At present, the use of veterinary B-ultrasound diagnostic equipment (hereinafter referred to as "veterinary B-ultrasound") in medical clinical practice is increasingly valued by people. In order to ensure the safety of patients and the accuracy of diagnostic results, and to avoid accidents and animal injuries caused by missed diagnosis or misdiagnosis, after several years of testing practice in China, the author believes that there are many issues that need to be addressed during the testing process and should be taken seriously. The calibration of B-Ultrasound Equipment is mainly divided into three parts: output sound intensity calibration, patient leakage current calibration, and comprehensive calibration of geometric dimensions.

1. Output sound intensity verification

The calibration index for output sound intensity is a very important indicator in the calibration of animal B-ultrasound equipment. Its qualification directly affects the scope of use of the B-ultrasound equipment. It is stipulated that the output sound intensity should generally not exceed 10mW/cm2. For instruments that exceed 10mW/cm2, the value of their output sound intensity should be announced and a warning should be displayed in a prominent position stating "strictly prohibited for use in pregnant women". The output sound intensity is obtained by measuring the output power of the B-ultrasound probe and comparing it to the effective area of the probe. In practical testing, most veterinary B-ultrasound machines meet the above requirements, but there are also a few B-ultrasound machines that exceed the standard, especially when the performance of the B-ultrasound machine cannot meet the requirements of geometric comprehensive data testing or when the lesion cannot be seen clearly on the screen during clinical diagnosis. The B-ultrasound machine operator usually compensates for the deficiency by increasing the gain and dynamic TGC (i.e. increasing the probe output power), which can easily lead to the output sound intensity index exceeding the standard. According to the verification regulations, the output sound intensity verification is carried out when the gain and TGC are adjusted to an appropriate position where the image can be clearly seen. Therefore, the output sound intensity at this time may not necessarily be the maximum value of the instrument's output sound intensity, and it is uncertain whether the maximum value exceeds the standard. So during calibration, it is generally necessary to measure the maximum output sound intensity of the tested B-ultrasound instrument. If it exceeds 10mW/cm2, the operator of the B-ultrasound instrument should be alerted to the existence and key points of the problem.

Beast B-ultrasound device BXL-V20

2. Verification of Patient Leakage Current

This verification is also a safety performance verification. The indicator specified in the verification regulations is that the patient leakage current should not exceed 100 μ A. However, in the actual verification process, the veterinary B-ultrasound instrument basically does not exceed this indicator. However, it should be reminded that during the verification process, it is necessary to change the polarity of the power supply. If not done, the detected patient leakage current may not be the highest leakage current of the B-ultrasound instrument.

3. Comprehensive verification of geometric dimensions

The comprehensive verification of geometric dimensions includes the verification of measurement depth, blind spots, geometric position accuracy, lesion diameter, and resolution. The quality of these indicators directly determines the grade of the B-ultrasound instrument used by the inspected animal, so careful and meticulous verification must be carried out. Based on our years of experience in calibration, firstly, in order to achieve accurate reading, the display screen should be dimmed as much as possible until it can be clearly distinguished. The frequency conversion probe should be based on the frequency that produces the best results during the detection process. For models with dynamic focusing function, it should be focused near the measured position to obtain the best set of measurement data*** Afterwards, for the verification results, it is necessary to archive and distinguish the B-ultrasound machine according to the detected data, and pay attention to whether the leakage current is qualified. For machines with output sound intensity exceeding the standard, it is necessary to specifically indicate and require the B-ultrasound machine to be labeled with a "strictly prohibited for inspection" sign as a reminder

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