NL8700632A - Medical spark erosion catheter - removes blockages in blood vessels using ultrasonic transducer to aid accurate placement - Google Patents

Medical spark erosion catheter - removes blockages in blood vessels using ultrasonic transducer to aid accurate placement Download PDF

Info

Publication number
NL8700632A
NL8700632A NL8700632A NL8700632A NL8700632A NL 8700632 A NL8700632 A NL 8700632A NL 8700632 A NL8700632 A NL 8700632A NL 8700632 A NL8700632 A NL 8700632A NL 8700632 A NL8700632 A NL 8700632A
Authority
NL
Netherlands
Prior art keywords
catheter
end
device
provided
characterized
Prior art date
Application number
NL8700632A
Other languages
Dutch (nl)
Original Assignee
Stichting Biomedical Engineeri
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Stichting Biomedical Engineeri filed Critical Stichting Biomedical Engineeri
Priority to NL8700632 priority Critical
Priority to NL8700632A priority patent/NL8700632A/en
Publication of NL8700632A publication Critical patent/NL8700632A/en

Links

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/44Constructional features of the ultrasonic, sonic or infrasonic diagnostic device
    • A61B8/4444Constructional features of the ultrasonic, sonic or infrasonic diagnostic device related to the probe
    • A61B8/4461Features of the scanning mechanism, e.g. for moving the transducer within the housing of the probe
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/22Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for
    • A61B17/22004Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for using mechanical vibrations, e.g. ultrasonic shock waves
    • A61B17/22012Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for using mechanical vibrations, e.g. ultrasonic shock waves in direct contact with, or very close to, the obstruction or concrement
    • A61B17/22022Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for using mechanical vibrations, e.g. ultrasonic shock waves in direct contact with, or very close to, the obstruction or concrement using electric discharge
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B18/04Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
    • A61B18/12Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
    • A61B18/14Probes or electrodes therefor
    • A61B18/1492Probes or electrodes therefor having a flexible, catheter-like structure, e.g. for heart ablation
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/12Diagnosis using ultrasonic, sonic or infrasonic waves in body cavities or body tracts, e.g. by using catheters
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B18/04Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
    • A61B18/12Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
    • A61B18/14Probes or electrodes therefor
    • A61B18/1402Probes for open surgery
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B2017/00017Electrical control of surgical instruments
    • A61B2017/00022Sensing or detecting at the treatment site
    • A61B2017/00106Sensing or detecting at the treatment site ultrasonic
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/00234Surgical instruments, devices or methods, e.g. tourniquets for minimally invasive surgery
    • A61B2017/00292Surgical instruments, devices or methods, e.g. tourniquets for minimally invasive surgery mounted on or guided by flexible, e.g. catheter-like, means
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B18/04Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
    • A61B18/12Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
    • A61B18/14Probes or electrodes therefor
    • A61B2018/1497Electrodes covering only part of the probe circumference
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B18/18Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
    • A61B18/1815Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using microwaves
    • A61B2018/1861Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using microwaves with an instrument inserted into a body lumen or cavity, e.g. a catheter
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B34/00Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
    • A61B34/20Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
    • A61B2034/2046Tracking techniques
    • A61B2034/2063Acoustic tracking systems, e.g. using ultrasound
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/44Constructional features of the ultrasonic, sonic or infrasonic diagnostic device
    • A61B8/4444Constructional features of the ultrasonic, sonic or infrasonic diagnostic device related to the probe
    • A61B8/445Details of catheter construction

Abstract

The catheter consists of a thin flexible plastics material tube with a cylindrical body at one end. At the outer, rounded end of the body are four embedded electrodes soldered to wires. The wires pass through the tube to the spark pulse generator outside the patient's body. Directly behind the electrodes is a cavity, the rear end of which is closed off by a plate with a piezo-electric crystal coating. The crystal is connected via wires to an external scanner, and acts as a send and receive transducer for ultrasonic pulses and echoes. The ultrasonic pulses are reflected by a rotatable angled mirror through the wall of the catheter body. The echoes from the blood-vessel or obstruction follow the same path in reverse.

Description

»* -1- .ι VO 9069

Intra-arterial device for removing obstructions in blood vessels by spark erosion.

