Unimodal Approaches Research Articles

A multi-resolution framework for multi-object tracking in Daubechies complex wavelet domain

Tracking multiple objects in a scenario that exhibits complex interaction is very challenging. In this work, we propose a multi-resolution framework for multi-object tracking in complex wavelet domain to resolve the challenges resulting from occlusions and splits. In the proposed approach the appearance model is computed at high resolution to achieve more discriminative power to object model, whereas all other tasks are performed at low resolution to get benefited from noise resilience nature of wavelet domain. In this paper, we have also discussed a simple and effective unimodal background subtraction approach to extract moving objects by exploiting the low sub-band characteristics of the object image in complex wavelet domain at low resolution. A scheme exploiting the spatial and appearance information is used to detect and correct the occlusion and split state. Experimental results illustrate the effectiveness and robustness of the proposed framework in ambiguous situations in several indoor and outdoor video sequences.

Combined Evaluation of FDG-PET and MRI Improves Detection and Differentiation of Dementia

IntroductionVarious biomarkers have been reported in recent literature regarding imaging abnormalities in different types of dementia. These biomarkers have helped to significantly improve early detection and also differentiation of various dementia syndromes. In this study, we systematically applied whole-brain and region-of-interest (ROI) based support vector machine classification separately and on combined information from different imaging modalities to improve the detection and differentiation of different types of dementia.MethodsPatients with clinically diagnosed Alzheimer's disease (AD: n = 21), with frontotemporal lobar degeneration (FTLD: n = 14) and control subjects (n = 13) underwent both [F18]fluorodeoxyglucose positron emission tomography (FDG-PET) scanning and magnetic resonance imaging (MRI), together with clinical and behavioral assessment. FDG-PET and MRI data were commonly processed to get a precise overlap of all regions in both modalities. Support vector machine classification was applied with varying parameters separately for both modalities and to combined information obtained from MR and FDG-PET images. ROIs were extracted from comprehensive systematic and quantitative meta-analyses investigating both disorders.ResultsUsing single-modality whole-brain and ROI information FDG-PET provided highest accuracy rates for both, detection and differentiation of AD and FTLD compared to structural information from MRI. The ROI-based multimodal classification, combining FDG-PET and MRI information, was highly superior to the unimodal approach and to the whole-brain pattern classification. With this method, accuracy rate of up to 92% for the differentiation of the three groups and an accuracy of 94% for the differentiation of AD and FTLD patients was obtained.ConclusionAccuracy rate obtained using combined information from both imaging modalities is the highest reported up to now for differentiation of both types of dementia. Our results indicate a substantial gain in accuracy using combined FDG-PET and MRI information and suggest the incorporation of such approaches to clinical diagnosis and to differential diagnostic procedures of neurodegenerative disorders.

Multimodal Integration Processes in Plan-Based Service Robot Control

Cross-modal integration processes are essential for service robots to reliably perceive relevant parts of the partially known unstructured environment. We demonstrate how multimodal integration on different abstraction levels leads to reasonable behavior that would be difficult to achieve with unimodal approaches. Sensing and acting modalities are composed to multimodal robot skills via a fuzzy multisensor fusion approach. Single modalities constitute basic robot skills that can dynamically be composed to appropriate behavior by symbolic planning. Furthermore, multimodal integration is exploited to answer relevant queries about the partially known environment. All these approaches are successfully implemented and tested on our mobile service robot platform TASER.

Gamma imaging of atherosclerotic plaques

Noninvasive gamma imaging of atherosclerotic plaques targets various metabolic aspects of atherogenesis. Vascular endothelial dysfunction or denudation resulting in the expression of adhesion molecules that attract inflammatory cells and increased vascular permeability has also been targeted. Enzymes and molecules associated with apoptosis of these inflammatory cells have provided additional targets, such as oxidized low-density lipoprotein, matrix metalloproteinases, and phosphatidylserine. In late atherosclerotic lesions, the lipid core as well as proliferating smooth muscle cells have been imaged successfully. Platelets and fibrin deposition may also be targeted to demonstrate thrombosis in plaque rupture or erosion. However, no unimodal approach can diagnose plaque vulnerability. It will require multi-modal, multitasking approaches for molecular diagnostic prediction of plaque vulnerability and impending rupture. Existing experimental and clinical gamma imaging applications in atherosclerotic lesion imaging are reviewed. Improvement by signal amplification to image small lesion and the concept of multimodal applications are introduced.

