DE102007004334A1 - Lithotripter for use with stone tracking and position interlocking device, has moving platform for accommodating patients, ultrasonic scanner and ultrasonic sensor under mobile platform - Google Patents

Abstract

The lithotripter has a x-ray unit (1) and a x-ray source (12), which is built on the x-ray unit and is in a position to illuminate an angle from zero degree to thirty degree, by which the spatial position of a stone in the body of the patient is determined. The lithotripter has a mobile platform (3) for accommodating the patients, an ultrasonic scanner (4) and an ultrasonic sensor under the mobile platform, which moves in lateral direction and up and down till it is in contact with the body of the patient such that the image of the stone is displayed on the monitor. An independent claim is also included for the tracking and position interlocking method of a lithotripter with stone tracking and positioning.

Description

Background of the invention

(a) Field of the invention

The The present invention relates to a kidney stone smasher and though a kidney stone smasher with stone tracking and position locking, which is why with Roentgengerät, ultrasound scanner, Ultrasonic sensor, mobile platform, monitor, system control, Stone tracking and position lock is equipped.

(b) Description of the current state of the technique

Use Kidney Stone Smasher Shock waves which are transmitted through water to human tissue and to the focal point F2 be concentrated. The resulting pressures are so high that they are healthy Damage tissue can. It is therefore important that the Focus F2 as possible coincides exactly with the location of the stone. The accuracy of focusing, Stone tracking and locking the position of the stone are therefore for the Success of treatment is of crucial importance.

Unfortunately The position of the stone is easily affected by movements of internal organs affected what cause it that can happen instead of the stone healthy tissue is located in focal point F2, which then in certain circumstances damaged becomes.

Summary of the invention

main goal The invention is a stone-chipped kidney stone smasher and position lock, in the roentgen device, ultrasound scanner, ultrasonic sensor, mobile platform, monitor, system control, stone tracking and Position locking are integrated. The Roentgen device illuminates the stone in the body the patient three-dimensional for position detection by the system control and to display the position on the monitor. The ultrasonic sensor is attached under the movable platform and can its location change laterally as well as in height until he's the body touched by the patient.

secondary objective The invention is a stone-chipped kidney stone smasher and position lock, which includes a position tracking process with position lock carry out which can be the steps process initialization, image acquisition, Stone discovery, image comparison and positioning of the stone can perform. The control unit then steers the platform into a position where the stone is in Focal point F2 comes to rest, where he then by shock waves destroyed can be.

additional The aim of the invention is the shadow of the stone for position determination to use and thus improve their accuracy. Yet Another object of the invention is to provide the centerlines of the ultrasonic sensor, shock generator and Roentgenquelle on the focus F2 to steer.

Brief description of the drawings

1 (A) Perspective illustration of stone-breaker and position lock kidney stone smasher according to the present invention

1 (B) Exploded view of the electromagnetic shock wave generator of a Nierensteinzentrümmerers according to the present invention

2 Further perspective view of the kidney stone smasher 1

3 Side view of the kidney stone smash 1

4 Representation of the rotation of the C-arm of the Roentgen source 1 of the kidney stone smoker in 1

5 Flowchart of Stone Trace and Position Locking Process of the Kidney Stone Destroyer according to the Present Invention

5-1 Flowchart of the stone discovery

5 (A) Local maximum detection

5 (B) Flowchart of the frame comparison

5 (B-1) Photo of the ultrasound image during the frame comparison

5 (C) Flowchart of the evaluation of the shadow

5 (D) Flowchart of stones supported by shadows

6 System diagram of the kidney stone smash 1

7 By scanning ultrasound image generated by the present invention

8th Defined crucial region of interest (ROI) of an ultrasound image

9 ROI of another ultrasound image

Detailed description of the preferred execution

Loud 1 (A) and 2 there is a stone-chipping stone-breaker with position lock out of a roentgen device ( 1 ), an ultrasound scanner ( 4 ), a mobile platform ( 3 ), a monitor ( 8th ), a shock wave source ( 5 ) and a system control ( 6 ). The X-ray radiation source ( 12 ) is at the end of the swivel arm ( 11 ) appropriate. The shock wave source ( 5 ) is at a predetermined location at the top of the X-ray radiation source ( 12 ) appropriate. The ultrasonic sensor ( 2 ) is also above the X-ray radiation source ( 12 ), the system control ( 6 ) can therefore put him in the correct position for the representation of an image of the stone.