The invention relates to an intra-arterial device for removing obstructions in blood vessels by means of spark erosion, comprising a catheter provided at or near the end with at least one electrode, which at least one electrode is connected via a catheter-extending electrical conductor can be coupled to an electrical spark generator.

Such a device is known from the article in J. American Coll, of Cardiology, Vol. 5, No. 6 (1985), 10 pp. 1382-1386. According to the article, experiments with the known device were performed in vitro on a number of segments of blood vessels in which obstructions occurred.

According to the article, changes will still be required before in vivo application is possible. Particular attention is drawn to the need to control spark erosion in order to treat asymmetric or eccentric obstructions.

According to the article, inventions will still have to be made for this. Apart from that, the article also does not teach how to detect obstructions and how the known device should be arranged to cause the spark erosion to occur at a detected obstruction.

The object of the invention is to improve the known device and to provide a device of the type described in the preamble, with which it is possible to work in vivo.

The object according to the invention is achieved according to the invention with a device which is provided with means for controlling the spark erosion and, if desired, taking place eccentrically with respect to the catheter axis, as well as detection means coupled to the end of the catheter for determining the location and possibly the nature of an obstruction to be treated.

l /. v:.

b 4 -2-

Obstruction relief methods used hitherto often require complicated surgical intervention. An example is the so-called by-pass operation. There is and therefore is a strong need in the medical world for a technique that entails fewer risks, is less invasive and less expensive. A new method that has already been widely used is described in the article in N. Engl. J. Med. 301, pp. 61-68. In this catheter-balloon dilation method, the obstruction 10 is, as it were, pushed away by inflating a balloon attached to a catheter. However, in a relatively large number of cases, the obstruction recurs.

Recently, a number of both mechanical and non-mechanical catheter methods have been developed to remove an obstruction within arteries and veins. A high speed rotating wire, provided with abrasive material, is presented in the article in Circulation 74: 11 “362. An atherectomy catheter tip method is described in the article in Circulation 74: 11-202. As an example 20 of a non-mechanical system, the so-called "hot-tip" method described in the article in J. Am. Coll. Cardiol 3: 490. The metal end of a catheter is heated via a glass fiber laser or electrically and burned through the obstruction, as it were. The laser energy transmitted via a glass fiber per se has also been described in recent publications as an opportunity to improve perfusion through a narrowed or clogged vessel.

The laser end may or may not be of e.g. a sapphire tip are provided, see e.g. Am. J. Cardiol 50: 1209-1211.

In the case of de-obstruction methods, the ability to locate the obstruction within e.g. the coronary artery in relation to the course of the vessel is important. After all, the obstruction is often eccentric. One only wants to remove the obstruction without damaging the vessel wall. The ultimate success of the therapy to be realized depends on the localization ability and possibly identification i! "*", · "(R \ RTT ** ** £

r \ 1 \ * *: V

*: \ v. - ·· kr -3- of the composition of the obstruction. With X-ray contrast angiography it is not possible, especially in curvy vessels, to obtain sufficient morphological data and to determine the orientation of the usually eccentric obstruction relative to the original vessel wall.

Furthermore, the aforementioned mechanical and non-mechanical methods for removing an obstruction are not easily controllable in the sense of being used eccentrically within a vessel if it also requires the inclusion of necessary detection means.

The spark erosion method can be made eccentrically controllable. However, this is only valuable if a detection method can be used to determine directly and on site how the spark erosion process must be carried out eccentrically. This is made possible with the device according to the invention in that it is provided with means for controlling spark erosion and with detection means for determining the location and nature of an obstruction to be treated. Preferably, the latter means comprise a transducer for emitting and receiving echoes of high-frequency ultrasonic vibrations.

An obvious detection method would be a method based on electrical impedance measurement. However, it has been found that most obstructions on the inside of a vessel are covered with an, electrically, not very different tissue layer. Impedance measurement therefore provides too little information. Detection by local observation of the obstruction via a fiber optic catheter 30 would also be possible. However, this requires continuous flushing with a transparent liquid, which is burdensome. In practice, only a deep penetration detection method will suffice. The preferred echo detection method according to the invention is one such. Thus, the combination in the device according to the invention of detection means with which a whole cross-sectional image and hence the correct morphology of the obstruction can be obtained and of means for controlling the spark erosion is a valuable improvement over the known.

