HRP20030990A2 - System for guidance and control of minimum invasive delivery of therapy with medical agents - Google Patents

Abstract

The present invention solves the problem of guiding and controlling the puncture of the heart. The invention includes for this purpose the following devices: an ultrasound-labeled introductory catheter through which the ultrasound-labeled catheter with a needle can be moved, as well as transponder circuits for ultrasound guidance, and ultrasonic pulse distance meters. One or more miniature piezoelectric marker transducers are mounted at the top of the introductory catheter, and a special transducer is mounted on the needle puncture catheter. The transducer marker electrodes are connected to the electrical conductors, which connect them along the catheter to the external electrical ports on the proximal side of the catheter. When the marker converter is on the catheter tip within the scope of the echoscope search then ultrasonic beams from the echoscopic transducer activate the marker transducer.

Description

The field of technology

This invention relates to cardiac therapy, in particular to an apparatus for guiding a system for the administration of genetic therapy or other pharmacotherapy. In particular, this invention relates to a system for conducting procedures in which medical preparations are directly administered into the heart muscle or other body structures.

State of the art

Nowadays, the implantation and placement of heart catheters is done with the help of X-rays. The disadvantage of X-ray methods is the danger of ionizing radiation and the poor representation of soft tissues such as papillary muscle, interventricular septum, heart valves, etc. Ultrasound imaging shows soft tissues well and does not pose a danger of X-ray radiation, but it has the disadvantage that it usually shows an image in one plane, i.e. tomographic. Ultrasound imaging can show flexible electrode catheters, but the tip or any other part of the catheter cannot be unambiguously identified because the apparent tip of the catheter can only be the place where the catheter leaves or enters the plane of examination. That is why so far ultrasound echoscopy has only rarely been used to visualize cardiac catheters. The use was limited to sonographically suitable situations and to tests during pregnancy when X-ray imaging is not recommended. In order to improve the localization of electrodes and catheter tips on electrode catheters, we have developed ultrasound-marked catheters.

Langberg (JACC Vol.12, No.1, July 1988:218-23) shows how to localize the catheter and its electrodes within the heart using our inventions described in US Patents 4,697,595 and 4,706,681 which he clearly cites in the references although he does not mention the numbers patents. In our US patent no. 5,840,030 we have shown how to use a directed ablation field by an indirect method of “energy visualization” within an echocardiographic image. This is where the knowledge of the relationship between the directionality of the two fields, namely the ultrasound field and the ablation field, is used, as well as the knowledge of how to monitor the contact of the electrode with the tissue.

In US patent no. 5,385,148 Lesh shows how ultrasound can characterize tissue.

The localization function can be realized in two ways: either by using a transponder or by using a passive localization system. The transponder is triggered by signals from marker transducers fed through the electrode catheter. Once triggered, the transponder generates a characteristic series of electrical pulses that are fed back to the same marker transducer. Because of this, the marker transducer emits a series of ultrasonic pulses. These pulses appear on the echoscope screen as a visible mark next to the marked part of the lead catheter regardless of whether the lead catheter itself is visible or not. Damping of ultrasound pulses in the body is compensated by a compensating amplifier (the so-called TGC amplifier) built into the transponder. This amplifier amplifies echoes from deeper structures more than echoes from shallower structures. Synchronization of the TGC amplifier is performed either directly from the echoscope or by using an inductive loop with the echoscope probe. The transponder delay is 40 ns. The mark appears along the line of sight of the echoscope as a bright flashing mark.

The passive localization system contains a time doubling circuit (TDC) that doubles the time that elapses between the transmission of an ultrasound pulse from the echoscope probe and the reception of that pulse at the marker transducer, and then activates the signal generator for the mark on the screen. This signal is fed to the signal bus of the ultrasound echoscope in the desired form, polarity and time sequence. In electrode catheters for electrophysiological studies, each of the marker transducers marking a different electrode may have a different label on the screen. Here, as with the transponder, the attenuation in the body is compensated by a TGC amplifier connected to the TGC amplifier of the echoscope. There is no difference in the properties of analog and digital time doubling circuits. The system contains electronic circuits for isolation from electric shock according to the standard for CF class equipment according to IEC 601-1.

