NUMERICAL PREDICTION OF THE COMPONENT-RATIO-DEPENDENT COMPRESSIVE STRENGTH OF BONE CEMENT

Changes in the compression strength of the PMMA bone cement with a variable powder/liquid component mix ratio were investigated. The strength test data served to develop basic mathematical models and an artificial neural network was employed for strength predictions. The empirical and numerical results were compared to determine modelling errors and assess the effectiveness of the proposed methods and models. The advantages and disadvantages of mathematical modelling are discussed

DIAGNOSTIC FACTORS FOR OPENED AND CLOSED KINEMATIC CHAIN OF VIBROARTHROGRAPHY SIGNALS

The paper presents results of preliminary research of vibroarthrography signals recorded from one healthy volunteer. The tests were carried out for the open and closed kinematic chain in the range of motion 90° - 0° - 90°. Analysis included initial signal filtration using the EMD algorithm. The aim was to investigate the occurrence of differences in the values of selected energy and statistical parameters for the cases studied. &nbsp

Nonlinear analysis of the ripping head power time series

We investigate the power of a ripping head in the process of concrete cutting. Using nonlinear embedding methods we study the corresponding time series obtained during the cutting process. The calculated maximal Lyapunov exponent indicates the exponential divergence typical for chaotic or stochastic systems. The recurrence plots technique has been used to get nonlinear process statistics for identification and description of nonlinear dynamics, lying behind the cutting process

USEFULNESS OF RAPID PROTOTYPING IN PLANNING COMPLEX TRAUMA SURGERIES

Orthopaedic trauma surgery is a complex surgical speciality in which anatomy, physiology and physics are mixed. Proper diagnosing and based on that planning and performing surgery is of crucial matter. This article presents usefulness of 3D reconstruction in diagnostics and surgical planning. It focuses on utility of computed tomography reconstruction in trauma surgery. Moreover, two cases in which this technique was used is described. Complex 3D reconstruction proved its usefulness and in future it may become a modality of choice for planning complex trauma procedures in which standard implants and approaches are insufficient.&nbsp

KONCEPCJA I WALIDACJA UKŁADU DO REJESTRACJI SYGNAŁÓW WIBROAKUSTYCZNYCH STAWU KOLANOWEGO

Cartilage degeneration is a serious health condition in modern society, leading to problems in mobility and significant reduction in the quality of life of patients of all ages. It is mainly caused by obesity, workload, sports or trauma to the joint. Proper diagnosis is crucial to implement appropriate treatment to stop the further degeneration of the tissue. Usually the assessment is performed by using magnetic resonance. This paper describes the design and application of an alternative measurement system for vibroartography of the knee joint. The use of such device allows for fast, safe, easy and cheap assessment of joint condition, which in turn can lead to proper treatment planning. Similar portable systems can be rapidly deployed and used by entry level medical staff in hospitals, clinics or at patient’s home. The system consists of an orthosis, set of three vibroacoustic sensors, encoder for reading knee position, microcontroller with galvanic barrier and battery power and a computer for data storage and processing. The system is light, simple and portable. Data is recorded in both closed and open kinematic chains. Results show over 90% diagnostic accuracy based on the data obtained in the process of testing this device. In the future, the system will be further miniaturized and completely placed on the orthosis, leading to more portability and diagnostic merit.Zwyrodnienie chrząstki jest poważnym schorzeniem współczesnego społeczeństwa, prowadzącym do problemów w poruszaniu się i znacznego obniżenia jakości życia pacjentów w każdym wieku. Jest to spowodowane głównie otyłością, obciążeniami, sportem lub urazami stawu. Właściwa diagnoza jest kluczowa dla wdrożenia odpowiedniego leczenia, które zapobiegnie dalszej degeneracji tkanki. Zwykle ocenę przeprowadza się za pomocą rezonansu magnetycznego. W artykule opisano konstrukcję i zastosowanie alternatywnego systemu pomiarowego do wibroartografii stawu kolanowego. Aplikacja takiego urządzenia pozwala na szybką, bezpieczną, łatwą i tanią ocenę stanu stawu, co z kolei może pomóc w zaplanowaniu odpowiedniego leczenia. Podobne systemy mobilne można szybko wdrożyć, ponieważ mogą być używane przez podstawowy personel medyczny w szpitalach, klinikach lub w domu pacjenta. System składa się z ortezy, zestawu trzech czujników wibroakustycznych, enkodera do odczytu pozycji stawu kolanowego, mikrokontrolera z barierą galwaniczną i zasilaniem bateryjnym oraz komputera do akwizycji, archiwizacji  i przetwarzania danych. System jest lekki, prosty i przenośny. Dane są rejestrowane zarówno w zamkniętych, jak i otwartych łańcuchach kinematycznych. Wyniki wykazują ponad 90% trafności diagnostycznej na podstawie danych uzyskanych w procesie testowania tego urządzenia. W przyszłości system będzie jeszcze bardziej zminiaturyzowany i całkowicie umieszczony na ortezie, co zapewni większą przenośność i wartość diagnostyczną