The device according to the invention can very suitably be used in coronary vessels. However, other applications such as in leg vessels or other body cavities are also possible.

The use of the echo detection methods in cavities in the human or animal body has been known for quite some time. An article in Polsk Przeglad Surgeon 33: 1071 (1961) describes how ultrasounds were obtained from the inside of the heart using a single element catheter inserted through a vein into a dog. An article in Ultrasonics 2: 82-86 15 (1964) describes the use of an intravenous ultrasound probe. This allowed to measure the size of an atrial septal defect in patients with a congenital vitium. Tomograms were obtained by rotation and withdrawal of the probe introduced into the right atrium through a vein. In the article in Ultrasonics (1967) 80-83, the intravenous method for obtaining a cross-section was even considered superior compared to a scanning method from the esophagus. The probe support consisted of a stainless steel tube with an outer diameter of 1.2 mm and a wall thickness of 0.2 mm. Since the movement of the transducer was very slow, the tomograms were obtained by triggering based on the electrocardiogram of the heart.

Developments in systems for use within the heart and based on the catheter end mounting of smaller transducers continued. In the article in Circ. Res. 22: 545-548 (1968), an omnidirectional single element catheter is disclosed which allows reconstructing the sizes of the ventricles by measuring the ultrasound arrival times. Ultrasonics 17: 143-153 (1970) describes a catheter with 4 elements that

* v. 'ï. T

% ό »-5- shifted 90 °. Slow rotation of this catheter (8 seconds for image capture) in combination with computer reconstruction yielded intracardiac tomograms.

Again, the long image acquisition times required triggering based on the EKG. The described catheter was introduced via the carotid and moved several millimeters during the cardiac cycle. Therefore, a tracking mechanism was necessary, otherwise the cross-sectional image could not be reconstructed later.

The first very fast real-time intracardiac scanner was described in Ultrasonics 10: 72-76 (1972). This catheter consisted of a circular array of 32 elements with an outer diameter of 3.2 mm mounted on the end of a No. 9 French catheter. The frame rate was no longer a limitation due to the electronic circuit. However, problems with this system have been shown by the excessive movement of the catheter in the ventricle during the cardiac cycle and the limited characteristics of the ultrasound beam. The catheter described operated at 5.7 MHz and although it had a narrow main beam, it had very pronounced sensitivity in the side direction. This led to unacceptable errors in the image.

In Proc. Conf. Engn. Med. Biol. 9:27 (1967), a catheter tip-mounted echo transducer for Doppler velocity measurement in the artery has been described. Excerpta Medica 150-161 (1974) describes a two transducer catheter system. When the catheter was bent in a curve within the ventricle, the size could be determined.

30 The partially invasive ultrasound scan methods, such as rectal examination and examination via the esophagus, were further developed. Nature 232: 335 (1971) describes results of Doppler methods from the esophagus. In J, Appl. Physiology 38: 6 (1975) describes a transesophageal or esophageal Doppler technique. In Circulation 54: 102 (1976) is the diagnostic method through the esophagus? "*" "S - * 4 -6- suggested. The first real time esophageal transducer is listed in Proc. Japan Soc. of Ultrasonics in Med. 32: 43-44 (1977) in the form of a rotating element in an oil-filled compartment, thereby yielding sector scans. In J. Nucl. Med. All Sci 28: 115-121 (1984) describes a similar system. A mechanical scanner with a linear system was also developed, which was described in Proc. Japan Soc. of Ultrasonics in Med. 35: 115-116 (1978). A single element moved parallel to the long axis of a tube, allowing 8-20 images per second to be obtained. Lancet I: 629 (1980) describes a real time 10 MHz linear array mounted on an endoscope. Furthermore, the article in IEEE mentions Trans. Biomed. Spooky. 29: 707 (1982) the first electronic 15 sector scanner mounted for examination from the esophagus.

In view of the foregoing, it can be stated that ultrasound systems consisting of a single or multiple elements mounted on a catheter end have been described. The same applies to a number of rotating enkei-element systems 20 with or without mirror for applications such as within the esophagus.

