Technology and health care: official journal of the European Society for Engineering and Medicine

New health technologies are often portrayed in the media as being low-cost innovations that will save health care costs. In the case of genomic sequencing – high-speed analysis of multiple genes in parallel fashion – there has been a great deal of media attention about the falling cost of sequencing, referred to as the “$1000 Genome” – with the implication that the full cost of testing is actually $1000. Genomic sequencing (herein called “sequencing”) – is entering clinical care even though there are ongoing challenges of accuracy and reporting.(1, 2) We examine how the full benefits and costs of sequencing will vary widely depending on how the technology is used – emphasizing that the net cost of sequencing will never simply be the cost of testing itself, even though sequencing may provide benefits in many scenarios. As providers and decisionmakers consider when sequencing might be useful clinically, we suggest a framework for evaluating sequencing’s full benefits and costs so that the focus on the “$1000 price tag” for the sequencing technology per se does not obscure the complex decisions to be made about its effective and efficient use.(3) We also provide simulations of the possible economic impact of sequencing using a case study. (Note: We use the term “sequencing” throughout as a simplifying term but discuss how the term has various definitions depending on the context and use.)

Tomographic techniques are attractive for the investigation of trabecular bone architecture. Using either conventional X-ray sources or synchrotron sources currently allows the acquisition of 3D images in a wide range of spatial resolution that may be as small as a few micrometers. Since it is technically possible to examine trabecular architecture at different scales, a question is to know what type of information it is possible to get at each scale. For this purpose, a series of ten vertebrae samples from healthy females of different ages (33 to 90) was imaged at various resolutions on three different micro-CT systems (cubic voxel size respectively 14, 6.7 and 1.4 microm). The comparison of morphometric parameters extracted from the different images is in agreement with simulation results on the influence of spatial resolution on structure parameters. The conclusion is that a 14 microm voxel size gives a reasonably good parameterisation of trabecular architecture. Besides the synchrotron radiation 2 microm level images reveal interesting features on the irregularities and rupture of trabecular surface, and on remodeling zones.

Midshaft clavicle fractures comprise up to 15% of all adult upper extremity fractures and account for 76% of all clavicle fractures. The treatment of choice remains controversial. The aim of our retrospective study was to compare the outcome of the surgical and conservative procedure in a trauma care unit (single center study). MATERIAL and In a cohort of 151 (mean age 36,1y/male 115/female 36) cases, between 2005 and 2009, 70 patients (46.4%) were treated conservatively (mean age 40.8y) and 81 (53.6%) underwent either surgical treatment with a locking compression plate (n=73/mean age 40.3y) or an intramedullary nail system (n=8, mean age 27.1y). Mean follow up was 15 months. Nine patients (5.9%) were lost to follow-up, due to poor compliance. The clinical outcome was assessed by the Disability of Arm, Shoulder and Hand (DASH) score and the Constant shoulder score. The average DASH score was 7.3 and the Constant score measured 91.7 in the surgical group. The conservative group achieved a DASH score of 11.1 and a Constant score of 88.1. The clinical scores showed a significant superiority for the benefit of the surgical treatment for the DASH (p=0.037) and Constant score (p=0.036). Totally nine patients had a non-union in the conservative group and six a hardware failure in the surgical group which were revised. The treatment options for midshaft clavicle fractures have to be discussed carefully for each patient with regard to the non-union risk, function, cosmesis and revision surgery. Both therapeutic modalities demonstrated comparable efficacy. For active and younger patients we would favour a surgical treatment due to the short time of rehabilitation, the return to sport activities and the high non-union rate after conservative treatment.

Fragmentation of sleep by brief arousals has become an acknowledged aspect of poor quality sleep but there is a shortage of normative data on such arousals, especially for children. Norms for arousals (defined according to American Sleep Disorders Association criteria) were compiled for 61 children age 5-16 years using the Oxford Medilog system for a single night of home polysomnography. No significant differences were seen between the five age subgroups considered in average number of arousals per hour of sleep although individual differences were apparent at each age level and arousal duration was somewhat longer at younger ages. The low arousal rates in the children studied are in keeping with other evidence that arousal rates increase throughout life. Boys were no different from girls in either arousal frequency or duration. Arousal frequency was correlated with PSG awakenings but only to a modest extent. These new normative values should be useful in clinical practice and research for the assessment of the quality of children's sleep.

Heart valve replacement has become, since many years, a common surgical practice. Along with the improvement that the patients' health has derived from it, however, a certain amount of risk could not be avoided, bound to the inevitable hemodynamic disturbances that an artificial device generates. A major shortcoming, often reported, is the formation of thrombus on the edge of the prosthetic valve, with a possible obstruction of the orifices through which blood should normally flow undisturbed. Hemolysis is another possible consequence of the implantation of a mechanical heart valve, generally correlated to turbulence downstream of prosthetic heart valves (PHV). As it is agreed upon by many researchers, the risk of thrombogenicity or hemolysis is higher in those valves that are more subject to promote turbulence and flow separation in the flow through them. In the following paper, we present a study of the turbulence-related shear stress downstream of a bileaflet valve of minimum size (19 mm external diameter) Sorin Bicarbon. This size was chosen, accordingly to the Food & Drug Administration (FDA) draft guidance suggestion to investigate the worst case in turbulence promoted by PHVs, in order to have the highest velocity gradients and shear stresses for the FDA-stated cardiac output (6 1/min), related to maximum Reynolds number conditions. Velocity data were collected with the two-dimensional laser Doppler anemometry (LDA) technique; whereas this approach does not investigate directly all three components of the flow field, in the present case (bileaflet valves) it is not a limitation to the assessment of the maximum turbulence shear stress (TSS), thanks to the two-dimensional flow nature downstream of bileaflet models. Data taken in coincident mode were elaborated in order to determine the maximum shear stress in the measured points in the flow field, using the 2D Principal Stress Analysis (PSA). The consequences of a variable principal normal stress direction all along the measured profile will be illustrated in terms of differences between measured and maximum shear stresses. Results show the need to estimate the maximum values for the TSS and the direction along which it is obtained to correctly define the turbulent flow field downstream of PHVs.

