Methodology for registration of distended rectums in pelvic CT studies.

PURPOSE: Accurate delineation of the rectum is of high importance in off-line adaptive radiation therapy since it is a major dose-limiting organ in prostate cancer radiotherapy. The intensity-based deformable image registration (DIR) methods cannot create a correct spatial transformation if there is no correspondence between the template and the target images. The variation of rectal filling, gas, or feces, creates a non correspondence in image intensities that becomes a great obstacle for intensity-based DIR. METHODS: In this study the authors have designed and implemented a semiautomatic method to create a rectum mask in pelvic computed tomography (CT) images. The method, that includes a DIR based on the demons algorithm, has been tested in 13 prostate cancer cases, each comprising of two CT scans, for a total of 26 CT scans. RESULTS: The use of the manual segmentation in the planning image and the proposed rectum mask method (RMM) method in the daily image leads to an improvement in the DIR performance in pelvic CT images, obtaining a mean value of overlap volume index = 0.89, close to the values obtained using the manual segmentations in both images. CONCLUSIONS: The application of the RMM method in the daily image and the manual segmentations in the planning image during prostate cancer treatments increases the performance of the registration in presence of rectal fillings, obtaining very good agreement with a physician's manual contours.

Three-dimensional quantitative evaluation method of nonrigid registration algorithms for adaptive radiotherapy.

PURPOSE: Current radiotherapy is progressing to the concept of adaptive radiotherapy, which implies the adaptation of planning along the treatment course. Nonrigid registration is an essential image processing tool for adaptive radiotherapy and image guided radiotherapy, and the three-dimensional (3D) nature of the current radiotherapy techniques requires a 3D quantification of the registration error that existing evaluation methods do not cover appropriately. The authors present a method for 3D evaluation of nonrigid registration algorithms' performance, based on organ delineations, capable of working with near-spherical volumes even in the presence of concavities. METHODS: The evaluation method is composed by a volume shape description stage, developed using a new ad hoc volume reconstruction algorithm proposed by the authors, and an error quantification stage. The evaluation method is applied to the organ delineations of prostate and seminal vesicles, obtained by an automatic segmentation method over images of prostate cancer patients treated with intensity modulated radiation therapy. RESULTS: The volume reconstruction algorithm proposed has been shown to accurately model complex 3D surfaces by the definition of clusters of control points. The quantification method, inspired by the Haussdorf-Chebysev distance, provides a measure of the largest registration error per control direction, defining a valid metric for concave-convex volumes. Summarizing, the proposed evaluation methodology presents accurate results with a high spatial resolution in a negligible computation time in comparison with the nonrigid registration time. CONCLUSIONS: Experimental results show that the metric selected for quantifying the registration error is of utmost importance in a quantitative evaluation based on measuring distances between volumes. The accuracy of the volume reconstruction algorithm is not so relevant as long as the reconstruction is tight enough on the actual volume of the organ. The new evaluation method provides a smooth and accurate volume reconstruction for both the reference and the registered organ, and a complete 3D description of nonrigid registration algorithms' performance, resulting in a useful tool for study and comparison of registration algorithms for adaptive radiotherapy.

Automated hexahedral meshing of knee cartilage structures - application to data from the osteoarthritis initiative.

We propose a fully automated methodology for hexahedral meshing of patient-specific structures of the human knee obtained from magnetic resonance images, i.e. femoral/tibial cartilages and menisci. We select eight patients from the Osteoarthritis Initiative and validate our methodology using MATLAB on a laptop computer. We obtain the patient-specific meshes in an average of three minutes, while faithfully representing the geometries with well-shaped elements. We hope to provide a fundamentally different means to test hypotheses on the mechanisms of disease progression by integrating our patient-specific FE meshes with data from individual patients. Download both our meshes and software at http://im.engr.uconn.edu/downloads.php .

Tissue consistency perception in laparoscopy to define the level of fidelity in virtual reality simulation.

