Software Framework for Customized Augmented Reality Headsets in Medicine

The growing availability of self-contained and affordable augmented reality headsets such as the Microsoft HoloLens is encouraging the adoption of these devices also in the healthcare sector. However, technological and human-factor limitations still hinder their routine use in clinical practice. Among them, the major drawbacks are due to their general-purpose nature and to the lack of a standardized framework suited for medical applications and devoid of platform-dependent tracking techniques and/or complex calibration procedures. To overcome such limitations, in this paper we present a software framework that is designed to support the development of augmented reality applications for custom-made head-mounted displays designed to aid high-precision manual tasks. The software platform is highly configurable, computationally efficient, and it allows the deployment of augmented reality applications capable to support in situ visualization of medical imaging data. The framework can provide both optical and video see-through-based augmentations and it features a robust optical tracking algorithm. An experimental study was designed to assess the efficacy of the platform in guiding a simulated task of surgical incision. In the experiments, the user was asked to perform a digital incision task, with and without the aid of the augmented reality headset. The task accuracy was evaluated by measuring the similarity between the traced curve and the planned one. The average error in the augmented reality tests was < 1 mm. The results confirm that the proposed framework coupled with the new-concept headset may boost the integration of augmented reality headsets into routine clinical practice

Off-Line Camera-Based Calibration for Optical See-Through Head-Mounted Displays

In recent years, the entry into the market of self contained optical see-through headsets with integrated multi-sensor capabilities has led the way to innovative and technology driven augmented reality applications and has encouraged the adoption of these devices also across highly challenging medical and industrial settings. Despite this, the display calibration process of consumer level systems is still sub-optimal, particularly for those applications that require high accuracy in the spatial alignment between computer generated elements and a real-world scene. State-of-the-art manual and automated calibration procedures designed to estimate all the projection parameters are too complex for real application cases outside laboratory environments. This paper describes an off-line fast calibration procedure that only requires a camera to observe a planar pattern displayed on the see-through display. The camera that replaces the user’s eye must be placed within the eye-motion-box of the see-through display. The method exploits standard camera calibration and computer vision techniques to estimate the projection parameters of the display model for a generic position of the camera. At execution time, the projection parameters can then be refined through a planar homography that encapsulates the shift and scaling effect associated with the estimated relative translation from the old camera position to the current user’s eye position. Compared to classical SPAAM techniques that still rely on the human element and to other camera based calibration procedures, the proposed technique is flexible and easy to replicate in both laboratory environments and real-world settings

Optical See-Through Head-Mounted Displays With Short Focal Distance: Conditions for Mitigating Parallax-Related Registration Error

Optical see-through (OST) augmented reality head-mounted displays are quickly emerging as a key asset in several application fields but their ability to profitably assist high precision activities in the peripersonal space is still sub-optimal due to the calibration procedure required to properly model the user's viewpoint through the see-through display. In this work, we demonstrate the beneficial impact, on the parallax-related AR misregistration, of the use of optical see-through displays whose optical engines collimate the computer-generated image at a depth close to the fixation point of the user in the peripersonal space. To estimate the projection parameters of the OST display for a generic viewpoint position, our strategy relies on a dedicated parameterization of the virtual rendering camera based on a calibration routine that exploits photogrammetry techniques. We model the registration error due to the viewpoint shift and we validate it on an OST display with short focal distance. The results of the tests demonstrate that with our strategy the parallax-related registration error is submillimetric provided that the scene under observation stays within a suitable view volume that falls in a ±10 cm depth range around the focal plane of the display. This finding will pave the way to the development of new multi-focal models of OST HMDs specifically conceived to aid high-precision manual tasks in the peripersonal space

New isobaric lignans from refined olive oils as quality markers for virgin olive oils.