To 1 (B) contains the shock wave source ( 5 ) an electromagnetic shock wave generator ( 7 ), consisting of the shock wave source base ( 71 ), the shockwave source module holder ( 72 ) on the underside of the shockwave source module ( 74 ) on the shockwave source base ( 71 ), a double concave focusing lens ( 73 ) and a shock wave source module ( 74 ) under the shock wave source ( 5 ). In addition, the shockwave source module ( 74 ) an insulating ceramic ( 741 ), a high voltage coil ( 742 ), an insulating membrane ( 743 ), a metallic membrane ( 744 ) and a rubber membrane ( 745 ). The high voltage coil ( 742 ) is supplied with a current that generates a magnetic field, the metallic membrane ( 744 ) then moves to the water within the shockwave source ( 5 ). The shock waves generated in this way collect at the focal point F2 and smash the stone there.

As 3 and 4 show the kidney stone smasher with stone tracking and position lock a X-ray source ( 12 ), which at the lower end of a swivel arm ( 11 ) is attached and by the system control ( 6 ) can be pivoted at an angle of 30 °, whereby it is possible to determine the position of the stone in the patient. The projection axes of X-ray radiation source ( 12 ), Ultrasonic sensor ( 2 ) and shock wave source ( 5 ) intersect at focal point F2. After the X-ray radiation source ( 9 ) has located the stone, is determined by means of the ultrasonic sensor ( 2 ) a picture of the stone on the monitor ( 8th ).

With the help of drives, gears and position detectors, the system control ( 6 ) the mobile platform ( 3 ) move in three axes in a controlled manner, thus positioning the patient so that the stone comes to rest at focal point F2.

• (A) Konfigurieren: Speicherzuweisung für Bahnverfolgung und Positionsverriegelung. Setzen der Startparameter. Initialisieren der Bilderfassungskarte.
• (B) Bilderfassung: Diese erfolgt über Threads mit Ablage in Puffern. Die über die grafische Benutzeroberfläche eingegebenen Befehle werden zur Verringerung der Reaktionszeit von einem ereignisgesteuerten System bearbeitet. Zur weiteren Erhöhung der Reaktionsgeschwindigkeit wird Doppelpufferung eingesetzt.
• (C) Steinentdeckung: Über Helligkeitsmaximum (lokales Maximum) Die Helligkeitsmaxima werden auf einen vorbestimmten Wert angehoben, um größere Flächen zu erhalten. Isolierte Maxima von nur wenigen Pixeln werden ignoriert. Es wird davon ausgegangen, daß die auf diese Art identifizierten Regionen potentielle Lagen von Steinen sind (siehe 5(A)).
• (D) Rahmenvergleich: Binäre Bilder von aufeinanderfolgenden Rahmen werden überlagert, wobei übereinstimmende Regionen mehr und nicht übereinstimmende Regionen weniger Gewicht erhalten. Die Summe aller Gewichtswertungen wird als Übereinstimmungswert bezeichnet. Die ROI wird dann in verschiedenen Richtungen verschoben, um verschiedene Übereinstimmungswerte zu erhalten. Die Richtung zum höchsten Übereinstimmungswert wird zur Bestimmung des Translationsvektors herangezogen.
• (E) Steinpositionsbestimmung: Der abgeleitete Translationsvektor wird zu der vorher bestimmten Lage des Steins addiert. Die neue Position ist das Zentrum des zuvor markierten Kandidaten für die Steinposition, die der berechneten neuen Position am nächsten kommt.

The stone tracking and position locking procedure of the present invention is described in U.S.P. 5 shown. It contains the following steps:

• (A) Configure: Memory Allocation for Trace Tracking and Position Lock. Set the start parameters. Initialize the image capture card.
• (B) Image capture: This is done via threads with storage in buffers. The commands entered through the GUI are edited by an event-driven system to reduce response time. To further increase the reaction rate double buffering is used.
• (C) Stone Discovery: Over Brightness Maximum (Local Maximum) The Brightness Maxima are set to ei NEN predetermined value raised to obtain larger areas. Isolated maxima of just a few pixels are ignored. It is assumed that the regions identified in this way are potential layers of rocks (see 5 (A) ).
• (D) Frame comparison: Binary images of successive frames are superimposed, with matching regions receiving more weight and mismatching regions receiving less weight. The sum of all weightings is called the match score. The ROI is then shifted in different directions to get different match values. The direction to the highest match value is used to determine the translation vector.
• (E) Stone Positioning: The derived translation vector is added to the previously determined location of the stone. The new position is the center of the previously selected stone position candidate closest to the calculated new position.

• (A) Finden lokaler Maxima;
• (B) Berechnung von Schatten, Nähe und Figurähnlichkeit für jedes lokale Maximum;
• (C) Berechnung der kombinierten Figurähnlichkeit für jedes lokale Maximum;
• (D) Bestimmung der Position des größten Wertes;
• (E) Neue Steinposition gefunden;
• (F) Ausgabe der neuen Steinposition;
• (G) Als letzte bekannte Position ablegen;
• (H) Wiederholung von (A) bis (G) für nächstes Bild.

