Daniel B. Sheffer

Breast Volume Measurement of 248 Women Using Biostereometric Analysis

A study of volumes of the right and left breasts of 248 subjects was undertaken using biostereometric analysis. This measurement technique uses close-range stereophotogrammetry to characterize the shape of the breast and is noncontact, noninvasive, accurate, and rapid with respect to the subject involvement time. Volumes and volumetric differences between breast pairs were compared, using chi-square tests, with handedness, perception of breast size by each subject, age, and menstrual status. No significant relationship was found between the handedness of the subject and the larger breast volume. Several groups of subjects based on age and menstrual status were accurate in their perception of breast size difference. Analysis did not confirm the generally accepted clinical impression of left breast volume dominance. Although a size difference in breast pairs was documented, neither breast predominated.

Breast volume measurement of 598 women using biostereometric analysis.

A study of the volumes of the right and left breasts of 598 subjects was undertaken using biostereometric analysis. This measurement uses close-range stereophotogrammetry to characterize the shape of the breast, and is noncontact, noninvasive, accurate, and rapid with respect to the subject involvement time. Using chi-square tests, volumes and volumetric differences between breast pairs were compared with handedness, perception of breast size by each subject, age, and menstrual status. No significant relationship was found between the handedness, age, or menstrual status of the subject and the breast volume. Several groups of subjects were accurate in their perception of breast size difference. Analysis did confirm the generally accepted clinical impression of left-breast volume dominance. These results are shown to be consistent with those of a previous study using 248 women.

Validity and reliability of biostereometric measurement of the human female breast

A measurement technique has been developed for application in the area of noninvasive breast cancer detection. The measurement process involves the use of closerange stereophotogrammetry as a data acquisition device necessary for determination of breast volume and volume distribution. This report details the methodology used to acquire and analyze stereopair photographs necessary to document the validity and reliability of this application. The volume of a test object was determined by both water displacement and stereophotogrammetric analysis to estimate the precision of the proposed methodology. Additionally, the reliability component of the study was documented by analyzing variability of coordinates representing a series of locations marked on the surface of an irregularly shaped object. Both tests confirm that this stereometric analysis is a reliable and valid method of measurement and may be well suited for further development in the field of breast cancer detection.

Study of detection efficiency of Cd/sub 1-x/Zn/sub x/Te detectors for digital radiography

In this paper, the signal-to-noise ratio (S/N) of resistive Cd/sub 1-x/Zn/sub x/Te semiconductor detectors, at different directions of irradiation, within the X-ray diagnostic energy range, has been experimentally studied. In addition, the dependence of the spatial resolution of a planar Cd/sub 1-x/Zn/sub x/Te substrate both on the applied bias voltage and thickness has been experimentally determined. The detection efficiency of semiconductor detectors depend upon the energy absorption efficiency as well as the collection efficiency. This study suggests that high signal-to-noise ratios can be obtained by optimally choosing which polarizing electrode is directly exposed to the incident X-ray beam, as well as on both the detector thickness and applied bias voltage. In addition, the experimental results on the temporal system MTF indicate a spatial resolution of >6 cy/mm. Besides the intrinsic charge transport characteristics of the semiconductor sample, by decreasing the collector size and optimizing the X-ray digital system geometry and temporal response, the temporal system MTF can be improved significantly. The research imaging detector system allows one to investigate methods to improve the detection and imaging performance parameters as part of the development of a digital radiographic system.

Ballistocardiogram Artifact Removal in EEG-fMRI Signals Using Discrete Hermite Transforms