APPLICATION OF EEMD-DFA ALGORITHMS AND ANN CLASSIFICATION FOR DETECTION OF KNEE OSTEOARTHRITIS USING VIBROARTHROGRAPHY

Osteoarthritis is one of the leading causes of disability around the globe. Up to this date there is no definite cure for cartilage lesions. Only fast and accurate diagnosis enables prolonging joint survivor time. Available diagnostic methods have disadvantages such as high price, radiation, need for experienced radiologists or low availability in some regions. The present study evaluates the use of vibroarthorgraphy as a method of cartilage lesion detection. 47 patients with diagnosed cartilage lesions, and 51 healthy control group patients have been enrolled in this study. The cartilage in the study group was evaluated intraoperatively by experienced orthopaedic surgeon. Signal acquisition was performed in open and closed kinematic chain based on 10 knee joint movements from 0-90 degrees. By using EEMD-DFA algorithms, reducing classifier inputs using ANOVA and then classifying using artificial neural networks (ANN), a classification accuracy of almost 93% was achieved. A sensitivity of 0.93 and a specificity of 0.93 with an AUC of 0.942 were obtained for the multilayer perceptron network. These results allow to apply this testing protocol in a clinical setting in the future

MEDICAL IMAGING AND 3D RECONSTRUCTION FOR OBTAINING THE GEOMETRICAL AND PHYSICAL MODEL OF A CONGENITAL BILATERAL RADIO-ULNAR SYNOSTOSIS

The paper presents results of a 3D reconstruction of a congenital bilateral radio-ulnar synostosis. Basics of anatomy and biomechanical analysis of the elbow joint were introduced. Case report of a congenital bilateral radio-ulnar synostosis was presented. Based on the data from computed tomography imaging, the model of a congenital bilateral radio-ulnar synostosis was constructed. Basic information on reverse engineering, rapid prototyping and methods of making physical models are presented. The creation of physical models was aimed at pre-operative planning and conceptualization. Physical models were also used in the educational form at the stage of communication with the patient

COMPARISON OF SELECTED CLASSIFICATION METHODS BASED ON MACHINE LEARNING AS A DIAGNOSTIC TOOL FOR KNEE JOINT CARTILAGE DAMAGE BASED ON GENERATED VIBROACOUSTIC PROCESSES

Osteoarthritis is one of the most common cause of disability among elderly. It can affect every joint in human body, however, it is most prevalent in hip, knee, and hand joints. Early diagnosis of cartilage lesions is essential for fast and accurate treatment, which can prolong joint function. Available diagnostic methods include conventional X-ray, ultrasound and magnetic resonance imaging. However, those diagnostic modalities are not suitable for screening purposes. Vibroarthrography is proposed in literature as a screening method for cartilage lesions. However, exact method of signal acquisition as well as classification method is still not well established in literature. In this study, 84 patients were assessed, of whom 40 were in the control group and 44 in the study group. Cartilage status in the study group was evaluated during surgical treatment. Multilayer perceptron - MLP, radial basis function - RBF, support vector method - SVM and naive classifier – NBC were introduced in this study as classification protocols. Highest accuracy (0.893) was found when MLP was introduced, also RBF classification showed high sensitivity (0.822) and specificity (0.821). On the other hand, NBC showed lowest diagnostic accuracy reaching 0.702. In conclusion vibroarthrography presents a promising diagnostic modality for cartilage evaluation in clinical setting with the use of MLP and RBF classification methods

Nonlinear analysis of the ripping head power time series

We investigate the power of a ripping head in the process of concrete cutting. Using nonlinear embedding methods we study the corresponding time series obtained during the cutting process. The calculated maximal Lyapunov exponent indicates the exponential divergence typical for chaotic or stochastic systems. The recurrence plots technique has been used to get nonlinear process statistics for identification and description of nonlinear dynamics, lying behind the cutting process

Nonlinear analysis of the ripping head power time series

We investigate the power of a ripping head in the process of concrete cutting. Using nonlinear embedding methods we study the corresponding time series obtained during the cutting process. The calculated maximal Lyapunov exponent indicates the exponential divergence typical for chaotic or stochastic systems. The recurrence plots technique has been used to get nonlinear process statistics for identification and description of nonlinear dynamics, lying behind the cutting process