Acoustic analysis of the knee joint in the study of osteoarthritis detection during walking

This thesis investigates the potential of non-invasive detection of knee Osteoarthritis (OA) using the sounds emitted by the knee joint during walking and captured by a single microphone. This is a novel application since, until now, there are no other methods that considered this type of signals. Clinical detection of knee OA relies on imaging techniques such as X-radiology and Magnetic Resonance Imaging. Some of these methods are expensive and impractical while others pose health risks due to radiation. Knee sounds on the other hand may offer a quick, practical and cost-effective alternative for the detection of the disease. In this thesis, the knee sound signal structure is investigated using signal processing methods for information extraction from the time, frequency, cepstral and modulation domains. Feature representations are obtained and their discriminant properties are studied using statistical methods such as the Bhattacharyya distance and supervised learning techniques such as Support Vector Machine. From this work, a statistical feature parameterisation is proposed and its efficacy for the task of healthy vs OA knee condition classification is investigated using a comprehensive experimental framework proposed in this thesis. Feature-based representations that incorporate spatiotemporal information using gait pattern variables, were also investigated for classification. Using the waveform characteristics of the acoustic pulse events detected in the signal, such representations are proposed and evaluated. This approach utilised a novel stride detection and segmentation algorithm that is based on dynamic programming and is also proposed in the thesis. This algorithm opens up potential applications in other research fields such as gait analysis.Open Acces

Acoustic Emission Measurement System in Diagnostic of Cartilage Injuries of the Knee

Abstract The measurement system BONEDIAS (Bone Diagnostic System) was developed as a non-invasive diagnostic method, based on the analysis on the acoustic emission from the knee joint. Knee squats of a patient will release acoustic emission in high temporal resolution and well correlated to the angle of knee flexion. The physician will get the relevant information concerning arthritic lesions in the knee joint (well characterized acoustic emission, singular events without a follow up of further emission), acoustic emission due to elevated intra-articular friction caused by e.g. cartilage lesions, inappropriate surface roughness, a lack of synovial fluid or crack initiation in the femur. Over 100 patients were analyzed with the measurement system BONEDIAS, afterwards the results were compared with the intra-operative views (arthroscopy and arthroplasty of the knee). Other parameters were studied, concerning the relation between the age and the sex of the subjects, the length of the femur, thigh thickness, the body mass index, the anatomical axis of the knee and the appearance and severity of the cartilage lesions. The study was made with the purpose to see if there was a correspondence between the cartilage disorders, the intraoperative views (arthroscopy and the arthroplasty of the knee) and the acoustic emission measurements, performed one day before the surgery. Because there arent at this moment cheap and standards methods who can determine the early cartilage injuries, this study is supposed (concording with the results) to open new ideas and new advantages in the diagnostic of this often disease, using the acoustic emission measurement system. The results obtained, 50% correspondence for the gr. 0, I and II Outerbridge lesions are more important, more significant that the other results, with over 60% correspondence for the advanced osteoarthrosis. The obtained acoustic emission signals, corresponding to the intra-arthroscopic findings showed the importance of this method to identify the early cartilage injuries. The method is not perfect and the results (50%) are not really statistically significant, so that we can introduce this method on a large scale, but offers important information that should be used in the future. Also, there isn’t a perfect method to compare the acoustic emission signals with the intra-arthroscopic findings. Every patient was analysed separately and with his corresponding measurement compared, that means a lot of time (20 – 30 minutes for the measurement and the other questions and clinical tests and another 15 minutes to analyse the signals and compare them with the intra-operative findings). For a study this can be accepted, but for clinical every day use maybe not. A standard interpretation and analyse method, maybe after clinical large trials, if such a method can be developed, could bring big advantages for the early determination of the cartilage injuries. In conclusion, the study had offered important informations about the importance of accoustic emission measurements, that can be used for the future studies and with some improvements, this method , cheap and non-invasive, but at this moment a little beat time-consuming, can be helpful in the diagnose of the early cartilage injuries

