Apparatus For Disintegrating Concretions In Body Cavities Of Living Organisms By Means Of An Ultrasonic Probe

Abstract

An ultrasonic probe for disintegrating concretions e.g. urinary calculus, in body cavities comprises a probe tube, ultrasonically vibrated in a longitudinal direction, having at one end a tubular impact element loosely coupled to it in the direction of vibration. The impact element is provided on its free end with a cutting edge, preferably formed by a plurality of teeth. The disintegrated concretions are continuously evacuated through the tubular impact element and the tubular probe.

Description

BACKGROUND OF THE INVENTION

This invention relates to an apparatus for disintegrating concretions in body cavities of living organisms by means of an ultrasonic probe.

It is known to treat hard and brittle materials by means of ultrasonic vibrations. In this case a tool profiled in any desired manner and excited to longitudinal vibrations is lowered into the material to be treated with interposition of a boron carbide suspension. By this means perforations, dies etc. can be made in hard and brittle materials.

The present invention pursues a totally different purpose, namely to produce brittle fractures in hard and brittle bodies in order to destroy the said bodies, e.g. urinary calculus. By this means it is desired to destroy or disintegrate a urinary calculus present in the human bladder to such an extent that the debris can be exhausted or removed from the bladder through natural channels without difficulty.

Now when it is attempted to obtain brittle fractures by means of ultrasonic vibrations, although e.g. in the case of disintegration of urinary calculus, relatively soft types of calculus such as phosphate calculus, can be reduced fairly rapidly by ultrasonic vibrations; on the other hand harder types, such as urate calculus, oxalate calculus, can only be disintegrated into small debris extraordinarily slowly, or even not at all.

Known apparatusses operate on the principle that a concretion present in a body cavity is touched by a rod-shaped ultrasonic probe introduced through natural channels, whereupon by pressing the concretion against the wall of the body cavity the ultrasonic vibrations are transmitted to the concretion and the latter is thereby destroyed. Because the pressure forces required in this case are relatively powerful, there is a risk, more particularly with small smooth concretions, that the sonic probe may slip off, so that the wall of the body cavity may become damaged. Moreover, if such small smooth concretions are also extremely hard, then in the majority of cases they cannot be disintegrated at all by this procedure, because they move away at the very first contact by the ultrasonic probe.

Furthermore, the known apparatus suffers from another disadvantage. When it is actually possible to disintegrate a concretion, then in every case initially the disintegrated debris of the calculus and the stone dust suspended in the liquor are left behind in the body cavity. This gives rise to on the one hand to a visual obstruction for the optical examination instrument (endoscope) introduced with the ultrasonic probe, and on the other hand to the necessity of removing the stone residues from the body cavity by a separate operation, which furthermore can no longer be performed under visual control. For this purpose the ultrasonic probe must be removed out of the body cavity and another instrument, for example a so-called suction syringe, must be used.

SUMMARY OF THE INVENTION

The invention aims at providing an apparatus for disintegrating concretions in body cavities by means of an ultrasonic probe, whereby the disadvantages of the apparatusses of this type hitherto known are obviated.

To this end, the present invention consists in an apparatus for disintegrating concretions in body cavities in living organisms, comprising a tubular probe ultrasonically vibrated longitudinally and a tubular impact element loosely coupled in the direction of vibration to one end of said tubular probe whereby the ultrasonic vibrations transmitted to the impact element are transformed into shock forces.

Due to the interposition of the impact element, the shattering effect of the ultrasonic vibrations is increased by orders of magnitude. The impact element should be as hard and highly elastic as possible, and is arranged loosely between the ultrasonic probe and the body to be disintegrated. This unyielding element is capable of "collecting" impulse shocks statistically from the ultrasonic vibrations acting periodically upon it, and to transmit them in very brief and highly intensive impact shocks to the body to be disintegrated. It has been found that these "collected" highly intensive impulse shocks can achieve orders of magnitude and can initiate percussive forces which exceed many times the pressure peaks transmitted periodically by the ultrasonic probe tube and are capable of causing the desired brittle fractures. Even the hardest types or urinary calculus (urate and oxalate calculus) can be destroyed by this means.