How out 5-1 As can be seen, the stone positioning procedure of the present invention still includes the following steps:

• (A) find local maxima;
• (B) calculating shadow, proximity, and figure similarity for each local maximum;
• (C) calculating the combined figure similarity for each local maximum;
• (D) determining the position of the largest value;
• (E) Found new stone position;
• (F) output of the new stone position;
• (G) Save as last known position;
• (H) Repeat from (A) to (G) for next frame.

For user intervention all you need to do is mark the ROI with the mouse. By definition The ROI will recalculate all gray levels of the pixels in the ROI of the local maxima.

A simple morphological process then eliminates very small regions. The white areas in the binary image are potential stone layers whose contours, as in 5 (A-1) and 5 (A-2) shown, are greatly simplified. The largest white area in the ROI that does not coincide with the limit of the ROI is interpreted as the location of the stone.

In most cases Although a correct discovery of the stone in the ROI, the Stone, however, moves with the internal organs, causing a change the stone position leads. It is therefore important the true location of the stone through tracking and lock the position.

• (A) Zurückholen des Binärbilds der ROI des vorhergehenden Rahmens;
• (B) Bewegen der ROI in einer beliebigen Richtung;
• (C) Gewinnung des Binärbilds der verschobenen ROI;
• (D) Vergleich der beiden Binärbilder;
• (E) Bewegen der ROI in anderen Richtungen und Berechnung der Figurähnlichkeit (FOM = figure of merit) in dieser Richtung;

As in 5 (B) As shown, the above-mentioned procedure of frame comparison includes the steps of:

• (A) retrieving the binary image of the ROI of the previous frame;
• (B) moving the ROI in any direction;
• (C) obtaining the binary image of the shifted ROI;
• (D) comparison of the two binary images;
• (E) moving the ROI in other directions and calculating figure of merit (FOM) in this direction;

wobei P der vorhergehende Rahmen, C der derzeitige Rahmen und W der Gewichtungswert sind.The FOM is used as a reference frame, and if the pixels of the brick in the previous frame match those of the current frame, the maximum value of the FOM is calculated using equation (1);

where P is the previous frame, C is the current frame, and W is the weight value.

at execution The calculation will convert the ROI of the current framework into different ones Moved directions to get a set of binary images. These are compared with the previous image to FOM values for different To get directions. The highest FOM value decides the direction of movement.

Of the derived translation vector becomes the previously determined position of the stone, so that the new one Position of the stone after the movement can be determined.

5 (B-1) According to the invention, two ultrasound images generated by the positioning / locking system of the present invention, namely the current (C) and the previous (P) are used as binary images for the ROI. The large region in the previous picture (P) corresponds to the position of the stone. Similarly, the smaller region in the current image (C), whose reduction comes from the movement of the surrounding tissue. The translation vector of the stone is determined by frame comparison. This allows the determination of the exact position of the stone.

Around to improve the accuracy of the position detection of the stone belongs to the present invention, an assistance system for position detection under assistance of the stone shadow. Ultrasonic waves can be dense Material like bones and stones do not penetrate, which is why Picture building behind a kidney stone a long shadow emerges whose pixels have a lower gray value than the surrounding tissue, because of the strong reflection through the stone but a higher than have the stone. If a region has a high gray value with a long consecutive shadow is usually assumed that yourself There is a stone there.

• (A) Ermittlung des Schattenpfads auf Basis des Umrisses eines Bildes;
• (B) Mögliche Kandidaten zurückrufen;
• (C) Kandidatenvergleich;
• (D) Auswahl eines Schattenpfads;
• (E) Feststellung der Lage des Steins.

In the 5 (C) The assistance procedure for determining and locking the position includes the following steps:

• (A) determining the shadow path based on the outline of an image;
• (B) recall possible candidates;
• (C) candidate comparison;
• (D) selecting a shadow path;
• (E) Determining the position of the stone.

Around to proceed with the procedure, a shadow path is predefined. Shadow start positions are always within an ROI. If the Shadow of a stone coincides with a traced path becomes optimal match scored as a shadow pattern has a stone and a shadow component Has.

5 (D) is a system block diagram of the combination of stone tracking / position locking with the assistance system for determining the position with the help of the shadow, in which a more precise positioning of the stone is achieved by the interaction of assistance system and frame comparison. After defining the ROI of a stone by the user, the position of the stone is determined by stone tracking / position locking, while frame comparison combined with stone shadow evaluation indicates the position of a moving stone with the desired accuracy.

6 is the block diagram of a stone-chipped kidney stone smasher with position lock that is activated by the system controller turning on power. An input / output module pivots the X-ray source in a range of 0 ° to 30 ° to determine the location of the stone in the body of the patient. The ultrasonic sensor, which is moved by a controller and a servo motor, determines the depth of the stone. Ultrasonic positioning and tracking, as well as position locking will then be as in 7 to 9 shown performed. The frames with the marked location of the stone are compared to determine the translation vector of the stone. The tracing process is started by moving the mobile platform so that the stone always remains in focus F2, or the fragmentation of the stone after locking the position (if the stone is not in focus F2, no shock waves are triggered until it returns there ).

