Device for producing a fluid jet used especially to remove biological tissue, and use thereof

[0001] This invention concerns a fluid jet device for producing a liquid jet especially to remove biological tissue, with an appliance in which a pump set is arranged for producing high liquid pressure within a range of up to 800 bars. A pressure supplying source can be connected to the fluid jet device for producing the liquid jet, and also connected to a nozzle which produces the liquid jet by a flexible connecting line. The discharge orifice of the nozzle is between 20 and 120 micrometers in diameter.

[0002] The generic type surgical device according to specification EP-A-0 232 678 has a pump set which generates pressure and is connected by a flexible metal line to a nozzle for delivering a liquid jet, and the initial speed of the jet is equal to or greater than the mach number. This pump set as well as the other accessories are normally arranged and mounted within a housing. Since such a liquid jet cutting device is used especially in surgery, as for example in liver operations for destroying liver parenchymas or the like, the design of this device, together with the pressure supply system designed as a compressor for the pump set, is appropriately solid and heavy.

[0003] However, the purpose of this invention is to create a device within the generic concept described at the beginning, but which is also particularly suitable, in its portable version carried by operators, for ambulatory treatment of patients. It must also be possible to use this device for new treatment applications not only administered by doctors and medics but also carers, paramedics and the like.

[0004] The invention achieves this purpose by the fact that the weight of the fluid jet device and the separate pressure supply source provided for the pump set is such that they are particularly suitable for use in portable applications and can accordingly be carried by hand.

[0005] This device according to the invention can be used for ambulatory treatment of patients practically independent of the locations where such treatment could not be performed with the use of existing equipment.

[0006] In addition, the purpose is also achieve in accordance with the invention thanks to the fact that this liquid jet can be used for cleaning wounds or treating wounds such as burns, abscesses, sores or the like.

[0007] The portable design of this device can thus be used for treating patients outside operating rooms, including those who are not hospitalized.

[0008] It has become surprisingly apparent that wounds treated by the fluid jet heal faster than those treated by conventional means.

[0011] FIG. 1 shows a block diagram of a fluid jet device 10 for producing a fluid jet to be used especially to remove biological tissue. This fluid jet device 10 can be used to great advantage for cutting away parts of tissue, especially parenchymal tissue, for example in liver, kidney and similar operations.

[0012] The device 10 has a housing 11 which contains a pump set 20 for generating a high pressure of the cutting fluid up to 800 bar. This pump set 20 is preferably designed as a conventional differential piston pump supplied with compressed air from a pressure supply source such as a compressed air main or a separate compressed air generating device. The pump 20 includes a first larger cylinder 21 in the form of a low pressure section with a large drive piston 27 reciprocating within it, and a second smaller high pressure cylinder 22 arranged coaxially in relation to the first cylinder. The second cylinder 22 includes smaller plunger piston 28 connected to the drive piston 27. The first larger cylinder 21 is connected to an air feed line 23 and an outlet valve 24 for compressed air while the high pressure cylinder 22 is connected to a feed line 25 and an outlet line 26 for the fluid. The feed line 25 and the outlet line 26 each lead to a connection plug 30, 31 accessible outside the housing 11. The first plug (fluid inlet) 30 is connectable to a hose 32 connected to a fluid tank (fluid source), and the second plug (fluid outlet) 31 is connectable to a flexible metal hose 33. The fluid tank contains a physiological solution, for example a sterile common salt solution with approx. 0.9% of common salt or similar component. A nozzle provided with a handle for manual operation of this cutting equipment, producing the fluid jet, is attached at the end of this flexible metal hose 33.

[0013] According to the invention, the total weight of the housing 11 with the pump 20 and the pressure supply source for the pump 20 separately connectable to the pump set 20 is such that they are suitable especially for portable use and can each be carried by hand. The pressure supply source 40 can operate independently of a main line or a gas pressure main line.

[0014] Furthermore, it is precisely due to the portable design of this device that a wound can be cleaned or treated with this fluid jet very economically in the case of burns, abscesses, sores or the like.

[0015] Moreover, a pressure relief valve 35, connected via a connecting line 36 to the outlet line 26 of the pump, is attached at the high-pressure outlet of the pump set 20.

[0016] The whole pump set 20 is advantageously mounted on a bearing element 15 within the housing 11 indicated by a dash dot line. This pump set 20 includes the differential piston pump with cylinders 21, 22 and the pistons 27, 28 arranged within them, the high-pressure side feed line 25 and outline 26 as the lines connecting to the connection plugs 30, 31, and the air-operated pressure relief valve 35. The compressed air inlet (feed) line 23 and the outlet valve 24 are also arranged at the cylinder 21.

[0017] Compressed air is carried from a pressure supply source 40, a pressure gauge 41, a safety pressure reduction valve 42, a regulating valve 43, an operating pressure gauge 44, and a control valve 50 through the air feed line (pressure supply line) 23 to the inlet at the LP cylinder 21.

[0018] The pressure supply source 40 can be a gas bottle containing gas under a pressure of between 4 and 10 bars, feeding gas to the low pressure cylinder 21. The gas cylinder is advantageously in the form of a plastic bottle which can be easily carried by hand.

[0019] The pressure supply source 40 and pump set 20 are switched off or into operation to produce the water jet by a conventional pedal 49. This pedal 49, which is provided with couplings 46 connected to the control line 47, operates a two-way valve 45 which causes, in the closed state shown, the valve 50 to be closed with the pressure relief valve 35 reducing the water pressure and, thus, with no water jet flowing. On the other hand, with the foot pedal 49 pressed down and thus the valve 45 open, valve 50 is open and valve 35 closed. This causes the pump set to be switched on and water to be delivered to the nozzle. On releasing the pedal 49, valve 50 closes automatically and switches the fluid jet device automatically to its pressureless state.

[0020] The nozzle with the handle for the actual operating action to produce the water jet (not shown here in detail) is made of high-quality metal no matter whether it is used for cutting out tissue or for the treatment of wounds. This offers a further advantage within the framework of the invention due to the fact that this nozzle can be used many times. Thus, the maintenance costs are lower than in the case of one-off use. Furthermore, the diameter of the nozzle outlet is between 20 and 120 micrometers.

[0021] The invention is sufficiently explained on the basis of the above embodiments. Nevertheless, it can be made in other versions. For example, the pump set can be designed differently than presented here. In principle, an electrically operated pump could also be used as the pressure supply source.