In the span of just a few decades, the advent of recombinant DNA technology as well as other tools of biotechnology have revolutionized the health sciences-dentistry, medicine, nursing and pharmacy. The original federal investment in basic science research, primarily through the creation of the National Institutes of Health and several other federal agencies, has delivered truly incredible dividends. Currently, this nation has 1,200 biotechnology companies which contribute over $11 billion a year to the nation's economy. These sales are expected to reach approximately $50 billion in the next decade. In addition to the creation of nearly 100,000 highly skilled jobs and contribution to the nation's economy, biotechnology provides the promise and some uncertainty to vastly improve the quality of life throughout the world. Yet do we have a strategy which encompasses federal, state and private sector policies and an infrastructure sufficient to sustain a substantial basic science investment to fuel the engine of technology and a process that enhances the quality of life for all Americans?

This paper presents the results obtained using radiochromic (MD-55 GafChromic) film for the 2D and 3D dosimetric reconstruction of the dose delivered by a proton beam under the real conditions of a programme of radiotherapy treatment for ocular tumours. Standard microdensitometric measurements were used to determine the variation in film optical density (O.D.) vs dose. Calibration curves were obtained by least-square fitting of the experimental OD values using a second order polynomial. This allows conversion of O.D. to dose. With this procedure it was possible to determine the distribution of the dose delivered by the proton beam in a phantom composed of layers of GafChromic film, with high surface spatial resolution and, through sections, the complete mapping of the dose delivered to a volume subjected to irradiation, as in a course of radiotherapy treatment.

Computational Fluid Dynamic (CFD) is increasingly being used for modeling hemodynamics in intracranial aneurysms. While CFD techniques are well established, need for validation of the results remains. By quantifying features in velocity patterns measured with 2D phase contrast magnetic resonance (pcMRI) in vivo and simulated with CFD, the role of pcMRI for providing reference data for the CFD simulation is explored. Unsteady CFD simulations were performed with inflow boundary conditions obtained from 2D pcMRI measurements of an aneurysm of the anterior communication artery. Intra-aneurysmal velocity profiles were recorded with 2D pcMRI and calculated with CFD. Relative areas of positive and negative velocity were calculated in these profiles for maximum and minimum inflow. Areas of positive and of negative velocity similar in shape were found in the velocity profiles obtained with both methods. Relative difference in size of the relative areas for the whole cardiac cycle ranged from 1%-25% (average 12%). 2D pcMRI is able to record velocity profiles in an aneurysm of the anterior commuting artery in vivo. These velocity profiles can serve as reference data for validation of CFD simulations. Further studies are needed to explore the role of pcMRI in the context of CFD simulations.

The characteristics of an individual's odor from sweat, breath and skin provide important information for criminal tracking in field of forensic science. Solid phase micro-extraction gas chromatography/mass spectrometry (SPME-GC/MS) was used to determine human sweat volatile organic compounds (VOCs) profiles. The mass spectrometric analysis (with electron impact mode) followed by 2nd dimensional separation with two different GC columns (one polar and one relatively nonpolar) connected in parallel were used to identify the 574 compounds from sweat samples. The components included alcohols, aldehydes, aliphatics/aromatics, carboxylic acids, esters, ketones, and other organic compounds (amides/amines, thio/thioesters, oxide, sulfides, nitro compounds). Of these compounds, 1-tridecanol, 1,3-bis(1,1-dimethyl ethyl)-benzene, 4,4'-(1-methylethylidene) bis-phenol and 7-acetyl-6-ethyl-1,1,4,4,-tetramethyl-tetraline were common components in all donor's sweat volatile samples. Age-related specific compounds were also detected. The results suggest that characteristic volatile profiles of human sweat emanations could provide the valuable information to forensic scientists.

The reorientation of the acetabular component in total hip replacement is currently carried out under consideration of the safe zone, respecting the best possible range of motion and is influenced by wear debris of different bearings. Is the preferred orientation a reconstruction of the native anatomy and are there sex-specific differences? On the basis of 168 CT datasets (72 women, 96 men) 336 native hip joints were analysed. The abduction and anteversion of the acetabulum as well as the location of the hip center were detected. As a reference the anterior pelvic plane was used. The 144 female hip joints showed a mean abduction of 53.0 degrees (SD 6.14 degrees ) and an anteversion of 24.63 degrees (SD 6.61 degrees ). The 192 male hip joints showed an abduction of 53.58 degrees (SD 6.68 degrees ) and an anteversion of 21.31 degrees (SD 6.17 degrees ). Significant differences were observed on comparison between the sexes in relation to the anteversion and the location of the hip center. Likewise, there was a significant correlation between the position of the hip center and the degree of anteversion. In total hip arthroplasty a reconstruction of the native acetabular orientation is not possible, gender specific characteristics should be considered.

In a complete dislocation of the talus, the talus is stripped of all its ligament connections in the triple articulated ankle joint. This case report describes the treatment and the 3-year follow-up of a complete dislocation of the talus with the use of intraoperative 3D imaging. The 19-year-old patient was involved as a driver in a car accident. After the radiological diagnosis of a complete talus dislocation, an emergency operation was performed due to the critical soft tissue condition. The ISO-C3D fluoroscope from the company Siemens (Erlangen, Germany) was utilized for reduction control. Follow-up evaluations were completed three years after the treatment, the patient had no complaints. Since these types of serious injuries are always combined with severe soft tissue damage, the main goals of this treatment have to be debridement and minimized iatrogenic surgical damage. By using intraoperative 3D imaging, immediate reduction control is available, so that revision operations can be avoided. Complete dislocation of the talus is an extremely rare injury, which may cause serious complications. A fast and careful reduction, whether open or closed, should be the goal of treatment. Successful reduction can be determined intraoperatively with the use of 3D imaging.

