Prostate Behandlung von Schockwellentherapie

Stosswellentherapie zur Fersenspor Behandlung - NDR Visite

Urologie Prostatakrebs

Die Erfindung betrifft ferner ein Verfahren zur Überwachung der Fragmentierung eines Zielobjekts 18 mit einem derartigen Lithotripter The invention further relates to a method Prostate Behandlung von Schockwellentherapie monitoring the fragmentation of a target object 18 with such a lithotripter Moreover, the invention relates to a method according to the preamble of claim sixteenth.

Lithotripter are now widely used as medical devices for disintegrating concretions such as kidney stones, in the body of a patient using focused shock waves. Such lithotripter are sold commercially by the applicant, for example, under the name "Dornier lithotripter S" or "Dornier Compact Delta". In all these devices the calculus must be located before starting treatment so that the patient can be positioned by means of a movable deck so that, for example, kidney stone is the focus of the shock waves generated by the shock wave generator of the lithotripter.

Diese anfängliche "Justage", dh Positionierung des Patienten erfolgt üblicherweise mit einer bildgebenden Ortungsvorrichtung, etwa einem bildgebenden Ultraschall-Scanner oder einer Röntgenortungsvorrichtung. This initial "adjustment", that positioning of the patient is usually performed with an imaging position-finding device, such as an ultrasound imaging scanner or an X-ray locating device. This Prostate Behandlung von Schockwellentherapie in addition to the initial first location of the calculus before the ESWL extracorporeal shock wave lithotripsy or ESWT treatment extracorporeal shock wave therapy also to continuously monitor the position of the calculus during the course of treatment, to ensure that it does not slipped in the body of the patient or has moved to a different location, or that the patient has not moved on his bed, so that the calculus may no longer in the focus of the shock waves.

Üblicherweise wird die genannte bildgebende Ortungsvorrichtung auch dazu verwendet, während des Verlaufs der Behandlung den Erfolg der Lithotripsie zu überwachen, Prostate Behandlung von Schockwellentherapie die Fragmentierung des Zielobjekts. Usually, said imaging locating device is also used to monitor the success of lithotripsy during the course of treatment, ie the fragmentation of the target.

Da eine Behandlung typischerweise ca. Since treatment typically lasts about 30 minutes, can not be continuously X-rayed, but at most at intervals of Prostate Behandlung von Schockwellentherapie to 5 minutes because of the excessive radiation exposure.

Shifts in the meantime, the target object, for example, by movement of the patient, it is up to the next control recording of the body affected by the shock waves without the target object is further fragmented, since it is no longer in the shock wave focus.

In lithotripters in which an ultrasound scanner is used as imaging locating device, this can indeed be used continuously for visualization of the target, but the positioning is partly because of the image quality is often much more difficult Prostate Behandlung von Schockwellentherapie with X-rays, so that even experienced medical professionals often have difficulty that to identify target or even to assess its degree of fragmentation.

However, it can not determine the effect of the shock waves on the target object itself. Fundamental problems such as lack of coupling of the shockwave device to the patient's body, shadowing of shock waves, for example, ribs, etc.

Daher wurden im Stand der Technik bereits Ultraschall-Dopplerverfahren zur kontinuierlichen Trefferkontrolle vorgeschlagen. Therefore ultrasonic Doppler methods have been proposed for the continuous monitoring results in the prior art. Namely, it was assumed that the calculus in the human body carries out a macroscopic motion on a hit due to the momentum transfer of the shock wave. Irradiation of the target object with the ultrasonic waves and measures the reflected ultrasonic waves to it, then these macroscopic motion manifests itself in a Doppler shift of the frequency of the reflected waves.

These devices have in common that the ultrasound transducer emits ultrasound waves into the body, detects light reflected from the body to the ultrasonic transducer ultrasonic waves, a Doppler signal Prostate Behandlung von Schockwellentherapie from the transmitted and received ultrasonic waves will generate a Doppler signal Prostate Behandlung von Schockwellentherapie evaluates, with essentially the amount of frequency shift of the reflected signal relative to the transmitted wave is calculated and from this to deduce the accuracy.

Diese Vorgehensweise weist verschiedene Nachteile auf: This approach has several disadvantages:. It is already known in the prior art, ie that containing the Doppler signal just in the vicinity of its zero time, Prostate Behandlung von Schockwellentherapie after the transmission of the shock wave artifacts. Means for time synchronization between Prostate Behandlung von Schockwellentherapie shock wave generator and the Doppler signal unit, Prostate Behandlung von Schockwellentherapie these devices complicated and expensive.

