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1.
Acad Radiol ; 7(9): 684-92, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10987329

ABSTRACT

RATIONALE AND OBJECTIVES: Bringing a new imaging technology to market is a complex process. Beyond conceptualization and proof of concept, obtaining U.S. Food and Drug Administration (FDA) approval for clinical use depends on the documented experimental establishment of safety and efficacy. In turn, safety and efficacy are evaluated in the context of the intended use of the technology. The purpose of this study was to examine a conceptual framework for technology development and evaluation, focusing on new breast imaging technologies as a highly visible and current case in point. MATERIALS AND METHODS: The FDA views technology development in terms of a preclinical and four clinical phases of assessment. With a concept of research and development as a learning model, this phased-assessment concept of regulatory review against intended use was integrated with a five-level version of a hierarchy-of-efficacy framework for evaluating imaging technologies. Study design and analysis issues are presented in this context, as are approaches to supporting expanded clinical indications and new intended uses after a new technology is marketed. CONCLUSION: Breast imaging technologies may be intended for use as replacements for standard-of-care technologies, as adjuncts, or as complementary technologies. Study designs must be appropriate to establish claims of superiority or equivalence to the standard for the intended use. Screening technologies are ultimately judged on their demonstrated effectiveness in decreasing cause-specific mortality through early detection, but they may be brought to market for other uses on the basis of lesser standards of efficacy (eg, sensitivity, specificity, positive and negative predictive value, and stage of disease detected).


Subject(s)
Breast Neoplasms/diagnosis , Device Approval , Diagnostic Imaging/standards , Research Design , Technology Assessment, Biomedical/methods , Female , Humans , ROC Curve , Randomized Controlled Trials as Topic/methods , Randomized Controlled Trials as Topic/standards , Technology Assessment, Biomedical/standards , United States , United States Food and Drug Administration
2.
Anal Chem ; 71(13): 2307-17, 1999 Jul 01.
Article in English | MEDLINE | ID: mdl-21662781

ABSTRACT

Relative dissociation energies (RDEs) are obtained for the major fragment ions produced by electrospray ionization/surface-induced dissociation of singly protonated triglycine, tetraglycine, leucine enkephalin, and leucine enkephalin arginine. A previously described data analysis method (Lim, H.; et al. J. Phys. Chem. B 1998, 102, 4753) is employed to analyze the energy-resolved mass spectra by subtracting out the distribution of energy transferred to the surface, integrating over the distribution of the incident ion energy, and taking into account the precursor ion initial internal energy and kinetic energy distributions. These variables are optimized by anchoring the RDE for the lowest energy fragment of a given precursor ion to its literature values and then using these optimized parameters to obtain the other RDEs. The RDEs of the four major fragments of triglycine vary from 2.4 eV for the b(2) fragment ion to 6.0 eV for the a(2) ion. The RDEs of the four major fragments of tetraglycine vary from 3.2 eV for the y(2) ion to 5.7 eV for the a(2) ion. The leucine enkephalin RDEs range from 1.1 eV for the b(4) ion to 2.1 eV for the b(2) ion. The leucine enkephalin arginine RDEs all lay between 2.5 and 3.5 eV. The overall trend of fragmentation order for all peptides is (y(n), b(n)) < a(n) and is consistent with the results from other experiments. The peptide RDEs presented here are only as accurate as the literature values to which they are anchored. Determination of absolute dissociation energies from SID data will require further refinement of the data analysis method.

5.
Med Instrum ; 17(6): 393-5, 1983.
Article in English | MEDLINE | ID: mdl-6669099

ABSTRACT

The anesthesiologist is the "systems" person in the operating room whose primary function is making decisions with respect to the patient's pharmacologic and physiologic status. The introduction of digital data processing equipment in the operating room must aid this decision-making function. Instruments that are used to monitor the anesthesia machine or patient variables will provide input to a digital computer. The computer will serve to aggregate and organize signals for data processing and display. Engineering a suitable display with appropriate interfacing with the anesthesiologist is one of the major problems to be solved. As higher levels of processing become available and as the display technique develops, the array of instruments in the operating room will become an integrated information system to better support and aid the anesthesiologist.


Subject(s)
Anesthesiology/instrumentation , Computers , Humans , Information Systems , Monitoring, Physiologic/instrumentation
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