HK1087603B - Single-blow shockwave generation device - Google Patents

Description

Single-shot shock wave generating device

Technical Field

The invention relates to a Single-stroke (Single-blow) shock wave generating device and an implementation process thereof.

Background

The shock wave generating device is particularly useful in urological procedures for comminuting urethral stones. The prior art includes two main types of shock wave generating devices: the first category relates to extra-corporeal (extracorporeal) shock wave generating devices, and the second category relates to percutaneous shock wave generating devices.

The first category of lithotripters employs an electric or piezoelectric shock wave generating device where the shock wave waveguide consists of a fluid-containing bag in contact with the patient's body equipped with an ellipsoidal reflector which first receives the shock wave scattered into a wide space to be focused through a widely open cone, the top of which is located within the urethral stone to be fragmented, so that the shock wave is of a small amplitude when passing through living tissue to minimize damage to said tissue and to a maximum when concentrated at the cone apex.

The second category of lithotripters uses, for example, special endoscopes to match the interventional characteristics to be performed, depending on the size and location of the urethral stones to be removed.

When the calculi are in the kidney, the endoscope is directly introduced into the kidney through the skin. When a stone is present in the ureter, it is preferable to guide an endoscope to the ureter through the bladder via a natural path (natural path). The shock wave is transmitted by a waveguide, which is a metal rod with a circular cross-section, with a diameter of ten to twenty millimeters, which is elastically deformable. The shock wave waveguide has a first end at which shock waves are generated and a second end that acts on the stone.

The first category of lithotripters does not allow the generation of large shock waves, with the risk of injury to the living tissue passed through. Thus, multiple impacts are required to break the stone into small pieces that can be expelled through the urethra.

A second type of prior art lithotripter, in particular the lithotripter described in EP 0317507, uses a small shock wave train (train) which is also characterized by fragmenting the stone to be fragmented into a plurality of fragments which can be removed by suction, flushing or discharge through a natural path.

Removal of the debris via the natural path is painful, which makes removal by flushing as possible a priority after endoscopic intervention. These methods of stone removal all have the particular disadvantage of always leaving behind undetached stone fragments which can act as a source of new stones.

The seal between the moving parts usually comprises an O-ring, the seal of which is obtained either by the engagement between the upper and lower sealing rings of the O-ring pressed between two planes or by the engagement between the inner and outer sealing rings of the O-ring pressed between the revolving chamber (revolving cylinder) and the revolving cylinder (revolving cylinder). These sealing devices can be classified into three categories, for example. The first type of sealing means comprises an O-ring placed in a groove made in a cavity, the sealing of which is ensured by the cooperation between an inner sealing ring and an outer sealing ring. The second type of sealing device comprises an O-ring placed in a groove machined in the revolving cylinder. A third type of sealing device comprises an O-ring placed in a groove recessed in a flat surface.

Disclosure of Invention

It is an object of the present invention to provide a wave generator which generates high amplitude waves transmitted through the skin or natural path, enabling controlled fragmentation of urethral stones through an endoscope for observing and grasping the fragments to fragment the stones into small fragments of necessary and sufficient size to enable the fragments to be manually removed through the endoscope by forceps.

Description of the drawings

The following description will be facilitated with reference to the accompanying drawings, in which

FIG. 1A is an elevational view of the apparatus of the preferred embodiment of the present invention.

FIG. 1B is a schematic cross-sectional view of a preferred embodiment of the present invention in an operating state.

FIG. 1C is a simplified cross-sectional view of FIG. 1A after a duty cycle has begun.

FIG. 1D is a detailed view of FIG. 1C as the shock wave occurs.

FIGS. 2A-2D show detailed views of FIG. 1B, all of which correspond to FIG. 1B as a whole.

Detailed Description

The invention consists of a single-shot mechanical shock wave generating device (fig. 1A, 1B) comprising a percussion device 2 of a high-speed shock generating device 3. The shock generating device generates shock waves which are transmitted to the object to be fragmented by the shock wave transmitting device 4. Said means 4 are brought into direct or indirect contact with the object, while the percussion device 2 is put into motion due to the expansion of the high-pressure gas introduced into the accumulating means 5 before each occurrence of a shock wave. The accumulator device 5 is supplied with high-pressure gas from a separate gas storage device 6 having a very high pressure by means of a gas expansion device 7 and a gas supply and sealing device. The gas present in the accumulation means 5 is released by manual manipulation of the control means 8. The control device 8 is firstly gas-tight for the communication between the separate storage device 6 and the expansion device 7 on the one hand and the communication with the accumulation device 5 on the other hand via sealing means, and secondly the establishment of the communication between the accumulation device 5 and the percussion device 2 back to the initial state of the percussion device 2 is ensured by the mechanical device by the release of accumulated energy during the shock wave generating cycle. The return to the initial state of the control device 8 is ensured by the action of the high-pressure gas stored in the expansion device 7 and by the corresponding supply device.