Claims (11)

A kidney stone smasher with stone chase and position lock, consisting of: A roentgen device; one Roentgen radiation source built on slides Roentgengerät and is able to illuminate an angle of 0 ° to 30 °, whereby they the spatial Position of a stone in the body can determine the patient; a mobile platform for Admission of the patient; an ultrasound scanner; one Ultrasonic sensor under said moving platform, which itself both in the lateral direction and up and down can move up he is in contact with the body the patient has, so that the Image of the stone can also be displayed on the monitor; at that a stone tracking and position locking system itself on the stone and a system control unit the mobile Platform so tracks, that the Stone on the bump cup is aligned to him with the help of focused shockwaves to pulverize. The kidney stone smasher with stone chase and position lock of claim 1, wherein the shockwave cup a shock wave generator module contains which in turn consists of a mounting unit, a double concave lens, a shockwave cup holder and a shockwave module There is an electrical current passing through a high voltage coil flows generates a magnetic field, which in turn on a metal membrane the water in the bump cup which makes shock waves produced by the concave lenses to the focal point F2 be concentrated where they find the stone located there in the body of the Destroying patients. The kidney stone smasher with stone chase and position lock of claim 2, wherein the shockwave module an insulating support, said high voltage coil, an insulating membrane, contains a metal membrane and a thin rubber film. The tracking and position locking method of a kidney stone smash with stone tracking and positioning, which includes the following steps: (A) Configure: Set various parameters, initialize the Image capture card; (B) Image capture: capturing the images multithreading and placing the images in a buffer; (C) Stone detection: finding brightness peaks (local maximum). The peaks are converted to a predetermined value to larger areas too get small isolated spots with just a few pixels eliminated. leftover surfaces are interpreted as potential stone positions; (D) frame comparison: Compare binary Images with each other, weighting of overlapping and non-overlapping Regions of two images, determination of a translation vector from the older to the newer Image; (E) Stone Positioning: Addition of the Translation Vector to a previous stone position to determine the new stone position. It seem claim 5 is missing The tracking and position locking method of stone-trapping and position locking kidney stone smashers of claim 4, wherein a formula is used for frame comparison that calculates a figure similarity value (FOM). The formula is:

where P is the previous frame, C is the current frame, and W is the weight value. The tracking and position locking method of a kidney stone smash with stone tracking and position locking of claim 6, at a method is used for frame comparison in which the Direction of frame movement by the maximum FOM value between the current and a preceding binary image is determined by the ROI in each of the frames in a number of possible directions is moved. The tracking and position locking method of a kidney stone smash with stone tracking and position lock, the following Steps contains: (A) Configure: Set various parameters, initialize the Image capture card; (B) Image capture: capturing the images multithreading and placing the images in a buffer; (C) Stone detection: finding brightness peaks (local maximum). The peaks are converted to a predetermined value to larger areas too get small isolated spots with just a few pixels eliminated. leftover surfaces are interpreted as potential stone positions; (D) frame comparison: Compare binary Images with each other, weighting of overlapping and non-overlapping Regions of two images, determination of a translation vector from the older to newer picture; (E) Stone Positioning: Addition of the Translation Vector to a previous stone position to determine a new stone position; (F) Use of the stone shadow for improved stone positioning: Based on a picture outline is a shadow path determined, retrieval of suitable candidates, comparison of candidates, selection of a candidate Shadow, securing the stone position. The tracking and position locking method of a stone tracing and position locking kidney stone smasher of claim 8, wherein the stone detection comprises the steps of: (A) finding a local maximum; (B) calculating shadow, proximity, corresponding figure or significance for each local maximum; (C) calculating the combined FOM for each maximum; (D) find location of the maximum FOM; (E) Found new stone position; (F) announce new position; (G) Save as previous local maximum. The tracking method of a kidney stone smash with stone tracking and position locking of claim 8, at the the stone shadow support used for positioning a scheme in which paths first determined and then the paths and the shadows are compared taking first the most likely section along the path and then the location is set. The tracking method of a kidney stone smash with stone tracking and position locking of claim 10, at the shadow path starts at an appropriate distance from an ultrasonic sensor, with a group of suitable candidates behind the said one Shadow Path collected and for everyone from them an average gray value is calculated and from one Maximum is reduced, being a stone by a maximum difference identified between gray value maximum and gray value average becomes. The tracking method of a kidney stone smash with stone tracking and position locking of claim 8, at the stone position controls the movable platform so that the Stone is always in focus F2. Does the stone have this position? leave, no shock waves sent out.