In vivo examinations of bone microarchitecture have become available recently through high resolution computed tomography (3D-QCT) and magnetic resonance imaging. The spatial resolution of the resulting images, however, is not sufficient to depict individual trabeculae in their true shape. Nevertheless, structural indices such as relative bone volume, trabecular number, mean thickness and mean separation can be extracted with the help of a ridge detection algorithm. Precision of the procedure is of the order of 1%, accuracy is ascertained using a micro-CT based calibration. In this work we report first results of time serial examinations. Eighteen healthy postmenopausal women (no HRT) were measured at months 0, 6, and 12, and the temporal changes were analyzed. Examination site was the distal radius. The above mentioned structural indices, the average densities and the thickness of the cortical shell were determined. Of the 18 women 6 showed no significant bone loss of any kind, 5 lost primarily cancellous bone, 4 lost primarily cortical bone, and 3 had a substantial loss of cortical as well as cancellous bone. We conclude that even in a homogenous group such as postmenopausal women, there are considerable differences in the reason why bone is weakened and that high resolution 3D-QCT allows to differentiate between various types of bone loss.

The use of 3D ultrasound imaging to follow the progression of scoliosis, i.e., a 3D deformation of the spine, is described. Unlike other current examination modalities, in particular based on X-ray, its non-detrimental effect enables it to be used frequently to follow the progression of scoliosis which sometimes may develop rapidly. Furthermore, 3D ultrasound imaging provides information in 3D directly in contrast to projection methods. This paper describes a feasibility study of an ultrasound system to provide a 3D image of the human spine, and presents a framework of procedures to perform this task. The framework consist of an ultrasound image acquisition procedure to image a large part of the human spine by means of a freehand 3D ultrasound system and a volume reconstruction procedure which was performed in four stages: bin-filling, hole-filling, volume segment alignment, and volume segment compounding. The overall results of the procedures in this framework show that imaging of the human spine using ultrasound is feasible. Vertebral parts such as the transverse processes, laminae, superior articular processes, and spinous process of the vertebrae appear as clouds of voxels having intensities higher than the surrounding voxels. In sagittal slices, a string of transverse processes appears representing the curvature of the spine. In the bin-filling stage the estimated mean absolute noise level of a single measurement of a single voxel was determined. Our comparative study for the hole-filling methods based on rank sum statistics proved that the pixel nearest neighbour (PNN) method with variable radius and with the proposed olympic operation is the best method. Its mean absolute grey value error was less in magnitude than the noise level of a single measurement.

Background: Revision joint replacements are challenging surgical tasks. Knowing the exact type of primary prosthesis is essential to avoid long preoperative organisation, long operation times, and especially loss of bone and soft-tissue during operation. In daily routine there is often no information about the primary prosthesis. Objective: We are developing methods for identifying implanted prostheses from x-ray images by means of matching template images generated from prosthesis CAD data. Methods: The application is separated into three major components: The "Template Image Generation" adds 3d models of endoprostheses to a database. The "X-ray Image Segmentation" extracts endoprostheses from provided sets of x-ray images. The "Template Matching" finds the best matching prosthesis types in the data base. At the current stage, one prosthesis model (Corin, Knee ProthesisUniglide) was used for evaluating these algorithms. Results: Very accurate identifications with accuracies of about 90% for lateral and over 70% for frontal images could be achieved. Conclusions: The current results of this feasibility study are very promising. A reliable and fast prosthesis identification process seems realistic to support the surgeon when planning and performing revision arthroplasty. Further improvements of segmentation accuracies and extending the prosthesis data base are intended next steps towards this goal.

A method for kinematic analysis of chest wall motion is presented, based on a TV-image processor which allows a three-dimensional assessment of volume change of the trunk by automatically computing the co-ordinates of several passive markers placed on relevant landmarks of the thorax and abdomen. The parallel computation used for the image processing allows a real time recognition of the passive markers with the necessary accuracy. A geometric model also allows the on-line computation of the contribution to the chest volume by the different parts. For this purpose the model is based on 96 tetrahedrons which can be grouped into 16 compartments and into four sections representing: upper thorax (reflecting the action of neck and parasternal muscles and the effect of pleural pressure), lower thorax (reflecting the action of diaphragm and the effect of pleural and abdominal pressure), upper and lower abdomen (reflecting the actions of diaphragm and abdominal muscles). The volume can also be split into two vertical sections pointing out asymmetrics between the right and left side. The method is non-invasive, non-ionizing and leaves the subject maximum freedom of movement during the test, thus being suitable for routine clinical analysis. The monitoring of the subject can be prolonged in time and can be performed in different postures: standing, sitting, supine and lying on one side. The method was tested on eight healthy subjects showing good accuracy, reliability and reproducibility.

Buying or creating a virtual reality (VR) software is very costly. A less expensive alternative could be to modify already existing 3D computer games. The goal of this study is to assess the effectiveness of in virtuo exposure in the treatment of arachnophobia using modified 3D games. Participants were 10 women and 1 man. Virtual worlds were created using the game editor of a 3D computer game (Half-Life), modified to offer graduals hierarchies of fearful stimuli (spiders). Analyses revealed significant improvement between pre and post results on the behavioral avoidance test, the Spider Beliefs Questionnaire, and perceived self-efficacy. These promising results suggest that therapy using virtual reality exposure via a modified computer game is useful in the treatment of arachnophobia.