Darüber hinaus kann es in der Umgebung von starken Streuern wie einem Konkrement im Dopplerspektrum zu dem sogenannten Prostate Behandlung von Schockwellentherapie kommen. Durch Zweifachreflektion wird die Bewegung eines Streuers zusätzlich in entgegengesetzer Richtung registriert. Dies führt zu einem zusätzlichen Betrag, der dem an der Nutlinie gespiegelten Nutzsignal entspricht.

This results in an additional amount corresponding to the mirrored at the grooved line useful signal. Wegen der Kurzlebigkeit des Prozesses und der starken Artefakte können den Spektren nicht einfach Geschwindigkeits-Zeit-Verläufe und somit eine Trefferinformation zugeordnet werden.

Because of the transient nature of the process and strong artifacts velocity-time curves and thus a hit information can not simply be assigned spectra. It is therefore an object of the present invention to provide a lithotriptor of the type mentioned, the information with regard to the Prostate Behandlung von Schockwellentherapie and disintegration control determined from the Doppler signal, and brings to display and requires no complicated means for synchronizing the shock wave generator with the Doppler signal unit.

This object is achieved according to the invention by a lithotripter with the features of patent claim 1 and by a corresponding method with the features of claim sixteenth. According to the invention, the Doppler signal unit is adapted to determine the time duration Prostate Behandlung von Schockwellentherapie the Doppler signal and to provide an associated time signal.

The time duration of the Doppler signal is largely independent of the above-mentioned artifacts and a Prostate Behandlung von Schockwellentherapie measure for a hit or a miss. In addition, can be determined by the display of this parameter on the treatment and the disintegration effect. The configuration of the Doppler signal unit according to Prostate Behandlung von Schockwellentherapie invention is based on new in vitro and clinical experiments, in each of which the entire time course of the doppler signal, that is Prostate Behandlung von Schockwellentherapie in the reflected signal frequency shift was investigated with respect to the transmitted signal as a function of time.

In the in vitro experiments, the question of whether and how accurately a shock wave has hit the target object was monitored with high-speed photography. The most important result was consistently found that the time duration of the Doppler signal represents a characteristic measure for a "hit". In other words, may be removed from the associated time duration signal which is outputted from the inventive Doppler signal unit, whether and to what extent a shock wave has hit the target object.

In principle here is that the time duration of the Doppler signal increases to the target object with stronger effect of the shock wave. Zerfällt das Prostate Behandlung von Schockwellentherapie, beispielsweise ein Konkrement, im Laufe der Behandlung in eine zunehmende Zahl von kleineren Fragmenten, so nimmt die Zeitdauer des Dopplersignals zu.

Decomposes the target object, such as a calculus, in Prostate Behandlung von Schockwellentherapie course Prostate Behandlung von Schockwellentherapie treatment in an increasing number of smaller fragments, the duration of the Doppler signal increases. Durch die Zunahme der Signallänge im Verlauf der Behandlung kann die Desintegrationswirkung der Schockwellentherapie abgelesen werden. The increase in signal length in the course of treatment, the disintegration effect of the shock wave therapy can be read.

At this point is to address the underlying mechanisms of interaction between the shock wave and the target object: In the prior art has hitherto been assumed that there is only one interaction mechanism, namely a macroscopic motion of the calculus when it is successfully hit by the shock wave.

However, the recent studies above show that this mechanism is only one of several mechanisms: while it actually observed such a macroscopic movement of the calculus, particularly when it is already partly or even largely fragmented.

Especially at the beginning of treatment if the calculus is still largely unfragmented, but dominate other Prostate Behandlung von Schockwellentherapie, namely in particular shooting out of fragments of the calculus and the occurrence of cavitation bubbles to the calculus around with a successful hit.

All these mechanisms lead to the Doppler shift in the frequencies of the reflected sound waves and hence the observed Doppler signal and cause its duration is greater, the stronger the interaction between the shock wave and stone and the stronger the concrement has already been fragmented. Hinsichtlich der Weiterverarbeitung der im Zeitdauersignal enthaltenen Trefferinformation sind zahlreiche Vorgehensweisen möglich: With regard to the further processing of the hit information contained in the time signal numerous approaches are possible:.

