Toward optimal display of physiologic status in critical care: I. Recreating bedside displays from archived physiologic data

BACKGROUND: Physiologic data display is essential to decision making in critical care. Current displays echo first-generation hemodynamic monitors dating to the 1970s and have not kept pace with new insights into physiology or the needs of clinicians who must make progressively more complex decisions about their patients. The effectiveness of any redesign must be tested before deployment. Tools that compare current displays with novel presentations of processed physiologic data are required. Regenerating conventional physiologic displays from archived physiologic data is an essential first step. OBJECTIVES: The purposes of the study were to (1) describe the SSSI (single sensor single indicator) paradigm that is currently used for physiologic signal displays, (2) identify and discuss possible extensions and enhancements of the SSSI paradigm, and (3) develop a general approach and a software prototype to construct such "extended SSSI displays" from raw data. RESULTS: We present Multi Wave Animator (MWA) framework-a set of open source MATLAB (MathWorks, Inc., Natick, MA, USA) scripts aimed to create dynamic visualizations (eg, video files in AVI format) of patient vital signs recorded from bedside (intensive care unit or operating room) monitors. Multi Wave Animator creates animations in which vital signs are displayed to mimic their appearance on current bedside monitors. The source code of MWA is freely available online together with a detailed tutorial and sample data sets.

Image-guided surgical microscope with mounted minitracker

A new image-guided microscope using augmented reality overlays has been developed. Unlike other systems, the novelty of our design consists in mounting a precise mini and low-cost tracker directly on the microscope to track the motion of the surgical tools and the patient. Correctly scaled cut-views of the pre-operative computed tomography (CT) stack can be displayed on the overlay, orthogonal to the optical view or even including the direction of a clinical tool. Moreover, the system can manage three-dimensional models for tumours or bone structures and allows interaction with them using virtual tools, showing trajectories and distances. The mean error of the overlay was 0.7 mm. Clinical accuracy has shown results of 1.1-1.8 mm.

The 14-bp deletion polymorphism in the HLA-G gene displays significant differences between ulcerative colitis and Crohn's disease and is associated with ileocecal resection in Crohn's disease

HLA-G is a non-classical MHC class Ib molecule predominantly expressed in cytotrophoblasts and under pathological conditions also in chronically inflamed and in malignant tissues. Recently an increased expression of HLA-G was found in ulcerative colitis (UC), but not in Crohn's disease (CD). The HLA-G gene is located in IBD3, a linkage region for inflammatory bowel disease (IBD). A 14-bp deletion polymorphism (Del+/Del-) within exon 8 of the HLA-G gene might influence transcription activity and is therefore of potential functional relevance. To investigate whether the 14-bp deletion polymorphism is associated with IBD, 371 patients with CD, 257 patients with UC and 739 controls were genotyped. The heterozygous genotype (P = 0.031) and the Del+ phenotype (P = 0.038) were significantly increased, whereas the homozygous Del- phenotype (P = 0.038) was significantly decreased in UC when compared with CD. Thus, the 14-bp deletion polymorphism within the HLA-G gene displayed significant differences between UC and CD. Moreover, a significant increase of the Del+ allele (P = 0.002) and the Del+/Del+ genotype (P = 0.013) and a consecutive decrease of the Del-/- genotype (P = 0.024) were observed in those CD cases positive for ileocecal resection. Thus, a potential effect of the HLA-G gene in IBD may affect both UC and CD. Other polymorphisms linked to the 14-bp deletion polymorphism might also contribute to immunopathogenesis. As there are several partly functional polymorphisms within the promoter region potentially influencing HLA-G expression, further studies in IBD are necessary in the context of differential expression of HLA-G between UC and CD.

Subject-ventilator synchrony during neural versus pneumatically triggered non-invasive helmet ventilation

OBJECTIVE: Patient-ventilator synchrony during non-invasive pressure support ventilation with the helmet device is often compromised when conventional pneumatic triggering and cycling-off were used. A possible solution to this shortcoming is to replace the pneumatic triggering with neural triggering and cycling-off-using the diaphragm electrical activity (EA(di)). This signal is insensitive to leaks and to the compliance of the ventilator circuit. DESIGN: Randomized, single-blinded, experimental study. SETTING: University Hospital. PARTICIPANTS AND SUBJECTS: Seven healthy human volunteers. INTERVENTIONS: Pneumatic triggering and cycling-off were compared to neural triggering and cycling-off during NIV delivered with the helmet. MEASUREMENTS AND RESULTS: Triggering and cycling-off delays, wasted efforts, and breathing comfort were determined during restricted breathing efforts (<20% of voluntary maximum EA(di)) with various combinations of pressure support (PSV) (5, 10, 20 cm H(2)O) and respiratory rates (10, 20, 30 breath/min). During pneumatic triggering and cycling-off, the subject-ventilator synchrony was progressively more impaired with increasing respiratory rate and levels of PSV (p < 0.001). During neural triggering and cycling-off, effect of increasing respiratory rate and levels of PSV on subject-ventilator synchrony was minimal. Breathing comfort was higher during neural triggering than during pneumatic triggering (p < 0.001). CONCLUSIONS: The present study demonstrates in healthy subjects that subject-ventilator synchrony, trigger effort, and breathing comfort with a helmet interface are considerably less impaired during increasing levels of PSV and respiratory rates with neural triggering and cycling-off, compared to conventional pneumatic triggering and cycling-off.