As noted, according to the invention, it is preferable to use a high-frequency ultrasound system for detection. It has been found that optimal imaging can be achieved at frequencies above 15 MHz.

According to a further preference, the transducer in the device according to the invention is therefore adapted to emit ultrasonic vibrations with a frequency of more than 15 MHz.

The device according to the invention can be designed such that a triggered pulsation is used for the spark erosion process. This can be helpful so as not to interfere with the heart's natural electrical stimulation.

In principle, a large number of forms of electrodes are possible for applying spark erosion. The electrode can e.g. be a hollow pipe, or comprise a conical or spherical 3 -7 conductive end.

The electrode can e.g. also contain a system of discrete metal "islets" embedded in an insulating material. These separate metal regions should then be capable of being fed by as many separate electrode wires. The surface of the electrode body need not be flat, but may be grooved or porous.

If, in the device according to the invention, precise positioning of the end of the catheter in a blood vessel is necessary or desired, this can be provided by mounting one or more balloons near the end of the catheter, that or those wholly or partially inflated. condition maintains or maintains the catheter end at the desired position in the appropriate blood vessel.

In an embodiment of the device according to the invention, the catheter can suitably be provided near the end with a number of fixedly arranged transducers, each of which occupies a different position with respect to the axis, while the device is further provided with electronic switching means for to energize the transducers alternately or in subgroups alternately. In this embodiment, the echoes are therefore used by suitable electronic switching so that the sound beam provides a cross-sectional image of the blood vessel concerned. Depending on the arrangement of the transducers, this cross-sectional image may be perpendicular to the longitudinal axis of the blood vessel or may represent a conical cross-section. It is also possible to use a limited number of transducers in this embodiment, so that the full cross-section is not shown, but is measured only in a limited number of directions, e.g. four.

It is thus possible to locate the outer wall of an artery 35 and therefore also any obstruction.

In another suitable embodiment of the -8- 3

a

The device according to the invention has a cavity in the fixed end of the catheter in which a mechanically rotatable or translatable mirror or echo crystal (transducer) is arranged, while the device 5 is provided with means for inserting the mirror or echo crystal into rotate or translate cavity.

In yet another suitable embodiment of the device according to the invention, the catheter is provided with a rotatable end, which end is provided on one side with an electrode and on the other side with either a mirror surface or the transducer, while the device it is further provided with means for rotating the catheter end. An advantage of this embodiment is that the ultrasonic beam scans almost the same cross-section which can be therapeutically treated by spark erosion from the electrode in a subsequent phase. Because only one electrode is used, this embodiment is relatively simple. Driving the rotatable end of the catheter can be accomplished by means of a flexible drive wire which is passed through the catheter and is rotated appropriately outside the catheter. However, it is also possible to provide a local drive of the catheter end, e.g. by means of a liquid to be injected and vanes or slots 25 on or in the part to be rotated.

When mirrors or mirror surfaces are used in the device according to the invention, these may be designed such that reflected radiation from a transducer is focused thereby. For this purpose, a somewhat hollow surface can, e.g. be helpful.

The advantage of the use of mirrors is, moreover, that it extends the starting path of the radiation beam. This suppresses so-called transient effects so that in fact one can measure closer to the catheter surface.

Suitably, in the device according to * 5 4 "* ....

"I! In the present invention, the catheter includes a lumen for passing a guidewire therethrough to guide the catheter to an obstruction. In addition, such a guide wire can already be arranged in the artery and the catheter can be slid, as it were, over the arranged guide wire. Furthermore, the catheter of the device according to the invention can be provided with one or more balloons near the end, while the device is provided with means for fully or partially inflating the balloon (s) after application of the catheter in a blood vessel, to position the catheter end therein.

If desired, an asymmetry can be built into the catheter end, so that when "looking" with the aid of the high-frequency ultrasonic radiation it is clear where one is relative to the catheter. The catheter may furthermore be provided with means known per se for passing a liquid through the catheter for rinsing a blood vessel to be examined, if desired. It is often also desirable to flush the space in which the transducers are located, since otherwise the passage of the high-frequency radiation is not quite possible.