Quantifying the Effects of Knee Joint Biomechanics on Acoustical Emissions

The knee is one of the most injured body parts, causing 18 million patients to be seen in clinics every year. Because the knee is a weight-bearing joint, it is prone to pathologies such as osteoarthritis and ligamentous injuries. Existing technologies for monitoring knee health can provide accurate assessment and diagnosis for acute injuries. However, they are mainly confined to clinical or laboratory settings only, time-consuming, expensive, and not well-suited for longitudinal monitoring. Developing a novel technology for joint health assessment beyond the clinic can further provide insights on the rehabilitation process and quantitative usage of the knee joint. To better understand the underlying properties and fundamentals of joint sounds, this research will investigate the relationship between the changes in the knee joint structure (i.e. structural damage and joint contact force) and the JAEs while developing novel techniques for analyzing these sounds. We envision that the possibility of quantifying joint structure and joint load usage from these acoustic sensors would advance the potential of JAE as the next biomarker of joint health that can be captured with wearable technology. First, we developed a novel processing technique for JAEs that quantify on the structural change of the knee from injured athletes and human lower-limb cadaver models. Second, we quantified whether JAEs can detect the increase in the mechanical stress on the knee joint using an unsupervised graph mining algorithm. Lastly, we quantified the directional bias of the load distribution between medial and lateral compartment using JAEs. Understanding and monitoring the quantitative usage of knee loads in daily activities can broaden the implications for longitudinal joint health monitoring.Ph.D

Prediction of Osteoarthritis in the Knee by KOA Diagnosis Using Artificial Intelligence Based Techniques

Knee Osteoarthritis is the most common form of knee arthritis. A healthy knee's articular cartilage, a smooth, slick tissue, allows for simple bending and straightening. The ends of the leg bones that make up your knee are covered, safeguarded, and cushioned by this material. Two c-shaped segments of meniscal cartilage between your bones serve as "shock absorbers" to cushion your knee joint. Osteoarthritis develops gradually. The cartilage becomes rough and ragged as it ages. It hurts to move the bones along this exposed area. The most prevalent signs and symptoms of knee osteoarthritis are pain and stiffness. After being inactive for a while or in the morning, symptoms typically worsen. The earlier you begin treatment, the better, as osteoarthritis gets worse with time. Your doctor may prescribe additional tests after reviewing your symptoms and medical history, such as X-rays, which can reveal bone and cartilage damage as well as the existence of bone spurs, and magnetic resonance imaging (MRI) scans. So, the KOA diagnosis will be based on two modalities: X-rays and MRIs. Depending upon the patient’s opinion about their knee problems, the doctor will decide whether to take X-rays or MRIs for KOA diagnosis.  To avoid such severe knee issues, researchers used many various techniques for KOA diagnosis in the existing system in order to treat it at an early stage of knee problems. In order to do that, we conducted a survey of research articles based on the KOA diagnosis published in the years 2021 and 2022 for this work. From the conducted survey, the methodologies which are AI-based techniques used for KOA diagnosis are discussed and their performance metrics are compared. The current review paper's goal is to do research on the various KOA diagnosis approaches employed in the years 2021 and 2022. As a result of this study, the methodologies which are AI-based techniques used for KOA diagnosis achieves good efficiency in predicting the osteoarthritis in the knee

Influence of Mechanical Choices on Development and Persistence of Osteoarthritis: How Alexander Technique Can Promote Prevention and Management

