Samsung SONOACE R3 Manual de usuario descargar pdf (Pagina 125)

Chapter 5 Measurements and Calculations

5-3

Measurement Accuracy

Measurement values can vary, depending on the nature of the ultrasound, the body’s response to ultrasound,

the measurement tools, algorithms, product settings, probe type and user operation.

Before using this product, make sure to read and understand the following information regarding the causes

of measurement errors, and measurement optimization.

Causes of Measurement Errors

Image Resolution

The resolution of ultrasound images may be limited by the available space.

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Errors due to a signal range may be minimized by adjusting focus settings. Optimizing focus settings

increases the resolution of the measurement area.

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In general, lateral resolution is lower than axial resolution. Therefore, measurements should be per-

formed along the axis of the ultrasound beam to obtain accurate values.

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Gain has a direct impact on resolution. Gain can be adjusted by using the Gain button for each

mode.

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In general, increasing the frequency of ultrasound enhances resolution.

Pixel Size

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An ultrasound images in the product consist of pixels.

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Since a single pixel represents the basic unit of an image, a measurement error may result in the dis-

placement of approximately ±1 pixel when compared to the original image size.

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However, this error becomes signicant only when a narrow area in an image is measured.

Ultrasound Velocity

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The velocity of ultrasound used during measurement is usually 1,540 m/s on average.

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The velocity of ultrasound may vary depending on the cell type.

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The possible range of error is between approximately 2-5% depending on the structure of cells (about

2% for typical cells and about 5% for fatty cells).

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Samsung SONOACE R3 Manual de usuario Pagina 125