Feasibility studies of multimodal nonlinear endoscopy using multicore fiber bundles for remote scanning from tissue sections to bulk organs.

Here, we report on the development and application of a compact multi-core fiber optical probe for multimodal non-linear imaging, combining the label-free modalities of Coherent Anti-Stokes Raman Scattering, Second Harmonic Generation, and Two-Photon Excited Fluorescence. Probes of this multi-core fiber design avoid moving and voltage-carrying parts at the distal end, thus providing promising improved compatibility with clinical requirements over competing implementations. The performance characteristics of the probe are established using thin cryo-sections and artificial targets before the applicability to clinically relevant samples is evaluated using ex vivo bulk human and porcine intestine tissues.

Relational local electroencephalography representations for sleep scoring.

Computational sleep scoring from multimodal neurophysiological time-series (polysomnography PSG) has achieved impressive clinical success. Models that use only a single electroencephalographic (EEG) channel from PSG have not yet received the same clinical recognition, since they lack Rapid Eye Movement (REM) scoring quality. The question whether this lack can be remedied at all remains an important one.

Multimodal nonlinear endomicroscopic imaging probe using a double-core double-clad fiber and focus-combining micro-optical concept.

Multimodal non-linear microscopy combining coherent anti-Stokes Raman scattering, second harmonic generation, and two-photon excited fluorescence has proved to be a versatile and powerful tool enabling the label-free investigation of tissue structure, molecular composition, and correlation with function and disease status. For a routine medical application, the implementation of this approach into an in vivo imaging endoscope is required. However, this is a difficult task due to the requirements of a multicolour ultrashort laser delivery from a compact and robust laser source through a fiber with low losses and temporal synchronization, the efficient signal collection in epi-direction, the need for small-diameter but highly corrected endomicroobjectives of high numerical aperture and compact scanners.

Continuous Heart Rate Monitoring for Automatic Detection of Life-Threatening Arrhythmias With Novel Bio-Sensing Technology.

Assessing the effectiveness of novel bio-sensing technology (CardiacSense), for accuracy and reliability of automatic detection of life-threatening arrhythmias. This prospective study consisted of Eighteen patients (13 males and 5 females, mean age 59.4 ± 21.

Reliable profile reconstruction of GRIN lenses produced by ion-exchange processes.

We propose a method that allows for a fast and accurate reconstruction of the refractive index profile of radially symmetric gradient index lenses fabricated by ion-exchange processes. The presented method enables the reconstruction of the profile up to the 10th polynomial order without direct spatially resolved refractive index measurements. It requires as input a working distance measurement at the paraxial limit and an accurate wavefront aberration measurement at full aperture.

Chip-on-the-tip compact flexible endoscopic epifluorescence video-microscope for in-vivo imaging in medicine and biomedical research.

We demonstrate a 60 mg light video-endomicroscope with a cylindrical shape of the rigid tip of only 1.6 mm diameter and 6.7 mm length.

Design and evaluation of new color-corrected rigid endomicroscopic high NA GRIN-objectives with a sub-micron resolution and large field of view.

We demonstrate new GRIN-based endomicroscopic objectives for high resolution single photon fluorescence imaging modalities. Two endoscopic optical design approaches are presented in detail utilizing firstly diffractive and secondly refractive optical elements for the color correction in a spectral range from 488 nm to 550 nm. They are compared with their precursor device experimentally and by simulation.

PET image segmentation using a Gaussian mixture model and Markov random fields.

Background: Classification algorithms for positron emission tomography (PET) images support computational treatment planning in radiotherapy. Common clinical practice is based on manual delineation and fixed or iterative threshold methods, the latter of which requires regression curves dependent on many parameters.

Methods: An improved statistical approach using a Gaussian mixture model (GMM) is proposed to obtain initial estimates of a target volume, followed by a correction step based on a Markov random field (MRF) and a Gibbs distribution to account for dependencies among neighboring voxels.

Increased thermal pain sensitivity in animals exposed to chronic high dose Vicodin but not pure hydrocodone.

Vicodin, the combination drug of acetaminophen and the opioid hydrocodone, is one of the most prescribed drugs on the market today. Opioids have demonstrated the ability to paradoxically cause increased pain sensitivity to users in a phenomena called opioid-induced hyperalgesia (OIH). While selected opioids have been shown to produce OIH symptoms in an animal model, hydrocodone and the combination drug Vicodin have yet to be studied.

Automatic ictal HFO detection for determination of initial seizure spread.

High-frequency oscillations (HFOs) are a reliable indicator for the epileptic seizure onset zone (SOZ) in ECoG recordings. We propose a novel method for the automatic detection of ictal HFOs in the ripple band (80-250 Hz) based on CFAR matched sub-space filtering. This allows to track the early propagation of ictal HFOs, revealing initial and follow-up epileptic activity on the electrodes.

Artefact reduction for cell migration visualization using spectral domain optical coherence tomography.

Visualization of cell migration during chemotaxis using spectral domain optical coherence tomography (OCT) requires non-standard processing techniques. Stripe artefacts and camera noise floor present in OCT data prevent detailed computer-assisted reconstruction and quantification of cell locomotion. Furthermore, imaging artefacts lead to unreliable results in automated texture based cell analysis.

Fast dispersion encoded full range optical coherence tomography for retinal imaging at 800 nm and 1060 nm.