The invention is elucidated with reference to the drawing, in which: Fig. 1 is a cross-sectional view through the end 25 of the catheter of an embodiment of the device according to the invention; fig. 2 shows a section along the line II-II in fig. 1; and FIG. 3 is a cross-sectional view through the end 30 of the catheter of another embodiment of the device of the invention.

Fig. 1 shows in cross section the end of the catheter of an embodiment of the device according to the invention. The catheter essentially comprises a thin flexible tube 1, e.g. made of plastic material. The diameter of the tube 1 is e.g. 0.8-2 mm in case the device,. «R- v '· Λ. ·' · Ί -10-; Λ ting is intended for the treatment of coronary vessels.

The diameter may be larger for leg vessels. The same goes for urological application.

The end of the catheter is formed by a rounded cylindrical body 2 of e.g. a ceramic insulating material. Four electrodes 3, 4, 5 and 6 are embedded on the surface in body 2. The surface of the body 2 with the electrodes arranged therein can be grooved. The electrodes 3 to 6 are separated from each other and are arranged symmetrically along the circumference of the body 2. Each of the electrodes 3 to 6 is connected to a conductive wire provided with an insulating jacket. The wire 7 is shown, which by means of e.g. the soldering mass 8 is connected to the electrode 15. Likewise, the electrode 5 is connected to the wire 10 by means of the soldering mass 9. The wires 7 and 10 exist e.g. made of copper or other suitable conductive material.

The end of the flexible tube 1 of the catheter is sealed by means of a plastic disc 11. The 20 wires, which have passed through the electrodes 3 to 6 through the catheter to be connected outside the catheter with a spark generator (not shown), are embedded at the location of the body 2 and the disc 11. These wires, inter alia 7 and 10, that disc 11 and that body 2 form a cage 12, as it were. In the cage 12, a beveled cylindrical body 13 is rotatably disposed about its axis. The beveled surface 14 of the cylinder 13 is a mirror surface. The body 13 can e.g. stainless steel and the surface 14 may be polished to a mirror surface. It is of course possible for a separate flat mirror to be mounted on the chamfered surface 14 of the cylinder 13. If desired, the mirror surface 14 can have a shape deviating from the flat shape, e.g. slightly concave, so that the mirror 14 operates in a focusing manner. The cylinder 35 13 is mounted on a flexible driving wire 15. The wire 15 is passed through the disk 11 and passes through the catheter f * · ** * r * * "* * 1 r /;: _1 v * 'ί« - linear outside, where it can be connected to a suitable actuator to rotate the wire 15 and thus the cylinder 13. In the disk 11, one or more channels 33 are provided for guiding a catheter 12 into the cage 12 in operation. Instead of channels, longitudinal grooves in the surface of the disc 11 can also be provided.

In the rounded body 2, a cavity 16 is provided on the side facing the cage 12. The cavity 16 is closed by a flat echo crystal 17 supported on suitably shaped shoulders 18 at the front of the cavity 16. The echo crystal 17 is e.g. a plate of piezoelectric ceramic material. It may also consist of a foil of piezoelectric material applied to a suitable support. The echo crystal 17 is connected to two electrical lines 19 and 20, which run along the wires 7 and 20, respectively. 10 have also been guided and also passed out through the catheter for connection to suitable known means for energizing the echo crystal and for signaling and converting echoes received by the crystal into images.

In operation, high-frequency ultrasonic radiation emitted by the crystal 17 is directed at the mirror 14 and from there reflected to the outside of the cage 12. From the received echoes, an image is created of the surroundings and just before the catheter end, partly because the mirror 14 is rotated during transmission and reception.

Thus, obstructions in a blood vessel in which the catheter end is disposed can be located. By selectively energizing one of the electrodes 3 to 6, depending on the location of the obstruction observed, spark erosion can thus be applied in an asymmetrically controllable manner.