Computer-assisted treatments have become increasingly common. Consequently, there is an increased desire for navigation methods with simplified workflow. Anatomic-based pair-point registration is often mentioned as a source of error. Alternatively, the use of preoperatively implanted markers for registration remains complex. The self-acting registration of Iso-C-3D at the moment of data acquisition can reduce essential errors. The aim of this study was to evaluate the effect of reference placement on accuracy, and to determine the maximum acceptable distance between the reference and a given isocentre. This study demonstrates the interdependence of the reference distance on the region of interest (ROI). The mean error of registration amounts to 0.04 mm (0.04-0.05 mm) up to a distance of 200 mm and beyond 0.25 mm (0.24-0.26) for distances beyond 200 mm. The accuracy was significantly lower (p<0.0001) with a distance more than 200 mm. For optimal accuracy when utilizing navigation for pelvic and long bone surgery, the reference base should not been placed at a distance more than 200 mm from the isocentre of interest.

In the present research a system for medical image processing has been proposed, which allows dynamic 3D visualization and successive left ventricular wall analysis. The 3D volume rendering algorithm results are presented using a friendly Graphical User Interface (GUI) giving the possibility to change interactively image processing and visualization parameters at any step, to perform simple and effective image manipulations. The left ventricular wall detection algorithm is based on the evaluation of classified volumetric data during volume rendering algorithm. In fact classification operation includes a 3D segmentation. The system has been tested in medical environment, for Magnetic Resonance (MR) images. Resulting studies have demonstrated a very high global efficiency in practical situations by using typical data volume dimensions.

The main problems in intra-medullary nailing of femoral shaft-fractures are leg-length discrepancies and rotational differences with an incidence of 2-18% and 20-40% respectively. These may lead to severe postoperative sequelae such as additional correctional operations and difficult rehabilitation. Insufficient visualization can be considered the main reason for these complications. Finally, retention of the fragments in the correct alignment before nail insertion is difficult. To overcome these problems we established a robotic telemanipulator system to support the reduction process. It was evaluated in 30 fractures of embalmed human femora. Specially programmed software used an image-dataset which was acquired by an isocentric 3D fluoroscope. For visualization, a surface projection was generated. Localization and tracking of the fragments and the robot-arm as well as accuracy measurement was performed by using an optical navigation system. Manipulation was controlled via a force-feedback joystick. This way, collisions of the fragments were transmitted back to the surgeon. At the end of the reduction the robot could rigidly retain the fragments' position.

Computer Tomography (CT) guided percutaneous bone biopsy has been established as a minimally invasive method for the rapidly obtaining samples from osseous lesions for histological examination. With this method, an overall accuracy of 90% can be obtained without a significant radiation exposure. The aim of this study was to develop a navigated sleeve for the Jamshidi needle in order to perform navigated, percutaneous bone biopsies with the help of Iso-C-3D. Utilizing this navigated biopsy needle, the procedure was analyzed for several parameters including precision, total operating time, and level of radiation exposure. By using the Iso-C-3D navigation the total operating time was 11.7 min (8-14.3) and radiation exposure was 1.6 (0.67-2.12 min). This study demonstrates that navigated percutaneous bone biopsies can be obtained fast and with low radiation exposure. The feasibility of Iso-C-3D navigated bone biopsies is tempered by the requirement a rigidly fixed dynamic reference frame.

Port films are used in radiotherapy for visual evaluation of the radiation fields and subsequent quantitative analysis. Common port films suffer from poor image quality compared to the simulator-diagnostic films and is desirable to determine the appropriate exposure required for the best image contrast. The aim of this work is to generate technique charts for the Kodak EC-L film screen system for use in a 6MV x-ray beam. Three homogeneous water phantoms were used to simulate head-neck, thorax and abdomen dimensions of adult human, correspondingly. The film screen system was calibrated in a 6MV x-ray beam and under various irradiation conditions. The film screen system behavior was studied as a function of phantom thickness, field size and air gap between the phantom and the film screen system. In each case the optimum film exposure which produces the maximum image contrast was determined. The generated technique charts for the EC-L film screen system and for a 6 MV x-ray beam are used in our radiotherapy department for daily quality assurance of the radiotherapy procedure.

Paralysis of the respiratory muscles in people with tetraplegia affects their ability to breathe and contributes to respiratory complications. Surface functional electrical stimulation (FES) of abdominal wall muscles can be used to increase tidal volume (V_{T}) and improve cough peak flow (CPF) in tetraplegic subjects who are able to breathe spontaneously. This study aims to evaluate the feasibility and effectiveness of a novel abdominal FES system which generates stimulation automatically, synchronised with the subjects' voluntary breathing activity. Four subjects with complete tetraplegia (C4-C6), breathing spontaneously, were recruited. The automatic stimulation system ensured that consistent stimulation was achieved. We compared spirometry during unassisted and FES-assisted quiet breathing and coughing, and measured the effect of stimulation on end-tidal CO_2 (EtCO_2) during quiet breathing. The system dependably recognised spontaneous respiratory effort, stimulating appropriately, and was well tolerated by patients. Significant increases in V_T during quiet breathing (range 0.05-0.23 L) and in CPF (range 0.04-0.49 L/s) were observed. Respiratory rate during quiet breathing decreased in all subjects when stimulated, whereas minute ventilation increased by 1.05-2.07 L/min. The changes in EtCO_2 were inconclusive. The automatic stimulation system augmented spontaneous breathing and coughing in tetraplegic patients and may provide a potential means of respiratory support for tetraplegic patients with reduced respiratory capacity.

An abdominal aorta aneurysm (AAA) is a disease that aortic vessel inflates abnormally. The aorta blows up continuously, which may lead to the rupture of the aorta. The mortality of rupturing the aorta is between 75 and 90% to properly treat this disease, we need to accurate measure about variation of AAA size. our team performed that AAA is reconstructed as three dimensional (3D) images by computer tomography (CT), and analyzed the elements of inflation through a geometric parameter measurement . Subjects (seven males) who undergo an AAA are enrolled for the analysis. The authors used CT images as a primary source, and obtained secondary CT images 12 months later.By means of these data, the authors constructed 3D images of AAA and performed examinations using a geometric analysis that calculates geometric parameter such as the tortuosity, diameter, saccular and so on based on volume, area of the segmented region of the CT slices that is set up by the centroids and 8 points around it. The result of the severity biomechanical factor shows increased AAA tortuosity ratio (4.9%), AAA diameter expansion ratio [cm/year] (6.8%), AAA total diameter ratio (4.7%), AAA saccular ratio (2.4%) than 12-month before. Through these results, We can plan to endovascular repair surgery to undergoing AAA patients and possible diagnosis estimation of AAA.