Herein we describe the influence of olive oil refining processes on the lignan profile. The detection of new isobaric lignans is suggested to reveal frauds in commercial extra-Virgin Olive Oils. We analyzed five commercial olive oils by HPLC-DAD-TOF/MS to evaluate their lignan content and detected, for the first time, some isobaric forms of natural (+)-pinoresinol and (+)-1-acetoxypinoresinol. Then we analyzed partially and fully-refined oils from Italy, Tunisia and Spain. The isobaric forms occur only during the bleaching step of the refining process and remain unaltered after the final deodorizing step. Molecular dynamic simulation helped to identify the most probable chemical structures corresponding to these new isobars with data in agreement with the chromatographic findings. The total lignan amounts in commercial olive oils was close to 2 mg/L. Detection of these new lignans can be used as marker of undeclared refining procedures in commercial extra-virgin and/or Virgin Olive Oils

Anemia Due to Inflammation in an Anti-Coagulated Patient with Blue Rubber Bleb Nevus Syndrome

Background: Blue rubber bleb nevus syndrome (BRBNS) is a rare disease characterized by vascular malformations mostly involving skin and gastrointestinal tract. This disease is often associated with sideropenic anemia and occult bleeding. Methods: We report the case of chronic severe anemia in an old patient under oral anticoagulation treatment for chronic atrial fibrillation. Results: At admission, the patient also presented fever and increased laboratory parameters of systemic inflammation (ferritin 308 mcg/L, C-reactive protein (CRP) 244 mg/L). A small bluish-colored lesion over the left ear lobe was observed. Fecal occult blood test was negative as well as other signs of active bleeding. Lower gastrointestinal endoscopy revealed internal hemorrhoids and multiple teleangiectasias that were treated with argon plasma coagulation. Videocapsule endoscopy demonstrated multiple bluish nodular lesions in the small intestine. Unexpectedly, chronic severe anemia due to systemic inflammation was diagnosed in an old anticoagulated patient with BRNBS. The patient was treated with blood transfusions, hydration, antibiotic treatment, and long-acting octreotide acetate, without stopping warfarin. Fever and inflammation disappeared without any acute gastrointestinal bleeding and improvement of hemoglobin levels at three-month follow up. Conclusions: This is the oldest patient presenting with chronic anemia, in which BRNBS was also diagnosed. Surprisingly, anemia was mainly caused by systemic inflammation instead of chronic gastrointestinal bleeding. However, we would recommend investigating this disease also in old subjects with mild signs and symptoms

Quality of child healthcare in European countries: common measures across international databases and national agencies

BACKGROUND: The evaluation of child healthcare is not yet widely explored, especially from a cross-country comparison perspective. The routine adoption of measures by national assessment agencies is under-investigated. Though the guiding principles developed at international level call for a child-centric multi-dimensional evaluation of child care, its feasibility is hampered by the availability of robust and harmonized data. METHODS: To explore the data availability, international databases (IDBs) were scrutinized and measures dealing with child health-related issues were collated. In parallel, an ad hoc questionnaire was administrated to 30 Country Agents (CAs) to gather measures routinely adopted at local level. To facilitate the comparison of measures, a three-level conceptual map was developed. RESULTS: The IDBs yielded at 207 measures that pertained mainly to non-health determinants of health, whereas the 352 measures obtained from CAs focused on process and outcome. A set of 33 common measures that related to immunization, morbidity and mortality were identified. CONCLUSIONS: A limited set of measures used both in IDBs and at national level identify common areas of concerns that certainly capture crucial issues with child prevention and health outcomes. However, they are far from satisfying a child-centric multi-dimensional approach to the evaluation of child well-being and well-becoming. There is room for improvement at both international and national levels. IDBs should include and harmonize measures that concern the provision of child-centric services and encompass physical, social and mental development. At the national level, efforts towards the inclusion of measures that concern non-health determinants of health should be pursued

Augmented Reality-Assisted Craniotomy for Parasagittal and Convexity En Plaque Meningiomas and Custom-Made Cranio-Plasty: A Preliminary Laboratory Report