Simultaneously recorded electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) is rapidly emerging as a powerful neurophysiological research and clinical tool. However, the quality of the EEG, recorded in the MRI scanner, is affected by the ballistocardiogram (BCG), which is an artifact related to the cardiac cycle. The BCG has a complete spectral overlap with the EEG and is nonstationary over time, making its suppression a signal processing challenge. We propose a novel method for the identification and suppression of this artifact using shape basis functions of the new dilated discrete Hermite transform. The BCG artifacts are modeled continuously, using these discrete Hermite basis functions and are subsequently subtracted from the ongoing EEG. Experimental EEG data was recorded within and outside a 3 Tesla MRI scanner, from a total of 6 subjects under a variety of experimental conditions. The efficiency of this algorithm was quantitatively assessed by adding known BCG templates, at varying Signal to Noise Ratios (SNRs), to EEG recorded outside the scanner. Significant suppression of the BCG artifact (p<0.05) was achieved without distorting the underlying EEG. Using EEG data recorded inside the MR scanner, this method was compared with existing BCG artifact removal techniques and its performance was found to be superior to the Average Artifact Subtraction (AAS) method and comparable to the Independent Component Analysis (ICA) based methods. The computational simplicity of this technique allows for real time implementation.

Polarimetric phenomenology of photons with lung cancer tissue

The objective of this study is to explore the polarimetric phenomenology of light interaction with healthy and early-stage lung cancer tissue samples by applying efficient polarimetric backscattering detection techniques combined with polarimetric exploratory data analysis. Preliminary results indicate that enhanced discrimination signatures can be obtained for certain types of early-stage lung cancers based on their depolarization, backscattered intensity and retardance characteristics.

Growth changes in measurements of upper facial positioning

Growth changes in the position of the midline upper face are examined for samples of Pan troglodytes, Gorilla gorilla, and modern humans. Horizontal and vertical distances between nasion and the anterior end of the cribriform plate are plotted against stage of dental development. Kendalls nonparametric correlations between facial positioning and stage of dental development are tested for significance. In African apes, the upper face becomes more projecting and positioned higher relative to the anterior cranial base. The extent of this horizontal and vertical separation reflects primarily facial size. In modern humans, the upper face becomes more projecting but is relatively stable in its vertical position. Comparison of Pan and modern human crania in the youngest dental age category indicates that the upper face of modern humans is positioned lower early in postnatal life. The position of the upper face (glabella) relative to the anterior and posterior cranial base is presented for several fossil hominid crania. The fossil crania are similar to Pan and modern humans in facial projection relative to the anterior cranial base. However, glabella is positioned low in the fossil crania. Total facial projection (relative to hormion) for Sts 5 is similar to the mean for Gorilla. Fossil Homo and robust australopithecine crania display very projecting upper faces. We suggest that the upper face of Homo is projecting due to the length of the anterior cranial fossa, while robust australopithecines possess a thick frontal bone.

Phase-shifting holographic interferometry for breast cancer detection

Using a mild pressure stressing device and a pulsed ruby-laser system, we apply phase-shifted holographic interferometry to the detection of breast cancer. We compare a four-step algorithm and a Carré algorithm for their ability to evaluate the interferograms. The results show the feasibility of holographic interferometry in the detection of anomalies in the human female breast.

Detection of breast lesions by holographic interferometry

The holographic interferometry (HI) technique commonly used for nondestructive testing of laminate materials was applied to create fringe contour distortion near the site of indwelling breast lesions. For this medical imaging application, the HI technique was successful in demonstrating abnormal mechanical properties of living tissue. Adequate density and contrast of fringes, crucial factors necessary for analysis of surface deformation of an object, can be made only with an appropriate stressing method. We have applied vibration and mild pressure to the surface of female breasts for the purpose of detecting localized densities and mass alterations of the tissue, which may be indicative of an abnormality of that tissue. Even though each stressing method had both positive and negative aspects, pneumatic pressure was adopted for the present study because it was more suitable for a noninvasive and noncontact breast examination. We also developed a computer based holographic imaging system to precisely control the stressing phase for the pressure and laser triggering so the resultant holograms had manageable fringe density and repeatability.

Near infrared light interaction with lung cancer cells

The objective of this study is to explore the phenomenology of near infrared (NIR) light interaction with healthy and early-lung cancer by combining efficient polarimetric backscattering detection techniques with Polarimetric Exploratory Data Analysis (pEDA). Preliminary results indicate that enhanced discrimination signatures can be obtained for certain types of lung cancers.