A lateral, transgluteal approach for hip resurfacing carries the risk of approach-related weakening of the hip abductors due to unsuccessful re-adaptation of the gluteal muscles to the greater trochanter or to injury to the inferior nerve branch of the superior gluteal nerve.OBJECTIVE: We investigated whether hip resurfacing using a soft tissue-sparing, modified transgluteal approach with limited cranial splitting of the gluteus medius muscle reduces hip abductor strength and the risk of approach-related injury to the superior gluteal nerve.METHODS: Thirty-one patients (14 female, 17 male; mean age 53.5 ± 5.2 years) underwent hip resurfacing using a modified transgluteal approach with limited cranial splitting of the gluteus medius muscle. Nerve conduction signals were measured by surface electromyography (EMG), hip abductor strength by isokinetic testing a mean 36.2 months (±11 mos) after surgery. The unoperated side was used as control. Surface EMG disclosed no neural lesions of the inferior branch of the superior gluteal nerve. Isokinetics revealed a significant reduction in muscle strength on the operated versus the contralateral side. Even a limited incision of the gluteus medius muscle resulted in significant impairment of hip abductor strength 2.5 years after surgery.

Supervision is defined by a visual acuity of 20/10 or 20/8 and may be attained by custom-correcting the aberrations of higher order of the human eye. Higher order aberrations are those aberrations which are left in the eye after having corrected lower order aberrations, i.e., defocus (myopia, hypermetropia) regular astigmatism, and which can be corrected by ordinary spectacle lenses or contact lenses. Higher order aberrations are found to a higher or lesser degree in normal or pathological human eyes and in eyes having undergone conventional corneal surgery. According to custom keratorefractive surgery limits, given by the neural visual apparatus and the receptor mosaic, supervision (i.e., 20/10 or even 20/8) may be attained. A number of dedicated sensors have been developed in recent years that are able to detect and measure aberrations of the wave front which is a sensitive procedure for the determination and surgical control of the optical quality of the eye. Not every custom keratorefractive procedure results in supervision, however. This is because not every "normal" eye is able to reach such limits because of its basic design (anatomy or function) and also because keratorefractive procedures neglect the plastic behaviour of the cornea. The plasticity of the central neural system may furthermore interact with corrected or non-corrected visual function.

Recurrence of hepatocellular carcinoma (HCC) after surgical treatment is a common problem. It can be treated by radiofrequency ablation (RFA) or repeated hepatic resection (HR). This report compares both in a retrospective, single-institution database. A prospectively collected database was retrospectively analyzed. RFA was performed under ultrasound control using two different monopolar devices. All kinds of access were used: open surgical (n=10), percutaneous (n=13) and laparoscopic (n=4). HR was performed using an ultrasound aspiration device. Indication for a particular treatment was allocated on a case-by-case basis; the final decision was often made intraoperatively. Survival after RFA (median 40 months) was similar compared to that after HR (48 months, p=0.641, logRank-test). Tumor-free survival was markedly impaired after RFA (15 vs. 29 months). This difference was however not significant (p=0.07, logRank-test). Both groups were different regarding occurrence of cirrhosis, maximal tumor size, time after initial diagnosis and duration of the procedure. In this non-randomized retrospective trial, survival and disease-free survival was not significantly different when compared between patients treated by RFA and HR. There was however a tendency towards a longer tumor-free survival in the resected patients.

Robotics-assisted tilt table technology was introduced for early rehabilitation of neurological patients. It provides cyclical stepping movement and physiological loading of the legs. The aim of the present study was to assess the feasibility of this type of device for peak cardiopulmonary performance testing using able-bodied subjects.METHODS: A robotics-assisted tilt table was augmented with force sensors in the thigh cuffs and a work rate estimation algorithm. A custom visual feedback system was employed to guide the subjects' work rate and to provide real time feedback of actual work rate. Feasibility assessment focused on: (i) implementation (technical feasibility), and (ii) responsiveness (was there a measurable, high-level cardiopulmonary reaction?). For responsiveness testing, each subject carried out an incremental exercise test to the limit of functional capacity with a work rate increment of 5 W/min in female subjects and 8 W/min in males. 11 able-bodied subjects were included (9 male, 2 female; age 29.6 ± 7.1 years: mean ± SD). Resting oxygen uptake (O _{2} ) was 4.6 ± 0.7 mL/min/kg and O _{2} peak was 32.4 ± 5.1 mL/min/kg; this mean O _{2} peak was 81.1% of the predicted peak value for cycle ergometry. Peak heart rate (HRpeak) was 177.5 ± 9.7 beats/min; all subjects reached at least 85% of their predicted HRpeak value. Respiratory exchange ratio (RER) at O _{2} peak was 1.02 ± 0.07. Peak work rate) was 61.3 ± 15.1 W. All subjects reported a Borg CR10 value for exertion and leg fatigue of 7 or more.CONCLUSIONS: The robotics-assisted tilt table is deemed feasible for peak cardiopulmonary performance testing: the approach was found to be technically implementable and substantial cardiopulmonary responses were observed. Further testing in neurologically-impaired subjects is warranted.

We present an Agent-Based Modelling Tool (ABMT) for scheduling patients at a diagnostic imaging facility. The ABMT accommodates multiple diagnostic imaging devices, a variety of patient classes, and an uneven distribution of server availability. The tool was tested using data and expertise from a hospital in Ontario, Canada. We show that the tool was able to identify a previously undetected increase in patient arrivals, establishing its effectiveness as a management tool.