The gas used can be considered to be equivalent to an ideal gas at an operating temperature of about 20 deg.C, at a high operating pressure of about 1500-; for example, the gas may be air or nitrogen from a cylinder at a pressure up to about 20000kPa, constituting a separate gas storage device with a capacity varying from half a litre to several litres; the gas cylinder is connected to the single-shot mechanical shock wave generating device 1 via a hose and via a pressure relief valve which, for example, constitutes a pressure relief device and is fixed to the gas cylinder, bringing the very high pressure of 20000kPa to a high pressure of 1500-.

In a preferred embodiment of the invention, the gas used is a carbon-containing gas such as is commercially available in the form of a single-use miniature gas cylinder 9 (fig. 2A) constituting a gas storage device with a pressure of about 7000kPa and a capacity of about 2 cl, wherein the carbon-containing gas is a liquid, so that a large amount of carbon-containing gas can be stored in the small storage device; the description below is applicable to other gases as well, but is within the scope of the invention.

The miniature cylinder 9 consists of a cylinder 10 with an outer diameter of about 18mm, a rear end 11 closed by a hemispherical wall, a front end 12 extending through a shoulder section and then through a neck 13, the neck 13 comprising a substantially cylindrical side closed by a closed cap 14. The total length of the shoulder section and the neck 13 is about 13mm, and the total length is about 80 mm; the micro gas cylinder 9 is directly incorporated into the single-click mechanical shock wave generating device 1; it is enclosed in a frame 15 consisting of two halves; the front half-frame 16 consists of a revolving cylindrical bore with a diameter slightly greater than that of the miniature cylinder 9, along a first axis of symmetry 17, and has a bottom section provided with a calibrated receptacle 18 for receiving the neck 13 of the miniature cylinder 9. The side portion is provided with first sealing means 19 of a first kind, opposite the side portion of the neck portion 13. While the central part of the receptacle 18 of determined caliber has perforating means 20 for perforating the closed cap 14; the rear half-frame 21 consists of a gripping device 22 for the hemispherical bottom section of the miniature cylinder 9, centred on the first axis of symmetry 17, able to slide, parallel to the first axis of symmetry 17, thanks to a clamping device 23 and a guide slot 24 supported on the front half-frame 16; the guide slot has a wide lateral opening allowing the front end 12 of the miniature cylinder 9 to slide into the calibrated receptacle 18 of the front half-frame 16 when the rear half-frame 21 is retracted; the clamping device 22 against the hemispherical bottom section 11 is simply slid and then the clamping device 22 is tightened to push the miniature gas cylinder 9 towards the piercing device 20 until the closed capsule 14 is pierced; the perforation device 20 has a gas transmission device; the perforation means 20 are for example of the type used on disposable butane gas bottles, the gas transmission means being a central cylindrical hole 25 which allows the passage of the gas coming from the micro-bottle 9. The perforating device 20 is communicated with a pressure relief device 27 through a first pipeline 26, and the pressure relief device 27 is combined with the single-shot mechanical shock wave generating device 1 to form a gas pressure relief device 7 (figures 1A and 1B); it consists, for example, of a first cylindrical chamber 28 (fig. 2A) in the rear section, to which chamber 28 the first duct 26 opens, the front part of which comprises a first circular hole equipped along the edge with a second sealing means 29 of the first type; the first bore extends to a second conduit 30, a gas supply valve stem 31 freely slidable for the passage of gas, said valve having a valve head 32 located in the first chamber 28, the valve head being of substantially smaller diameter than the first chamber 28, and having an annular sealing surface on its lower section surrounding the stem 31; the upper part of the valve head 32 is pushed back by a first calibrated spring 33 so as to press the annular sealing surface of the valve head 32 against the second sealing means 29 of the first type; the free end of the stem 31 slides a limited depth through a first chamber 34, which acts as a guide, the stem 31 acting on a first cylindrical piston 35 shaped head, the bottom of this piston in the first chamber 34 acting as a push rod, pushing the stem 31 backwards; the first piston 35 slides in a second cylindrical chamber 36, which is divided into a first and a second space of variable volume, sealed from each other by first sealing means of a second type, which are integral with the first piston 35; the second duct 30 opens into the rear section 38 of the second chamber 36, partly separating the first space of the second chamber 36, through a second circular hole which allows the free sliding of the valve rod 31 and the communication of the second chamber 36 with the air circuit; the rear section 38 of the second chamber 36 acts as a mechanical stop for the head of the first piston 35; the second space, which is partly divided by the first section 39 of the second chamber 36, comprises a piston stop 40, which is coaxial with the second chamber 36, thereby limiting the stroke of the first piston 35 and acting as a guide for a second calibration spring 41.

