Wearable Sensor-Based Assessments for Remotely Screening Early-Stage Parkinson's Disease.

Prevalence estimates of Parkinson's disease (PD)-the fastest-growing neurodegenerative disease-are generally underestimated due to issues surrounding diagnostic accuracy, symptomatic undiagnosed cases, suboptimal prodromal monitoring, and limited screening access. Remotely monitored wearable devices and sensors provide precise, objective, and frequent measures of motor and non-motor symptoms. Here, we used consumer-grade wearable device and sensor data from the WATCH-PD study to develop a PD screening tool aimed at eliminating the gap between patient symptoms and diagnosis.

Tablet-Based Cognitive Impairment Screening for Adults With HIV Seeking Clinical Care: Observational Study.

Background: Neurological complications including cognitive impairment persist among people with HIV on antiretrovirals; however, cognitive screening is not routinely conducted in HIV clinics.

Objective: Our objective for this study was 3-fold: (1) to determine the feasibility of implementing an iPad-based cognitive impairment screener among adults seeking HIV care, (2) to examine the psychometric properties of the tool, and (3) to examine predictors of cognitive impairment using the tool.

Methods: A convenience sample of participants completed Brain Baseline Assessment of Cognition and Everyday Functioning (BRACE), which included (1) Trail Making Test Part A, measuring psychomotor speed; (2) Trail Making Test Part B, measuring set-shifting; (3) Stroop Color, measuring processing speed; and (4) the Visual-Spatial Learning Test.

Simultaneous Border Segmentation of Doughnut-Shaped Objects in Medical Images.

Image segmentation with specific constraints has found applications in several areas such as biomedical image analysis and data mining. In this paper, we study the problem of simultaneous detection of both borders of a doughnut-shaped and smooth objects in 2-D medical images. Image objects of that shape are often studied in medical applications.

Assessment of the reliability of the determination of carotid artery lumen sizes by quantitative image processing of magnetic resonance angiograms and images.

In order to use MR imaging to assess progression or regression of atherosclerosis, one must have an idea of the reproducibility of the imaging and image processing techniques. The ability of dark-blood MRI and semiautomated image processing to reproducibility measure the inner boundary of the carotid arteries was evaluated and compared with results obtained using bright-blood MRA. MRI and MRA images were obtained for two normal and two diseased volunteers six times each over a short period of time (6 months).

Unobtrusively tracking eye gaze direction and pupil diameter of mammographers.

Rationale And Objectives: The visual process that radiologists use for diagnosis is incompletely understood. This study developed techniques to unobtrusively track direction and pupil diameter of radiologists reading a wide variety of films. We evaluated the eye gaze patterns of mammographic experts to gain knowledge that might improve the rate of early detection of breast cancer.

Noninvasive quantitative evaluation of atherosclerosis using MRI and image analysis.

A new medical image analysis system to quantify atherosclerosis in the lower abdominal aorta using magnetic resonance imaging is described. This medical image analysis and display system permits the quantification of the three-dimensional (3D) properties of the vessel wall and lumen cross-sectional area and volumes. Preliminary results of employing this medical image analysis capability on magnetic resonance images demonstrated a twofold increase in wall volume per unit vessel length, corresponding to intimal thickening, before luminal narrowing was detected.

Quantitative monitoring of capsular contraction around smooth and textured implants.

The purpose of this study was to assess the efficacy of textured silicone implants in reducing the incidence of capsular contracture. Each of 10 female New Zealand, albino rabbits received 2 saline-filled implants, 1 on either side of the lateral chest wall. The surface of 1 implant was smooth silicone, whereas the other implant's surface was textured silicone.

Applications of hierarchical image segmentation techniques: aorta segmentation.

The segmentation of objects from complex images is difficult due to indistinct boundaries between objects and similarity of objects. We have used a hierarchical segmentation approach to accurately distinguish between objects and identify the corresponding boundaries. This approach has been used successfully to extract the aorta from transverse magnetic resonance (MR) images of the abdomen.

Breast lesion discrimination using statistical analysis and shape measures on magnetic resonance imagery.

Magnetic resonance images of intact human breast tissue are evaluated using statistical measures and shape analysis. In this paper, the Mahalanobis distance measurement and a related F-statistical value demonstrate that breast lesions are statistically separable from normal breast tissue. The minimum set of parameters to provide first order statistical separability between fibroadenomas, cysts, and carcinomas are T1-weighted, T2-weighted, and Dixon opposed pulse sequences.

Image analysis and quantification of atherosclerosis using MRI.

This paper describes an image processing, pattern recognition, and computer graphics system for the noninvasive identification and evaluation of atherosclerosis using multidimensional Magnetic Resonance Imaging (MRI). Particular emphasis has been placed on the problem of developing a pattern recognition system for noninvasively identifying the different plaque classes involved in atherosclerosis using minimal a priori information. This pattern recognition technique involves an extension of the ISODATA clustering algorithm to include an information theoretic criterion (Consistent Akaike Information Criterion) to provide a measure of the fit of the cluster composition at a particular iteration to the actual data.