By virtue of the tubular construction of the impact element and of the ultrasonic probe tube, it becomes possible to exhaust the fragments of calculus continuously by an exhauster device as they are detached during the actual disintegration operation, so that it is unnecessary to use additionally a further apparatus to exhaust them after the disintegration of the concretion. Furthermore, the continuous exhaustion of the fragments of calculus and of the stone dust produce the further advantage that no obstruction of vision for the optical observation instrument (endoscope) occurs. And lastly, the exhaustion of the fragments of calculus also sucks the calculus itself towards the front end of the tubular impact element, so that on the one hand it centres itself automatically upon the impact element, so that the latter is largely prevented from slipping off, while at the same time a certain contact pressure is generated whereby the contact force against the wall of the body cavity which was hitherto necessary is substantially reduced. Since furthermore the shocks of the impact element only have a destructive effect when they strike hard bodies, no injury to the soft wall of the body cavity occurs even if the latter is accidentally touched.

The characteristic property of the impact element to transform the ultrasonic vibrations transmitted to it into powerful shock forces of low frequency produces a number of advantages:

Only a much weaker contact pressure is required to achieve the desired effect, compared to the apparatusses hitherto known. Furthermore, it is possible to destroy with ultrasonic vibrations of hitherto customary amplitude and power, concretions which would have withstood destruction without the interposition of an impact element.

Preferably, the end of the tubular impact element remote from said coupling is constructed as a cutting edge which may advantageously be constituted by a plurality of teeth. The efficacity of the destruction of concretions is increased by these measures.

It is furthermore advantageous to make the teeth of undercut trapezoidal construction so that their cutting surfaces are larger than their root surfaces, since in this manner the disintegrated culculus material can easily be discharged by the exhaustion operation. Furthermore, if the teeth are arranged mutually joggled or twisted, so that their cutting edges project partly beyond the outer circumference of the tube supporting them and into the interior space of the said tube, then on the one hand the risk of the impact element seizing in the calculus is reduced, while on the other hand it has the effect that the diameter of the hole generated is greater than the diameter of the impact element carrying the teeth, and the stone fragments are smaller than the internal diameter of the impact element and of the tubular ultrasonic probe. In this way a clogging of the entire instrument by the disintegrated stones is reliably obviated. Furthermore the advantage is obtained that with this mode of construction the tubular impact element tends to "dance" in the peripheral direction, so that it repeatedly strikes fresh points of the concretion to be destroyed.

The impact element is preferably guided loosely with slight radial and axial play on the end of the ultrasonic probe tube. In this case the impact element can be prevented from falling out by various measures which later be more fully explained.

It has further been found particularly advantageous to construct the ultrasonic vibrator tube and/or the impact element coupled to it, at the mutual contact surfaces, so that a linear or punctiform contact occurs, since in the case of an areal contact the recoil of the element is considerably impaired by the adherence layer of interlying liquid. The elastic shock conditions are also appreciably improved.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more readily understood, reference is made to the accompanying drawings which illustrate diagrammatically and by way of example several embodiments thereof, and in which:

FIG. 1 shows the front end of an ultrasonic probe with tubular impact element, partly in section;

FIG. 2 shows the side elevation of the cutting edge of the impact element with trapezoidal teeth;

FIG. 3 shows the plan of the cutting edge with twisted teeth and of the impact element (in a section along the line III--III of FIG. 1);

FIG. 4 shows an impact element with rounded and corrugated impact surface;

FIG. 5 shows an impact element with conical impact surface and cap sleeve;

FIG. 6 shows an impact element with helicoidal spring retaining means; and

FIG. 7 shows an impact element with tubular retaining means.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, an ultrasonic probe comprises a tube 1 and an impact element 2. The tube 1 is oscillated longitudinally by an ultrasonic generator indicated by the double arrow 27. The impact element 2 is likewise of tubular construction and carries at one end teeth 7 as a cutting edge. Due to the longitudinal oscillations of the tube 1, impulses are transmitted to the impact element 2, which are intensified in the above described manner into very powerful impulse peaks, because the impact element 2 is supported loosely in the radial and axial direction in or on the tube 1. The loose mounting of the impact element is ensured in that a sufficient tolerance in the radial direction is provided by shank guide means 4 in the end of the tube 1, whilst axial movement of the impact element 2 is limited on the one hand by an impact surface 3 on the element 2 and on the other hand by retaining pins 5, 5' which engage in slots 6, 6' in the impact element 2, so that the impact element 2 is prevented from dropping out of the tube 1. The teeth 7 of the impact element 2 constructed as a tube section are arranged joggled, so that only those fragments of the concretion treated which have a smaller diameter than that of the tube can penetrate into the tube 1, so that easy evacuation of the fragments in the direction of the arrow 27 through the tube 1 is possible.