The assembly of first and second chambers 28, 36, gas supply valve, first piston 35, first and second calibration springs 33, 41 constitutes a gas pressure relief device 7 (fig. 1A, 1B) which enables a nominal pressure, defined with good accuracy and comprised between 1500 and 3000kPa, to be established in the second gas duct 30 (fig. 2A) surrounding the valve stem 31.

The third duct 42 (fig. 2B) coming out of the second duct 30 opens through the side wall into the third cylindrical chamber 43; said third chamber comprises a rear section 44 in which a second piston 45 slides; this piston comprises a second airtight device 46 of a second type, a rear section 47 and a front section 48; the bottom of the rear section 44 of the third chamber 43 has a circular hole through which a first cylindrical push rod 49 freely passes, said push rod 49 being integral with the rear section 47 of the second piston 45 and preferably coaxial with the second axis of symmetry 50 of the third chamber 43, the push rod 49 controlling the actuation of the manual operating means of the device 8 (fig. 1A, 1B); said manual operating means of the first push rod 49 preferably comprise pushing the second piston 45 into the third chamber 43; the manual means consist, for example, of a lever 51 hinged on a shaft 52, vertically offset with respect to the axis of symmetry 50 of revolution of the third chamber 43, comprising a plane of symmetry containing the axis of symmetry 50 of revolution and perpendicular to the shaft 52; the movement of the hinge lever 51 is limited by the stop 53; the forward section 48 of the second piston 45 has a pivoted cylindrical control rod 54, the rod 54 having a free end 55 which passes freely through a fourth pivoted cylindrical tube 56 and a capture (captive) end on the forward section 48 of the first piston 45 and being coaxial with the axis of rotational symmetry 50 of the third chamber 43. The fourth tube 56, which communicates with the bottom of the front section 57 of the third chamber 43, is a coaxial conical surface of revolution along its edge, which guides the third sealing means 58 of the second type in the middle, allowing the gas to flow into the fourth tube 56; the second piston 45 rests, for example, at the bottom of the rear section 44 of the third chamber 43, and when the first push rod 49 is driven by the hinge rod 51, the second piston 45 extends into the fourth tube 56 and ensures the airtightness of the front section 57 of the third chamber 43; the control rod 54 extends with its free end into a second chamber 59 integral with the body of the third chamber 43; the free end of the control rod 54 within the second chamber 59 comprises a fourth sealing means 60 of the second type; the stroke of the second piston 45 is limited in the rear position by the mechanical stop of its rear section 47 on the bottom of the rear section 44 of the third chamber 43 and in the front position by the mechanical stop of the free end 55 of the control rod 54 on the bottom 61 of the second chamber 59; at a position forward of the second piston 45, a third sealing device 58 of a second type seals off the fourth tube 56.