Identification and boundary extraction of blobs in complex imagery.

Automated identification and boundary extraction of blobs in "real world" imagery is a difficult task because the boundaries are so irregular that there is often insufficient a priori information describing these boundaries and traditional methods fail. This paper has proposed a progressive segmentation approach and a boundary estimation method to identify the blobs and to yield an accurate description of its boundary. The multiresolution image processing technique is incorporated into the whole work.

Evidence for an alteration of the tonotopic map in the gerbil cochlea during development.

We have investigated developmental alterations in the tonotopic projection of the gerbil lateral superior olive. Single neurons were characterized in the frequency domain and the recording site marked with fast green. Transverse tissue sections from the auditory brainstem of each animal were visualized with a video-equipped microscope, and the image was digitized for subsequent alignment.

High-resolution 1H NMR spectral signature from human atheroma.

Coronary artery disease due to atherosclerosis takes the lives of approximately 550,000 Americans each year--an enormous toll. Put in economic terms, the cost to the United States alone has been estimated to exceed 60 billion dollars annually. We have found that well-resolved proton (1H) NMR spectra can be obtained from human atheroma (fatty plaque), despite its macroscopic solid appearance.

Identification and 3-D quantification of atherosclerosis using magnetic resonance imaging.

Cardiovascular disease due to atherosclerosis is a leading cause of death in the United States as well as other developed countries. This paper describes the development of image processing, pattern recognition, and graphical display techniques to non-invasively quantify the atherosclerotic disease process using magnetic resonance imaging (MRI). We have demonstrated the ability to identify the soft tissue classes of (1) normal, smooth muscle wall, (2) fatty plaque, (3) complex, fibrous plaque, and (4) calcified plaque.

High-resolution proton NMR spectra of human arterial plaque.

Well-resolved proton (1H) NMR spectra of solid human arterial plaque can be acquired. Studies have been carried out of human fatty plaque obtained postmortem (ex vivo), the total lipids extracted from human atheroma, and a model mixture of cholesteryl esters whose lipid composition resembles that of human atheroma. In each case, well-resolved 1H NMR spectra were obtained at body temperature (37 degrees C), with little or no underlying broad signal.

Cultured muscle from myotonic muscular dystrophy patients: altered membrane electrical properties.

Myotonic muscular dystrophy (MyD) is an inherited human disease involving skeletal muscle as well as many other organ systems. We have approached the study of this disorder by growing normal and diseased human muscle in a primary tissue culture system and investigating some of the electrical properties of the resulting myotubes. The most distinctive abnormality noted in MyD myotubes was an increased tendency to fire repetitive action potentials.

Design of a single electrode voltage clamp.

The detailed schematic diagrams and construction techniques are presented for a single microelectrode voltage clamp. The devices is used to study the membrane processes of small cells not able to be penetrated with the traditional two microelectrode system. The technique utilizes the same microelectrode alternately for current injection and membrane potential sampling on a time-sharing basis controlled by electronic switching circuitry.

Investigation of burst generation by the electrically coupled cyberchron network in the snail Helisoma using a single-electrode voltage clamp.

This paper describes the results of investigating burst generation by the cyberchron network in the snail Helisoma. The cyberchron network is composed of aproximately 20 electrically coupled neurons and controls the feeding behavior of the snail. The electrical coupling between network members has made it particularly difficult to distinguish between the importance and involvement of single-cell and network properties in burst generation by this system.

Single cell isolation: a way to examine network interactions.

A procedure for isolating identified, small neurons from snail ganglia is described. The technique allows a particular neuron, previously identified by morphological and electrophysiological characteristics, to be marked and then isolated from the ganglia. This procedure was developed to permit the detailed comparison of the electrical characteristics of a neuron before and after isolation from an intact system.

Burst generation by electrically coupled network in the snail helisoma: analysis using computer simulation.

The effectiveness of electrical coupling between neurons as a mechanism for mediating single and repetitive bursts is investigated here using computer simulation. The cyberchron network in the snail Helisoma generates repetitive bursts controlling the animal's feeding behavior and served as the basic model for the simulation studies described in this paper. The action potential properties of individual neurons were modeled by the Rall equations describing generalized action potentials.

Centrally programmed feeding in Helisoma: identification and chracteristics of an electrically coupled premotor neuron network.

(1) The oscillatory network underlying centrally programmed feeding in the fresh water pulmonate, Helisoma trivolvis, was studied using intracellular recording and staining techniques. These premotor neurons have been termed cyberchron neurons. (2) Intracellular staining with Procoin yellow has allowed the construction of a soma map and tentative identification of axonal projections of the cyberchron neurons.