Is osteoarthritis a fate unconditionally vested in genetic makeup, or are joints aggravated into inflammation by the way they are treated? Humans are a complicated conglomeration of experiences, decisions, and inheritance. Osteoarthritis, likewise, has evaded simplicity in any explanation of its causation, so it necessitates a multi-dimensional perspective. This research considers the relevance of Alexander Technique in filling a void in which treatment and management of osteoarthritis is not equally equipped to answer this multi-dimensional causation. Alexander Technique is classified as a movement therapy, but this does not quite encompass the mindset of it—that it is indeed largely a mindset about movement. More concisely, Alexander Technique emphasizes self-awareness about how a person uses his or her body to perform daily tasks. It is physical minimalism, and involves continual recognition of muscle tension along with the ability to let go of any tension that is burdensome and unnecessary. This technique has diminished pain and increased the ease of movement for those who have experienced it, even people with osteoarthritis. To build the argument that osteoarthritis can be hindered through a heightened consideration of how joints are treated, the initial component of this research investigated the vast amount of information already gleaned about the pathogenesis of this disease. The fields of physiology, genetics, immunology, and clinical practice already have much to share, and this knowledge has been combined with studies about the benefits and goals of Alexander Technique to discover the common ground of osteoarthritis treatment. The experimental component assesses the association of Alexander Technique to the minimization of pain from osteoarthritis. An online survey asks osteoarthritis cohorts about the history of their disease, the effect it has had on their pain levels and activities of daily living, and about the efficacy of their management strategies. Because each participant will be asked if he or she has received Alexander Technique lessons, the survey can be used to analyze each respondent’s experience of osteoarthritis with respect to that. It was found that participants who had received Alexander Technique lessons reported an average of one more pain-free day per week, and experienced diminished pain levels for daily physical activities such as walking. Management strategies also indicated the benefit of Alexander Technique; those who had taken lessons less frequently used pain and anti-inflammatory medications and were able to be more physically active than the unexposed group. No statistical significance was achieved from the data, largely owing to small sample size (Alexander Technique, n=12, no Alexander Technique, n=25). This study is a step in the direction of better osteoarthritis management, promoting prevention-minded awareness of joint use and providing preliminary fuel for more extensive research

Development and Implementation of Mathematical Modeling, Vibration and Acoustic Emission Technique to Correlate \u3cem\u3eIn Vivo\u3c/em\u3e Kinematics, Kinetics and Sound in Total Hip Arthroplasty with Different Bearing Surfaces

The evaluation of Total Hip Arthroplasty (THA) outcome is difficult and invasive methods are often applied. Fluoroscopy has been used as an in vivo diagnostic technique to determine separation which may lead to vibration propagation and audible interactions. The objective of this study was to develop a new, non-invasive technique of digitally capturing vibration and sound emissions at the hip joint interface and to correlate those with the hip kinematics derived from fluoroscopy. Additionally, an examination of the role of hip mechanics on walking performance in THA subjects of various bearings surfaces was performed. In vivo kinematics, kinetics, corresponding vibration and sound measurements of THA were analyzed post-operatively using video-fluoroscopy, mathematical modeling, sound sensors and accelerometers during gait on a treadmill. Twenty-seven subjects (31 hips) with a metal-on-metal, metal-on-polyethylene, ceramic-on-ceramic, ceramicon- polyethylene or metal-on-metal polyethylene-sandwich THA were analyzed. A data acquisition system was used to amplify the signal and filter out associated frequencies attributed to noise. The sound measurements were correlated to in vivo kinematics. A mathematical model of the human extremity was derived to determine in vivo bearing and soft-tissue forces. For all bearings a distinct correlation of a high frequency sound occurring at the time when the femoral head slides back into the acetabular component was observed. Subjects having a hard-on-hard bearing seemed to attenuate a squeaking and/or impacting sound, while those having polyethylene liner only revealed a knocking sound attributed to impact loading conditions. For the first time, audible effects can be derived in vivo and the examined correlation brings valuable insight into the hip joint performance in an inexpensive and non-invasive manner. This research may allow for a further correlation to be derived between sound and different types of failure mechanisms. Results from this study will give surgeons and engineers a better understanding of in vivo mechanics of the hip joint and this way improve the quality of life of THA patients. In addition, the developed technique builds the first milestone in the design and implementation of a cost effective, non-invasive diagnostic technique which has the potential to become a routine diagnosis of joint conditions

Exploring the effect of space and place on response to exercise therapy for knee and hip pain-a protocol for a double-blind randomised controlled clinical trial:the CONEX trial

