Substantially equivalent materials

Material Biocompatibility Testing 4.1 Substantially Equivalent Materials... 

The establishment of performance criteria for a given tumor marker test is not a simple process because accuracy and precision are unique for each type of analyte and its application. Establishing methodological limits for accuracy, precision, sensitivity, and specificity often requires standard reference materials, quality control materials, comparative studies, and actual clinical specimens. Accuracy and precision must be measured over the analyte reportable range for which the device is intended to be used. Sensitivity and specificity must be considered with respect to the intended clinical use of the device. Also, the indications for use should be carefully considered in the design of the study protocol. The indications for class II should be to monitor residual tumor after surgery (or radiation), the recurrence of tumor, or response to therapy. A 510(k) must provide clear evidence that the device is accurate, safe, effective, and substantially equivalent to a device legally marketed in the United States. 

Substantially Equivalent) and thereby automatic Class III designation can request a de novo classification of the product as Class I or Class II. This provision has been used sparingly since its enactment, but proposed changes to the FDA regulations may increase access to the de novo process which in turn may allow new technology or materials with definable and mitigated risks to be cleared to market through this process. 

AH of the medical devices and the dental implants discussed in this paper fall in Class IQ. Devices, including designs and materials that were used prior to 1976 were allowed to continue based on past successful experience. Since 1976, devices could be given market clearance, without clinical testing, if it could be shown that these devices were substantially equivalent to devices used prior to 1976 or to another device that had... 

The environmental effects on mechanical properties once again demonstrate that the interrelationships between various mechanical properties are material specific and rely on many factors, from temperature to humidity. A higher yield strength for one alloy under one environmental condition might imply better fatigue resistance however, specific supporting data are required to draw any inference to any other alloy in different circumstances. In summary, the demonstration of equivalent material durability and part life limitation in reverse engineering requires part-specific substantiation data. 

Chromium—Cobalt—Iron Alloys. In 1971, a family of ductile Cr—Co—Fe permanent-magnet alloys was developed (79). The Cr—Co—Fe alloys are analogous to the Alnicos in metallurgical stmcture and in permanent magnetic properties, but are cold formable at room temperature. Equivalent magnetic properties also can be attained with substantially less Co, thereby offering savings in materials cost. 

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