The safety consequences of breaking the electrical insulation, which would cause the marker signal to connect to the body, were verified by measuring the total impedance in saline. The dependence of impedance on frequency was measured.

The maximum operating voltage is 5V peak-peak. This voltage source is isolated by a membrane that normally covers the marker transducer. Impulses 5Vpp at 4MHz central frequency in series of 5 to 10 and echoscope repetition frequency (about 1 kHz). In case of insulation failure during operation with the transponder, this signal can appear between the electrode for electrostimulation and the bare electrode of the marker transducer. The physiological solution behaves like tissue and provides the impedance necessary to calculate the energy transferred from the transponder to the tissues in the event of such a failure.

The maximum temporal, maximum spatial intensity of ultrasound is in the worst case below 0.5 W/cm2 for pulses shorter than 3 microseconds. Average temporal, maximum spatial intensity is three orders of magnitude lower with today's echoscopes. These intensities are within acceptable diagnostic limits.

The localization accuracy depends on the physical dimensions and position of the marker transducer as well as on the beam width and the sensitivity of the system. With today's available piezoceramics, the length of the transducer marker can be reduced to 1.5 mm, giving with the current constructions a length positioning error of about 2 mm. The error due to the echoscope beamwidth is equal to or greater than this and is dominant. In addition, there is a basic possibility of operator error in different settings of the TGC characteristics of the echoscope and localization electronics. Such an error is possible only where the TGC amplifiers of the echoscope and the transponder are not directly connected. The lowest possible accuracy is in the direction of the highest sensitivity of the marker transducer. A practical compromise is to use about 15 dB higher sensitivity than that required for basic echoscope pulse detection in the most sensitive direction.

In cardiac catheter applications, only one form of label is normally required, but in electrophysiological applications, multiple forms of labels are required to distinguish between different electrodes. In this sense, the passive system has more flexibility than the transponder.

On the safety side, a transponder is easier to electrically isolate than a passive system, but both must meet the IEC601-1 requirements for CF class medical equipment. On the other hand, no signals are sent from the passive system to the marker transducer. A routine check of the isolation and function of the marker system before application is easily possible. In a passive system, a single breakdown of the insulation does not lead to the sending of additional electrical signals to the heart.

The requirement to operate at the resonant frequency of the marker transducer is strict and does not allow the piezoelectric properties to change with time or require knowledge of the resonance all the time. Thus, the choice of piezoelectrics is limited to very stable types.

An ultrasound marker system can help to avoid a significant part of the use of X-rays in cardiac catheterization and implantation of electrode catheters or electrophysiological studies. In addition, this system can enable the detection of electrode catheter failures. The radiation dose to the operator's hands can easily exceed 300 μGy per application, so avoiding the use of X-rays is justified whenever possible.

A transponder and a passive system have different properties and should be used in different circumstances. The transponder is suitable for implantation of a temporary electrode catheter for electrostimulation and catheterization because it is not dependent on the echoscope by design and is easy to isolate electrically. In this case, the required insulation check can be performed before use. The transponder is less suitable for electrophysiological studies due to the problematic recognition of different transponder signatures, and it is not easy to use in permanent electrostimulation due to high energy consumption.

The construction of the passive system depends on the echoscope with which it is applied, but it has a much lower energy consumption than the transponder and can generate easily recognizable marks for electrophysiological studies because there is no intermediate step of transmitting ultrasound.

These and other aspects are described in our scientific papers B. Breyer, B. Ferek-Petrić and I. Čikeš: Properties of Ultrasonically Marked Leads. Pacing and Clinical Electrophysiology. Vol.12, (1989), p.1369, and in B. Breyer & B. Ferek-Petrić. Possibilities of Ultrasound Catheters. Int.Journ. of Cardiac Imaging, Vol. 6, (1991), p. 277.

Description of the invention

The main objective of the present invention is to enable accurate control of the direction and depth of therapeutic and diagnostic punctures within the heart or other body structures normally accessible only by catheters or similar devices. Such a puncture can be used to administer a medical agent into the punctured tissue. Said medical agent can be a genetic agent, a chemotherapy agent, or any drug that can be injected. In cases where implantation is required at a precisely determined depth, our invention serves for accurate depth control. The advantage of the diagnostic aspect of such a puncture is again the strict control of the puncture depth.

