Jozef Zivcak

The digital pre-operative planning of total hip replacements

Over the past few years, an increasing appreciation of the usefulness of digital technology has emerged among various professions. This is also the pre-operative planning of interventions for lumbar joints (especially reimplantation of total hip and hip). Pre-operative planning is realized with caliper, protractor, plastic templates and x-ray images. The measurement is time consuming with many errors. This paper presents current applications of computer technology in the field of surgery and pre-operative planning of total hip implantation. The new deceloped CoXaM software offers simple solution of the problems by using the digital x-ray images and handmade plastic templates. The developed software combines the digital x-ray images with the digital templates for planning implantation and reimplatation interventions of hip joints.

Pitfalls and fallacies interfering with correct identification of embryonic stem cells implanted into the brain after experimental traumatic injury

Cell-therapy was proposed to be a promising tool in case of death or impairment of specific cell types. Correct identification of implanted cells became crucial when evaluating the success of transplantation therapy. Various methods of cell labeling have been employed in previously published studies. The use of intrinsic signaling of green fluorescent protein (GFP) has led to a well known controversy in the field of cardiovascular research. We encountered similar methodological pitfalls after transplantation of GFP-transfected embryonic stem cells into rat brains following traumatic brain injury (TBI). As the identification of implanted graft by intrinsic autofluorescence failed, anti-GFP labeling coupled to fluorescent and conventional antibodies was needed to visualize the implanted cells. Furthermore, different cell types with strong intrinsic autofluorescence were found at the sites of injury and transplantation, thus mimicking the implanted stem cells. GFP-positive stem cells were correctly localized, using advanced histological techniques. The activation of microglia/macrophages, accompanying the transplantation post TBI, was shown to be a significant source of artefacts, interfering with correct identification of implanted stem cells. Dependent on the strategy of stem cell tracking, the phagocytosis of implanted cells as observed in this study, might also impede the interpretation of results. Critical appraisal of previously published data as well as a review of different histological techniques provide tools for a more accurate identification of transplanted stem cells.

The methodics of medical thermography in the diagnostics of the human body musculoskeletal system

Medical thermography is a powerful tool for the study of surface temperature of the human body. It is non-invasive, non-radiation, painless and non-contact imaging technique with numerous medical applications including musculoskeletal system, its disorders and injuries. Often it is useful to cross-reference the resulting thermograms with visual images of the body; either to see which part of the musculoskeletal system is affected by a certain disease or injury or to judge the efficacy of the treatment. Presented paper deals with application of the thermal imaging to measure lower extremities surface temperature distribution in 20 healthy individuals. The aim was to asses the proper technical way of the measurement.

Application of medical thermography in the diagnostics of Carpal Tunnel Syndrome

Presented paper deals with infrared thermography (IRT) used for the diagnostics of Carpal Tunnel Syndrome (CTS). More studies on medical thermography in the relation with CTS diagnostics were published. Jesensek Papez B. et al. in 2008 and 2009 improved outcome with classification success rates near to or over 80% in dorsal segments of hand. The background of this study is the skin physiological temperature distribution difference on the dorsal hands and pathophysiological temperature distribution on hands with CTS and non-invasiveness and painlessness of IRT. For presented study, the database of 268 thermal images of the dorsal side of 120 healthy (n= 120) and 14 pathological hands (n=14) with clinically diagnosed CTS of 8 patients were examined. We observed the temperature distribution of the whole hand and the partial temperatures of the center point of carpals (D1), the center point of metacarpals (D2) and the finger tips of the third finger from proximal phalanges (D3), the intermediate phalanges (D4) to the distal phalanges (D5) and the Median Nerve Index (MI=(D1–D5)) were calculated. Results obtained from measurements of the five defined points on the dorsal side of hands showed, that the temperature of CTS hands is characterized by a higher temperature in the phalanges unlike the wrist (MI<0, 71,4%), while the temperature is the lowest on distal phalanges (D5) of healthy hands (MI≥0, 85,8%). The results showed that the skin temperatures of median nerve distribution area on dorsal hands were significantly different between CTS and the control group. The sensitivity of IRT in diagnostic process of CTS is 0,714. Results will be confirmed by further screening of statistically significant group of patients.