Is the measurement of maximal oxygen intake passé?

A recent and controversial review1 suggests that the measurement of maximal oxygen intake is passe. The author concludes (p. 554) “ It is now time to develop novel testing methods....That...

Person Surveillance Using Visual and Infrared Imagery

This paper presents a methodology for analyzing multimodal and multiperspective systems for person surveillance. Using an experimental testbed consisting of two color and two infrared cameras, we can accurately register the color and infrared imagery for any general scene configuration, expanding the scope of multispectral analysis beyond the specialized long-range surveillance experiments of previous approaches to more general scene configurations common to unimodal approaches. We design an algorithmic framework for detecting people in a scene that can be generalized to include color, infrared, and/or disparity features. Using a combination of a histogram of oriented gradient (HOG) feature-based support vector machine and size/depth-based constraints, we create a probabilistic score for evaluating the presence of people. Using this framework, we train person detectors using color stereo and infrared stereo features as well as tetravision-based detectors that combine the detector outputs from separately trained color stereo and infrared stereo-based detectors. Additionally, we incorporate the trifocal tensor in order to combine the color and infrared features in a unified detection framework and use these trained detectors for an experimental evaluation of video sequences captured with our designed testbed. Our evaluation definitively demonstrates the performance gains achievable when using the trifocal framework to combine color and infrared features in a unified framework. Both of the trifocal setups outperform their unimodal equivalents, as well as the tetravision-based analysis. Our experiments also demonstrate how the trained detector generalizes well to different scenes and can provide robust input to an additional tracking framework.

Inverse modeling of multimodal conductivity distributions

We present a method for the calibration of multimodal hydraulic conductivity distributions and apply this method to the particular case of confining layers with a complex geological architecture. The basis of our technique is the transformation of the original multimodal conductivity distribution to the standard normal distribution, thus fulfilling the condition of normality which is required by the used representer‐based inverse algorithm (Valstar et al., 2004). Using this transformation, a calibration that starts from a homogeneous prior field is shown to radically improve the estimation of the protective properties of the confining layer compared to a unimodal approach to the calibration. The method is also used for the calibration of multimodal heterogeneous prior fields. The inevitable distortion of the original parameter covariances in the posterior fields that results from the transformation process is absorbed by an iterative postprocessing procedure, in which lithologic information obtained from the distorted calibrated fields is used to condition the generation of a new multimodal field that complies again with the original geostatistics. After transformation, this new field can be calibrated again, and this process is repeated until the newly generated field agrees with the measurement information sufficiently well. Then, the lithologic distribution of this new field is fixed, and the intrafacies conductivity distributions are calibrated. This approach is shown to preserve the original geostatistics, both of the lithology field and of the intralithology hydraulic conductivity distributions.

Development of internal solitary waves in various thermocline regimes - a multi-modal approach

Abstract. A numerical analysis is made on the appearance of oceanic internal solitary waves in a multi-modal setting. This is done for observed profiles of stratification from the Sulu Sea and the Bay of Biscay, in which thermocline motion is dominated by the first and third mode, respectively. The results show that persistent solitary waves occur only in the former case, in accordance with the observations. In the Bay of Biscay much energy is transferred from the third mode to lower modes, implying that a uni-modal approach would not have been appropriate. To elaborate on these results in a systematic way, a simple model for the stratification is used; an interpretation is given in terms of regimes of thermocline strength.

Is multimodal analgesia necessary to facilitate postoperative recovery?