The dispersion mismatch between sample and reference arm in frequency-domain optical coherence tomography (OCT) can be used to iteratively suppress complex conjugate artifacts and thereby increase the imaging range. In this paper, we propose a fast dispersion encoded full range (DEFR) algorithm that detects multiple signal components per iteration. The influence of different dispersion levels on the reconstruction quality is analyzed experimentally using a multilayered scattering phantom and in vivo retinal tomograms at 800 nm.

Dispersion encoded full range frequency domain optical coherence tomography.

We propose an iterative algorithm that exploits the dispersion mismatch between reference and sample arm in frequency-domain optical coherence tomography (FD-OCT) to effectively cancel complex conjugate mirror terms in individual A-scans and thereby generate full range tomograms. The resulting scheme, termed dispersion encoded full range (DEFR) OCT, allows distinguishing real structures from complex conjugate mirror artifacts. Even though DEFR-OCT has higher post-processing complexity than conventional FD-OCT, acquisition speed is not compromised since no additional A-scans need to be measured, thereby rendering this technique robust against phase fluctuations.

New methods for fast on-site measurement of odorous compounds.

New methods for measurement of odorous gases, especially for aerosol-bound chemical compounds, have been developed in the Department of Measurement Technology (Technical University of Hamburg Harburg--MT-TUHH). Odorous compounds in the waste gases produced by the food industry were analysed based on high-volume aerosol sampling techniques, enrichment on solid phase micro extraction (SPE) cartridges and analytical measurement techniques using thermal desorption gas chromatography-mass spectrometry. The analysis results were compared to classic analytical procedures using adsorbence materials (Tenax) for enrichment.

The development of antibiotic resistant organisms with the use of ototopical medications.

Objective: There is growing concern over the use of systemic antibiotics and the development of bacterial resistance. The question remains as to whether ototopical medications may also promote antibiotic-resistant organisms, either on a local level (in the ear) or in other areas of the aerodigestive tract. We performed an evidence-based review to answer the following clinical question, "Do antibiotic ototopical medications induce antibiotic resistant organisms?"

Study Design: We performed a MEDLINE search of the published literature from 1966 to the present.

Ototoxicity of ototopical antibiotic drops in humans.

Objective: We sought to determine the incidence of injury to the cochlea or vestibular system from the use of ototopic antibiotic ear drops.

Study Design: We conducted a MEDLINE search of the published literature from 1966 to the present using the search items of "ototopic antibiotics," "ototopic drops," "antibiotic resistance," and others to identify pertinent articles. These articles were reviewed and graded according to evidence quality.

Animal ototoxicity of topical antibiotics and the relevance to clinical treatment of human subjects.

Objective: The objective of this study was to systematically review the literature on animal ototoxicity from ototopical medications. A secondary objective was to assess the relevance of animal data to the use of ototopical drops in clinical situations involving humans.

Study Design: We performed a MEDLINE search of the published literature using appropriate search terms to identify pertinent articles, which were reviewed, summarized, and tabulated.

Macro- and microscopic in-situ observation of gas bubbles and sludge particles in a biogas tower reactor.

Macroscopic and microscopic in-situ observation of particles and gas bubbles are used to get precise impressions of the hydrodynamical characteristics of a biologically active suspension. Moreover, values of in-situ velocities and particle densities can be gained by using these methods. The suspended anaerobic sludge revealed an extensive fibrous structure ('fur') on its surface.

Phase II evaluation of paclitaxel in combination with carboplatin in advanced head and neck carcinoma.

Background: Two-thirds of patients with squamous cell carcinomas of the head and neck (SCCHN) at diagnosis have advanced disease with projected 5-year survival rates of 30%. In those patients with distant metastatic or previously treated recurrent disease, response rate to the standard regimen of cisplatin and 5-fluorouracil is approximately 30%. The authors investigated the use of paclitaxel and carboplatin in a limited Phase II study in recurrent or metastatic SCCHN to evaluate tumor response, time to progression, survival, and toxicities of this regimen.

Ototoxicity resulting from combined administration of metronidazole and gentamicin.

Hypothesis: The hypothesis that metronidazole can augment the ototoxicity of gentamicin was tested.

Background: Metronidazole and gentamicin are antibiotics that are used in combination to provide broad-spectrum antimicrobial coverage. It has been observed clinically that an increased ototoxic effect occurs when these agents are used in combination.

Ototoxicity resulting from combined administration of cisplatin and gentamicin.

The hypothesis that cisplatin can augment the ototoxicity of gentamicin was tested. Seven groups of 11 guinea pigs each were given a single dose of cisplatin either alone or 14 days before, at the beginning, midway through, or at the end of a course of gentamicin administered daily for 14 days. Blood and perilymph gentamicin and cisplatin concentrations were determined in three of the animals from each group.

Quantitative study of vestibulotoxicity induced by gentamicin or cisplatin in the guinea pig.

Although aminoglycoside vestibulotoxicity is well established, the question of cisplatin vestibulotoxicity is controversial. The goals of this study were 1. to determine whether cisplatin induces vestibulotoxicity as measured histologically, and 2.

Longitudinal assessment of quality of life in laryngeal cancer patients.

Background: Although quality of life (QL) and performance status are important outcomes in head and neck (HN) cancer, there is little systematic inclusion of these parameters in treatment trials.

Methods: Rate and recovery of function were evaluated over a 6-month period in 21 laryngeal cancer patients, 7 in each of 3 treatment groups: total laryngectomy (group 1), hemilaryngectomy (group 2), and radiotherapy only (group 3). Assessment included Performance Status Scale for Head and Neck Cancer Patients (PSS-HN: Diet, Speech, and Eating in Public subscales) and the FACT-HN, a multidimensional QL measure.