JPS605134A - Endoscopic ultrasonic diagnostic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an ultrasound diagnostic apparatus capable of performing diagnosis from within the body.

[Background of the invention]

Conventional ultrasonic diagnostic devices have been designed for diagnosis from outside the body. However, there are limits to the ability to perform ultrasound diagnosis of the digestive system, such as the beta stomach and duodenum, outside the body, so an internal ultrasound diagnostic device was developed for the purpose of diagnosis from inside the body.
Its use is attracting attention.

FIG. 1 schematically shows the transmitting/receiving section and system configuration of a conventional ultrasonic diagnostic apparatus used in AFL.

IU pulse motor, 2 is a flexible cable for transmitting the rotation of the pulse motor 1 to the ultrasonic probe (hereinafter abbreviated as the probe) 5, 3 is the case of the wedding probe, 6 is the internal liquid 40 nols, 7 is the A rotation detector for detecting the co-rotation state of the probe 5, 8 a slip ring for transmitting and receiving ultrasonic signals to the rotating probe 5, 9 a drive circuit for the pulse motor 1, and 1O a display device. 12 two-star control circuit, 11
is an ultrasonic transmitting/receiving circuit.

When the probe 5 rotates around the drive system (pulse motor 1, flexible cable 2, drive circuit 9) around the Z axis, the ultrasonic beam radiated from the probe 5 is , is set in front of the object to be measured in a plane perpendicular to the Z axis, and a tomographic image in the scanning plane is obtained by the reflected waves.

However, in the conventional device described above, the signal from the rotation detector 7 is used only for raster control of the display device 12, and is asynchronous with the transmission signal from the ultrasonic transceiver circuit 11. Therefore, if the probe 500 rotates unevenly due to bending of the flexible goople 2 (nonuniform rotational speed), if the ultrasound beam is transmitted at equal time intervals, the image displayed on the display device 12 will be is as shown in FIG. 2(a). That is, the number of rasters is small in sections where the rotational speed is high and increases in sections where the rotational speed is small, so there is a disadvantage that the displayed image is uneven and the image is deteriorated.

[Purpose of the invention]

An object of the present invention is to provide an ultrasonic diagnostic device capable of always obtaining high-quality images regardless of the rotational state of the probe, by eliminating the drawbacks of the prior art as described above. be.

[Summary of the invention]

In order to achieve the above object, the present invention provides an ultrasonic diagnostic apparatus that includes a rotatable ultrasonic probe and a rotation detector that detects the rotational state of the ultrasonic probe. The present invention is characterized in that means is provided for controlling the transmission time of ultrasonic waves emitted from the probe by a detection signal from the rotation detector, so that a high-quality image is always obtained regardless of the rotational state of the probe.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows the overall configuration of a congratulatory ultrasonic diagnostic apparatus according to an embodiment of the present invention.

This device has a pulse generation circuit 1 in addition to the conventional device shown in FIG.
It is distinctive in that it has the number 3 added. The noculus generation circuit 13 generates a raster control signal for the display control circuit 10' and a transmission timing signal for the transmission/reception circuit 11 from the signal from the rotation detector 7.

Here, the detection signal of the rotation detector 7 becomes a signal synchronized with one rotation as shown in FIG. In FIG. 4, one revolution is divided into 16 and detected at π/8 intervals, and the diameter of the time interval of the valley detection signal represents rotational unevenness. in this way,
Since the signal from the rotation detector 7 is synchronized with one rotation, the uneven rotation of the probe 5 due to bending of the flexible cable 2 depends on the rotation angle position, and the angular velocity at the valley position is 1.
It can be seen that it is almost the same as before rotation. Note that in FIG. 4, a indicates the entire one-rotation synchronization signal, and b indicates the 16-division detection signal.

Therefore, the signal (Pi-PN) at the position divided by N at equal angular intervals of one revolution is detected, the detection time interval (Tl - TN) of this signal (Pt-PN) is memorized, and the same Ultrasonic waves are transmitted at time intervals of T, /M in the section.

However, M is the number of rasters in the valley section (the number of transmissions: the same number for the valley section). Also, it is assumed that the angular velocity is constant within each section. In this way, waves are transmitted at short intervals in sections where the angular velocity is high, and waves are transmitted at long intervals in sections where the angular velocity is small, so that the rasters in all sections have equal angles.

FIG. 5 shows an embodiment of the pulse generating circuit 13 configured to control the transmission time of the ultrasonic wave from the detection signal of the rotation detector 7 as described above.

14 is a counter that counts the time interval (Ti) of the detection signal of the rotation detector 7 using the clock of the oscillator 17, and 15 is a counter that writes the wave transmission time interval Δ1 (=Ti/M) in the i-th section of the next rotation into the memory 16. 1/M register, 19 is Δi
1-8 is a Δi-adic counter for generating a transmission pulse, 20 is an M-adic counter for loading the next take Δ1+1 into the register 19, and 21 is a write address of the memory 16. 22 is a read address cost register indicating the read address; 23 is the memory 16;
This is an address changeover switch.

Next, the operation of the pulse generating circuit 13 will be explained with reference to the time chart of FIG. 6.