Nociception can be defined as the detection of noxious stimuli and the subsequent transmission of information to the brain. The activity in the nociceptive pathways leads to the experience of pain. Such activity can be modulated by endogenous (eg, neuronal and nonneuronal damage) and exogenous (eg, psychosocial, environmental) stress. The resultant pain behaviors and suffering can be measured and provide useful parameters for clinical assessment. Based on the understanding that basic pain pathophysiology is a complex of interrelated systems, it is clear that one method of analgesia cannot be sufficient to provide optimal pain relief. Therefore, additive and synergistic effects of different types of analgesics would provide sufficient analgesia with fewer side effects. Over the last decade, there have been several studies on the efficacy and side effects of combination therapy compared with the traditional unimodal approach. From the available data, it seems advantageous to use multimodal pain therapy, although more needs to be known on the regimens used, optimal drug composition, and interpatient variability. The introduction of hospital acute pain services has been instrumental for optimizing postoperative pain treatment. Realization by our surgical and nursing colleagues that efficient analgesia is associated with beneficial physiologic effects has prompted several institutions to recognize pain relief as an indicator of patient outcome. The effect of multimodal pain relieving techniques on postoperative morbidity has been studied with the intent to show that patient outcome would be influenced by the type and quality of analgesia. The lack of significant positive results, so far reported, might be explained by the lack of integrating pain relief within an overall recovery program tailored for each specific type of surgery. At this point, it might be necessary to revise the concept of multimodal analgesia in the context of surgical rehabilitation. In this article, all these aspects are reviewed critically to provide the reader with some basis for improving perioperative care so that the benefits of good pain relief become evident.

Biopsychosocial approaches to the treatment of chronic pain.

Biopsychosocial treatments address the range of physical, psychological, and social components of chronic pain. This review sought to determine how effective unimodal and multimodal biopsychosocial approaches are in the treatment of chronic pain. The literature search identified three systematic reviews of the literature and 21 randomized controlled trials to provide the evidence for this review. The systematic reviews and 12 randomized controlled trials reported on chronic low back pain. Other randomized controlled trials studied fibromyalgia (three trials) and back or other musculoskeletal disorders (five trials). Biopsychosocial components reviewed were electromyogram feedback and hypnosis as unimodal approaches, and behavioral and cognitive-behavioral treatments and back school, or group education, as multimodal approaches for chronic low back pain. For other chronic pain disorders, cognitive-behavioral treatments were reviewed. Comparisons were hindered by studies with heterogeneous subjects, varied comparison groups, different cointerventions and follow-up times, variable outcomes, and a range of analytic methods. Multimodal biopsychosocial treatments that include cognitive-behavioral and/or behavioral components are effective for chronic low back pain and other musculoskeletal pain for up to 12 months (level 2). There is limited evidence (level 3) that electromyogram feedback is effective for chronic low back pain for up to 3 months. The remaining evidence of longer-term effectiveness and of effectiveness of other interventions was inadequate (level 4a) or contradictory (level 4b). Future studies of cognitive-behavioral treatments should be condition specific, rather than include patients with different pain conditions.

Multimodal SPECT and MRT imaging data analysis for an improvement in the diagnosis of idiopathic Parkinson's syndrome

Parkinson's disease (PD) is characterized by a degeneration of nigrostriatal dopaminergic neurons, which can be imaged with 123I-labeled 2 beta-carbomethoxy-3 beta-(4-iodophenyl) tropane ([123I]beta-CIT) and single-photon emission computed tomography (SPECT). However, the quality of the region of interest (ROI) technique used for quantitative analysis of SPECT data is compromised by limited anatomical information in the images. We investigated whether the diagnosis of PD can be improved by combining the use of SPECT images with morphological image data from magnetic resonance imaging (MRI)/computed tomography (CT). We examined 27 patients (8 men, 19 women; aged 55 +/- 13 years) with PD (Hoehn and Yahr stage 2.1 +/- 0.8) by high-resolution [123I]beta-CIT SPECT (185-200 MBq, Ceraspect camera). SPECT images were analyzed both by a unimodal technique (ROIs defined directly within the SPECT studies) and a multimodal technique (ROIs defined within individual MRI/CT studies and transferred to the corresponding interactively coregistered SPECT studies). [123I]beta-CIT binding ratios (cerebellum as reference), which were obtained for heads of caudate nuclei (CA), putamina (PU), and global striatal structures were compared with clinical parameters. Differences between contra- and ipsilateral (related to symptom dominance) striatal [123I]beta-CIT binding ratios proved to be larger in the multimodal ROI technique than in the unimodal approach (e.g., for PU: 1.2 vs. 0.7). Binding ratios obtained by the unimodal ROI technique were significantly correlated with those of the multimodal technique (e.g., for CA: y = 0.97x + 2.8; r = 0.70; P < 0.001). Concerning the correlations between SPECT data and clinical parameters, the significance levels in the multimodal ROI technique, for example, for the correlation between CA and the UPDRScom subscore (r = -0.49 vs. -0.32). These results show that the impact of [123I]beta-CIT SPECT for diagnosing PD is affected by the method used to analyze the SPECT images. The described multimodal approach, which is based on coregistration of SPECT and morphological imaging data, leads to improved determination of the degree of this dopaminergic disorder.