A fourth conduit 62 (fig. 2B) comprises an inlet port leading into the fourth tube 56 downstream of the location of a fourth sealing means 58 of the second type, and an outlet port leading into a rear section of a fourth chamber 64, the fourth chamber 64 preferably being a high pressure gas accumulation means of a cylinder of revolution on an axis of symmetry merging with the axis of symmetry of the second stage 59; this fourth chamber includes a relief valve 65 consisting of a valve body 66, a valve head 67 and a valve body seat 68. The valve body 66 is tubular, has a cylindrical shape of revolution, is coaxial with the fourth chamber 64, and has a diameter of about one third of the fourth chamber 64. The valve head 67 has a flat rear section and a conical forward section 122 of revolution, the diameter of which is effectively twice the diameter of the valve body to which it is attached. The valve body seat 68 slides through a third chamber bore 69 of substantially the same diameter as the valve body 66. The relief valve 65 has a third sealing means 70 of the first type cooperating with the seat 68, while a third chamber 69 is formed at the bottom above the front section 71 of the fourth chamber 64 and communicates with the fifth chamber, which is an expansion chamber; the rear surface of the valve head 67 is held by a first coil spring 73 against the bottom of the rear section 63 of the fourth chamber 64, the coil spring 73 being supported on the bottom of the front section 71 of the fourth chamber 64; the rear face of the circular valve head 67 has, close to its edge, an annular sealing zone which cooperates with a first sealing means 74 of a third type integral with the bottom of the rear section 63 of the fourth chamber 64; the tubular inner space of the valve 66 forms a sixth duct 75, the inlet orifice of which is flared and generally conical at the rear face of the valve head 67; the middle section of the valve head 67 has a second cylindrical pushrod 76 coaxial with the second bore 59, the pushrod 76 including a free end 77 and a capture end connected by a gasket 78 to the rear of the valve head 67 and fitted into the flared bore of the sixth tube 75 and sliding in a fourth swivel bore 79, the bore 79 interconnecting the bottom of the rear section 63 of the fourth chamber 64 with the bottom of the second bore 59; a fourth sealing means 80 of the first type integral with the fourth chamber bore 79 ensures the seal between the second chamber bore 59 and the sixth conduit 75; the second pushrod 76 has a diameter which is substantially smaller than the diameter of the second chamber 59 and an overall length such that the free end 77 of the second pushrod 76 opens into the bottom of the second chamber 59 when the valve head 67 mates with the third type of first sealing means 74 to isolate the sixth conduit 75 from the fourth chamber 64; when the second piston 45 is in the forward position, the free end 55 of the control rod 54 abuts the free end 77 of the second push rod 76 and thereby pushes the valve head 67 back away from the bottom of the rear section 63 of the fourth chamber 64, compressing the first helical spring 73 and thereby releasing the opening of the sixth conduit 75; the fourth chamber 64 communicates with the fifth chamber 72 via a sixth conduit 75; the fifth chamber 72 is of a cylinder of revolution, with a rear section 81, towards which the sixth conduit 75 opens, and a front section 82, from which the fifth cylindrical bore 83 of revolution starts; preferably, the fifth bore 83 is coaxial with the axis of symmetry of the fifth chamber 72. Fifth chamber 72 has a diameter slightly larger than valve body seat 68 and a much shorter length; the fifth bore 83 (fig. 2C) opens into a sixth cylindrical turnaround chamber 84 coaxial with the fifth bore 83, substantially equal in diameter to the valve body seat 68, and substantially twice as long as the fourth chamber 64; the fifth bore 83 has a decompression zone 85 of slightly larger diameter, opening into the sixth chamber 84, of length substantially equal to one third of the length of the fifth bore; a sixth chamber 84 having a rear section 86 into which the fifth chamber opens and from which at least one seventh conduit 87 starts, said conduit 87 being open to the atmosphere either directly or via a check valve 88; the sixth chamber 84 comprises a front section 89 into which a seventh rotating cylindrical chamber opens, which is coaxial with the seventh chamber 90 (fig. 2C, 2D), communicates with the sixth chamber 84 through a sixth rotating cylindrical bore 91, the diameter of which is significantly greater than the fifth bore 83 and smaller than the seventh chamber 90; the fifth chamber 83 (fig. 2C) serves as a guide and as a drive for the percussion hammer 92 forming a percussion device; the impact hammer 92 is composed of a hammer body 93 of small thickness and slightly smaller diameter than the diameter of the sixth chamber in which it is located, having a rear surface directed toward the rear section 86 of the sixth chamber 84 and a front surface directed toward the front section 89 of the sixth chamber 84; a third rotary cylindrical piston 94 coaxial with the fifth bore 83 is closely attached to the rear surface of the hammer body 93 and slides through the fifth bore 83; the third piston 94 has a diameter slightly smaller than the fifth bore 83 in order to obtain sufficient sealing to be pushed by the gas; a rotary cylindrical impact head 95 coaxial with the third piston 94 is fixed to the front surface of the hammer body 93; the impact head 95 is significantly larger in diameter than the third piston 94 and approximately one-quarter the length of the third piston 94; a second coil spring 96 supported on the front section 89 of the sixth chamber 84 and the hammer block 93 presses the hammer block against the bottom of the rear section 86 of the sixth chamber 84, thereby keeping the third piston 94 pressed into the fifth chamber 83.