As FIG. 2 shows, the teeth 7 are advantageously of trapezoidal construction with their wide side acting as chisels, so that they do not jam in the case of a less brittle concretions, but can automatically bore themselves free. The discharge of the material to the exhaustor device is furthermore greatly facilitated by this means.

FIG. 3 illustrates the impact element 2 viewed axially in plan and partly in section along the line III--III of FIG. 1. The teeth 7 are arranged twisted so that a line connecting the outer edges of the teeth has a greater diameter than the outside diameter D of the impact element 2, whilst a line connecting the inner edges of the teeth has a smaller diameter than the inside diameter d of the impact element 2.

FIG. 4 shows a construction of the impact surfaces at the front end of the ultrasonic probe tube 8 and on the impact element 9. The end of the tube 8 is substantially conically countersunk at its end face 9a, whereby an automatic centering of the impact element 9 is created. The impact element 9 is rounded at its contact surface 10, so that its rests not upon a plane surface but only upon an encircling line. If desired, the rounded support surfaces 10 may be corrugated as at 10a, so that only support points remain.

FIG. 5 shows the mode of supporting an impact element 11 on an ultrasonic probe tube 12 by a cap sleeve 13. In this case, for the purpose of automatic centering, both the impact surfaces 14, 15 are conically tapered.

FIG. 6 illustrates an embodiment in which an impact element 16 is loosely supported on an ultrasonic probe tube 17 by means of a helical spring 18. The spring is dimensioned so that in the rest position a small gap 19 remains between the impact element 16 and the tube 17, which is closed only when the impact element 16 is pressed against the tube 17, so that energy is transmitted only then. By virtue of this construction, during idle running, the excited but inoperative ultrasonic vibrator does not touch the impact element at all and avoids unnecessary wear of the impact surfaces and stressing of the support means.

FIG. 7 shows means for supporting an impact element 20 on an ultrasonic probe tube 21 by means of a soft resilient sleeve 22 which can be adjusted so that again a small gap 23 remains between impact surfaces 24, 25. The impact surfaces may be rounded and/or conically tapered.

Claims

We claim:

1. An apparatus for disintegrating concretions in body cavities in living organisms, comprising a tubular probe adapted to be ultrasonically vibrated longitudinally and a tubular impact element loosely coupled in the direction of vibration to one end of said tubular probe whereby the ultrasonic vibrations transmitted to the impact element are transformed into shock forces.

2. An apparatus as claimed in claim 1, wherein the end of the tubular impact element remote from said coupling is constructed as a cutting edge.

3. An apparatus as claimed in claim 2, wherein the cutting edge is constituted by a plurality of teeth.

4. An apparatus as claimed in claim 3, wherein the teeth are of an undercut, trapezoidal construction so that their cutting surfaces are larger than their root surfaces.

5. An apparatus as claimed in claim 3, wherein the teeth are arranged mutually joggled or twisted so that a line connecting the outer edges of the teeth has a greater diameter than the external diameter of the impact element and a line connecting the inner edges of the teeth has a smaller diameter than the internal diameter of the impact element.

6. An apparatus as claimed in any of the claim 2, wherein the impact element is guided loosely with slight radial and axial play on the end of the tubular probe.

7. An apparatus as claimed in claim 6, wherein the impact element is prevented from dropping out of the tubular probe by retaining pins which engage in slots provided in the impact element.

8. An apparatus as claimed in claim 6, wherein the impact element is loosely supported by a cap sleeve secured to the tubular probe.

9. An apparatus as claimed in claim 6, wherein the impact element is supported by a helicoidal spring contacting the tubular probe and the impact element.

10. An apparatus as claimed in claim 6, wherein the impact element is supported by a resilient tube contacting the tubular probe and the impact element.

11. An apparatus as claimed in claim 6, wherein those parts of the ultrasonic probe tube and of the impact element where the two components are in mutual contact during their axial movement caused by the ultrasonic vibrations are of rounded tapered construction of at least one of said parts.

12. An apparatus as claimed in claim 1, wherein the ultrasonic probe tube is adapted to be connected to an exhaustor device.