Introduction: Context effects are described as effects of a given treatment, not directly caused by the treatment itself, but rather caused by the context in which treatment is delivered. Exercise is a recommended core treatment in clinical guidelines for musculoskeletal disorders. Although moderately effective overall, variation is seen in size of response to exercise across randomised controlled trial (RCT) studies. Part of this variation may be related to the fact that exercise interventions are performed in different physical environments, which may affect participants differently. The study aims to investigate the effect of exercising in a contextually enhanced physical environment for 8 weeks in people with knee or hip pain. Methods and analysis: The study is a double-blind RCT. Eligible participants are 35 years or older with persisting knee and/or hip pain for 3 months. Participants are randomised to one of three groups: (1) exercise in a contextually enhanced environment, (2) exercise in a standard environment and (3) waiting list. The contextually enhanced environment is located in a newly built facility, has large windows providing abundant daylight and overlooks a recreational park. The standard environment is in a basement, has artificial lighting and is marked by years of use; that is, resembling many clinical environments. The primary outcome is the participant\u27s global perceived effect rated on a seven-point Likert scale after 8 weeks exercise. Patient-reported and objective secondary outcomes are included. Ethics and dissemination: The Regional Scientific Ethical Committee for Southern Denmark has approved the study. Study findings will be disseminated in peer-reviewed publications and presented at national and international conferences

Gait sonification for rehabilitation: adjusting gait patterns by acoustic transformation of kinematic data

To enhance motor learning in both sport and rehabilitation, auditory feedback has emerged as an effective tool. Since it requires less attention than visual feedback and hardly affects the visually dominated orientation in space, it can be used safely and effectively in natural locomotion such as walking. One method for generating acoustic movement feedback is the direct mapping of kinematic data to sound (movement sonification). Using this method in orthopedic gait rehabilitation could make an important contribution to the prevention of falls and secondary diseases. This would not only reduce the individual suffering of the patients, but also medical treatment costs. To determine the possible applications of movement sonification in gait rehabilitation in the context of this work, a new gait sonification method based on inertial sensor technology was developed. Against the background of current scientific findings on sensorimotor function, feedback methods, and gait analysis, three studies published in scientific journals are presented in this thesis: The first study shows the applicability and acceptance of the feedback method in patients undergoing inpatient rehabilitation after unilateral total hip arthroplasty. In addition, the direct effect of gait sonification during ten gait training sessions on the patients’ gait pattern was revealed. In the second study, the immediate follow-up effect of gait sonification on the kinematics of the same patient group is examined at four measurement points after gait training. In this context, a significant influence of sonification on the gait pattern of the patients was shown, which, however, did not meet the previously expected effects. In view of this finding, the effect of the specific sound parameter loudness of gait sonification on the gait of healthy persons was analyzed in a third study. Thus, an impact of asymmetric loudness of gait sonification on the ground contact time could be detected. Considering this cause-effect relationship can be a component in improving gait sonfication in rehabilitation. Overall, the feasibility and effectiveness of movement sonification in gait rehabilitation of patients after unilateral hip arthroplasty becomes evident. The findings thus illustrate the potential of the method to efficiently support orthopedic gait rehabilitation in the future. On the basis of the results presented, this potential can be exploited in particular by an adequate mapping of movement to sound, a systematic modification of selected sound parameters, and a target-group-specific selection of the gait sonification mode. In addition to a detailed investigation of the three factors mentioned above, an optimization and refinement of gait analysis in patients after arthroplasty using inertial sensor technology will be beneficial in the future.Akustisches Feedback kann wirkungsvoll eingesetzt werden, um das Bewegungslernen sowohl im Sport als auch in der Rehabilitation zu erleichtern. Da es weniger Aufmerksamkeit als visuelles Feedback erfordert und die visuell dominierte Orientierung im Raum kaum beeinträchtigt, kann es während einer natürlichen Fortbewegung wie dem Gehen sicher und effektiv genutzt werden. Eine Methode zur Generierung akustischen Bewegungsfeedbacks ist die direkte Abbildung kinematischer Daten auf Sound (Bewegungssonifikation). Ein Einsatz dieser Methode in der orthopädischen Gangrehabilitation könnte einen wichtigen Beitrag zur Prävention von Stürzen und Folgeerkrankungen leisten. Neben dem individuellen Leid der Patienten ließen sich so auch medizinische Behandlungskosten erheblich reduzieren. Um im Rahmen dieser Arbeit die Einsatzmöglichkeiten der Bewegungssonifikation in der Gangrehabilitation zu bestimmen, wurde eine neue Gangsonifikationsmethodik auf Basis von Inertialsensorik entwickelt. Zu der entwickelten Methodik werden, vor dem Hintergrund aktueller wissenschaftlicher Erkenntnisse zur Sensomotorik, zu Feedbackmethoden und zur Ganganalyse, in dieser Thesis drei in Fachzeitschriften publizierte Studien vorgestellt. Die erste Studie beschreibt die Anwendbarkeit und Akzeptanz der Feedbackmethode bei Patienten in stationärer Rehabilitation nach unilateraler Hüftendoprothetik. Darüber hinaus wird der direkte Effekt der Gangsonifikation während eines zehnmaligen Gangtrainings auf das Gangmuster der Patienten deutlich. In der zweiten Studie wird der unmittelbare Nacheffekt der Gangsonifikation auf die Kinematik der gleichen Patientengruppe zu vier Messzeitpunkten nach dem Gangtraining untersucht. In diesem Zusammenhang zeigte sich ein signifikanter Einfluss der Sonifikation auf das Gangbild der Patienten, der allerdings nicht den zuvor erwarteten Effekten entsprach. Aufgrund dieses Ergebnisses wurde in einer dritten Studie die Wirkung des spezifischen Klangparameters Lautstärke der Gangsonifikation auf das Gangbild von gesunden Personen analysiert. Dabei konnte ein Einfluss von asymmetrischer Lautstärke der Gangsonifikation auf die Bodenkontaktzeit nachgewiesen werden. Die Berücksichtigung dieses Ursache-Wirkungs-Zusammenhangs kann einen Baustein bei der Verbesserung der Gangsonifikation in der Rehabilitation darstellen. Insgesamt wird die Anwendbarkeit und Wirksamkeit von Bewegungssonifikation in der Gangrehabilitation bei Patienten nach unilateraler Hüftendoprothetik evident. Die gewonnenen Erkenntnisse verdeutlichen das Potential der Methode, die orthopädische Gangrehabilitation zukünftig effizient zu unterstützen. Ausschöpfen lässt sich dieses Potential auf Grundlage der vorgestellten Ergebnisse insbesondere anhand einer adäquaten Zuordnung von Bewegung zu Sound, einer systematischen Modifikation ausgewählter Soundparameter sowie einer zielgruppenspezifischen Wahl des Modus der Sonifikation. Neben einer differenzierten Untersuchung der genannten Faktoren, erscheint zukünftig eine Optimierung und Verfeinerung der Ganganalyse bei Patienten nach Endoprothetik unter Einsatz von Inertialsensorik notwendig