Another object of this invention is to guide and localize the exact points where medical therapy is given by injection or instillation of a medical agent directly into human tissues in places in the body that are not visible or cannot be made visible by optical means but can be shown with an ultrasound echoscope. .

The puncture is performed in two steps, namely the first step is to bring the puncture assembly to the right place and in contact with the tissues to be punctured, and the second step is the actual puncture with the administration of a medical agent or aspiration of a diagnostic sample.

Said puncture is performed with specific equipment for catheter puncture. Accessories for catheter puncture consist of a hollow introducer catheter and inside it another catheter with a puncture needle at the distal end. The inner member can be just a flexible puncture needle. The introducer catheter is used to maneuver the tip of the device to the point of interest. The internal puncture catheter is then pushed out to perform a therapeutic or diagnostic puncture. Both steps, accurate placement and accurate puncture, require guidance and control to make everything safer and more accurate than a blind procedure. X-ray guidance is not entirely adequate due to the danger of radiation and because soft tissues are poorly visualized in this way.

Ultrasound echoscopy does not pose a radiation hazard for the patient and the operator and has an excellent ability to visualize soft tissues. The representation of said catheter, its tip and the tip of the puncture needle is essential for ultrasound guidance of said procedures with puncture accessories.

The method for unequivocal localization of a point on a device introduced into the body, for example said introducer or electrophysiological catheter, consists of ultrasound marking of the catheter and the use of a transponder to generate a visible mark on the screen of the ultrasound echoscope. This means that the method described herein includes the ultrasound echoscope and the ultrasound-marked catheter puncture kit described herein.

One or more miniature piezoelectric marker transducers are mounted at the tip of the catheter introducer and a separate transducer is mounted on the needle puncture catheter. Marker transducer electrodes (vaporized silver or similar) are attached to electrical conductors that are laid along the catheter to an external electrical connector at the proximal end of the catheter. When the transducer is on the tip of the catheter in the search field of the echoscope, it is activated by ultrasound from the beam generated by the echoscopic probe. The high-frequency pulses created in this way are guided by built-in electrical conductors to the localization electronic circuits.

The simplest electronic circuit for localization is a transponder. The transponder is a generator of a series of pulses triggered by signals from said marker transducer when the marked part of the catheter is in the plane of the echoscope search. When the ultrasonic pulse reaches the marker transducer, it creates an electrical impulse that triggers the pulse generator whose output is fed back to the marker transducer. Thus, the marker transducer becomes an ultrasound transmitter that produces a visible mark indicating its position on the ultrasound screen. The method does not depend on whether the search is performed in two or three dimensions. This procedure completed the first part of the task, i.e. bringing the puncture catheter to the desired position.

The next step of the procedure is the actual controlled puncture. To achieve this, the needle is pushed out of the external catheter and punctures the adjacent tissue. It is necessary to establish that the puncture was actually performed and to measure the depth of the puncture. The fact that the needle has exited and entered the tissue is done with the help of a transponder and an ultrasound marker transducer on the needle. The puncture depth is determined by ultrasonic pulse measurement of the distance between the marker transducer on the introducer catheter and on the needle. A special electronic circuit measures said distance by measuring the time it takes for the ultrasonic pulses to travel the distance between the two marker transducers. In this way, the depth of the puncture is controlled in detail.

Thus, this invention solves the problem of conducting and controlling puncture procedures in the heart. For this purpose, the invention includes the following devices: an ultrasound-marked introducer catheter through which an ultrasound-marked catheter with a needle can be moved, and transponder circuits for conducting ultrasound echography, as well as an ultrasound distance meter.

Short description of the pictures

According to Figure 1, the interventricular septum is punctured using a puncture catheter assembly that is introduced through the right heart ventricle. Catheter introducer 1 marked with marker transducer 2 is placed in the right heart. Through this introducer catheter, a needle catheter 11 marked with a marker transducer 12 is introduced, and the needle 13 is pushed forward and thus punctures the cardiac structure 10, in the case shown, the interventricular septum.