BACKGROUND: What degree of fidelity must a laparoscopic simulator have to achieve a training objective? This difficult question is addressed by studying the sensory interaction of surgeons in terms of a surgical skill: tissue consistency perception. METHODS: A method for characterizing surgeon sensory interaction has been defined and applied in an effort to determine the relative importance of three components of perceptual surgical skill: visual cues, haptic information, and previous surgical knowledge and experience. Expert, intermediate, and novel surgeons were enrolled in the study. Users were asked to rank tissue consistency in four different conditions: a description of the tissue alone (Q), visual information alone (VI), tactile information alone (TI), and both visual and tactile information (VTI). Agreement between these stages was assessed by a coefficient of determination (R2). RESULTS: Tissue is a determinant factor (p < 0.001) in the perception of tissue consistency, whereas the expertise of the surgeon is not (p = 0.289). Tissue consistency perception is based mainly on tactile information (TI-VTI agreement is high, R2 = 0.873), although little sensory substitution is present (VI-VTI agreement is low, R2 = 0.509). Agreement of Q-VI increases with experience (R2 = 0.050, 0.290, and 0.573, corresponding with to novel, intermediate, and expert surgeons), which has been associated with the "visual haptics" concept. CONCLUSIONS: Virtual reality simulators need haptic devices with force feedback capability if tissue consistency information is to be delivered. On the other hand, the visual haptics concept has been associated with a kind of tactile memory developed by surgical experience.

The M2DM Project--the experience of two Italian clinical sites with clinical evaluation of a multi-access service for the management of diabetes mellitus patients.

OBJECTIVES: This paper presents a multi-access service for the management of diabetes mellitus patients and the results of its assessment in two Italian clinical sites. METHODS: The service was evaluated for one year in order to prove the advantages of these kind of systems from different points of view. In this paper the clinical, usability and technical outcomes are presented. RESULTS: The evaluation results show that, thanks to the high flexibility of the implemented service, the telemedicine management of diabetes patients is feasible, well accepted by patients and clinically effective. However, in Italy the problem of quantifying the reimbursement rate of telematic services and the impact they have on the organization are factors that may hamper their introduction in routine clinical practice. CONCLUSIONS: The evaluation study showed that the telemedicine intervention has been satisfactory both for physicians because it allows to constantly monitor the patients' blood glucose level and for patients because it strengthens their motivation to self-monitor the metabolic situation.

Modelling Ecological Cognitive Rehabilitation Therapies for Building Virtual Environments in Brain Injury.

BACKGROUND: Brain Injury (BI) has become one of the most common causes of neurological disability in developed countries. Cognitive disorders result in a loss of independence and patients' quality of life. Cognitive rehabilitation aims to promote patients' skills to achieve their highest degree of personal autonomy. New technologies such as virtual reality or interactive video allow developing rehabilitation therapies based on reproducible Activities of Daily Living (ADLs), increasing the ecological validity of the therapy. However, the lack of frameworks to formalize and represent the definition of this kind of therapies can be a barrier for widespread use of interactive virtual environments in clinical routine. OBJECTIVES: To provide neuropsychologists with a methodology and an instrument to design and evaluate cognitive rehabilitation therapeutic interventions strategies based on ADLs performed in interactive virtual environments. METHODS: The proposed methodology is used to model therapeutic interventions during virtual ADLs considering cognitive deficit, expected abnormal interactions and therapeutic hypotheses. It allows identifying abnormal behavioural patterns and designing interventions strategies in order to achieve errorless-based rehabilitation. RESULTS: An ADL case study ('buying bread') is defined according to the guidelines established by the ADL intervention model. This case study is developed, as a proof of principle, using interactive video technology and is used to assess the feasibility of the proposed methodology in the definition of therapeutic intervention procedures. CONCLUSIONS: The proposed methodology provides neuropsychologists with an instrument to design and evaluate ADL-based therapeutic intervention strategies, attending to solve actual limitation of virtual scenarios, to be use for ecological rehabilitation of cognitive deficit in daily clinical practice. The developed case study proves the potential of the methodology to design therapeutic interventions strategies; however our current work is devoted to designing more experiments in order to present more evidence about its values.