Vernier thresholds rise much more rapidly in the periphery than do grating thresholds. A similar dissociation between acuity and hyperacuity has been shown to be present in strabismic but not in anisometropic amblyopia, thus leading to the suggestion ...

Vernier thresholds rise much more rapidly in the periphery than do grating thresholds. A similar dissociation between acuity and hyperacuity has been shown to be present in strabismic but not in anisometropic amblyopia, thus leading to the suggestion that the strabismic fovea is similar to the normal periphery. Here it is shown that a quantitative model for spatial pattern discrimination, which accounts for foveal hyperacuity data, can be extended to encompass both the periphery and amblyopia if appropriate alterations are made. For the periphery it is necessary to increase the size of model receptive fields and to introduce both spatial undersampling and position irregularity (i.e. irregularity in the location of cortical filters). The strabismic fovea also requires spatial undersampling and position irregularity but no change in receptive field size. Defects in the good eye of strabismus can be explained by spatial irregularity. Finally, the anisometropic fovea requires a reduction in mechanism sensitivity but neither spatial untersampling nor position irregularity.

Background: In recent times there has been a significant change in lifestyle in many parts of the world, with most people experiencing a more sedentary existence combined with an abundance of food. This has resulted in the modern epidemic of obesity and consequent hyperinsulinemia - situations which in women may precipitate expression of fertility problems; effective methods to evaluate the fertility status are required. Ultrasonographic imaging is an effective, easy to use, safe, and readily available noninvasive means to evaluate fertility potential. Objective: Manual recognition of the follicles in terms of area measurement and counting the number of follicles is laborious; often fatigue may lead to error-prone conclusions. The paper attempts an automated classification of the ovaries based on the biomarking done by the physician. Also, biomarked data correlates with the hormones values such as androgen, testosterone and leutinizing hormone. Methods: Despeckled images are segmented by improved active contour with split-Bregman optimization. The features are extracted from images using geometric and intensity method. The significant features selected by particle swarm optimization and dimension reduction by principal component analysis and classification by probabilistic neural network. Results: Proposed probabilistic neural network achieves maximum efficiency of 97% compared to SVM 92% and RBF 88%. Conclusions: The results obtained show that using a very large number of features combined with a feature selection approach allows us to achieve high classification rates.

An amount of 70,000 minor/major amputees are annually performed for different reasons such as tumor, trauma, perivascular diseases or diabetic ulcera yearly in Germany. Over the course of time a lot of patients get problems with their stump, which leads to an incompatible prosthetic treatment and immobilisation. Handicapped patients are often characterized by a long history of pain. The fact that they often had comorbidities as diabetes, vascular diseases or other metabolic affection, leads to the situation that no other differential diagnoses are taken into account. We present a case of a 62 year old patient with a history of burning pain with punctum maximum at the dorso-medial part of the distal femur stump 40 years after a traumatic above-knee amputation. He had sought different medical consultations and had a lot of modifications on his prosthesis shaft with partial benefit. The clinical examination confirmed the suspected diagnosis of a stump neuroma from the sciatic nerve, which has been verified in the MRI. Concerning the symptoms and the increasing immobilisation caused by the burning pain, we indicated a surgical revision which includes a resection from the neuroma and a local flap graft correction. Postoperatively he described a complete pain relief. After 6 weeks under weight bearing mobilisation he was 100% free of pain in his new custom-made shaft prosthesis and could mobilised under full bearing. We conclude that neurinoma needs to be considered in handicapped patients with such symptomatology and has to be surgically revised, even if that decision especially for handicapped patients is often difficult for the surgeon.

The purpose of this study is to examine relationship between the accident and injury occurrence and the absence appearance in adults. Materials of this study were based on the raw data of "Korea National Health and Nutrition Examination Survey 2011", which was conducted by the Ministry of Health and Welfare (MW) and Korea Centers for Disease Control and Prevention (CDC) in 2011. Totally 5904 people were targeted by selecting data without missing value in addition to age in more than 20 years old. And the appearance of absence through the occurrence of injury had the final subjects of absence targeting 379 people among 5904 people. An analytical method was made by using SPSS WIN program (Version 12.0). As a result of research, the occurrence of injury was higher (p< 0.01) in men than women. The age group was high in the 30s (about 1.5 times, p< 0.05) and the 40 s (about 1.9 times, p< 0.01). The higher in household income (about 1.5 times, p< 0.05) and educational level (about 1.6 times, p< 0.001) led to the higher occurrence of injury. As for the occurrence of absence, fall and slip (abut 1.8 times, p< 0.05) had higher absence than other accidents. As for a place of cure, the absence were higher (p< 0.001) in users of emergency room than entering hospital/clinic. Finally, the more bed-ridden led to the higher absence (p< 0.001).

Ultrasound studies evaluating bone tissue generally concentrate on two parameters--velocity and attenuation. This study aimed to determine whether ultrasound signal analysis techniques could provide additional information on the structural and mechanical characteristics of bone. In vitro measurements were made on 26 left index fingers from human cadavers. Ultrasound measurements at the distal metaphysis and epiphysis; dual-energy X-ray absorptiometry of the whole phalanx; micro-computed tomography at the distal quarter of the phalanx (that is, the distal epiphysis and metaphysis), and mechanical three-point bending tests were performed. Univariate and multivariate linear regression techniques were used to analyze the results. The ultrasound parameters, speed of sound and ultrasound peak amplitude correlated significantly with the three micro-computed tomography measures used to describe the characteristics of mineralized material (r=0.69-0.79, p<0.05). Low frequency ultrasound correlated significantly with micro-computed tomography parameters describing inter-trabecular or marrow spaces (r=0.68-0.78, p<0.05). Comparison of ultrasound parameters with geometric characteristics showed that while speed of sound and ultrasound peak amplitude were related to the cortical area, moment of inertia, and mechanical load (r=0.57-0.83, p< 0.05), the amplitude of the fastest part of the ultrasound signal and full width at 80% maximum of the low frequency peak were related to the relative area of the medullary canal (r=0.40-0.43, p<0.05). Quantitative ultrasound may provide information on structural, material and mechanical characteristics of bone to the same extent and even better than DXA Bone Mineral Density. These results have been obtained by a complete and exhaustive use of QUS technology in situ but under clinical conditions. The ultrasound parameters, correctly used and combined, seem to be effective tools for investigating bone tissue.