According to Figure 2, the hollow catheter 1 is marked by a transducer 2 which is connected to the proximal side by longitudinal guides 3 and 4. The second internal catheter 11 with a puncture needle 13 on the tip is marked by a piezoelectric marker transducer 12. Guides 5 and 6 running along this catheter connect the marker. transducer 12 with the proximal side of the catheter 11.

According to Figure 3, the hollow catheter 1 is marked by a transducer 2 which is connected to the proximal side of the catheter 1 by longitudinal guides 3 and 4. The second internal catheter 111 with a puncture needle 13 at the top is marked by a piezoelectric transducer 12. Longitudinal guides 105 and 106 connect the marker transducer 12 with the proximal side of the catheter 111.

According to Figure 4, the ultrasound echoscope 30 is used to image the inside of the patient's body 33. The probe of the echoscope 34 searches the area 35 inside the patient's body. Said catheter 1 is introduced into the body and connected to marking circuits 37, eg transponders. The catheter assembly described in Figures 1, 2 and 3 is marked by marker transducers 2 and 12. When said marker transducers 1 or 12 are located in the imaged area 35, electronic marking circuits 37 generate such electrical signals as to generate visible and recognizable markings on the screen of the ultrasound echoscope. 30.

According to Figure 5, the electronic marking circuits are dual if there are two marker transducers as illustrated in Figures 1 and 2. According to the illustration in Figure 5, the electronic circuit consists of two transponders or equivalent circuits 41 and 43, and distance meters 42 and 44. These are interconnected with the corresponding switching circuits 45, and with the catheter assembly 1 from Figures 1-4 via switching and connecting circuits 47. The control circuit 45 is used to coordinate the operation of individual parts.

According to Figure 6, the marking circuits may have a multiplexer switch 55 to function as a dual if there are two marker transducers 2 and 12 according to Figures 1 and 2. As illustrated in Figure 6, the circuits consist of a single transponder 52 and distance measuring circuits 51 and 56. These are connected to each other by appropriate switching circuits 55 and to the catheter assembly 1 from pictures 1-4 via switching and connection circuits 57 and 58. Control circuit 55 is used to coordinate the work of individual parts.

Description of one performance

As can be seen in Figure 1, the problem that needs to be solved is the guidance and control of the puncture of a structure inside the living heart. Guiding means bringing the device to the desired structure in the body. Control means that the puncture depth measured from the surface of the structure is controlled. Puncture can be diagnostic or therapeutic. Therapeutic punctures include the administration of gene therapy, chemotherapy, or the administration of any other medical agent.

A flexible catheter 1 containing another flexible catheter or needle 11 is introduced and positioned at the site of interest 10, in this case the interventricular septum. A practical problem is the control of this setup. This is done with the help of an ultrasound echoscope, which can see the heart's soft tissue structures as well as said catheters in real time. However, due to the constant movement and small dimensions of said devices, the exact position of the tip containing the needle 13 can hardly be known without this technical invention. In order to solve this, a marker transducer 12 is mounted on the inner catheter 11. This inner catheter 11 can be moved longitudinally inside the outer catheter 1 and can be pushed out so as to expose the puncture needle 13, thereby puncturing the structure of interest 10. The external ultrasound echoscope and transponder are used with said catheter assembly.

Said catheters are illustrated in more detail in Figures 2 and 3.

As illustrated in Figures 2A and 2B, the external catheter 1 is controllable so that its distal portion can be bent in at least one axis using external controls. As seen in Figure 2A, a piezoelectric transducer 2 is mounted at the tip of the catheter 1. This transducer may be of a composite type composed of several transducers and connected to the proximal part of the catheter by electrical conductors 3 and 4 so that it can receive and send electrical signals to the electronic connected circuits. . The second catheter 11 has a smaller diameter and is placed inside the catheter 1 and can be fully retracted into it. It has a needle 13 or some other device of that type on its tip. The needle is shown protruding from the external catheter 1, but during maneuvering in the body it is fully retracted so that it does not catch on anything until it reaches the target. When the goal is reached, a therapeutic or diagnostic puncture can be performed by pushing the internal catheter 11 out (Figure 2B), which penetrates the tissue in front of the device with the needle 13. At the same time, the second marker transducer 12 is exposed and it can now receive and transmit electrical signals from electronic circuits connected to it by internal conductors 5 and 6 leading to the proximal side of the catheter 11 and can be connected to electronic circuits that will be described later. The needle 13 is a hollow needle that is used for therapeutic punctures, i.e. administration of medical agents through the hollow catheter 11 into body structures 10 to be treated.

