Sensitivity response, defined

The terms defined above are all important in the consideration of the overall performance of an analytical method. The greatest sensitivity (response) does not necessarily imply the lowest limit of detec-tion/determination as a more intense signal may also be observed from... 

Assay sensitivity is defined here as the concentration of analyte that inhibits the observed absorbance by 50% or the IC50. The lower limit of detection (LLD) is the lowest analyte concentration that elicits a detector response significantly different from the detector response in the absence of analyte. In some cases, the LLD is defined as three standard deviations from the mean of the zero analyte control. In other cases, the LLD is defined empirically by determining the lowest concentration of analyte that can be measured with a given degree of accuracy. Readers are referred to Grotjan and Keel for a simplified explanation and to Rodbard for the complete mathematics on the determination of LLD. 

The signal tram gas chroaatographic detectors can be further characterized as nass or concentration dependent. For concentration-dependent detectors the aost notable feature is that the detector response is dependent upon the flow rate through the detector (carrier gas and makeup gas, if any) and, therefore, the sensitivity of the detector is usually defined as the product of the pe dc area and flow rate divided by the wei t of the sanple. For B ss-dependent detectors sensitivity is defined as the product of the peak area divided by the sanple wel t in grans or noles and is independent of flow rate through the detector. 

Sensitivity is a significant characteristic in all scientific disciplines which have to do with measurements. Sensitivity is defined from the viewpoint of instrumental measuring as the change in the response of a measuring instrument divided by the corresponding change in the stimulus (ISO... 

Grading Approach Fire Detection—based on defining fire detection performance requirements for sensitivity, response time, and availability based on risk of fire escalation. 

The ITAE is sensitive to initial and, to a certain extent, unavoidable deviations. Optimum control responses defined through ITAE consequently have short response times and larger overshoots than in the case of the other two aiteria. However, ITAE has proven to be very useful for evaluating the regulation of coating processes. 

In 2001, Weber et al. [82] showed in a study cohort of 40 patients with locally advanced adenocarcinoma of the esophagogastric junction that prediction of histopathologic response is possible by metabolic imaging with [ F]-FDG as early as 2 weeks after induction of chemotherapy. Application of the criterion metabolic response—defined as a reduction of baseline SUV of more than 35%—allowed prediction of clinical response with a sensitivity of 93% and specificity of 95%, respectively (Fig. 2). 

Wieder et al. [80] evaluated the time course of therapy-induced changes in tumor glucose metabolism during chemoradiotherapy of esophageal SCC in a cohort of 38 patients. Early metabolic response, defined as a reduction of baseline SUV of more than 30%, predicted histopathologic response 2 weeks after induction of chemotherapy with a sensitivity of 93% and a specificity of 88%, respectively. Changes in tumor metabolic activity early in the time course of preoperative chemoradiotherapy were also significantly correlated with patient survival (p < 0.011). 

Sensitivity is defined via the equation R = R0 + SC, where R is the detector output, S is the response factor or sensitivity, and C is the concentration (or mass flow rate if applicable). R0 is the response at zero concentration. It is obvious that when S is high, a slight change in concentration will produce a more detectable signal. 

The pT-index scale appraises the relative hazard of aquatic environmental samples by assigning them to a numerical class. As bioassays within a test battery are considered equal in rank, the most sensitive test with its pTmax-value defines the toxicity class of the test material. If, for example, an effluent yields pT-values of 7, 2, 8 and 0 for the bacterial, algal, daphnid and fish tests, respectively, its pT-index is therefore assigned to toxicity class 8, based on the most sensitive response obtained with the Daphnia test. Since, by convention, sample toxicity classes are designated by Roman numerals, the test material is then assigned to toxicity class Vm. A toxicity class is not a strictly defined value, but rather the consequence of the... 

Test sensitivity is defined as the lowest TU at which a toxic response can be observed for instance, a test run at 10% of the full concentration (e.g., 10% v/v) would have a detection limit of 10. For quantal data, this normalization step requires the determination of a minimum non toxic percent response (Rmi ), i.e., the minimum percent response which designates a sediment sample as non-toxic. The formula for quantal tests is as follows ... 

For a reversible sensor, sensitivity is defined as the change in sensor output signal obtained for an incremental change in the concentration or mass of the analyte, i.e., the slope of the response-vs-concentration curve. Sensitivity for a reversible AW sensor typically has units of [frequency change]/[concentration change], e.g., Hz/M (M mol/L), Hz/(/ug/L), or even ppm >pm (normalized frequency shift/concentration). For an irreversible sensor, sensitivity is more appropriately defined in terms of frequency change/integrated exposure, e.g., Hz/M-min. 

Sensitivity is defined as the change in the response of a measuring instrument divided by the corresponding change in the stimulus . In analysis the stimulus is often the amount of measurand present in the sample under test. Therefore, with reference to Example 2.19, Figure 3, sensitivity is the slope of the calibration curve. Note In some applications, particularly clinical and medical, the term sensitivity is often associated with the lower limit of applicability e.g. limit of detection) of a method. 

The sensitivity of an analytical method can be defined as the slope of the calibration curve, that is, as the ratio of change in the instmment response with a change in the analyte concentration. Other definitions are also used. In AAS, sensitivity is defined as the concentration of analyte that produces an absorbance of 0.0044 (an absorption of 1%), for example. When the term sensitivity is used, it should be defined. 

Sensitivity This term refers to the overall response of the instrument to the investigated analyte when the apparams is operated under well-defined methods. The sensitivity is defined as the slope of a plot of analyte concentration versus signal strength. 

Let me open this section with a short remark on the term sensitivity. In the first instance, sensitivity is defined as the slope of the response function that describes the signal change depending on a change in analyte amount or concentration. The slope, also known as response factor, always has a physical... 

The frequency response of a microphone describes the sensitivity of the device as a function of frequency. The range of response defines the highest and lowest frequencies the microphone can successfully reproduce. The shape of a microphone s response curve indicates how it responds within this range. Figure 3.37 shows a typical microphone frequency-response plot. 

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