The seventh chamber 90 (fig. 2D) includes a rear section 97 and a front section 98 communicating with the sixth chamber 84 via the sixth chamber bore 91, the bottom of the front section 98 having a seventh rotating cylindrical bore 99 of substantially equal diameter to the fifth chamber 83 coaxial with the seventh chamber 90, thereby allowing the seventh chamber 90 to communicate with the rear section 100 of the eighth chamber 101; the seventh chamber 90 contains a shock wave generating interface 102 which is comprised of a rotating cylindrical interface body 103 which is slidable within the seventh chamber 90 and includes a second type of fifth sealing means 104, the sealing means 104 separating the forward section 98 from the rearward section 97 of the seventh chamber 90. The interface body 103 has a rear surface facing the rear section 97 of the seventh chamber 90 and a front surface facing the front section 98 of the seventh chamber 90; the rear surface of the interface device body 103 includes an impact anvil 105 of the same diameter as the impact head 95 and having a length, when integrated with the length of the interface device body 103, substantially equal to the length of the impact head 95 integrated with the length of the hammer block 93; the length of the sixth chamber 91 is such that the free end 106 of the impact anvil 105 protrudes from the bottom of the forward section 89 of the sixth chamber 84 and such that the distance 108 (fig. 2C) separating the free end 106 of the impact anvil 105 from the free end 107 of the impact head 95 is substantially the same as the length of the third piston 94, when minimized to ensure a back-end guiding action of the third piston 94 at the end of the stroke in the fifth chamber 83; the interface body 103 has a front surface with a first shock wave transmitting device 109 shaped like a cylinder of revolution and coaxial with the seventh chamber 90, having substantially the same diameter as the third piston 94 and substantially the same length as the impact anvil 105; the length of the seventh bore 99 is sufficient to ensure proper guidance of the shock wave generating interface device 102; however, it is necessary that the first shock wave transmitting means 109 may protrude at the bottom of the rear section 106 of the eighth chamber 101; a third helical spring 110 bearing on the one hand the bottom of the rear section 97 of the seventh chamber 90 and on the other hand on the rear section of the body 103 of the interface device presses the body 103 of the interface device against a first annular damping (toroidal damping) device 111 bearing on the one hand against the edge of the front section 103 of the body 103 of the interface device and on the other hand surrounding the first shock wave transmission means 109 at the bottom of the front section 98 of the seventh chamber 90; the front section 112 of the eighth chamber 101 comprises an eighth chamber 113, the eighth chamber 113 being of a cylindrical shape of revolution, coaxial with the eighth chamber 101, having a diameter smaller by about half the diameter of the third piston 94 communicating with the outside; the eighth chamber 101 contains a shock wave guide head 115 of the second shock wave guide means 114, the shock wave guide head 115 being of a cylindrical shape of revolution having a diameter slightly smaller than that of the eighth chamber 101, its rear surface 116 being flat and its front surface 117 also being substantially flat and comprising a shock wave guide rod 118 passing through the eighth bore 113 and stably fixed in its centre and serving to guide the shock wave guide head 115 of the second shock wave guide means 114; when the single-shot mechanical shock wave generating device 1 (fig. 1A, 1B) is in operation, the rear section 116 of the shock wave head 115 is in contact with the free end 119 of the first shock wave transmission means 109, the front section 117 of the shock wave head 115 is in abutting contact with the second annular damping means 120, the damping means 120 surrounding the base of the shock wave guide rod 118 and resting on the one hand on the bottom of the front section 112 of the eighth chamber 101 and on the other hand on the front surface 117 of the shock wave head 115; the extension of the first shock wave transmitting means 109 and the length of the eighth chamber 101 are also determined in particular to meet these requirements; when the free end of the first shock wave transmitting means 109 presses against the second shock wave transmitting means 114 located in the eighth chamber 101, the interface means 102 is slightly pushed towards the rear section 97 of the seventh chamber 90, and the third helical spring 110 is also slightly compressed; the length and diameter of the shock wave guide rod 118 are generally dictated by the conditions of use; the maximum efficiency of the shock wave is obtained when the weight of the hammer 92 (fig. 2C) is equal to the weight of the second shock wave transmission device 114; the impedance adjustment can be carried out while taking into account the operating requirements, on the one hand by the diameter of the shock wave guide head 115 (fig. 2D) and, on the other hand, as much as possible by the length of the third piston 94.

