Measuring Dynamics of Scattering Centers in the Ocular Fundus

The study is focused on the analysis of the diffusing-wave-spectroscopy signalrecorded invivo on the ocular fundus of a rabbit eye. The motion of the scattered sites wasmeasured as a function of the pressure exerted by a Goldmann contact lens and during themoderate temperature increase induced by a therapeutic laser diode. Temporal fluctuations ofthe signal revel motion of molecules and thus changes in tissues temperature andchorioretinal blood velocity. Experimental results show the ability of the system to detectmotion of the scattering sites in the ocular fundus layers during variations of the ocularpressure and laser heating

In vivo diffuse correlation spectroscopy investigation of the ocular fundus

Diffuse correlation spectroscopy (DCS) measurements in vivo recorded from rabbits' ocular fundus are presented. Despite the complexity of these ocular tissues, we provide a clear and simple demonstration of the DCS abilities to analyze variations in physiological quantities of clinical interest. Indeed, the reported experimental activities demonstrate that DCS can reveal both choroidal-flow and temperature variations and detect nano- and microaggregates in ocular fundus circulation. Such abilities can be of great interest both in fundamental research and practical clinical applications. The proposed measuring system can be useful in: (a) monitoring choroidal blood flow variations, (b) determining the end-point for photo-dynamic therapy and transpupillary thermo therapy and, (c) managing the dye injection and determining an end-point for dye-enhanced photothrombosis. Moreover, it could allow both diagnoses when the presence of nano- and micro-aggregates is related to specific diseases and verifying the effects of nanoparticle injection in nanomedicine. Even though the reported results demonstrate the applicability of DCS to investigate ocular fundus, a detailed and accurate investigation of the limits of detection is beyond the scope of this article. \uc2\ua9 2013 Society of Photo-Optical Instrumentation Engineers

In-vivo diffusing-wave-spectroscopy measurements of the ocular fundus

We present what is to our knowledge the first observation of a diffusing-wave-spectroscopy signal recorded in-vivo on the ocular fundus. A modified ophthalmic microscope was developed which can acquire diffusing-wave-spectroscopy signal from the eye fundus. The diffusing-wave-spectroscopy signal was recorded in-vivo on a rabbit eye during transpupillary thermotherapy. Experimental results show the ability of the system to detect motion of the scattering sites in the ocular fundus layers during laser thermal heating. (c) 2007 Optical Society of America

Feasibility Study on a Measurement Method and a Portable Measuring System to Estimate the Concentration of Cloxacillin and β -Lactamase in Milk

Antibiotics are nowadays used and abused worldwide in common veterinary practice to treat diseases, prevent infections, and promote animal's growth. Drug resistance occurrence is a relevant phenomenon that can inactivate the antibiotic. Moreover, antibiotics used for animals are also found in milk and it poses serious health risks to humans. Another negative effect is related to milk processors since antibiotics cause detrimental effects on cheese and yogurt starter bacteria. Given its consumption as both beverage and derivatives, milk is one of the most regulated products in food industry. Nowadays several commercial tests are available to investigate antibiotics in milk, but they generally provide a qualitative result, require bulky procedure, and are time consuming. In this paper, we investigate the use of a chromogenic cephalosporin to quantify the concentration of cloxacillin - a β-lactam difficult to be detected by using "cowside" screenings which is the drug of choice in the method of mastitis control. The proposed measurement method and prototype have been demonstrated to be able to detect cloxacillin in milk at concentrations lower than the MRL set by the European Commission. Moreover, they are also able to detect the illegal practice of using β-lactamase to degrade β-lactams in milk

light storing photocatalyst the possibility of activating titanium dioxide by photoluminescence

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Zero-Field Readout Electronics for Planar Fluxgate Sensors Without Compensation Coil

A simple and sensitive readout electronics for planar fluxgate sensors is presented. The system exploits the sense coils to directly generate the compensation static field avoiding the additional coil/s required in standard closed loop configuration, thus providing clear advantages in terms of size and cost. Moreover, feedback configurations are known to provide better linearity and stability of the system. The sensitivity of the developed demonstration system can be easily set from 13.3 to 104.9 mV/μT with nonlinearity ranging from 0.17% to 0.38% of the measuring interval, whereas the corresponding measuring intervals vary from ±301 to ±38 μT. The measuring uncertainty, the noise field spectral density, and the system bandwidth have been estimated in 12.2 nT, ≈ 10 nT/√{Hz}, and ≈1.5 Hz, respectively. The proposed measuring instrument is extremely easy to use and versatile. Moreover, due to the use of commercially available ferromagnetic material and the simple and via-less design, the proposed fluxgate sensor results in a very low cost and reliable device

A Novel Method for Noninvasive Monitoring of Ocular Fundus Status During Transpupillary Thermotherapy Treatment

A novel optical method for noninvasive monitoring of the ocular fundus status is presented. The method could provide an optimal end-point for transpupillary thermotherapy treatment, thus overcoming the severe over- and under-treatment issues currently affecting about 10% of patients. The developed instrument and measurement procedure have been tested on both a mechanical eye model and animal models. The presented results demonstrate the ability of our system to potentially detect variations in both blood flow and optical properties. Much more work will be needed before the developed instrument will be ready for clinical test, nevertheless the proposed method may provide an important improvement in the treatment of several disabling ocular diseases

Measuring haemolysis in haemodialysis: Comparison between a new and existing data processing algorithms

Acute haemolysis in haemodialysis is a relatively rare complication, but it can lead to life-threatening issues up to the death of the patient. Due to the lack of measurement methods able to provide a realtime and in-line measurement of the haemolysis in extracorporeal circulation, in current medical practice the haemolysis level is not monitored during haemodialysis. In last two years we proposed a measurement method capable to measure in-line and in real-time the haemolysis level during haemodialysis. Such method is based on the estimation of the filter permeability to haemoglobin. To estimate the filter permeability we proposed two data processing algorithms: one simplified algorithm supposing constant permeability and the other supposing the filter permeability to be a linear function of the time integral of the filtered volume of solvent. However, the constant permeability algorithm is reasonably prone to errors, whereas the algorithm based on the time integral of the solvent volume does not allow the integration of the developed measuring system with hemodialyzers already in use. To overcome such limitation, in this paper we propose a new data processing algorithm based on the time integral of the mass of filtered haemoglobin. Such quantity can be easily estimated by the measuring system, allowing straightforward integration with hemodialyzers already in use. The performed experimental activities indicate as the new data processing algorithm is reasonably able to provide performance equal or better than the previous data processing algorithms