US 5,507,293 A · Ultrasonic diagnostic apparatus

Abstract

Ultrasonic wave is emitted into an examined body. A first electric echo signal is generated in response to an echo of the ultrasonic wave. A controllable filter responsive to a control signal serves to extract components of the first electric echo signal which are in a desired frequency band, so that the first electric echo signal is converted into a second electric echo signal. A logarithmic detection device serves to subject the second electric echo signal to logarithmic compression and detection. A signal generator is operative for outputting plural calibration signals having different frequencies and different amplitudes. An input selection device is operative for connecting the signal generator with an input terminal of the filter during a calibration mode of operation. A control device is operative for calculating a corrective value from an output signal of the logarithmic detection device during the calibration mode of operation, and correcting a logarithmic conversion characteristic and an offset of the logarithmic detection device and the control signal to the filter in response to the calculated corrective value during reception of echoes of the ultrasonic wave.

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Claims8

Dependent claims

An ultrasonic diagnostic apparatus comprising:

means for emitting an ultrasonic wave into an examined body;
means for generating a first electric echo signal in response to an echo of the ultrasonic wave;
a controllable filter responsive to a control signal for extracting components of the first electric echo signal which are in a desired frequency band, and thereby converting the first electric echo signal into a second electric echo signal;
a logarithmic detection device for subjecting the second electric echo signal to logarithmic compression and detection;
a signal generator for outputting plural calibration signals having different frequencies and different amplitudes;
input selection means for connecting the signal generator with an input terminal of the filter during a calibration mode of operation;
control means for calculating a corrective value from an output signal of the logarithmic detection device during the calibration mode of operation, and correcting a logarithmic conversion characteristic and an offset of the logarithmic detection device and the control signal to the filter in response to the calculated corrective value during reception of echoes of the ultrasonic wave.

4 more elements

An ultrasonic diagnostic apparatus comprising:

means for emitting ultrasonic wave into an examined body;
means for generating a first electric echo signal in response to an echo of the ultrasonic wave;
a controllable filter responsive to a control signal for extracting components of the first electric echo signal which are in a desired frequency band, and thereby converting the first electric echo signal into a second electric echo signal;
a logarithmic detection device for subjecting the second electric echo signal to logarithmic compression and detection;
a signal generator for outputting plural calibration signals having different frequencies and different amplitudes;
input selection means for connecting the signal generator with an input terminal of the filter during a calibration mode of operation;
a filter control device for controlling a pass band of the filter at a desired pass band;
a gain control device for generating a gain control signal;
an adder for adding an output signal of the logarithmic detection device and the gain control signal;
an A/D converter for converting an output signal of the adder into a corresponding digital signal;
a reference voltage control device for controlling a reference voltage fed to the A/D converter;
a memory for storing an output signal of the A/D converter;
and
control means for controlling the input selection means to connect the signal generator with the input terminal of the filter during the calibration mode of operation, controlling the signal generator in accordance with a calibration sequence, reading out the signal from the memory and calculating corrective values for control signals outputted from the filter control device, the gain control device, and the reference voltage control device in response to the readout signal, and correcting the control signals outputted from the filter control device, the gain control device, and the reference voltage control device in response to the corrective values during reception of echoes of the ultrasonic wave.

11 more elements

Dependencies are inferred from the claim text.

Description8,138 words

Summary883 words

#1. Field of the Invention

#This invention relates to an ultrasonic diagnostic apparatus for producing an image, for example, a sectional image, of an examined body by emitting a beam of ultrasonic wave thereinto and receiving related echoes therefrom.

#2. Description of the Prior Art

Brief description of the drawings6 figures

#FIG. 1 is a block diagram of a prior-art ultrasonic diagnostic apparatus.

#FIG. 2 is a block diagram of an ultrasonic diagnostic apparatus according to a first embodiment of this invention.

#FIG. 3 has a diagram of a relation between a detection value and a filter control signal in the apparatus of FIG. 1, and also a diagram of relations between a filter control signal and a filter passband central frequency in the apparatus of FIG. 1.

Detailed description7,118 words

#Before the description of embodiments of this invention, a prior-art ultrasonic diagnostic apparatus will be described for a better understanding of this invention.

#With reference to FIG. 1, a prior-art ultrasonic diagnostic apparatus includes an ultrasonic probe 1 electrically connected to a transmission circuit 2 and a receiving circuit 3. When the prior-art ultrasonic diagnostic apparatus is actually used, the ultrasonic probe 1 remains in contact with the surface of an examined body M such as a human body.

#The ultrasonic probe 1 includes an array of piezoelectric transducers (electric-ultrasonic transducers). The piezoelectric transducers are sequentially activated by electric output signals of the transmission circuit 2 so that pulses of a beam of ultrasonic wave are emitted into the examined body M.

Facts

Application

08/354,003Filed 5 Dec 1994

Priority

JP 5-3063927 Dec 1993

Granted

16 Apr 1996

Term ended

5 Dec 2014

Estimated · how

Pre-1995 term; greater of 17 years from grant or 20 years from filing when eligible. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification6 codes

G01S 15/8954
Characterised by the transmitted frequency spectrum: using a broad-band spectrum
G01S 7/52026
For pulse systems: extracting wanted echo signals
G01S 7/52036
Details of receivers: using analysis of echo signal for target characterisation
G01S 7/52004
Of systems according to group G01S15/00: means for monitoring or calibrating

Ultrasonic diagnostic apparatus

Life of this patent

Ultrasonic diagnostic apparatus

Life of this patent

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims8

Description8,138 words

Classification6 codes

Description8,138 words

Drawings