It is assumed that bone mineral density (BMD) measurement by dual-energy X-ray absorptiometry (DXA) has its limitation in identifying bone strength, and therefore other methods should be developed. Non-invasive strength measurement, which is needed to diagnose and monitor metabolic bone diseases such as osteoporosis, can become an alternative to current methods. In this study, mechanical vibration analysis was compared to BMD measured by DXA in human female tibia. Seven mother (Ms) and daughter (Ds) pairs' (total n = 14) left and right tibiae were evaluated by DXA and mechanical vibration analysis. Mechanical vibration analysis was consistent in the same bone and also in both sides. Correlation between BMD measured by DXA and vibration analysis was found in the Ds and Ms groups; the former being stronger than the latter. Natural frequencies of the Ms group were higher than that of the Ds group, and the response velocity of the Ds group was shorter than that of the Ms group. It is concluded that mechanical vibration analysis is consistent in bones and a correlation between BMD measured by DXA and vibration analysis can be established in young females that may be used in field studies to predict peak bone strength.

A new method was developed to estimate the in vivo time of absorption of alpha-hydroxy polyester type polymers. This method is based on the pH Stat titration of the polymer as a function of time which can be related to the absorption time of the polymer in the body.

Gait impairment seems to be a risk factor for falls and mortality. Because gait change cannot be determined easily with classical clinical tests, some authors have suggested that it might be useful to use a gait-analysis system among elderly community-dwelling people. The main objective of the present study was to determine the predictive value of a quantitative evaluation of the gait characteristics in nursing home residents for the occurrence of falls and death performed using a tri-axial accelerometer (Locométrix®). One hundred elderly nursing home residents (80 women and 20 men, mean age 86.4 ± 6.04 years) were included in this study with the aim to follow them for 2 years. Deaths and falls were systematically recorded. A quantitative evaluation of a 10-second walk was performed with a tri-axial accelerometer (Locometrix®). Demographic data (i.e age, sex, body mass index) and clinical data (i.e. fall risk evaluated by the Tinetti test) were also recorded. During the two years of follow-up, 27 patients died. After adjustment on all potential confounding variables, only body mass index was significantly associated with the risk of mortality with an odds ratio of 0.86 (95% CI: 0.77-0.96, p=0.04). At the end of the study period, 440 falls had occurred (mean: 4.44 ± 6.79 falls per patient) but no single factors were independently associated with fall incidence. Our results show that a quantitative gait analysis performed using a tri-axial accelerometer is not predictive of long-term falls and mortality among nursing home residents.

An effective way for preventing injuries and diseases among the elderly is to monitor their daily lives. In this regard, we propose the use of a "Hyper Hospital Network", which is an information support system for elderly people and patients. In the current study, we developed a wearable system for monitoring electromyography (EMG) and acceleration using the Hyper Hospital Network plan. The current system is an upgraded version of our previous system for gait analysis (Yoshida et al. [13], Telemedicine and e-Health 13 703-714), and lets us monitor decreases in exercise and the presence of a hemiplegic gait more accurately. To clarify the capabilities and reliability of the system, we performed three experimental evaluations: one to verify the performance of the wearable system, a second to detect a hemiplegic gait, and a third to monitor EMG and accelerations simultaneously. Our system successfully detected a lack of exercise by monitoring the iEMG in healthy volunteers. Moreover, by using EMG and acceleration signals simultaneously, the reliability of the Hampering Index (HI) for detecting hemiplegia walking was improved significantly. The present study provides useful knowledge for the development of a wearable computer designed to monitor the physical conditions of older persons and patients.

We used the Recursive Least Squares algorithm and a predictor filter to automatically identify the start and stop times of 6 simple nursing activities. The dataset included continuous acceleration recordings obtained with a single accelerometer sensor attached to the backs of 8 nurses. The algorithm requires no training. It identifies the start and stop time of each activity when at least 2 of 3 axes show significant acceleration changes not more than a second apart. The overall accuracy of the algorithm for a total of 96 start and stop events was 86.46% ± 12.55%. The accuracy was higher than 91% for 5 out of 8 subjects. The algorithm also indicated the onset of subcomponents of nursing activities for the majority of the subjects. The results of this study suggest that the presented algorithm may be useful in identifying transition points of human activities recorded with accelerometers.

3D orientation obtained by integrating the rate gyroscope signals can be improved by fusion with inclination information obtained from

Being well-informed and knowledgeable about their illnesses would be a great advantage to children with epilepsy (CWE). Subsequently, an effective education programme which could secure interest and simultaneously improve their awareness, knowledge and attitudes (AKA) is essential in enhancing well-being and health outcomes. To describe the development of a new interactive animated epilepsy education programme (IAEEP) for children and to assess its feasibility, acceptability and practicality. The IAEEP was developed by an interdisciplinary group of neurologist, paediatrician, pharmacist, biomedical scientist and educators which was based on two established epilepsy education programmes: the educational programme for patients with epilepsy and their relatives (MOSES) and the modular educational program for children with epilepsy and their parents (FAMOSES). CWE from paediatric department of three general hospitals in Terengganu were initially introduced to the IAEEP and were requested to complete an evaluation form assessing its feasibility, acceptability and practicality. Descriptive statistics were employed for data analyses (SPSS 20.0). Sixteen CWE (median age=13.0; male=56.2%; Malay=81.2%; secondary school=56.2%) and their corresponding parents were recruited. Each CWE owned at least a computer/notebook/tablet (100%). The cost of distribution of IAEEP (in compact disc form) among CWE was estimated at about MYR 17.99/USD 5.90 per CWE. The average time required to interact with the programme was 22.8 minutes (SD=3.3, range 18-28 minutes). The programme was 100% acceptable and received full support from both CWE and their parents (100%). The favourable findings from this study adds to the growing evidence suggesting that investment in interactive and animated education programme would be both feasible, well-received by patients and could be a potentially valuable approach to increase access and effectiveness of epilepsy care especially among CWE.