As illustrated in Figures 3A and 3B, the external catheter 1 is controllable so that its distal part can be bent in at least one axis using external controls. As seen in Figure 3A, a piezoelectric transducer 2 is mounted at the tip of the catheter 1. This transducer can be of a composite type composed of several transducers and connected to the proximal part of the catheter by electrical conductors 3 and 4 so that it can receive and send electrical signals to the connected electronic circuits. . The second catheter 111 is smaller in diameter and is placed inside the catheter 1 and can be fully retracted into it. It can be pushed out of the catheter 1 to the side. It has a needle 13 or some other device of that type on its tip. The needle is shown protruding from the external catheter 1, but during maneuvering in the body it is fully retracted so that it does not catch on anything until it reaches the target. When the goal is reached, a therapeutic or diagnostic puncture can be performed by pushing the internal catheter 111 out (Figure 3B), so that the needle 13 penetrates the tissue in front of the device. At the same time, the second marker transducer 12 is exposed and it can now receive and transmit electrical signals from electronic circuits connected to it by internal conductors 5 and 6 leading to the proximal side of the catheter 111 and can be connected to electronic circuits that will be described later. The needle 13 is a hollow needle used for therapeutic punctures to administer medical agents through the hollow catheter 111 or 11 into body structures 10 to be treated. This form of device is used when the structure of interest is easier to access by leaning the steerable catheter 1 on it or when the structure is narrow, for example a blood vessel.

Said puncture procedures are guided and controlled using an external ultrasound echoscope and special localization electronic circuits as illustrated in Figure 4. The ultrasound echoscope 30 images an area 35 inside the human body 33. Said catheter assembly 1 described by means of Figures 1, 2, 3 is embedded in body. In addition to the other parts that have already been described, it also has two sets of piezoelectric marker transducers 2 and 12 that are connected to electronic circuits 37 and 38 by means of conductors inside the catheter assembly. When the ultrasonic pulses from the echoscopic probe 34 hit the piezoelectric marker transducers 2 and 12, electrical signals are generated that are led to the electronic circuit 37, preferably a transponder. A transponder is a device that generates its characteristic electrical signal when it receives a signal from a piezoelectric transducer and sends that characteristic electrical signal-signature back to the transducer from which it was removed.

Two different tasks must be performed with this device, namely guiding the device to its intended position and controlling the puncture itself.

In accordance with the first aspect of the present invention, the catheter assembly 1 is guided to a desired position using an external ultrasound echoscope 30 in conjunction with a transponder 37 or other equivalent positioning circuit.

In accordance with another aspect of the present invention, the depth and success of that puncture is determined and controlled by measuring the distance between marker transducers 2 and 12 using an ultrasonic pulse distance meter 38.

In more detail, there are various possibilities for realizing the described basic principle.

As illustrated in Figure 5, it is possible to take two transponders 42 and 44 that are connected to marker converters 2 and 12, respectively. These are connected by a switch 45 during the guidance phase. Each of said transponders generates its own electrical and consequently ultrasonic pulse sequence - signature. These different signatures give different markings on the echoscope screen 30. When the catheter 1 is brought to the point of interest and rests on it, then the second catheter 11 is pushed out so that the needle 13 penetrates the tissue, eg the cardiac ventricular septum. The depth of needle penetration is controlled by measuring the distance between marker transducers 2 and 12. For this purpose, the two transducers are switched to the distance measuring circuits 41 and 43 by means of a switch 45 and under the control of a control circuit 42 which can be operated by the operator. These ultrasonic distance measuring circuits basically measure the time the ultrasound travels from place to place as is known in the art. The marker converters can be switched with the switch 45 between said measuring circuits as often as desired.

