ultrasonography

(redirected from A-scan)
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Related to A-scan: ophthalmic biometry

ultrasonography

(acoustics)
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01mm) that is an order of magnitude better than A-scan.
Once cataract was diagnosed and surgery was planned, keratometry was done on Haag-Strait manual keratometer and A-scan was done by applanation contact method on SonoMed machine.
The instrument can acquire a 256 A-Scan low-resolution image in 125 ms or 512 A-Scan high-resolution image in 250 ms.
The purpose of this study was to measure the intraocular distances (using A-scan ultrasound biometry) and corneal curvature (using keratometry) of feline eye and to use these data to predict appropriate posterior chamber IOL strength to achieve emmetropia after lens removal.
0001) and A-Scan ultrasonography can be used for screening and early detection of primary angle closure glaucoma.
What this means is a Fast Fourier Transform can decompose A-scans to yield a separate acoustic image for each sinusoid.
2(d) show respectively an example of a through-transmission A-scan, a water-path A-scan and the corresponding inverse Fourier transform of their cross correlation calculated using (5).
Typically, up to 100'000 A-Scans can be stored on the device.
Eye pattern ultrasonography display in A-scan and B-scan modulation and with usage of this technique, can be discovered some eye diseases from normal statue and by also this tool can be studied the structures of eye [6,10].
The most commonly and widely used method is the A-Scan ultrasonic method and its measurements of ACD and other axial parameters represent the "Gold Standard" for biometric dimension.
The other features of the product include built-in datalogger that stores 5,000 readings, settings and A-scan waveforms (in sequential or grid (row/column) format.
Ultrasonography was first introduced in ophthalmic diagnosis by Mundt and Hughes in 1956,1 using A-scan.