Automated Delineation of Vessel Wall and Thrombus Boundaries of Abdominal Aortic Aneurysms Using Multispectral MR Images.

A correct patient-specific identification of the abdominal aortic aneurysm is useful for both diagnosis and treatment stages, as it locates the disease and represents its geometry. The actual thickness and shape of the arterial wall and the intraluminal thrombus are of great importance when predicting the rupture of the abdominal aortic aneurysms. The authors describe a novel method for delineating both the internal and external contours of the aortic wall, which allows distinguishing between vessel wall and intraluminal thrombus. The method is based on active shape model and texture statistical information. The method was validated with eight MR patient studies. There was high correspondence between automatic and manual measurements for the vessel wall area. Resulting segmented images presented a mean Dice coefficient with respect to manual segmentations of 0.88 and a mean modified Hausdorff distance of 1.14 mm for the internal face and 0.86 and 1.33 mm for the external face of the arterial wall. Preliminary results of the segmentation show high correspondence between automatic and manual measurements for the vessel wall and thrombus areas. However, since the dataset is small the conclusions cannot be generalized.

iCarer: AAL for the Informal Carers of the Elderly.

In the context of the long-term care for older adults, informal carers play a key role. Daily competing priorities or a care-skills deficit may lead them to stress, anxiety and/or depression. The iCarer project (AAL-2012-5-239) proposes the design and implementation of a cloud-inspired personalised and adaptive platform which will offer support to informal carers of older adults with cognitive impairment. By means of a holistic approach comprising technologies and services addressing the intelligent and interactive monitoring of activities, knowledge management for personalised guidance and orientation, virtual interaction, e-learning, care coordination facilities and social network services, iCarer aims to reduce the informal carer stress and to enhance the quality of care they provide, thus improving their quality of life. The iCarer platform will be evaluated through a multi-centre non-controlled study (4 months; 48 homes located in England and in Slovenia). Currently the iCarer project is completing the development work. The evaluation trial is expected to start in August 2015.

A broadband multimedia collaborative system for advanced teleradiology and medical imaging diagnosis.

This paper presents a new telemedicine system currently in routine clinical usage, developed within the European Union (EU) ACTS BONAPARTE project (1). The telemedicine system is developed on an asynchronous transfer mode (ATM) multimedia hardware/software platform comprising the following set of telemedicine services: synchronous cooperative work, high-quality video conference, multimedia mail, medical image digitizing, processing, storing and printing, and local and remote transparent database access. The medical information handled by the platform conforms to the Digital Imaging and Communications in Medicine (DICOM) 3.0 medical imaging standard. The telemedicine system has been installed for clinical routines in three Spanish hospitals since November 1997 and has been used in an average of one/two clinical sessions per week. At each clinical session, a usability and clinical evaluation of the system was carried out. Evaluation is carried out through direct observation of interactions and questionnaire-based subjective data. The usability evaluation methodology and the results of the system usability study are also presented in this article. The experience gained from the design, development, and evaluation of the telemedicine system is providing an indepth knowledge of the benefits and difficulties involved in the installation and clinical usage of this type of high-usability and advanced multimedia telemedicine system in the field of teleradiology and collaborative medical imaging diagnosis.

Evaluation of DIABNET, a decision support system for therapy planning in gestational diabetes.