Fig. 3 shows a cross section through the end of a catheter of another embodiment of the device according to the invention. In this embodiment f .; · "

The catheter tube 21 is sealed at the front by a disc-shaped or plug-shaped body 22. An echo crystal 23 is mounted on the front surface of the disc or plug 22 facing away from the tube 21. Electrically conductive wires 24 and 25 are attached to the crystal 23, which are passed through the disk or plug 22 and lead out through the catheter tube 21. A rounded cylindrical body 26 is rotatably disposed on the disk or plug 22. The body 26 consists e.g. from a suitable ceramic insulating material. On the side facing away from the disc 22, an eccentrically-oriented part of the body 26 is designed as an electrode 27 embedded in the ceramic insulating material. The electrode 27 is connected to the axis 26 of the body 26 and conductor wire 28 passed through the ceramic material. The conductor wire 28, provided with an insulating jacket, is further passed through the crystal 23, the disc 22 and the catheter tube 21 and, in addition to supplying the spark erosion electrode 27, also serves as a driving wire for the rotating the body 20 26.

On the side facing the plug or disc 22, the body 26 is provided with a notch 29. The oblique surface 30 of the body 26 delimiting the notch 29 is designed as a mirror surface. This can e.g. This has been done in that a mirror coating has been applied to the surface 30. At least a channel 34 is provided in the plug or disc 22 for guiding a flushing fluid through the catheter into the space of the notch 29 during operation.

In operation, ultrasound radiation emitted by the echo crystal 23 is reflected against the mirror surface 30 and directed against the blood vessel wall outside the catheter tip. Collected ultrasounds are processed in a known manner. By rotating the body 26, a cross-sectional image of the blood vessel can be obtained. Obstructions present can be removed by spark erosion applied via the electrode 27.

♦ * -13-

In the embodiment of the device according to the invention shown in Fig. 3, means are further provided for determining the position of the notch 29 and therefore the direction of the radiation of the transducer 23 directed against the mirror surface 30 and thereby deflected.

These means comprise an encoded disc 31 mounted on the drive wire 28 and rotating with the wire 28. A glass fiber 32 is further fixedly arranged in the catheter tube 21, via which the code disc 31 can be observed. By observing which part of the disc 31 is in front of the end of the fiber 32, the position of the notch 29 corresponding to this part is known to the observer. Other methods of location detection are of course also possible.

Only two embodiments of the device according to the invention are explained with reference to the figures.

It will be clear that many variants are possible.

Claims (9)

  1. Intra-arterial device for the removal of obstructions in blood vessels by spark erosion, comprising a catheter provided at or near the end with at least one electrode, coupling at least one electrode via an electrical conductor extending through the catheter with an electric spark generator, characterized in that the device is provided with means to control the spark erosion and, if desired, to take place eccentrically with respect to the catheter axis, as well as 10 means of detection coupled to the end of the catheter of the location and possibly nature of an obstruction to be treated.
  2. 2. Device as claimed in claim 1, characterized in that the detection means comprise a transducer for emitting and receiving echoes of high-frequency ultrasonic vibrations.
  3. Device according to claim 2, characterized in that the transducer is adapted to emit ultrasonic vibrations with a frequency of more than 15 MHz.
  4. Device as claimed in claims 2-3, characterized in that the catheter is provided near the end with a number of fixedly arranged transducers, each of which occupies a different position relative to the axis, while the device is further provided with electronic switching means for To energize the transducers alternately or in subgroups alternately.
  5. 5. Device as claimed in claims 2-3, characterized in that the fixed end of the catheter has a cavity in which a mechanically rotatable or translatable mirror or echo crystal (transducer) is arranged, while the device is provided with means for rotating or translating the mirror or echo crystal in said cavity.
  6. 6. Device according to claims 2-3, characterized in that the catheter is provided with a rotatable end, which end is provided on one side with an electrode and on the other side by either a mirror surface, either the transducer, while the device further includes means for rotating the catheter end.
  7. Device according to claims 5-6, provided with a mirror or mirror surface, characterized in that the mirror or mirror surface is formed in such a way that reflected radiation from a transducer is focused thereby.
  8. Device as claimed in claims 1-7, characterized in that the catheter is provided with a lumen for guiding a guide wire therethrough for guiding the catheter to an obstruction.
  9. 9. Device as claimed in claims 1-8, characterized in that the catheter is provided with one or more balloons near the end and the device is provided with means for inflating the or the balloon (s) in whole or in part after application of the catheter into a blood vessel to position the catheter end therein. Γ = '<v
NL8700632A 1987-03-17 1987-03-17 Medical spark erosion catheter - removes blockages in blood vessels using ultrasonic transducer to aid accurate placement NL8700632A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
NL8700632 1987-03-17
NL8700632A NL8700632A (en) 1987-03-17 1987-03-17 Medical spark erosion catheter - removes blockages in blood vessels using ultrasonic transducer to aid accurate placement