Multimodal analgesia approach to postoperative pain management in ambulatory surgery

Surgical procedures performed in an ambulatory setting are increasingly frequent and complex. Providing patients with effective postoperative pain management is the challenge to be met by an anesthesiologist. The traditional unimodal approach to postoperative pain management using systemic opioids is limited by significant side effects which may contribute to delayed discharge and unanticipated hospital admission. Multimodal analgesia and preemptive analgesia are two recent concepts directed toward effective and safe postoperative analgesia which could afford a minimal side effect profile. Multimodal or balanced analgesia techniques seek to enhance analgesia by combining medications and analgesic techniques to exploit possible additive or synergistic effects; thereby reducing the requirement of each medication to minimize side effects. Preemptive analgesic techniques pursue prevention of acute pain by minimizing afferent nociceptive input from injured tissue by preinjury intervention with local anesthetics or opioids. Postoperative analgesic strategies require a multidisciplinary approach that will enable procedures such as knee and shoulder reconstruction to be performed on an ambulatory basis. An anesthesiologist with expertise in regional anesthesia and the pharmacology of analgesics will play a crucial role in applying optimal pain management strategies in an ambulatory surgery setting.

2.3 Clinical test evaluation. Unimodal and bimodal approaches

2.3 Clinical test evaluation. Unimodal and bimodal approaches

Modification of Stepped Care Approach to Antihypertensive Therapy

"Stepped care" is a standardized recipe for uniform treatment of hypertension that has produced useful information on the effectiveness of long-term antihypertensive therapy. However, experience with this unimodal approach to treatment has also revealed its weaknesses. Conceptually, stepped care ignores the possible importance of the means by which blood pressure is reduced and leads to drug overuse since there is no systematic plan for drug subtraction or dose reduction. Moreover, stepped care has never been critically tested against other algorithms. From a practical standpoint, stepped care has never been shown to protect from coronary events, the major burden of hypertension; in several studies, these events may have been increased, probably by the inclusion of a diuretic in the regimen. Such results indicate that a single recipe for all, based on a single process hypothesis, may be hazardous. A critical current issue is the question of whether it matters how the blood pressure is reduced. Thus, diuretics reduce pressure by lowering volume and flow whereas the modern agents, converting enzyme inhibitors and calcium influx inhibitors, reduce pressure while actually improving flow to the target organs. With the availability of more potent and palatable agents with different specificities, and with the increasing awareness of the heterogeneity of essential hypertension and the means to demonstrate it (that is, renin profiling), treatment strategies should be designed and tested in which single drug types are selected for their specificity and their long-term benefits evaluated. In a proposed model, beta blockers or converting enzyme inhibitors are given first to patients with medium or high renin levels and calcium blockers or diuretics to patients with low renin levels. The likely possibility that preservation of flow is a more relevant goal than reduction of pressure per se requires critical examination.

Follow-up of the Cancer Patient

Contemporary treatment by an oncologist is presumed to have preceded the starting point of this text. The editors have allowed no indulgence in speculative measures; for example, adjuvant chemotherapy is considered at points where it is of demonstrable value or noted as a question for research protocol. At several points, particularly in the follow-up of successfully treated neoplasms, greater concern for nonneoplastic or second primary neoplastic disease should be demonstrated. The toxic effects of therapy should also be in diagnostic differentials. The one flawed chapter was that on breast cancer, where a unimodal surgical approach mentioned neither a combined modality treatment option with radiation therapy, nor any role for postprimary treatment, adjuvant chemotherapy. Diligent editing has eliminated redundancy in the brief chapters, all four to six pages devoted to each tumor type. The editorial belief that the nononcologist can provide excellent and cost-effective follow-up seems fulfilled in all solid-tumor areas.

The effectiveness of unimodal versus bimodal presentations of material to be learned by hearing-impaired students.

This study was designed to examine the effectiveness of seven different methods of input upon the learning rate of hearing-impaired students. Different combinations of both unimodal and bimodal methods were utilized to teach Spanish number words to previously naive subjects. The results indicate that bimodal presentations are significantly more effective than unimodal approaches and that fingerspelling can be an important aid to learning for the subjects used in this study.