HMIS will incorporate a paradigm shift in health such as removing manual records and transformation of data through the complex structure of health departments in Tamilnadu. Thus developing a model of technology acceptance in HMIS contest is important and necessary in order to promote usage of the HMIS in rural health care system.OBJECTIVE: The papers purpose is to formulate a model of technology acceptance of Health Management Information System (HMIS) by generating and validating a research model that best describes rural health care workers usage behavior and behavior intention. This research proposes a theoretical framework which is comprised of key determinants that influence usage behavior of HMIS together with moderator. It has been tested through different parametric test and confirmatory factor analysis. Data analysis shows that health workers innovativeness and voluntariness have a direct and positive influence on Technology Acceptance level and that the basic TAM hypotheses are fulfilled. HMIS usage behavior and behavior intention can be increased with factors that are effecting the successful implementation of HMIS when it remains high. This research enables health departments to know which aspects of their HMIS components and variables to improve. This shows that HMIS usage and health workers/staffs acceptance level are key tools in the success of HMIS. This research has seemed to be done at the right time and in the right place to the best of its kind.

In the United States, Hispanic populations tend to have higher incidences of chronic disease such as diabetes, cardiovascular disease, hypertension, obesity and hyperlipidemias [1]. They are also more likely to be underinsured or uninsured than other populations [2]. The purpose of this descriptive technology assessment survey study was to determine computer and internet access, skill level and health education information preferences of a rural Hispanic (primarily Mexican-American) population in the United States. Among the sample, 81% of individuals who answered the survey had a computer and internet access in their home. Nineteen percent did not have computers or internet access in their homes. Compared to the average 54% home internet access found by the Pew Hispanic Research Center the rural convenience sample in this study had a high percentage of technology access. Recommendations include using multimedia to improve the health information accessability among Hispanic persons.

Recent research works examine the potential employment of public-key cryptography schemes in e-health environments. In such systems, where a Public Key Infrastructure (PKI) is established beforehand, Attribute Certificates (ACs) and public key enabled protocols like TLS, can provide the appropriate mechanisms to effectively support authentication, authorization and confidentiality services. In other words, mutual trust and secure communications between all the stakeholders, namely physicians, patients and e-health service providers, can be successfully established and maintained. Furthermore, as the recently introduced mobile devices with access to computer-based patient record systems are expanding, the need of physicians and nurses to interact increasingly with such systems arises. Considering public key infrastructure requirements for mobile online health networks, this paper discusses the potential use of Attribute Certificates (ACs) in an anticipated trust model. Typical trust interactions among doctors, patients and e-health providers are presented, indicating that resourceful security mechanisms and trust control can be obtained and implemented. The application of attribute certificates to support medical mobile service provision along with the utilization of the de-facto TLS protocol to offer competent confidentiality and authorization services is also presented and evaluated through experimentation, using both the 802.11 WLAN and General Packet Radio Service (GPRS) networks.

The insertion site for an antegrade femoral intramedullary nail in the treatment of a femoral shaft fracture has traditionally been performed using a free-hand technique. An inappropriate starting point can result in suboptimal nail insertion leading to malreduction, or iatrogenic fracture. Furthermore, repeated attempts to establish the optimal starting point can cause additional soft tissue trauma and radiation exposure. In the following study we compared a robot-guided technique with the standard free-hand technique for establishing the entry point of an antegrade femoral nail. We hypothesized that the robot-guided technique is more reliable and efficient. A custom-made drill-guide was mounted onto the arm of an industrial robot. Two orthogonal fluoroscopic images were acquired from the proximal femur of five cadaveric human specimens. Images were processed with a special software in order to create an enhanced contour-recognition map from which the bone axes were automatically calculated. The drilling trajectory was computed along the extension of the bone-axis. The robot then moved the drill-guide on this trajectory toward the entry point. The drilling was then performed by the surgeon. In the control group, five cadaveric human femora were utilized to manually establish the starting point using the free-hand technique. 100% of the intramedullary cavities were successfully accessed with both the robot-guided and the manual techniques. In the manual technique repositioning of the drill was necessary in three out of five cases. The mean number of acquired fluoroscopic images was significantly reduced from 11.6 (manual) to 4 (robot-guided). Robot-assisted drilling of the entry-point in antegrade femoral nailing is more reliable and requires fewer radiographic images than the free hand technique. Yet, based on economical and logistical considerations, its application will probably only be accepted when a concomitant application for fracture reduction is available.

Accessibility to specialized health care is important for residents in rural areas. Videoconsultation can provide increased accessibility to health care. Before implementation of new technologies, it is important to study residents' views. This study describes views of residents of rural areas on accessibility to specialist care and the use of videoconsultation as tool to increase accessibility. A questionnaire was distributed via the primary health care centres in rural areas of northern Sweden. Data was analysed with both quantitative and qualitative methods. The quantitative analysis revealed three main areas: savings in time, environmental damage and cost of not having to travel were important; security of information must be coupled with increased availability of specialist care; responses depended on an individual's specific health care needs. The open-ended answers resulted into two categories: 1) experiences related to availability of specialist care and 2) views on participating in VC. Despite the fact that rural residents considered the distance as important factor in access to care, there was uncertainty regarding videoconsultation as solution. Although respondents were familiar with different types of communication technologies, they probably hesitated because they did not have information on what videoconsultation would mean to them.