It is possible to use only one transponder as illustrated in Figure 6. In this case, one transponder 52 is switched between marker transducers 2 and 12 by means of switch 57. Controller 55 controls the frequency of switching between the two transducers. When a point of interest in the body is reached and the catheter 1 rests on it, the second catheter 11 is pushed out so that the needle 13 penetrates the tissue, eg the cardiac ventricular septum. The depth to which the needle penetrates the tissue is controlled by measuring the distance between marker transducers 1 and 12. For this purpose, these two transducers are switched to the distance measuring circuits 51 and 56 via a switch 57 and under the control of control circuits 55 which can be operated by the operator. These ultrasonic distance measuring circuits basically measure the transit time of ultrasonic pulses as is known in the art. Marker transducers can be switched between said electronic circuits 55, 57, 58 as often as desired.

Therefore, the previously mentioned objectives of guiding the active tip of the device to deliver the medical agent into the body structure of interest and the subsequent control of the puncture procedure are thereby achieved.

Claims (32)

1. A system for guiding and controlling the administration of minimally invasive therapy by medical means, characterized by the fact that it contains an assembly of an ultrasound-marked catheter means adapted for installation and introduction into the human body, where said assembly of a catheter means contains an external ultrasound-marked catheter and one ultrasound-marked injection needle or a flexible puncture needle that can be pulled out of said catheter assembly, and which is adapted for puncturing the surrounding tissue and administering a therapeutic medical agent to said tissue, whereby the selected point on the catheter and the tip of said needle are visible as marks on the image of the ultrasound echoscope. 2. A system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claim 1, characterized in that said catheter device contains an ultrasound transducer fixedly mounted on the body of said external catheter. 3. A system for guiding and controlling the administration of minimally invasive therapy by medical means, from claim 1, characterized in that said injection needle contains an ultrasound transducer fixedly mounted near its tip. 4. A system for guiding and controlling the administration of minimally invasive therapy by medical means, from claims 1 and 2, indicated by the fact that it contains a means to make an ultrasound-marked point of interest on said catheter visible on the image of said ultrasound echoscope whenever the search area of said echoscope intersects said ultrasonic marker transducer. 5. A system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claims 1 and 3, characterized in that the ultrasonically marked tip of the said needle is made visible on the image of the said ultrasound echoscope whenever the said needle protrudes outside the said catheter and the search area of the said echoscope intersects said ultrasonic marker transducer. 6. The system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claims 2 and 3, characterized by the fact that it contains means by which the ultrasound-marked points of interest on said catheters and the ultrasound-marked tip of said needle are made visible in the image of said ultrasound echoscope as two separate markings whenever the search area of said echoscope intersects both said transducer ultrasound markers and said needle protrudes beyond the body of said catheter. 7. A system for guiding and controlling the administration of minimally invasive therapy with medical means, from claim 6, characterized by the fact that it contains a means for measuring the distance between two said marks on the echographic image of the ultrasound echoscope or by using a separate ultrasound distance meter, which precisely monitors the puncture in the surrounding tissue. 8. The system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claims 6 and 7, characterized in that said distance measuring device is an ultrasonic pulse distance meter that measures the distance between said ultrasonic transducers by measuring the time required for the passage of ultrasound between said transducers. 9. A system for guiding and controlling the administration of minimally invasive therapy by medical means, characterized by the fact that it contains an ultrasound-marked catheter suitable for implantation in the human heart or vessels, where said catheter contains an ultrasound-marked injection needle that can be pushed out of said catheter for puncturing the heart muscle and administering therapeutic medical agent into said tissue, whereby the selected part of the catheter and the tip of said needle are visible as marks on the image of the echocardiographic apparatus. 10. A system for guiding and controlling the administration of minimally invasive therapy with medical means, from claim 9, characterized in that said catheter contains an ultrasound transducer fixedly mounted on the body of said catheter. 11. A system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claim 9, characterized in that said injection needle contains an ultrasound transducer fixedly mounted on the tip of said needle. 12. A system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claims 9 and 10, indicated by the fact that it contains a means by which the ultrasound-marked point of interest on the said catheter is made visible in the image of the said echocardiograph whenever the search area of the said echocardiographic apparatus intersects the said ultrasonic transducer. 