When the gas pressure in the second duct 30 (fig. 1B) is less than the nominal value, the second calibrated spring 41 pushes the first piston 35 back towards the rear section 38 of the second chamber 36; the valve stem 31 penetrates the first chamber 34 of the head of the first piston 35 until the valve stem 31 abuts against the bottom of the chamber so that the gas supply valve head 32 is pushed back, thereby compressing the first calibration spring 33 and emitting gas from the micro gas cylinder 9; when the gas pressure in the second duct 30 (fig. 1C) is again built up, the first piston 35 is advanced, thereby compressing the second helical spring 41 until the valve stem 31 will loose contact with the bottom of the first chamber 34, although the valve head 32 is moved back under the action of the first calibrated spring 33 so as to rest against the second sealing means 29 of the first type; it should be noted that since the gas expansion is of the adiabatic type, the expanding gas, being cooler than the ambient temperature, heats up again causing its pressure to increase, thereby compressing the second calibration spring 41, until it can come into contact with the piston stop 40, the increase in pressure being limited by the additional back movement of the first piston 35. The gas injected into the second duct 30 (fig. 1B, 2A) flows into the third duct 42, from there into the third chamber 43 and pushes the second piston 45 back against the stop on the rear section 44 of the third chamber 43, unless it has come into contact; a second type of third seal 58 is then placed in the third chamber 43, allowing the gas to flow into the fourth conduit 56 and then into the fifth conduit 62 to reach the fourth chamber 64, which in turn is itself charged to a high pressure of, for example, 1500-; the valve head 67 is now pressed by the first helical spring 73 on the one hand and by the high gas pressure on the other hand against the first sealing means 74 of the third type; when the nominal pressure is reached in the fourth chamber 64, the shock wave generator is ready to operate. The shock wave generation is initiated by operating the hinged lever 51 (fig. 1C, 2B) which pushes the first push rod 49 in, which in turn pushes the second piston 45 back into the third chamber 43, the control rod 54 translating in the third chamber 43 until the second type of third sealing means 58 penetrates into and plugs the fourth duct 56, isolating the fourth chamber 64 from the high pressure gas source; then, as the first push rod 49 continues to be pressed in, the free end 55 of the control rod 54 penetrates into the second chamber 59 until it pushes the free end of the second push rod 76 in, and then separates the valve head 67 from the third type of first sealing means 74 and compresses the first helical spring 73; the gas thus flows into the sixth duct 75 and into the fifth chamber 72, pushing back the third piston 94 (fig. 1C, 2C), the third piston 94 being previously in the pressed-in position in the fifth chamber 83 by the action of the second helical spring 96; the hammer striker 92 is thus driven at high speed into the sixth chamber 84, thereby compressing the second helical spring 96, while the impact head 95 impacts the impact anvil 105 (fig. 1D, 2D) of the interface device 102, generating a shock wave which propagates itself successively in the interface device body 103, then into the first shock wave transmission device 109, and then into the rear section 116 of the shock wave guide head 115, in order to further propagate itself in the shock wave guide rod 118 and to the object to be fragmented.

At the end of the stroke of the third piston 94 in the fifth chamber 83, the decompression zone 85 opens gradually and gas begins to escape into the rear section 86 of the sixth chamber 84 and is drawn outside through the check valve 88 (if any) and through the seventh duct 87: the pressure downstream of the second type of third sealing device 58 becomes substantially equal to atmospheric pressure; the second helical spring 96 thus pushes the hammer 92 and the third piston 94 back into the fifth chamber 83; the first helical spring 73 pushes the release valve 65 back into the bottom of the rear section 63 of the fourth chamber 64 (fig. 1B, 2B) and restores the initial seal by means of the first sealing means 74 of the third type when the second push rod 76 is again in its initial position by releasing the operation of the hinge rod 51, so that the second piston 45 can move towards the rear section 44 of the third chamber 43 under the effect of the high pressure of the third chamber 43; the displacement movement of the second piston 45 causes a movement of the control rod 54 until the third sealing means 58 of the second type escape from the fourth duct 56, allowing gas to be supplied to the fourth chamber 64; the pressure drop in the third chamber 43 causes a pressure drop in the third duct 43 and the second duct 30, so that the aforesaid air supply cycle starts.

In a modified embodiment of the invention, the third chamber 43 (fig. 2B) is interconnected to the outside by a second calibrated relief valve 121, in order to avoid possible overpressures associated with post-expansion gas reheating or leaks at the valve head 32 (fig. 1A) and at the first sealing means 19 of the first type.

For reference, the one-shot mechanical shock wave generating device 1 for fragmenting urethral stones has a fourth chamber 64 with a volume of preferably 1-3cm3 and a percussion hammer with a weight of about 10 grams.

In a further embodiment of the invention, it is necessary to generate a sustained shock wave train when used in situations other than those involving urethral stone fragmentation; for this purpose, a continuous shock wave triggering device is inserted between the articulated lever 51 and the first push rod 49; this triggering device is actuated by means of a lever 51; this may, for example, initiate several successive shock waves of a number and rhythm predetermined by the successive operation of the first push rod 49 without releasing the articulated lever 51.