Background: This report discusses the utility of a wearable augmented reality platform in neurosurgery for parasagittal and convexity en plaque meningiomas with bone flap removal and custom-made cranioplasty. Methods: A real patient with en plaque cranial vault meningioma with diffuse and extensive dural involvement, extracranial extension into the calvarium, and homogeneous contrast enhancement on gadolinium-enhanced T1-weighted MRI, was selected for this case study. A patient-specific manikin was designed starting with the segmentation of the patient’s preoperative MRI images to simulate a craniotomy procedure. Surgical planning was performed according to the segmented anatomy, and customized bone flaps were designed accordingly. During the surgical simulation stage, the VOSTARS head-mounted display was used to accurately display the planned craniotomy trajectory over the manikin skull. The precision of the craniotomy was assessed based on the evaluation of previously prepared custom-made bone flaps. Results: A bone flap with a radius 0.5 mm smaller than the radius of an ideal craniotomy fitted perfectly over the performed craniotomy, demonstrating an error of less than ±1 mm in the task execution. The results of this laboratory-based experiment suggest that the proposed augmented reality platform helps in simulating convexity en plaque meningioma resection and custom-made cranioplasty, as carefully planned in the preoperative phase. Conclusions: Augmented reality head-mounted displays have the potential to be a useful adjunct in tumor surgical resection, cranial vault lesion craniotomy and also skull base surgery, but more study with large series is needed

c-Src and IL-6 inhibit osteoblast differentiation and integrate IGFBP5 signalling

Interleukin-6 (IL-6) and c-Src impair osteoblast maturation in vitro and in vivo. Given the similar effects of these factors, they are likely to establish a functional loop to maintain osteoblasts in a less mature status. Here we describe a pathway whereby c-Src stimulates IL-6 expression through the STAT3 factor, which, in response to IL-6 induces insulin-like growth factor 5 (IGFBP5), a c-Src activating factor that amplifies this loop only in immature osteoblasts. In contrast, in mature osteoblasts, IGFBP5 is enhanced by Runx2, but is no longer able to stimulate c-Src activation, as this tyrosine kinase at this stage is downregulated. We find that the IGFBP5 produced by osteoblasts stimulates osteoclastogenesis and bone resorption, acting as an osteoblast-osteoclast coupling factor. Finally, we demonstrate that the integrated actions of c-Src, IL-6 and IGFBP5 also have a role in vivo. We conclude that this pathway is relevant for bone metabolism, both in physiological and in pathological conditions

Mechanisms for the inhibition of amyloid aggregation by small ligands

The formation of amyloid aggregates is the hallmark of systemic and neurodegenerative disorders, also known as amyloidoses. Many proteins have been found to aggregate into amyloid-like fibrils and this process is recognized as a general tendency of polypeptides. Lysozyme, an antibacterial protein, is a well-studied model since it is associated in human with systemic amyloidosis and that is widely available from chicken eggs (HEWL, hen egg white lysozyme). In the present study we investigated the mechanism of interaction of aggregating HEWL with rosmarinic acid and resveratrol, that we verified to be effective and ineffective, respectively, in inhibiting aggregate formation. We used a multidisciplinary strategy to characterize such effects, combining biochemical and biophysical methods with molecular dynamics (MD) simulations on the HEWL peptide 49–64 to gain insights into the mechanisms and energy variations associated to amyloid formation and inhibition. MD revealed that neither resveratrol nor rosmarinic acid were able to compete with the initial formation of the β-sheet structure. We then tested the association of two β-sheets, representing the model of an amyloid core structure. MD showed that rosmarinic acid displayed an interaction energy and a contact map comparable to that of sheet pairings. On the contrary, resveratrol association energy was found to be much lower and its contact map largely different than that of sheet pairings. The overall characterization elucidated a possible mechanism explaining why, in this model, resveratrol is inactive in blocking fibril formation, whereas rosmarinic acid is instead a powerful inhibitor