Accuracy of a new electronic nose for prostate cancer diagnosis in urine samples.

OBJECTIVE: To evaluate the accuracy of a new electronic nose to recognize prostate cancer in urine samples. METHODS: A blind, prospective study on consecutive patients was designed. Overall, 174 subjects were included in the study: 88 (50.6%) in prostate cancer group, and 86 (49.4%) in control group. Electronic nose performance for prostate cancer was assessed using sensitivity and specificity. The diagnostic accuracy of electronic nose was reported as area under the receiver operating characteristic curve. RESULTS: The electronic nose in the study population reached a sensitivity 85.2% (95% confidence interval 76.1-91.9; 13 false negatives out of 88), a specificity 79.1% (95% confidence interval 69.0-87.1; 18 false positives out of 86). The accuracy of the electronic nose represented as area under the receiver operating characteristic curve 0.821 (95% confidence interval 0.764-0.879). CONCLUSIONS: The diagnostic accuracy of electronic nose for recognizing prostate cancer in urine samples is high, promising and susceptible to supplemental improvement. Additionally, further studies will be necessary to design a clinical trial to validate electronic nose application in diagnostic prostate cancer nomograms.

A MEMS Real-Time Clock With Single-Temperature Calibration and Deterministic Jitter Cancellation.

This article presents a real-time clock (RTC) system based on a microelectromechanical system (MEMS) resonator coupled to an integrated circuit (IC) that implements a frequency-compensating machine. The MEMS resonator is built with a standard, industrial-grade polysilicon process characterized by a -30-ppm/K linear temperature coefficient of frequency ( TCf ) and the frequency-drift compensation is entirely carried out within the IC using a fractional frequency division. The large, but deterministic, output jitter (≈1 µsrms ) is then suppressed down to less than 40 nsrms with a low-power digital-to-time converter (DTC), whose usefulness in this kind of application is then analyzed. With a single-point temperature calibration, a ±8-ppm output frequency stability is demonstrated at ≈800-nA current consumption from a 1.2-V supply.

Combining transverse field detectors and color filter arrays to improve multispectral imaging systems.

This work focuses on the improvement of a multispectral imaging sensor based on transverse field detectors (TFDs). We aimed to achieve a higher color and spectral accuracy in the estimation of spectral reflectances from sensor responses. Such an improvement was done by combining these recently developed silicon-based sensors with color filter arrays (CFAs). Consequently, we sacrificed the filter-less full spatial resolution property of TFDs to narrow down the spectrally broad sensitivities of these sensors. We designed and performed several experiments to test the influence of different design features on the estimation quality (type of sensor, tunability, interleaved polarization, use of CFAs, type of CFAs, number of shots), some of which are exclusive to TFDs. We compared systems that use a TFD with systems that use normal monochrome sensors, both combined with multispectral CFAs as well as common RGB filters present in commercial digital color cameras. Results showed that a system that combines TFDs and CFAs performs better than systems with the same type of multispectral CFA and other sensors, or even the same TFDs combined with different kinds of filters used in common imaging systems. We propose CFA+TFD-based systems with one or two shots, depending on the possibility of using longer capturing times or not. Improved TFD systems thus emerge as an interesting possibility for multispectral acquisition, which overcomes the limited accuracy found in previous studies.

Spectrally reconfigurable pixels for dual-color-mode imaging sensors.

The use of full color-sensitive photodetectors with three electrically tunable spectral responses allows the design of sensors that can be real-time reconfigured for different color acquisition modes. All the (physically identical) pixels can be biased in the same way, each giving the same set of RGB spectral responses: in this situation the conversion from the sensor color space to a reference color space can be implemented as usual, giving typical color errors ΔE(a,b) in the order of 2-3. Alternatively, pixels can be biased in two different ways (e.g., row by row), forming pairs: by joining the information from adjacent pixels, the sensor has six spectral responses, with a reduced resolution. By exploiting this plurality of spectral responses, color reproduction accuracy can be increased. In this work, an improved design of the Transverse Field Detector, a filterless and tunable three-color pixel, is used as the experimental device to propose a dual-color-mode reconfigurable sensor.

White balance by tunable spectral responsivities.

The development of color pixels in modern digital imaging has led to devices in which color detection is not based on the use of physical color filters but relies on the wavelength dependence of the silicon absorption coefficient in the visible range. In some of these devices the responsivity of each color channel can be electrically tuned by changing the applied voltages. Exploiting this feature, this paper presents a new method of white balance that compensates for changes in the illuminant spectrum by changing accordingly the spectral responsivities, and therefore the native color space, of the detector. Different sets of responsivities corresponding to the different RGB color channels can be selected, depending on the illuminant, in order to keep the chromatic components of a white object independent of the illuminant. An implementation of this method with the transverse field detector, a color device with tunable spectral responsivities, is discussed. Experimental data show that the method is effective for three spectral sources that are strongly different from a chosen reference source. The color error in a perceptive color space after the subsequent color correction (specific for each set of base filters) does not change significantly in the tuning interval of interest for image acquisition.