DIABNET is a knowledge-based system designed to aid doctors with therapy planning in gestational diabetes. The system core is a qualitative model, implemented by a Causal Probabilistic Network, that is able to detect the insulin effectiveness on a daily basis. DIABNET analyses monitoring data and proposes quantitative changes in insulin therapy and qualitative diet modifications. This paper proposes an evaluation methodology to assess the system performance when working in a real scenario. The methodology manages the absence of a gold standard and includes: a subjective analysis based on questionnaires and an objective analysis based on a quantitative comparison of the system's and experts' proposals. The paper also shows the results of two experiments in which expert diabetologists evaluated the therapeutical advice provided by DIABNET during the follow up of 9 patients with gestational diabetes. DIABNET detected the need of a therapy modification in 92% of the cases showing its appropriateness for automatic alarm generation. Around 80% of the proposals were accepted by experts. The evaluation results are encouraging and allow characterisation of the system's performance when proposing therapy modifications. Evaluation in its turn helps to refine the knowledge managed by DIABNET and enables us to look towards the further clinical use of DIABNET as a decision tool in gestational diabetes integrated in a telemedicine service.

Optimisation and evaluation of an asynchronous transfer mode teleradiology co-operative system: the experience of the EMERALD and the BONAPARTE projects.

This paper describes the work carried out to optimise and evaluate in clinical routine a multimedia telemedicine application for co-operative imaging diagnosis. This research has been attained within the framework of two European research projects, namely the EMERALD [1] and the BONAPARTE [2]. A user-centred telemedicine application was developed on an existing advanced broadband multimedia teleradiology platform to exploit the possibilities offered by Asynchronous Transfer Mode (ATM) technology to support real-time teleconsultation services for medical imaging. The evaluation of this telemedicine system in both projects has been performed with the aim of (1) characterising and optimising the ATM teleradiology platform, minimising the bandwidth requirements without degrading the quality of service offered to users and (2) evaluating the telemedicine system usability to improve the fulfillment of user's needs. The assessment outcomes have provided insights into technical limitations of broadband multimedia technologies for an optimum usage of a teleradiology co-operative diagnosis systems and the organisational difficulties and limitations involved in setting-up these new advanced telemedicine services to achieve the expected clinical benefits.

A web-based self-monitoring system for people living with HIV/AIDS.

Available evidence indicates that the internet is becoming the main source for delivering information on the prevention, control and treatment of HIV/AIDS. This paper presents a further step in the use of the internet to meet the new challenge of managing HIV as a chronic illness. It describes a work carried out under the SEAHORSE EU project to build and test a Web-based self-monitoring system for HIV/AIDS patient care. The user interface has been carefully designed to provide a high-level of interaction and therefore improve some of the current limitations of Web applications. The system comprises three modules: (1) a patient self-monitoring personal diary, to create a follow-up patient record; (2) a data analysis and visualisation tool; and (3) a section to allow patients to ask for advising and remote doctor support. One of the crucial system design issues has been the system security and users anonymity features required in this clinical domain. A feasibility pilot has been carried out to test the system in three organisations involved in the research project: the Immune Development Trust (London), the Lambeth, Southwark and Lewisham Health Authority (London) and Apoyo Positivo in Madrid. The preliminary results of the system evaluation show the potential validity and usefulness of the tool for helping people living with HIV/AIDS to promote and manage their health and for providing health professionals with new means for tele-monitoring and tele-caring patients.

A telemedicine system for remote cooperative medical imaging diagnosis.