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL8700632A NL8700632A (en) 1987-03-17 1987-03-17 Medical spark erosion catheter - removes blockages in blood vessels using ultrasonic transducer to aid accurate placement

Publications (1)

Publication Number Publication Date
NL8700632A true NL8700632A (en) 1988-10-17

Family

ID=19849721

Family Applications (1)

Application Number Title Priority Date Filing Date
NL8700632A NL8700632A (en) 1987-03-17 1987-03-17 Medical spark erosion catheter - removes blockages in blood vessels using ultrasonic transducer to aid accurate placement

Country Status (1)

Country Link
NL (1) NL8700632A (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1990013253A1 (en) * 1989-04-28 1990-11-15 Du-Med B.V. An intra-arterial device
EP0423895A1 (en) * 1989-10-16 1991-04-24 Du-Med B.V. Disposable intra-luminal ultrasonic instrument
FR2729845A1 (en) * 1995-02-01 1996-08-02 Centre Nat Rech Scient Endocavity echographic imaging catheter
US6159225A (en) * 1995-10-13 2000-12-12 Transvascular, Inc. Device for interstitial transvascular intervention and revascularization
US6190353B1 (en) 1995-10-13 2001-02-20 Transvascular, Inc. Methods and apparatus for bypassing arterial obstructions and/or performing other transvascular procedures
US6283951B1 (en) 1996-10-11 2001-09-04 Transvascular, Inc. Systems and methods for delivering drugs to selected locations within the body
US6302875B1 (en) 1996-10-11 2001-10-16 Transvascular, Inc. Catheters and related devices for forming passageways between blood vessels or other anatomical structures
US8007440B2 (en) 2005-02-08 2011-08-30 Volcano Corporation Apparatus and methods for low-cost intravascular ultrasound imaging and for crossing severe vascular occlusions
US8047996B2 (en) 2005-10-31 2011-11-01 Volcano Corporation System and method for reducing angular geometric distortion in an imaging device
US8401610B2 (en) 2003-04-28 2013-03-19 Board Of Regents, The University Of Texas System Rotating catheter probe using a light-drive apparatus
US8727988B2 (en) 1995-10-13 2014-05-20 Medtronic Vascular, Inc. Tissue penetrating catheters having integral imaging transducers and their methods of use
US8996099B2 (en) * 2003-04-28 2015-03-31 Board Of Regents, The University Of Texas System Catheter imaging probe and method

