ULTRASONIC INVESTIGATION OF THE EYE WITH A NEW CONTACT METHOD AND WITH THREE DIFFERENT REAL‐TIME PRESENTATIONS
The ultrasound examination was carried out by means of a crystal with a 40° sector scan, which was pressed either against the eyelid or directly against the sclera. The real‐time display was obtained by either A‐mode, B‐mode or combined A/B‐mode scanning. In clinical applications, both the resolution capacity and the sensitivity of the device were good. A‐mode scanning gave the greatest accurary in amplitude measurement, while the A/B‐mode yielded the most concrete topographic picture of the target.
The application of ultrasonic locating techniques to ophthalmology. II. Ultrasonic slit lamp in the ultrasonic visualization of soft tissues.
Introduction This is a preliminary report of the visualization of the interior of the lightopaque eye and the retro-ocular areas by pulsed ultrasonic echographic methods. Non-radio-opaque foreign materials, such as wood and plastics, may also be visualized, as well as soft tissue pathology. At present no other method can yield the information obtained by the technique to be described. A comparison of the visual appearance of a normal beef eye, the x-ray appearance, and the sonic appearance graphically illustrates this contention (Fig. 1). The x-ray demonstrates only the gross outline of the eye. The ultrasonogram reveals a cross section of the internal structure of the eye equivalent in detail to a low-power photomicrograph. Serial ultrasonic tomograms (Figs. 13 to 21) yield a composite picture of the eye at all levels without in any way altering the tissues. Precise direct measurement of the depth within the tissue is possible with this
A new mixed chain sampling plan based on the process capability index for product acceptance
ABSTRACT This article proposes a new mixed chain sampling plan based on the process capability index Cpk, where the quality characteristic of interest follows the normal distribution with unknown mean and variance. The advantages of this proposed mixed sampling plan are also discussed. Tables are constructed to determine the optimal parameters for practical applications. In order to construct the tables, the problem is formulated as a nonlinear programming where the objective function to be minimized is the average sample number and the constraints are related to lot acceptance probabilities at acceptable quality level and limiting quality level under the operating characteristic curve. The practical application of the proposed mixed sampling plan is explained with an illustrative example. Comparison of the proposed sampling plan is also made with other existing sampling plans.