The invention relates generally to a focusing system for a device for generating shock waves that is connected to the output of the shock waves and more particularly to directing the shock waves.
Devices for generating focused acoustic waves generally involve reflecting the shock waves between two reflection planes that are aligned in relation to one another in such a way that all reflected portions of the shock wave are combined at a common focal point. The focal point is the treatment plane of the human or animal body.
Devices of this kind can be used, for example, for lithotripsy of kidney stones and have been a component of medical technology for several decades. However, conventional devices for generating shock waves suffer from certain disadvantages. For example, the kidney stone that is the target of the lithotripsy has to be positioned exactly at the focus of the shock wave to both shatter the kidney stone with sufficient energy and to exclude the possibility of destruction of adjacent human tissue by incorrect positioning of the focal point. The treatment often takes a long time, and the patient receiving therapy must remain as immobilized as possible in the targeted focal point. Any movement by the patient therefore requires realignment of the focal point of the device for generating shock waves with the treatment focus inside the patient.
The invention provides a focusing system for a device for generating shock waves of the aforementioned kind such that individually created shock waves are split into multiple shock wave components without the individual components of the reflected or combined shock wave being brought together in a single focal point. Instead, the components of the reflected or combined shock waves pass through the patient in such a way that the reflected shock wave is combined into a line of focal points in an axial emission direction.
In one aspect of the invention, a reflector, a lens, or a shock wave generation system can possess a curvature in accordance with the length of the focal line and the therapy. Further, the device for generating the shock wave can be arranged so it can move in relation to the focusing direction.
The invention allows for the precise calculation of the arrangement of the individual reflection mirrors and for accurate positioning of the focal lens segments. Therefore, each primary shock wave is split into specific reflected components, each of which takes a different path, with the effect that the components of a shock wave pass through a plurality of focal points outside the focal direction. These individual focal points form a focal line that runs in line with the axis of symmetry of a rotationally symmetrical body. The treatment focus of the patient is positioned within the focal line.
One advantage of positioning the patient on a focal line of this type is that the therapist can apply treatment largely independently of the depth information relating to the treatment location. Furthermore, certain geometries of the reflector or the lens segments give rise to both tensile and pressure wave components along the focal line, which can be used in a targeted manner for lithotripsy of kidney stones and for healing or stimulating bone tissue, insertion tendonitis, wound healing, or other therapies. The superimposed or time-sequential pressure and tensile or tensile and pressure wave components lead to more rapid therapeutic successes in the medical therapy of a patient and make it possible to reduce the shock wave energy required, thereby reducing the treatment time while the neighboring tissue is not affected or not impaired to any significant extent.
Furthermore, the patient does not have to be arranged precisely in a focal point or fixed in one position for the duration of treatment. Rather, the treatment focus is significantly loaded in the area of the focal line with the effect that the kidney stone, for example, is shattered simultaneously with its concretions. This process means the treatment focus can be arranged in the area of maximum convergence without the need for the patient to be moved and repositioned
a and 3b illustrate a focusing system combining shock waves by means of lens segments, in which the shock waves are generated by a device, according to exemplary embodiment.
Referring to the drawings, in which like numerals represent like elements, aspects of the exemplary embodiments will be described.
The focusing system 11′ is configured as a rotationally symmetrical body 12. The device 1 is arranged on the axis of symmetry 13 of the rotationally symmetrical body 12 so that the source of the device 1 for generating shock waves 2 lies exactly on the axis of symmetry 13.
The inner surface of the rotationally symmetrical body 12 has a plurality of reflection mirrors 14 that are shown schematically. Therefore, a certain shock wave component 3 of the shock wave 2 is assigned to each reflection mirror 14, so that, because of the prevailing geometrical alignment of the reflection mirror 14, the shock wave component 3 of the shock wave 2 is reflected according to the physical law of the angle of incidence (a, B)=angle of reflection (a, B). The shock wave 2 is therefore split into primary shock wave components 3, before they strike the surface of the focusing system 11′, and secondary components 4 that are reflected by the reflection mirrors 14 of the focusing system 11′. The rotationally symmetrical body 12 has an output plane 17 through which all the reflected secondary components 4 of the shock waves 2 pass.
Outside the focusing system 11′, on the right next to the output plane 17, the reflected secondary components 4 of the shock wave 2 pass through a plurality of focal points 15 because each secondary component 4 of the shock wave 2 is combined in a different focal point 15 lying on the axis of symmetry 13. Each of the focal points therefore forms a common focal line 16 that runs in line with the axis of symmetry 13. The focal line 16 is therefore created outside the focusing system 11′ and has a length a of approx. 0 to 25 cm.
Pressure and tensile wave components of the reflected secondary components 4 of the shock wave are superimposed on the focal line 16. In the shock wave arrangements described herein with reference to
Various focal lines and lengths are recommended for different shock wave therapies according to the anatomical conditions, with measurements taken starting from the output plane 17:
a and 3b show that the individual primary shock wave components 3 or the shock wave 2 are combined by a focal lens 21 with a plurality of lens segments 22, with the effect that the primary shock wave components 3 of the shock wave 2 are deflected into a plurality of focal points 15. The lens segments 22 can be set and have different focusing properties for the shock wave 2.
All known generating devices can be used as the device 1 for generating shock waves 2, in addition to the examples in
In
Accordingly, the configuration of the primary and secondary shock wave components 3 and 4 does not change because the performance parameters of the device 1 are kept constant. However, the movement of the device 1 relative to the focusing system 11′ allows a larger spatial treatment center to be covered because the focal line 16 can be extended by moving the device 1, for example, in an axial direction corresponding to a movement of the device 1 to the west (W) or east (O), causing the primary and secondary shock wave components 3 and 4 to stretch, and moving the device 1 to the north (N) or south (S) moves the focal line 16 in a lateral direction. A lateral arrangement of the shock wave components 3 and 4 of this kind can be seen by the designations F1S, FiS, and FNS. In this case, the number 1 indicates it is the first focal point on the focal line 16, the letter i indicates the middle focal point, and the letter N indicates the last focal point of focal line 16. The other letters N, O, S, W indicate the focal point created by the corresponding movement of the device 1, for example, north.
Number | Date | Country | Kind |
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10 2005 017 724 | Apr 2005 | DE | national |
This patent application claims priority to and is a national stage application of PCT Patent Application No. PCT/EP2006/003327, filed Apr. 11, 2006 and titled “Focusing System for a Device for Producing Shockwaves,” which claims priority to German Patent Application No. DE 44 21 938 C2, filed Apr. 15, 2005 and titled “Focusing System for a Device for Producing Shockwaves.” The disclosure of each of the above-identified patent applications is hereby fully-incorporated herein by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2006/003327 | 4/11/2006 | WO | 00 | 1/23/2009 |