When P1+1 is the input signal as the detection signal a of the rotation detector 7, the counter 14id counts the time interval TI between the previous signal P1 and the signal p1+1, and at the same time the write address counter 21 indicates l. , read address register 22Ui+2e are shown.

Next, the contents ΔI of the p,1/M register 15 are written to the address (i) of the memory 16 shown in FIG. 7 at write timing C (operates at startup). The case is that before P1+1 in signal a is inputted, signal d (i+1
), the existence J'l+1 of the read address (i+1)
(The wave transmission time interval of the (i+1) period before one revolution) is taken into the register 19.

Then, Δ′l+1 is loaded into the counter 18,
A pulse as shown above is transmitted to the display control circuit 10' and the transmitting/receiving circuit 11 every Δ'141 hours. When the counter 20 counts the transmission timing signal S M times, the counter 20 reads out the next transmission time interval Δ'1+2.
2) is generated. The change-over switch 23 for switching between write and read addresses of the memory 16 is controlled by the changeover signal e, -An, and is set at H level to set the read address, and at L level, the read address is specified.

As explained above, by controlling the transmission time so that ultrasonic waves are transmitted at equal angular intervals using the rotation detection signal from one rotation before, the display image on the display device 12 is
As shown in Figure (b), the raster has no density and no distortion.

In the above embodiment, the transmission time was determined by equally dividing the rotation detection signal from the time interval of the rotation detection signal in the same section before one rotation. By also using signals, it is also possible to continuously change the wave transmission time in each section.

An example of this is shown in the eighth example.

14. 15, 16, 17, 18, and 20 are the same as in FIG. 19' is the trough transmission time interval Δ' between the i-th section and the sections before and after it. Δ′1. There are three registers that read out Δ′ ball +1 from the memory 16.
m(J) to the current 1st section/Jth transmission time interval ΔI
(J) Perform all calculations. 21' are three counters indicating write and read addresses of the memory 16.

The timing of each signal is shown in FIG. With the configuration shown in FIG. 8, data Δ'l-1, Δ/1 . Δ'l+1 is read out from the memory 16 to the register 19'. Next, at the same time as Pl is detected, the current data Δto1 of the i-1th section is convoluted into the (i-x) address of the memory 16 at the timing of time C.

Therefore, the wave transmission time Δl (J) of the i-th interval (p l −p ++1 interval) is determined as follows. Since the average angular velocity (wi = TI/M) in each section is almost the same as before one rotation, the angular velocity W shown in Fig. 9 is 1
The i-th
The angular velocity W1 of the section is approximated by a straight line.

That is, The i-th interval is approximated by uniform angular acceleration.

Here, B+=Δ′t1 ・・・・・・・・・(3), and (2
), substituting (3) into (1), ΔI(Jn is...
・・・・・・・・・ (4) It is given by n.

As for the transmission time Δ1(J)k and n obtained from equation (4), the transmission pulse in the first section changes continuously, as shown by the transmission timing b'. In this way, since the change in the transmission time interval for each section is continuous in this method, the fifth
As in the embodiment shown in the figure, it is possible to determine the transmitting time so that the transmitting directions are at equal angles, which is more convenient than considering Wl as a constant angular velocity and determining Δl at equal time intervals. can.

In addition, as the number of ultrasonic wave transmissions (raster number) kn, 2π
In C, which detects the angular velocity every /n rotations and directly generates all transmission pulses using the detection signal, it is also possible to display with real-time rotational unevenness correction.

The configuration of this embodiment is shown in FIG. The signal a from the rotation detector 7 is directly used as the raster control pulse b1 of the display control circuit 10' and the transmission signal pulse b of the ultrasonic transceiver circuit 11. Therefore, the signal timing becomes as shown in FIG. Since the signal a is a signal detected every 2π/n, it is not affected by rotational unevenness, and is transmitted at equal angles (2π/n) in real time by the transmission signal pulse b, and can be displayed at equal angles. can.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to control the transmission time of ultrasonic waves based on the rotation detection signal of the probe, so that high-quality ultrasonic waves can be always obtained regardless of the rotational state of the probe. l
I! il images can be obtained.

[Brief explanation of drawings]

Figure 1 is an overall configuration diagram of a conventional ultrasound diagnostic device;
3 is a diagram showing a display image, FIG. 3 is a diagram showing the first embodiment of the present invention, FIG. 4 is a diagram showing an example of a rotation detection signal when there is uneven rotation, and FIG. 6 is a time chart of FIG. 5, FIG. 7 is a diagram explaining a memory map of the memory of FIG. 5, and FIG. 8 is a diagram of a second embodiment of the present invention. 9 is a diagram showing a pulse generation circuit, FIG. 9 is a time chart of FIG. 8, FIG. 10 is a diagram showing a third embodiment of the present invention, and FIG. 11 is a time chart of FIG.

Claims (1)

[Claims] 1. In an ultrasonic diagnostic apparatus having a rotatable ultrasonic probe and a rotation detector for detecting the rotational state of the ultrasonic probe, the transmission time of the ultrasonic waves emitted from the ultrasonic probe is An ultrasonic diagnostic device for congratulations on marriage, characterized in that it is provided with means for controlling based on a detection signal from a rotation detector.