Testing of displays of protection and control relays with machine vision

Human-machine interface is the link between a user and a device. In protection and control relays the local human machine interface consist of a display, buttons, light-emitted diode indicators and communication ports. Human-machine interfaces are tested before assembly with visual inspection to ensure quality of LCDs and LEDs. The visual inspection test system of HMIs consists of a camera and lens, a light emitted diode analyser, software and a computer. Machine vision operations, such as corner detection and template matching, are used to process and analyse captured images. Original camera and measurement device set-up have been used several years, and it should be upgraded. New camera and lens were installed in the system, and the aim of the thesis was to evaluate and improve the testing set-up and software to support each other, to get better images, and further, to improve the first pass yield. Camera position and settings were adjusted to capture images with good quality. Features of upgraded set-up and software were tested, and development ideas are given for further improvement. Changes in the set-up and software show promising results by giving more accurate test results from production.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Delivering Agents Locally into Articular Cartilage by Intense MHz Ultrasound

There is no cure for osteoarthritis. Current drug delivery relies on systemic delivery or injections into the joint. Because articular cartilage (AC) degeneration can be local and drug exposure outside the lesion can cause adverse effects, localized drug delivery could permit new drug treatment strategies. We investigated whether intense megahertz ultrasound (frequency: 1.138 MHz, peak positive pressure: 2.7 MPa, I-spta: 5 W/cm(2), beam width: 5.7 mm at -6 dB, duty cycle: 5%, pulse repetition frequency: 285 Hz, mechanical index: 1.1) can deliver agents into AC without damaging it. Using ultrasound, we delivered a drug surrogate down to a depth corresponding to 53% depth of the AC thickness without causing histologically detectable damage to the AC. This may be important because early osteoarthritis typically exhibits histopathologic changes in the superficial AC. In conclusion, we identify intense megahertz ultrasound as a technique that potentially enables localized non-destructive delivery of osteoarthritis drugs or drug carriers into articular cartilage. (E-mail: [email protected]) (C) 2015 World Federation for Ultrasound in Medicine & Biology.Peer reviewe

Histochemical quantification of collagen content in articular cartilage

Abstract Background: Articular cartilage (AC) is mainly composed of water, type II collagen, proteoglycans (PGs) and chondrocytes. The amount of PGs in AC is routinely quantified with digital densitometry (DD) from Safranin O-stained sections, but it is unclear whether similar method could be used for collagens. Objective: The aim of this study was to clarify whether collagens can be quantified from histological AC sections using DD. Material and methods: Sixteen human AC samples were stained with Masson’s trichrome or Picrosirius red. Optical densities of histological stains were compared to two commonly used collagen parameters (amide I and collagen CH2 side chain peak at 1338cm-1) measured using Fourier Transform Infrared (FTIR) spectroscopic imaging. Results: Optical density of Modified Masson’s trichrome staining, which included enzymatic removal of PGs before staining, correlated significantly with FTIR-derived collagen parameters at almost all depths of cartilage. The other studied staining protocols displayed significant correlations with the reference parameters at only few depth layers. Conclusions: Based on our findings, modified Masson’s trichrome staining protocol is suitable for quantification of AC collagen content. Enzymatic removal of PGs prior to staining is critical as us allows better staining of the collagen. Further optimization of staining protocols may improve the results in the future studies