Die momentanen Dopplersignale werden, wie oben bereits erwähnt, in einem Koordinatensystem dargestellt, dessen Abszisse die Zeit und deren Koordinate die per Fourier-Transformation aus den reflektierten Ultraschallwellenamplituden berechnete Frequenzverschiebung angibt. The instantaneous Doppler Prostate Behandlung von Schockwellentherapie are, as already mentioned above, in a coordinate system whose abscissa is time and the coordinate indicating the calculated by Fourier transformation from the reflected ultrasonic wave amplitudes of frequency shift.

Insbesondere kann im Verlauf der gesamten Behandlung die gemessene Zeitdauer der Dopplersignale in Form einer fortlaufenden Anzeige dargestellt werden, um die Entwicklung der Dopplersignallänge zu verfolgen. In particular, the measured time duration of the Doppler signals Prostate Behandlung von Schockwellentherapie represented in the form of a continuous display in the course of the entire treatment, in order to follow the evolution of the Doppler signal length.

Mit erfolgreicher fortschreitender Zertrümmerung des Zielobjekts sollte die Dopplersignallänge kontinuierlich zunehmen. With successful progressive destruction of the target object, the Doppler signal length should increase continuously. Als Anzeigevorrichtung kann hierbei gegebenenfalls der Bildschirm verwendet werden, auf dem auch die von der bildgebenden Ortungsvorrichtung gelieferten Bilder dargestellt werden.

Takes the signal length away, be this is a strong indication that the calculus has moved out of the shockwave focus, either through a Konkrementbewegung for example the movement of a kidney stone within the kidney of the patient or by shifting the patients themselves. As display device, the screen may in this case be optionally used, on which also the images supplied by the imaging device location are Prostate Behandlung von Schockwellentherapie.

Zusätzlich oder alternativ dazu kann der Alarm dann ausgelöst werden, wenn das Zeitdauersignal einen negativen Trend aufweist. Additionally or alternatively, the alarm can be triggered if the time duration signal has a negative trend. Bei einer Desintegration ist nämlich von einer steigenden Signallänge auszugehen.

At a disintegration is in fact assumed Prostate Behandlung von Schockwellentherapie increasing signal length. Alternatively or additionally, it may be provided that the shock wave generator is connected to the Doppler signal unit and adapted to stop the generation of shockwaves as a function of time or continue signal. Prostate Behandlung von Schockwellentherapie this way, an automatic shutdown of the shockwave generator can be Prostate Behandlung von Schockwellentherapie when apparently the target object no longer in the shock wave focus.

Thus is avoided regardless of the attention or the reaction time of the lithotripter-use medical staff an unnecessary burden on the patient's body by shockwave misses. Der Ultraschall-Transducer kann dann unabhängig von anderen Teilen des Lithotripters zur Optimierung des Dopplersignals justiert und in der optimalen Position festgestellt werden. The ultrasonic transducer can then be adjusted independently of other parts of the lithotripter for optimizing the Doppler signal and determined in the optimum position.

In particular, this can be ensured that the ultrasonic transducer is aimed at the shockwave focus. As an alternative to this so-called isocentric scanner guidance even a so-called in-line transducers can be used, that is an ultrasonic transducer, which is integrated in the shockwave source. Grundsätzlich ist hierbei folgendes zu beachten: Durch den einstellbaren Halter wird lediglich eine Linie festgelegt, entlang der sich beispielsweise bei einem PW-Verfahren pulse wave ein ausgesandter Ultraschallpuls im Gewebe ausbreitet und Echos generiert werden.

Basically, the following case is considered: The adjustable holder, a line is simply set, propagates along the, for example, in a PW pulse wavea beam emitted ultrasound pulse in the tissue and echoes will be generated.

In the isocentric construction is ensured that the shock wave focus, ie the target area, located on this line. By known means, such as a displacement sensor, the distance of the transducer can be determined to focus. Due to the known transit time of ultrasonic pulses in the tissue, a time window can be determined from this distance in turn define the cutting out that portion of the echo that has been generated in the target area.

Alternativ zu diesem Puls-Echo-Verfahren kann ein Dopplersignal auch durch einen CW-Transducer continuous wave generiert werden, bei dem ein Sendeelement kontinuierlich Ultraschallwellen aussendet und ein Empfangselement kontinuierlich das Echo empfängt.

