Device modifications

Device Modifications Special Controls and Declarations of Conformity... 

One of the alternative approaches under the 510(k) paradigm is Special 510(k) Device Modifications. This approach utilizes certain aspects of the Quality System Regulations (Quality System Requirements for Good Manufacturing Practices). The other alternative is the Abbreviated 510(k). This approach utilizes special controls in which standards or voluntary guidelines can facilitate 510(k) review and expedite evaluation. 

Table 3. Aerosol delivery devices (modification of National Institutes of Health, 1997) ...

The FDA s review of annual reports will allow the Agency to assess several important issues related to postmarket safety of approved devices. These issues include the nature and adequacy of reported modifications and the adequacy of report documentation. If, after reviewing your annual report, we need additional information or if we believe the device modifications you have reported require a PMA Supplement or a 30-Day Notice, we will notify you in writing. 

An obvious device modification is to separate the two electrodes, so that the gases evolving may be collected easier through separate channels. Typically, a separator in the form of a perfluorised membrane would be used in analogy to proton exchange membrane fuel cells (see section 3.7). 

Figure 11 Distribution Device Modifications to Enable Desorber Mode...

Surface science is an invisible yet exceedingly important branch of physics and organic chemistry that studies the behavior and characteristics of molecules at or near the surface or interface. The interface can be between solids, liquids, gases, and combinations of these states. Sophisticated apparatus have been developed to identify and quantify surfaces and interfaces. Polymer surfaces are of special interest in industrial and biological applications examples of the latter include dental implants and body part prosthetic devices. Modification of surfaces of these devices allows formation of controlled interfaces to achieve characteristics such as bondability and compatibility. 

The nonlinear optical properties in solution of selected functionalized PDAs, described herein, have also been evaluated by means of the z-scan technique. Off resonance studies (at 705 nm) show that nonlinear refraction is only comparable to that of the solvent for these dilute solutions, but that nonlinear absorption, characterized by p values, varies significantly, with the nature of the side-chains. O It can be inferred that if bulk films of these PDAs possess suitable nonresonant nonlinear refractive properties for optical devices, modification of side-chain structure can reduce the magnitude of undesirable two photon absorption. 

Along with conventional parameters constraining photovoltaic devices, modification of the electrolyte (solution phase) chemistry is a key to understanding the mechanism of energy conversion and device characteristics of PECs. The fundamental importance of modification of the electrolyte in terms of the distribution of species in photoelectrolytes and the pragmatic importance in terms of enhanced solar to electrical conversion efficiency is reiterated by studies... 

A clinical engineer may also be involved in implants or prostheses and ensuring that these devices are working correctly and providing the patient with the best possible outcome. He or she may make suggestions as to device modifications that may help the patient. Engineers may also be involved with manufacturers who make these types of equipment to help incorporate changes. 

As a further device modification, a thin porous metal foam with tunable proton concentration and vanishing electrocatalytic activity could be inserted between PEM and UTCLs. This layer could reduce proton concentration in the UTCL to a level that optimizes the interplay of ORR rate and Pt dissolution rate. 

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