JPH0120704Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a phased array transmitter that controls the transmission time phase of a phased array transducer used in an ultrasound imaging device.

Traditionally, as a transmission time phase control method for phased array transducers, data set in advance is loaded into a preset counter attached to each transducer element from a ROM (Read Only Memoey), and this counter is controlled by a high-speed clock. There is a method of counting up (or counting down) all at once and independently energizing individual pulsers corresponding to each element at the timing of overflow (or underflow). This method is widely used because it has many degrees of freedom and is excellent in timing accuracy.

However, this method also has problems. That is,
In the case of sector scanning, where a predetermined transmission delay map must be stored in the ROM as firmware, and the delay map changes for each sound ray, the memory capacity of the ROM is enormous, and as I wrote once.
The ROM can no longer be freely changed; for example, if the physical constants or scanning method of the array change, the ROM must be replaced with a ROM with completely different contents, which is inconvenient.

The present invention was devised in view of these points, and its purpose is to utilize the flexibility of the preset counter as it is, and to make it possible to change the transmission delay map arbitrarily without changing the hardware configuration. The object of the present invention is to realize a phased array transmitter.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of the present invention.
PC1~PCN are preset counters, PL1~
PLN is a pulser, DC is a decoder, CPU is a central processing unit of a microcomputer, RAM1 is a parameter storage RAM (Random Access Memory),
RAM2 is a rewritable memory that stores the day map (database that uses RAM)
It is.

Preset counters PC1 to PCN are stored in RAM2.
Preset data is set, the timing clocks are counted all at once, and the overflow is applied to each pulser PL1 to PLN to energize them.

Pulsers PL1 to PLN are connected to array transducers (not shown) and generate transmission pulses to individually excite each transducer. CPU is for parameter storage
The parameters of RAM1 are read, a predetermined delay map is determined, and this is written to RAM2.
Also, at the same time as giving the address signal to the decoder DC, the delay map data is read from the RAM 2 and given to the preset counters PC1 to PCN. Decoder DC decodes the supplied address and outputs it to preset counters PC1 to PCN. As a result, the data in RAM2 is preset to the preset counter specified by the CPU. Note that parameters are input into the parameter storage RAM 1 from a keyboard (not shown), etc.
The latest parameters are now stored there.

In this configuration, the CPU calculates the delay map every time the parameters of RAM1 change,
Preset data for all elements
Write to RAM2. These preset data are sent out one by one from the data buffer of RAM2 under the control of the CPU, and are sequentially preset into the counter specified by the decoder DC. When all preset data settings are completed, all preset counters PC1 to PCN start counting the timing clocks at the same time, and send the overflow (or underflow) signal to the pulsers PL1 to PLN.
Output to.

Note that the CPU calculates the delay map (delay time T) using the following equation.

T=√ ² + ² −2−/v+T ₀ However, Xn: Distance from the array center (0 point) to the nth element r: Distance to the focal point when focusing the beam θ: Beam angle v: Sound velocity (constant ) To: delay time offset (constant) N: total number of elements The delay time T obtained by this calculation is written into the RAM 2 as quantized data in units of the period of the timing clock.

As explained above, in this invention, each time the parameters change, the CPU performs calculations to determine a new delay map, stores it in RAM, reads it out one by one, and writes it to each preset counter via the data buffer in RAM. This eliminates the inconvenience of having to replace the ROM that stores the delay map every time the physical constants or scanning method change. Therefore, it is possible to easily adapt to changes in physical constants and scanning methods.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a phased array transmitter according to the present invention, and FIG. 2 is a diagram showing the relationship between elements and beams. PC1~PCN...Preset counter, PL1~
PLN...Pulser, DC...Decoder, CPU...Central processing unit, RAM1...For parameter storage
RAM, RAM2...Memory.

Claims (1)

[Claim for Utility Model Registration] A preset counter is provided for each vibrator constituting the phased array, and at the time of transmission, delay map data is loaded into the preset counter, and a timing clock is applied to the preset counter all at once. , a phased array transmitter that drives each transducer by an overflow signal or an underflow signal, includes a rewritable first memory that stores the latest parameters set externally, and a rewritable first memory that stores the latest parameters set externally, and a central processing unit that reads the parameters stored in the first memory and calculates a delay map necessary for transmission; and a rewritable second memory that stores the delay map obtained by the calculation; A phased array transmitting device characterized in that the contents of a memory are loaded into the preset counter as delay map data.