Claims (14)

1. A single-shot mechanical shock wave generating device (1) employing a percussion device (2) driven by gas and impacting at high speed a generating device (3) generating shock waves which are transmitted via a shock wave transmitting device (4) to an object to be comminuted with which said shock wave transmitting device (4) is in direct or indirect contact, characterized in that the percussion device (2) is driven by means of expansion of high-pressure gas introduced into a accumulating device (5) before each generation of a shock wave, that the accumulating device (5) is provided with high-pressure gas from a separate gas storage device (6) at very high pressure by means of a gas expansion device (7), a gas supply device (25, 26, 30, 42, 56, 62) and a first sealing device (19, 37, 46, 60, 70, 74, 80), that the gas stored in the accumulating device (5) is released by manual manipulation of a control device (8), the control device (8) firstly seals the communication between the separate gas storage device (6) and the gas expansion device (7) on the one hand and the communication between the separate gas storage device (6) and the accumulation device (5) on the other hand by means of the second sealing device (58) and secondly forms the communication between the accumulation device (5) and the percussion device (2), and the return of the percussion device (2) to the initial state is ensured by the release of the accumulated energy by the mechanical energy accumulation device (73, 96) during the shock wave generating cycle, and the return of the control device (8) to the initial state is ensured by the high gas pressure which has been retained in the expansion device (7) and the respective gas supply device part (25, 26, 30, 42).

2. A device according to claim 1, characterized in that the gas used at the operating temperature and pressure and chemically adapted to the application is obtained from a high-pressure gas cylinder forming a separate gas storage means, which is connected to the single-shot mechanical shock wave generating means (1) via a conduit and which is brought from a very high pressure to the operating pressure via a pressure relief valve constituting the expansion means.

3. Single-click mechanical shock wave generating device according to claim 1 or 2, characterized in that the gas used is stored in a miniature gas cylinder (9) forming a separate gas storage means (6), which is attached directly to the single-click mechanical shock wave generating device by means of a frame base (15), which frame base (15) consists of two halves, a front half (16) and a rear half (20), the front half (16) having a bottom section provided with a calibrated receptacle (18) comprising a piercing means (20), the rear half (21) consisting of a clamping means (22), which allows the piercing means (20) to slide and which communicates the gas cylinder via a first conduit (26) with an integrated expansion means (27) forming the gas expansion means (7).

4. Single-click mechanical shock wave generating device according to claim 1, characterized in that the integrated expansion means consists of a first chamber (28), into which first chamber (28) a first duct (26) opens, and a second duct (30) starting from the first chamber (28), in which second duct (30) there is a valve stem (31) freely slidable, the head (32) of which valve stem located in the first chamber (28) is pushed back by a first calibrated spring (33), while the free end of the valve stem (31) is driven by a cylindrical first piston (35) acting as a pusher for the valve stem (31), while the first piston (35) slides in a second chamber (36), the second chamber (36) acting as a guide for a second calibrated spring (41) acting as a pusher for the first piston (35).

5. The single-stroke mechanical shock wave generating device as claimed in claim 1, characterized in that the control device (8) consists of a third chamber (43) into which a third duct (42) communicating with the second duct (30) opens and in which a second piston (45) slides, said second piston (45) comprising a first push rod (49) allowing said piston to be pushed into the third chamber (43) by means of a hinged rod (51), while the second piston (45) has a control rod (54) with an open end (55), the control rod (54) passing freely through a fourth duct (56), the fourth duct (56) comprising a third sealing device (58) of a second type, the third sealing device (58) plugging the fourth duct (56) upstream of a fifth duct (62) opening into the fourth duct (56) when the second piston (45) is pushed into the third chamber (43), and the free end (55) engaged in the second chamber (59) rests against the bottom (6) of said chamber.

6. The single click mechanical shock wave generating device according to claim 1, wherein the accumulating means (5) is composed of a fourth chamber (64), the fifth conduit (62) opens into the fourth chamber (64), wherein a relief valve (65) is included, the relief valve (65) is composed of a tubular valve body (66) forming a sixth conduit (75), and a hollow valve head (67) and a valve body seat (68) sliding in a third bore (69) opening into the fifth chamber (72), and the valve head (67) is kept sealed by means of a first coil spring (73) constituting the mechanical energy accumulating means, the valve head (67) includes a second push rod (76) with a free end (77) sliding in the fourth bore (79) and opening into a bottom section of the second bore (59), and the free end (77) of the second push rod (76) is pushed back when the free end (55) of the control rod (54) abuts against the bottom (61), the second push rod (76) pushes back the valve head (67) and releases the opening of the sixth conduit (75) by compressing the first coil spring (73), thereby communicating the fourth chamber (64) with the fifth chamber (72).