The novel ATP-competitive inhibitor of the MET hepatocyte growth factor receptor EMD1214063 displays inhibitory activity against selected MET-mutated variants

The receptor tyrosine kinase MET is a prime target in clinical oncology due to its aberrant activation and involvement in the pathogenesis of a broad spectrum of malignancies. Similar to other targeted kinases, primary and secondary mutations seem to represent an important resistance mechanism to MET inhibitors. Here, we report the biologic activity of a novel MET inhibitor, EMD1214063, on cells that ectopically express the mutated MET variants M1268T, Y1248H, H1112Y, L1213V, H1112L, V1110I, V1206L, and V1238I. Our results demonstrate a dose-dependent decrease in MET autophosphorylation in response to EMD1214063 in five out of the eight cell lines (IC50 2-43nM). Blockade of MET by EMD1214063 was accompanied by a reduced activation of downstream effectors in cells expressing EMD1214063-sensitive mutants. In all sensitive mutant-expressing lines, EMD1214063 altered cell cycle distribution, primarily with an increase in G1 phase. EMD1214063 strongly influenced MET-driven biological functions, such as cellular morphology, MET-dependent cell motility and anchorage-independent growth. To assess the in vivo efficacy of EMD1214063, we used a xenograft tumor model in immunocompromised mice bearing NIH3T3 cells expressing sensitive and resistant MET mutated variants. Animals were randomized for the treatment with EMD1214063 (50mg/kg/day) or vehicle only. Remarkably, five days of EMD1214063 treatment resulted in a complete regression of the sensitive H1112L-derived tumors, while tumor growth remained unaffected in mice with L1213V tumors and in vehicle-treated animals. Collectively, the current data identifies EMD1214063 as a potent MET small molecule inhibitor with selective activity towards mutated MET variants.

The Influence of Self-efficacy and Compensatory Health Behavior in Bicycle Helmet Use

Individuals show compensatory health behavior (e.g. safer cycling without helmet) to compensate for risky behavior. Compensatory health behavior is facilitated by high self-efficacy. A total of 134 cyclists with different helmet wearing frequencies (occasionally (OH) or never helmet (NH)) were asked to fill out a questionnaire on their compensatory health behavior when cycling without a helmet and on their general self-efficacy. An interaction between self-efficacy and use of a helmet on compensatory health behavior was found. OH-users with high self-efficacy showed more compensatory health behavior than OH-users with low self-efficacy. This effect was not present in NH-users. We assume that OH-users engage in compensatory health behavior, whereas NH-users remain unprotected by behavioral adaptation. These persons are vulnerable and may require specific attention in preventive actions.

Reading on LCD vs e-Ink displays: effects on fatigue and visual strain

Purpose:  Most recently light and mobile reading devices with high display resolutions have become popular and they may open new possibilities for reading applications in education, business and the private sector. The ability to adapt font size may also open new reading opportunities for people with impaired or low vision. Based on their display technology two major groups of reading devices can be distinguished. One type, predominantly found in dedicated e-book readers, uses electronic paper also known as e-Ink. Other devices, mostly multifunction tablet-PCs, are equipped with backlit LCD displays. While it has long been accepted that reading on electronic displays is slow and associated with visual fatigue, this new generation is explicitly promoted for reading. Since research has shown that, compared to reading on electronic displays, reading on paper is faster and requires fewer fixations per line, one would expect differential effects when comparing reading behaviour on e-Ink and LCD. In the present study we therefore compared experimentally how these two display types are suited for reading over an extended period of time. Methods:  Participants read for several hours on either e-Ink or LCD, and different measures of reading behaviour and visual strain were regularly recorded. These dependent measures included subjective (visual) fatigue, a letter search task, reading speed, oculomotor behaviour and the pupillary light reflex. Results:  Results suggested that reading on the two display types is very similar in terms of both subjective and objective measures. Conclusions:  It is not the technology itself, but rather the image quality that seems crucial for reading. Compared to the visual display units used in the previous few decades, these more recent electronic displays allow for good and comfortable reading, even for extended periods of time.

Table-mounted ring retractor for consistent visualization in endoscopy-assisted anterior reconstruction of burst fractures of the thoracolumbar junction

The authors tested an autoclavable external ring retractor, fixed to the operation table, for the endoscopic reconstruction of anterior column injuries of the thoracolumbar junction. It served as a retractor for the diaphragm, and offered a stable support for the scope and other instruments, making an assistant superfluous. Moreover, it allowed bimanual manipulation. Of course, the two-dimensional image, provided by the scope, necessitated proper eye-hand coordination. Twenty-eight consecutive patients underwent either a monosegmental (n = 10) or a bisegmental (n = 18) anterior stabilization in the area Th11L1. Three portals were necessary, but an assistant was not needed. The overall (mean +/- SD) operating time was 196 +/- 56 min, the blood loss was 804 +/- 719 mL. Intraoperatively, one epidural bleeding and a single screw cut-out occurred. All complications were managed endoscopically. Postoperatively, evacuation of a haemothorax (n = 1) was necessary. In all patients, wounds and fractures healed uneventfully. The combination of the endoscopic technique and the retractor system was feasible, successful, safe, and time efficient. Moreover, it allowed for anterior instrumentation of thoracolumbar fractures by a single surgeon. It became the standard approach in the authors' department.