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1990013253A1 (en) * 1989-04-28 1990-11-15 Du-Med B.V. An intra-arterial device
EP0423895A1 (en) * 1989-10-16 1991-04-24 Du-Med B.V. Disposable intra-luminal ultrasonic instrument
FR2729845A1 (en) * 1995-02-01 1996-08-02 Centre Nat Rech Scient Endocavity echographic imaging catheter
WO1996023444A1 (en) * 1995-02-01 1996-08-08 Centre National De La Recherche Scientifique (Cnrs) Intracavitary echographic imaging catheter
US6159225A (en) * 1995-10-13 2000-12-12 Transvascular, Inc. Device for interstitial transvascular intervention and revascularization
US6190353B1 (en) 1995-10-13 2001-02-20 Transvascular, Inc. Methods and apparatus for bypassing arterial obstructions and/or performing other transvascular procedures
US8753366B2 (en) 1995-10-13 2014-06-17 Medtronic Vascular, Inc. Catheters and related devices for forming passageways between blood vessels or other anatomical structures
US8727988B2 (en) 1995-10-13 2014-05-20 Medtronic Vascular, Inc. Tissue penetrating catheters having integral imaging transducers and their methods of use
US6655386B1 (en) 1995-10-13 2003-12-02 Transvascular, Inc. Transluminal method for bypassing arterial obstructions
US7670329B2 (en) 1995-10-13 2010-03-02 Medtronic Vascular, Inc. Systems and methods for delivering drugs to selected locations within the body
US7059330B1 (en) 1995-10-13 2006-06-13 Medtronic Vascular, Inc. Methods and apparatus for bypassing arterial obstructions and/or performing other transvascular procedures
US7134438B2 (en) 1995-10-13 2006-11-14 Medtronic Vascular, Inc. Methods and apparatus for bypassing arterial obstructions and/or performing other transvascular procedures
US6685648B2 (en) 1996-10-11 2004-02-03 Transvascular, Inc. Systems and methods for delivering drugs to selected locations within the body
US6283951B1 (en) 1996-10-11 2001-09-04 Transvascular, Inc. Systems and methods for delivering drugs to selected locations within the body
US6302875B1 (en) 1996-10-11 2001-10-16 Transvascular, Inc. Catheters and related devices for forming passageways between blood vessels or other anatomical structures
US8996099B2 (en) * 2003-04-28 2015-03-31 Board Of Regents, The University Of Texas System Catheter imaging probe and method
US8401610B2 (en) 2003-04-28 2013-03-19 Board Of Regents, The University Of Texas System Rotating catheter probe using a light-drive apparatus
US9591961B2 (en) 2003-04-28 2017-03-14 Board Of Regents, The University Of Texas System Rotating catheter probe using a light-drive apparatus
US8480593B2 (en) 2005-02-08 2013-07-09 Volcano Corporation Apparatus and methods for intravascular ultrasound imaging and for crossing severe vascular occlusions
US8007440B2 (en) 2005-02-08 2011-08-30 Volcano Corporation Apparatus and methods for low-cost intravascular ultrasound imaging and for crossing severe vascular occlusions
US9474506B2 (en) 2005-02-08 2016-10-25 Volcano Corporation Apparatus and methods for low-cost intravascular ultrasound imaging and for crossing severe vascular occlusions
US8047996B2 (en) 2005-10-31 2011-11-01 Volcano Corporation System and method for reducing angular geometric distortion in an imaging device
US8414496B2 (en) 2005-10-31 2013-04-09 Volcano Corporation System and method for reducing angular geometric distortion in an imaging device

Similar Documents

Publication Publication Date Title
US10052121B2 (en) Method for ablating body tissue
US10105062B2 (en) Miniaturized photoacoustic imaging apparatus including a rotatable reflector
JP6673985B2 (en) Method of controlling operation of an imaging system
JP6622854B2 (en) Multimodal imaging system
US20160296208A1 (en) Intravascular Photoacoustic and Ultrasound Echo Imaging
JP2019162507A (en) Imaging probe with combined ultrasound and optical means of imaging
JP6346971B2 (en) Imaging system
US8721633B2 (en) Ablation devices with sensors structures
EP2637566B1 (en) Systems and computer program for making and using rotational transducers for concurrently imaging blood flow and tissue
US20180344283A1 (en) Method for focused acoustic computed tomography (fact)
JP5754022B2 (en) System for multifrequency imaging of patient tissue using an intravascular ultrasound imaging system
US4928695A (en) Laser diagnostic and treatment device
US20180368675A1 (en) Devices, systems, and methods for visualizing an occluded vessel
US7194294B2 (en) Multi-functional medical catheter and methods of use
US20190053942A1 (en) Ablation devices and methods with ultrasonic imaging cross-reference to related applications
US5199437A (en) Ultrasonic imager
EP0706345B1 (en) Imaging, electrical potential sensing, and ablation catheters
ES2360524T3 (en) Configured ecogen water catheter to produce an improved improved ultrasound picture.
US6863653B1 (en) Ultrasound device for axial ranging
JP4612263B2 (en) Forward and side-looking ultrasound imaging
US7622853B2 (en) Micromachined imaging transducer
JP3307646B2 (en) Body cavity probe for treatment / image and treatment device using the same
JP3782107B2 (en) Acoustic imaging, Doppler catheters and guidewires
US7288244B2 (en) Determining vulnerable plaque in blood vessels
JP4675613B2 (en) Medical examination and / or treatment system

Legal Events

Date Code Title Description
A1B A search report has been drawn up
BV The patent application has lapsed