As an alternative to this pulse-echo method, a Doppler signal can also be generated by a CW transducer continuous wavein which a transmitting element continuously emits ultrasonic waves and a receiving element continuously receives the echo. Bei dieser einfacheren Ausführung ist jedoch keine Tiefenselektion möglich. In this simpler design but no depth selection is possible.

Die Ermittlung der wesentlichen Information des Dopplersignals, nämlich ihrer Zeitdauer, in der Dopplersignaleinheit kann auf verschiedene Weisen Prostate Behandlung von Schockwellentherapie Beispielsweise kann die Dopplersignaleinheit dazu ausgelegt sein, als Zeitdauer des Dopplersignals ein Zeitintervall zu bestimmen, innerhalb dessen der Betrag des Dopplersignals auf einen vorbestimmten Bruchteil eines Anfangsbetrags gefallen ist, insbesondere auf den e-ten Teil des Anfangsbetrags.

Eine derartige Auslegung der Dopplersignaleinheit ist dann vorteilhaft, wenn der Betrag eines Dopplersignals jeweils weitestgehend einer exponentiell abfallenden Einhüllenden-Kurve entspricht, da dann die Zeitdauer des Dopplersignals durch automatisiertes Anpassen von Test-Exponentialfunktionen Fitten schnell und zuverlässig ermittelt werden kann.

Such an interpretation of the Doppler signal unit is advantageous when the magnitude of a Doppler signal in each case corresponds largely an exponentially decaying envelope curve, because then the Prostate Behandlung von Schockwellentherapie of the Doppler signal by automated adjusting of test-exponential functions fitting can be determined quickly and reliably.

Basically, these thresholds can be preset in the Doppler signal unit of the lithotripter invention and here both especially his performance as well as typical patient data into account the specifications of the shock wave generator. Dann können diese Schwellenwerte zu Beginn der Prostate Behandlung von Schockwellentherapie abhängig vom auftretenden Rauschen des Dopplersignal-Untergrunds individuell eingestellt werden.

Then these thresholds can be set individually depending on the occurring noise of the Doppler signal underground at the beginning of treatment.

Die Schwellenwerte können jedoch auch automatisch aus dem Signal selbst bestimmt werden. From the acquired signal before the start timing signals namely, a noise can be determined. The thresholds may then be defined as a predetermined multiple of the noise amplitude, and are set automatically by the inventive Doppler signal unit. In an advantageous further development of the lithotripter according to the invention, the Doppler signal unit may be further adapted to the period of the Doppler signal over several shock waves to be averaged.

For this, the following geometric conditions of a typical lithotripsy treatment Prostate Behandlung von Schockwellentherapie be considered: The shockwave focus typically has an extension of approximately 4 mm. Ein typisches Konkrement, beispielsweise ein Nierenstein, weist am Anfang der Behandlung Abmessungen zwischen 5 und 20 mm auf, und seine Hin- und Herverlagerung durch die reine Atmung des Patienten kann mit einer Amplitude von ca.

A typical calculus, for example, a kidney stone, has at the beginning of treatment dimensions Prostate Behandlung von Schockwellentherapie 5 and 20 mm, and its round Herverlagerung by the mere breathing of the patient can be carried out with an amplitude of about 30 mm. Under these conditions, inevitably some shock waves would then sending out shock waves typically performed without consideration of the particular respiratory condition of the patient, miss the calculus.

The properties measured on such shock waves immediately following Doppler signal durations are - as already explained above - particularly short, so that for example, actuates the alarm device according to the use of the assigned time signal or the shock wave generator would shut down, although no misalignment is given.

Rather, the next shock waves are already going back to meet the calculus because they are sent in another respiratory condition of the patient. Prostate Behandlung von Schockwellentherapie provided in this embodiment of the invention averaging the time of the Doppler signal over several shockwaves averaging over example, five shockwaves can be done initially in a first setting of the Doppler signal unit, but it is recommended to further increase the efficiency of treatment, the number of Doppler signals on the averaged, depending on the start of treatment the patient from his typical breathing pattern, adjust etc.

In principle, other types of signal filtering are possible instead of averaging, for example a median filtering. Not only in the number of Doppler signals on should be suitably averaged but also in the typically expected absolute Doppler signal durations has shown a marked dependence on individual patients in clinical experiments. Therefore, the Doppler signal unit can be designed in an expedient development Prostate Behandlung von Schockwellentherapie the lithotripter invention to normalize the duration of a Doppler signal to the reference period of a reference Doppler signal.