YY/T 1749-2020External-vibration based ultrasonic elasticity measurement equipment for liver tissue (English PDF)

3.1 External-vibration Based Ultrasonic Elasticity Measurement Equipment for Liver Tissue

External-vibration based ultrasonic elasticity measurement equipment for liver tissue refers to the equipment that applies low-frequency vibration with a mechanical device through the skin from outside the body to generate shear wave propagation in the liver tissue, uses the ultrasonic pulse-echo method for measurement, and calculates and displays the elasticity parameters (Young's modulus and / or shear wave velocity, shear modulus) of the liver tissue based on the echo information.

3.2 Ultrasonically Tissue-mimicking Phantom, Ultrasound Tissue

Phantom Ultrasonically tissue-mimicking phantom / ultrasound tissue phantom refers to a B- ultrasonic performance inspection device composed of tissue-mimicking materials and one or more sets of targets embedded in it. [YY/T 0937-2014, Definition 3.1]

3.3 Sono-elasticity Tissue-mimicking Phantom

Sono-elasticity tissue-mimicking phantom refers to a passive device that is composed of ultrasonic elasticity tissue-mimicking materials in different modes and used to detect the performance of ultrasonic elasticity image diagnostic equipment. [YY/T 1521-2017, Definition 3.1]

3.4 Depth of Ultrasonic Penetration

Depth of ultrasonic penetration refers to the distance between the farthest target line and the acoustic window in the longitudinal line-shaped target group that can be clearly imaged (or can be displayed as an echo signal along the ultrasonic beam axis) in the ultrasonically tissue-mimicking phantom.

NOTE: unit: (mm).

3.5 Measurement Accuracy

Measurement accuracy refers to the consistency between the measured value and the nominal value. In this Standard, measurement accuracy is expressed by absolute error or relative error, and the calculation is shown in Formula (1) and Formula (2):

The depth of ultrasonic penetration shall comply with the requirements announced by the manufacturer.

4.4 Measurement Accuracy of Young's Modulus

The measurement accuracy of Young's modulus shall comply with the requirements announced by the manufacturer.

4.5 Repeatability of Measurements of Young's Modulus

The repeatability of measurements of Young's modulus shall comply with the requirements announced by the manufacturer.

4.6 Functions

The equipment shall be equipped with the functions specified by the manufacturer in the accompanying documents, which shall at least include a reminder of whether the pressure is appropriate during operation.

NOTE: this clause does not involve product design parameters or functional items that cannot be verified by intuitive test methods.

4.7 Accompanying Documents

The accompanying documents shall clarify the following contents:

a) Whether it has a directive function when selecting the measurement site;

b) The frequency of the applied external mechanical vibration;

c) The depth range of elasticity inspection of liver tissue.

4.8 Environmental Test

The requirements of environmental test of the equipment shall be implemented by the manufacturer in accordance with the stipulations of the climate environmental test group II and the mechanical environmental test group II in GB/T 14710; the test time, recovery time and test items shall comply with the supplementary stipulations of Table 1. The special requirements and methods of environmental test may be implemented in accordance with the principles and provisions of YY/T 1420. signal) farthest from the probe surface can be resolved. The distance between the target line and the probe surface is the depth of ultrasonic penetration.

6.4 Measurement Accuracy of Young's Modulus

The equipment enters the elasticity measurement mode. Within the measurement range specified by the manufacturer, at least choose two different sono-elasticity tissue-mimicking phantoms. The Young's modulus of one of the sono-elasticity tissue- mimicking phantoms is <= 7 kPa; the Young's modulus of the other sono-elasticity tissue-mimicking phantom is >= 10 kPa. For each sono-elasticity tissue-mimicking phantom, in accordance with the method specified by the manufacturer, measure the Young's modulus of the sono-elasticity tissue-mimicking phantom for 5 times; each time, the probe shall be removed, and then, placed in the same test position. For the sono-elasticity tissue-mimicking phantom whose Young's modulus is <= 7 kPa, in accordance with Formula (1), calculate the absolute error. For the sono-elasticity tissue-mimicking phantom whose Young's modulus is >= 10 kPa, in accordance with Formula (2), calculate the relative error, which shall comply with the requirements announced by the manufacturer.

6.5 Repeatability of Measurements of Young's Modulus

For the test data of each sono-elasticity tissue-mimicking phantom in 6.4, in accordance with Formula (3), respectively calculate the repeatability of measurements of Young's modulus. Take the most unfavorable one, which shall comply with the requirements announced by the manufacturer.

6.6 Functions

In accordance with the provisions of the instruction manual of the equipment, conduct item-by-item inspection on the main functions, so as to verify whether it can normally work.

NOTE: the functional inspection does not include product design parameters or functional items that cannot be verified by intuitive test methods.

6.7 Accompanying Documents

Review the accompanying documents of the equipment, which shall comply with the requirements of 4.7.

6.8 Environmental Test

The environmental test of the equipment shall be conducted in accordance with the methods and procedures specified in GB/T 14710 and YY/T 1420. The test time and conditions shall comply with the supplementary stipulations of Table 1.