Telemedicine is changing the classical form of health care delivery, by providing efficient solutions to an increasing number of new situations: here we consider those which require some type of computer-supported cooperative work (CSCW) between health care professionals located in different clinical sites. This paper presents the design and development of a telemedicine system for remote computer-supported cooperative medical imaging diagnosis. The main and novel component of our system is a new CSCW distributed architecture, comprised by a collaborative toolkit to add audioconferencing, telepointing, window sharing, user's coordination and application synchronization facilities, either to existing or new medical imaging diagnosis applications. In comparison with existing CSCW products, mainly based on centralized architectures, our distributed toolkit is specially designed for telemedicine applications: to allow different levels of sharing between participants, to improve user feedback in highly interactive user interfaces, and to optimize the required communication bandwidth in order to implement a telemedicine CSCW application on almost any telecommunication network. This telemedicine CSCW system has been applied to build a cooperative medical imaging diagnosis application, in which two doctors, located in different hospitals, need to achieve a cooperative diagnosis on haemodynamic studies using cardiac angiography images. The design of the graphical user interface for this kind of telemedicine CSCW systems, a critical component which conforms any telemedicine application, is also addressed with a new methodological approach, to assure the system usability and final user acceptance. The telemedicine cardiac angiography pilot has been implemented, tested and evaluated within the Research Project 'FEST-Framework for European Services in Telemedicine' funded by EU AIM Programme.

Telemedicine as a tool for intensive management of diabetes: the DIABTel experience.

This paper presents the current features of the DIABTel telemedicine system and the evaluation outcomes of its use in clinical routine. This telemedicine system is designed to complement the daily care and intensive management of diabetic patients through telemonitoring and telecare services. The system comprises a patient unit (PU) used by patients in their day-to-day activities and a Medical Workstation used by physicians and nurses at hospitals. Both applications offer tools to collect, manage, view and interpret data and to exchange data and messages. The system was evaluated for usability, telemedical protocols, metabolic control and quality of life. This evaluation consisted in a 6-month cross-over pilot study with ten Type I diabetic patients. The results of the evaluation allowed assessment of the telemedicine protocols in terms of the number of communications/patient (21.6+/-7.7); days between communications (5.4+/-2.66); messages sent by physicians (118 text messages); and data and messages transmitted by patients (3524 blood glucose readings, 1649 day-to-day insulin adjustments, 24 exercise reports, ten diet modifications and 63 text messages). Physicians performed more therapeutic changes during the DIABTel period than in the control period. There was a trend towards HbA1c improvement during DIABTel use with no incidence in the number of hypoglycaemias. This pilot study demonstrates the feasibility of the DIABTel system in clinical routine use and its potential benefits for diabetes care: improving the availability of information necessary for therapy adjustments; offering new physician-patient communication tools; increasing patient empowerment and education; and showing a positive trend towards improving the metabolic control of patients. Further studies are needed to validate these findings and to promote telemedicine as an opportunity to better diabetes care.

A telemedicine support for diabetes management: the T-IDDM project.

In the context of the EU funded Telematic Management of Insulin-Dependent Diabetes Mellitus (T-IDDM) project, we have designed, developed and evaluated a telemedicine system for insulin dependent diabetic patients management. The system relies on the integration of two modules, a Patient Unit (PU) and a Medical Unit (MU), able to communicate over the Internet and the Public Switched Telephone Network. Using the PU, patients are allowed to automatically download their monitoring data from the blood glucose monitoring device, and to send them to the hospital data-base; moreover, they are supported in their every day self monitoring activity. The MU provides physicians with a set of tools for data visualization, data analysis and decision support, and allows them to send messages and/or therapeutic advice to the patients. The T-IDDM service has been evaluated through the application of a formal methodology, and has been used by European patients and physicians for about 18 months. The results obtained during the project demonstration, even if obtained on a pilot study of 12 subjects, show the feasibility of the T-IDDM telemedicine service, and seem to substantiate the hypothesis that the use of the system could present an advantage in the management of insulin dependent diabetic patients, by improving communications and, potentially, clinical outcomes.

A home telecare management system.

The increasing tendency to discharge chronic patients from hospital, as well as the growing expectation of improved quality of life for elderly and disabled people at home, was the original motivation for the development of a home telecare management system. The system allows a service centre to perform remote monitoring of biological signals and other data via the public telephone network, as well as to manage different emergency situations arising at home. The system is part of the FU-funded EPIC project (European Prototype for Integrated Care). It was tested in Belfast (Northern Ireland) and is currently being installed in Torre del Mar (Spain). This paper describes the system design and preliminary evaluation. The results indicate that the system operators find it highly acceptable in terms of efficiency, effectiveness, helpfulness, control and learnability. Integration of home telecare data with community-care information systems is essential if data captured at home are to be incorporated into the care process effectively.