13. A system for guiding and controlling the administration of minimally invasive therapy by medical means, from claims 9 and 11, characterized by the fact that it contains a means by which the ultrasonically marked tip of said needle is made visible in the image of said echocardiograph whenever said needle protrudes from said catheter and the examination area of said of the echocardiographic apparatus is cut by the said ultrasound transducer. 14. A system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claims 10 and 11, characterized by the fact that it contains means by which the ultrasound-marked points of interest on said catheters and the ultrasound-marked tip of said needle are made visible in the image of said ultrasound echoscope as two separate markings whenever the search area of said echoscope intersects both said transducer ultrasound markers and said needle protrudes beyond the body of said catheter. 15. A system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claims 10 and 11, characterized by the fact that it contains means for measuring the distance between two said marks on the image of said echocardiographic apparatus for precise monitoring of the puncture of the surrounding tissue. 16. A system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claims 1 - 15, characterized in that the distance between said transducers can be continuously measured by an ultrasonic distance meter. 17. A system for guiding and controlling the administration of minimally invasive therapy with medical means, from claim 9, characterized in that it contains means for ultrasound monitoring of the contact between said catheter and the heart muscle. 18. A system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claims 1 and 8, characterized by the fact that where said medical device gen. 19. A system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claims 1 and 8, characterized by the fact that the RNAi medical device is said. 20. A system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claims 1 and 8, characterized by the fact that where said medical device is a protein. 21. A system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claims 1 and 8, characterized by the fact that where said medical device is a cytostatic. 22. A method for providing tissue therapy with medical agents, characterized in that the method includes implantation of a catheter into the human body, wherein said catheter contains means for marking a point of interest within the image of the ultrasound apparatus whenever the plane of examination of said echoscope intersects the catheter and thereby enables precise placement said catheter to the anatomical site where therapy is to be administered. 23. A method for administering medical therapy to tissues, according to claim 22, characterized in that the method also includes a catheter with an injection needle for tissue puncture, where said needle contains means for marking its tip within the echoscope image whenever the search plane of said echoscope intersects that needle, which enables visual control of the puncture and administration of therapy with the help of said image. 24. The method of providing tissue therapy with medical means, from claim 22, characterized in that it includes ultrasound monitoring of the contact between said catheter and the surrounding tissue. 25. A method of administering therapy to the heart which includes implantation of a catheter into the heart or a vessel, wherein said catheter contains means for marking a point of interest within an image on an echocardiograph whenever the plane of examination of said echocardiograph intersects the catheter, thereby enabling precise placement of said catheter in the anatomical position where it is needed give therapy. 26. A method for administering medical therapy to the heart, characterized in that the method contains a catheter that contains a means for marking its point of interest within the image of the echocardiographic apparatus whenever the search plane of said echocardiograph intersects the catheter and thereby enables precise placement of said catheter in an anatomical position where therapy should be given. 27. A method for administering medical therapy to the heart, according to claim 22, characterized in that it includes an injection needle for puncturing the heart muscle, wherein said needle has a means for ultrasound marking the tip with an ultrasound transducer. 28. A method for administering medical therapy to the heart, according to claim 22, characterized in that it includes monitoring the contact between said catheter and the endocardium. 29. The method for administering medical therapy to the heart, according to claim 22, characterized in that it includes measuring the mutual distance between the ultrasound markers on said catheter and the ultrasound marker on said needle. 30. The system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claims 2 and 3, characterized in that it contains two transponders where said ultrasound transducer on said catheter is connected to said first transponder and said ultrasound transducer on said needle is connected to said another transponder. 31. The system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claim 30, characterized in that the reception of an ultrasound signal in one of the transponders triggers the immediate transmission of an ultrasound signal from that same transponder, while the reception of the signal is blocked during the transmission of the signal from both said transponders. 32. The system for guiding and controlling the administration of minimally invasive therapy with medical devices, from claims 2 and 3, characterized in that it contains a transponder to which said ultrasound transducer from said catheter and ultrasound transducer from said needle are alternately connected via a switch.