7. The single-click mechanical shock wave generating device as claimed in claim 1, characterized in that the percussion device comprises a fifth chamber (72) into which a sixth conduit (75) leads and which communicates with a fifth chamber bore (83) opening into the sixth chamber (84), comprising a pressure-reducing zone (85) opening into the sixth chamber (84), at least one seventh conduit (87) opening into the atmosphere either directly or via a non-return valve (88) starting from the sixth chamber (84), the fifth chamber (83) acts as a guide and drive for the hammer (92), the hammer (92) being formed by a hammer body (93), a third piston (94) sliding in the fifth chamber (83), and a striking head (95) with a free end (107), a second helical spring (96) forming a mechanical energy accumulation device being pressed against the hammer body (93) in order to keep the third piston (94) pressed into the fifth chamber (83).

8. The single-click mechanical shock wave generating device as claimed in claim 1, characterized in that the shock wave generating device (3) comprises a shock wave generating interface means (102) comprising an interface means body (103), the body (103) slides in a seventh chamber (90) communicating with the sixth chamber (84) via a sixth chamber (91), and the interface body (103) has a percussion anvil (105) passing through the sixth chamber (91), having a free end (106) located in the sixth chamber (84) and a first shock wave transmission means (109) with a free end (119), the shock wave transmission means (109) passing through the seventh chamber (99) interconnecting the seventh chamber to the eighth chamber (101), the free end (119) of the first shock wave transmission means being held in contact with the rear surface (116) of the shock wave guide head (115) by a third helical spring (110) located in the eighth chamber (101).

9. The single-shot mechanical shock wave generating device as claimed in claim 1, characterized in that the shock wave transmitting means (4) comprises a second shock wave guide means (114), the guide means (114) comprising a shock wave head (115) in the eighth chamber (101), the shock wave head (15) having a shock guide rod (118) extending through an eighth bore (113) leading to the shock wave head (115) and leading to the outside.

10. Single click mechanical shock wave generating device according to claim 1, characterized in that the gas injected under high pressure through the second tube (30) flows into the third tube (42) and then into the third chamber (43), and, if the second piston (45) is trapped in the third chamber (43), pushes back the second piston (45), which releases the third sealing means (58) of the second kind from the fourth tube (56), allowing gas to flow into the fifth tube (62) in order to fill the fourth chamber (64) with high pressure gas, while the valve head (67) remains sealed due to the pressure exerted by the first coil spring (73) on the one hand and by the high pressure on the other hand, until the nominal pressure is reached in the fourth chamber (64), when the single click mechanical shock wave generator (1) is ready to operate.

11. The single-stroke mechanical shock wave generating device as claimed in claim 1, characterized in that the generation of the shock wave is initiated by operating a hinged lever (51), the hinged lever (51) pressing in a first push rod (49) which pushes the second piston (45) back into the third chamber (43), the control rod (54) translating in the third chamber (43) until a third sealing means (58) of the second type penetrates into and plugs the fourth duct (56), and then as the first push rod (49) continues to be pressed in, the free end (55) of the control rod (54) penetrates into the second chamber (59) until the free end (77) of the second push rod (76) is pushed in, whereby the valve head (67) separates and compresses the first helical spring (73), and then gas flows into the sixth duct (75) to penetrate into the fifth chamber (72), whereby the third piston (94) is pressed back violently, the second coil spring (96) is compressed, whereupon the impact head (95) impacts the impact anvil (105) of the interface device (102), generating a shock wave, which then continues to transmit itself into the interface device body (103) and to the shock wave guide head (U5) via the first shock wave transmission device (109) to finally propagate itself via the shock wave guide (118) until the object to be fragmented is impacted.

12. The single stroke mechanical shock wave generating apparatus of claim 7, 10 or 11, wherein at the end of the stroke of the third piston (94), the decompression zone (85) is gradually opened, gas starts to escape into the sixth chamber (84) and is discharged to the outside through the seventh pipe (87), while the pressure downstream of the third sealing means (58) of the second type plugging the fourth pipe (56) becomes substantially equal to atmospheric pressure, and then the second coil spring (96) can push back the hammer (92), the third piston (94) of the hammer (92) penetrates into the fourth chamber (83),

13. the single stroke mechanical shock wave generating device as claimed in claim 10, wherein once the hinged lever (51) is released, the second piston (45) is pushed back by the high pressure gas existing in the third chamber (43), the second push rod (76) is released, so that the release valve (65) is released and pushed back by the first coil spring (73) to restore the initial sealing, and then the fourth tube (56) is released, so that the high pressure gas can refill the fourth chamber (64) in preparation for generating another shock wave.

14. The single-shot mechanical shock wave generating device as claimed in claim 1, characterized in that the gas used is a carbon-containing gas stored at an extremely high pressure of about 7000kPa, the high pressure in the fourth chamber (64) is about 1500-³The impact hammer (92) weighs about 10 grams.