatrial junction 20, proceeding with successive forward movements on pre-established positions.

For each position, the ECG device 2 provides the electronic device 9 with a surface ECG strip and an intracavitary ECG strip 8, both of which can be displayed on a specific monitor connected to the output unit 16.

In each position, furthermore, the module 10 detects and acquires the signal of the intracavitary ECG strip 8 to be processed.

In particular, the first processing means 11 process the signal of the ECG strip to obtain the recognition data Q, R, S, P, T, V, W, J.

The first data processing unit 12 finds the maximum and minimum points, processing the signal of the ECG strip and providing the first recognition data Q, R, S, P, T, V, W at output.

The second data processing unit 13 finds the points of equal potential and provides second recognition data J for the definition of the isoelectric line K on the ECG strip.

The recognition data Q, R, S, P, T, V, W, J are sent to the second processing means 14 which process them so as to obtain the usage information H.

The usage information H is in turn sent to the output unit 16 and therefore the medical operator manages to display them for each detection operation.

In particular, the usage information H has the character of measurement, and derives from the average of three detection operations.

By moving the distal ending part 6 gradually towards the cavoatrial junction 20, the usage information H changes, providing the medical surgeon with a reliable support, of a numerical character, on the positioning of the catheter element 5. The processing operations described above are reiterated for every different position until the information H is congruent with the correct position of the catheter element 5, i.e., at the cavoatrial junction 20.

For example, in the case of the information H being a height proportionate to the vector of the electrical activity of the heart, the information will be congruent when the height is maximum.

The memory unit 15 receives the data both from the ECG device 2 and from the module 10, allowing the recording of the usage information H and of the processed data in general, as well as of the ECG strips sent by the ECG device 2.

This way all the operations performed during implanting and related data can be filed and recorded.

The memory unit 15 also receives the data entered manually by the user interface module 17, thus enabling the medical operator to manage a greater amount of information, including during phases following the operation.

The ultrasound device 18 provides ultrasound data translatable into images to the memory unit 15 and to the output unit 16.

This way, the medical operator can have at disposal further information, e.g., on the diameters of the vein and the relative position for a correct introduction of the catheter element 5.

In the first embodiment (figures from 2 to 6), the first data processing unit 12 comprises an additional unit 19 wherein the first recognition data Q, R, S, P, T, V, W are further processed to provide further information.

In particular, the additional unit 19 identifies the first input data Q, R, S, corresponding to the group Q, R, S on the ECG strip and, starting with this, backs up along the ECG strip until it finds point P. The latter is provided at output as second input data P.

The second processing means 14 process the second output data P and the second recognition data J so as to obtain as usage information H the value of the heights of the point P on the ECG strip with respect to the isoelectric line K. As it gradually moves forward towards the cavoatrial junction 20, the value of the height H grows until it reaches its maximum precisely at the junction 20 (figure 5).

The medical staff can display this information and thus understand the positioning of the distal ending part 6.

In moving forward inside the heart (figure 6), in fact, the value of the height H starts to drop again, with the ECG strip which could appear to be "biphase" at the point P, i.e., a section with negative gradient (figure 6).

At this point, the doctor returns to the position whereby H appears maximum and can terminate the implant operations.

In a second embodiment, shown in the figures from 7 to 9, the first processing unit 12 sends the first recognition data Q, R, S, P, T, V, W directly to the second processing means 14, without identifying the point P.

Such embodiment is particularly suitable for those cases in which the patient is in a state of fibrillation, and consequently the ECG strip is not regular and it is not possible to identify the group Q, R, S and the point P.

In this case, the second processing means 14 receive the data referring to the values of the maximums and minimums of the ECG strip, in particular of the absolute maximum V and of the absolute minimum W and combine them with the second recognition data J.

The latter provide information useful for plotting lines with equal potential passing through the points V and W.

On the basis of these data and this information, the second processing means 14 provide usage information H at output which corresponds to the height measurable between the point V and the point W.

The usage information H, therefore, is at least in part of the type of heights measurable between the point V and the point W.

Similarly to what has been described for the first embodiment, in this case too, with the forward movement of the catheter element towards the junction 20 there is an increase in the height H which reaches its maximum value at the junction itself.

It has in practice been ascertained that the described invention achieves the intended objects and in particular the fact is underlined that the medical apparatus for the introduction of catheters into the human body permits improving the operations required for the implant of catheters.

The medical operator, in fact, can count on effective support whose information is reliable and sustained by the fact that it is obtained from an ECG strip with high resolution, higher than the resolution achievable using the naked eye from printed strips.

Furthermore, such apparatus allows minimizing the errors due to the doctor's assessments based on observations of the intracavitary ECG strip.

The information H, in fact, derives from the average of the three detected values, and consequently these can be considered real and true measurements. Consequently, the conditions of safety and health of the patients undergoing implants of central venous catheters appear improved.

Finally, the medical apparatus for the introduction of catheters into the human body allows providing information on the operating conditions of the already- implanted central venous catheters.

The operations described above, in fact, can also be easily performed for already- implanted catheters.

In this case it would be possible to monitor the position of the implanted catheter without maneuvering the catheter itself, thus enabling the doctor to make assessments as to the state of the implant before actually intervening.

This involves benefits both in terms of procedures, inasmuch as the number of operations can be reduced in the case of the control being successful, and in terms of the patient's health and safety, considering that there will be less risk of infections caused by maneuvers or repositioning jobs of the catheter.