High-quality conforming hexahedral meshes of patient-specific abdominal aortic aneurysms including their intraluminal thrombi.

In order to perform finite element (FE) analyses of patient-specific abdominal aortic aneurysms, geometries derived from medical images must be meshed with suitable elements. We propose a semi-automatic method for generating conforming hexahedral meshes directly from contours segmented from medical images. Magnetic resonance images are generated using a protocol developed to give the abdominal aorta high contrast against the surrounding soft tissue. These data allow us to distinguish between the different structures of interest. We build novel quadrilateral meshes for each surface of the sectioned geometry and generate conforming hexahedral meshes by combining the quadrilateral meshes. The three-layered morphology of both the arterial wall and thrombus is incorporated using parameters determined from experiments. We demonstrate the quality of our patient-specific meshes using the element Scaled Jacobian. The method efficiently generates high-quality elements suitable for FE analysis, even in the bifurcation region of the aorta into the iliac arteries. For example, hexahedral meshes of up to 125,000 elements are generated in less than 130 s, with 94.8 % of elements well suited for FE analysis. We provide novel input for simulations by independently meshing both the arterial wall and intraluminal thrombus of the aneurysm, and their respective layered morphologies.

Minimally invasive surgical video analysis: a powerful tool for surgical training and navigation.

Analysis of minimally invasive surgical videos is a powerful tool to drive new solutions for achieving reproducible training programs, objective and transparent assessment systems and navigation tools to assist surgeons and improve patient safety. This paper presents how video analysis contributes to the development of new cognitive and motor training and assessment programs as well as new paradigms for image-guided surgery.

AMELIE: Authoring Multimedia-Enhanced Learning Interactive Environment for medical contents.

This paper presents the AMELIE Authoring Tool for medical e-learning applications. The tool allows for the creation of enhanced-video based didactic contents, and can be adjusted to any number of platforms and applications. Validation provides preliminary good results on its acceptance and usefulness.

Characterization of nerve growth factor-induced mechanical and thermal hypersensitivity in rats.

BACKGROUND: Injection of nerve growth factor (NGF) produces mechanical and thermal hypersensitivity in rodents and humans. Treatment with sequestering antibodies demonstrates the importance of NGF in various pain states, with efficacy seen in a number of animal pain models and in painful human conditions. However, these phenomena have not been evaluated in the context of using NGF-induced hypersensitivities as a model of pain. METHODS: NGF-induced behaviours were characterized using von Frey filament, pinprick and thermal endpoints and then pharmacologically evaluated with known reference agents. RESULTS: Intraplantar NGF injection produced a dose-dependent increase in thermal sensitivity that lasted through 24 h post-injection and an immediate long-lasting (2 week) increase in mechanical sensitivity at the injection site, with no effects detected at secondary sites. NGF-induced mechanical sensitivity was pharmacologically characterized at 4 h and 1 week post-NGF injection. The nonsteroidal anti-inflammatory drugs (NSAIDs), celecoxib and diclofenac, were minimally effective against both thermal and mechanical endpoints. Gabapenitn and duloxetine were only moderately effective against thermal and mechanical hypersensitivity. Morphine was effective against thermal and mechanical endpoints at every time point examined. Treatment with the transient receptor potential vanilloid 1 (TRPV1) antagonist A-784168 partially attenuated NGF-induced thermal and mechanical sensitivity at all time points examined. CONCLUSIONS: The results reported here suggest that effects of NGF on thermal and mechanical sensitivity in rats are similar to those reported in human and are partially driven by TRPV1. The rat NGF model may serve as a potential translational model for exploring the effects of novel analgesic agents.