Thermographic atlas of the human body

The presented study deals with temperature distribution of healthy human bodies which were measured by infrared thermography. We used Infrared Imager with detector type 320×240 Focal Plane Array, Vanadium Oxide (VOx), Uncooled Microbolometer. A database of 240 thermograms from different position or locality of human body was created. The following eight views of human body were captured: TBA (Total Body — Anterior view), TBD (Total Body — Dorsal view), ToA (Torso — Anterior view), ToD (Torso — Dorsal view), DH (Dorsal side of Hand), PH (Palmar side of Hand), F (Foot) and FT (Facial Title). The database can be helpful in the diagnostics of many neurovascular and musculoskeletal diseases or injuries.

Medical thermography application in neuro-vascular deseases diagnostics

The measurement of the surface temperatures by infrared thermography is not frequently used in medicine despite of its safety, painlessness and invasiveness, good reproducibility and low running costs. Promising results have been achieved in nerve entrapment syndromes or neuropathies, although thermography has never represented as a real alternative to the electromyography. Here an attempt is described to improve the diagnosis of carpal tunnel syndrome by thermography using a computer-based system with special software to analyse obtained thermograms.

Rat skin wounds tensile strength measurements in the process of healing

The goal of our investigation was to evaluate mechanical properties of the skin wounds during the first seven days of primary healing. We realized two parallel symmetrical skin incision (on the left and right side of the spine) in the general anaesthesia. Rats were divided into 7 groups. We measured tensile strength of the wound in 24, 48, 72, 96, 120, 144 and 168 hours after wounding in every group. After each day of measurement we obtained complex of tensile strength diagrams of wound tensile strength-time dependence. We observed the highest absolute strength increase after 24 hours within 5 days after wounding. In the period between 2nd and 5th day of testing we observed stagnation of the strength, labelled as “plató phase”. Next significant strength increase was observed only after 6 days, with following increase of the tensile strength of skin wound.

Infrared diagnostics of the human hand

The study deals with thermographic (IRT) diagnosing in neuro-vascular diseases of the human hands such as the Carpal Tunnel Syndrome (CTS). It is considered to be an approach to screening thermal manifestations of the difference between the physiological temperature distribution in the skin of dorsal hands and pathophysiological temperature distribution in hands affected by CTS. We created a database of 178 thermal images of dorsal side of 162 healthy (nRS= 162) and 16 pathological hands (nCTS=16) with clinically diagnosed CTS of 9 patients. Pre-surgical thermograms of the hands with CTS of each subject were taken and stored using IRT (Thermocamera Fluke Ti55/20). We observed the temperature distribution in the entire hand and partial temperatures of the center point of carpals (D1) as well as the area of distal phalanges on middle fingers (D5). The Index of Median Nerve (DMI=(TD1−TD5) was determined based on resulting data. Test results obtained from measurements of the two points on the dorsal side of hands showed that the temperature of CTS hands is typically higher in the phalanges as opposed to the wrist (DMI<0, 62.5%), while the temperature is the lowest in distal phalanges (D5) of healthy hands (DMI≥0, 81.5%). The sensitivity of IRT diagnostic test in our diagnostic process of CTS was calculated to be 0,625. Results will be confirmed by further termal screening of statistically significant group of patients.

MECHANICAL PROPERTIES AND POROSITY OF Ti-6Al-4V ALLOY PREPARED BY AM TECHNOLOGY

PATRIK PETROUSEK1, JANA BIDULSKA1, ROBERT BIDULSKY1, ROBERT KOCISKO1, ALICA FEDORIKOVA1, RADOVAN HUDAK 2, VIKTORIA RAJTUKOVA 2, JOZEF ZIVCAK 2 1Technical University of Kosice, Faculty of Metallurgy, Institute of Materials, Kosice, Slovak Republic 2Technical University of Kosice, Faculty of Mechanical Engineering, Department of Instrumental and Biomedical Engineering, Kosice, Slovak Republic DOI: 10.17973/MMSJ.2017_02_2016190

MECHANICAL PROPERTIES OF POWDER CoCrW-ALLOY PREPARED BY AM TECHNOLOGY

This study is focused on the evaluation of mechanical properties and microstructure of fabricating Ni-free CoCrWalloy. Samples were prepared by additive manufacturing technology – selective laser melting. The chemical composition of used metal powder was – 60.5% Co, 28% Cr and 9%W. Parameters of SLM were given by powder supplier. The shape of thesampleis designed according to MPIF. After recommended heat treatment, the static tensile test was carried out at Tinius Olsen machine, the microstructure and porositywere observed, also. In results is interpreted the relations between porosity, microstructure, and mechanical properties. This report is the basis for further experiments aimed at improving the mechanical properties about manufacturing conditions.