Metronome-Cued Stepping in Place after Hemiparetic Stroke: Comparison of a One- and Two-Tone Beat

Hemiparetic gait is characterised by temporal asymmetry and variability, and these variables are improved by auditory cueing. Stepping in place incorporates aspects of gait and may be a useful tool for locomotor training. The aim of this pilot study was to investigate the use of a single-tone and dual-tone metronome to cue stepping in place after hemiparetic stroke. Eight participants completed an uncued baseline stepping condition and two cued stepping conditions utilising a single-tone and a dualtone metronome. Step times were determined from force plate data, and asymmetry and variability were calculated for the three conditions. Step time asymmetry was significantly reduced in the single-tone condition compared to baseline, and paretic step time variability was significantly reduced in both cued conditions.The single-tone metronome appeared to be preferred to the dual-tone metronome based on participant feedback.The results of this pilot study suggest that metronome cueing produces similar benefits on stepping in place to previously reported findings in walking. Further research on whether stepping in place to a metronome can be used for locomotor training is needed

Biomechanics of foetal movement.

© 2015, AO Research Institute. All rights reserved.Foetal movements commence at seven weeks of gestation, with the foetal movement repertoire including twitches, whole body movements, stretches, isolated limb movements, breathing movements, head and neck movements, jaw movements (including yawning, sucking and swallowing) and hiccups by ten weeks of gestational age. There are two key biomechanical aspects to gross foetal movements; the first being that the foetus moves in a dynamically changing constrained physical environment in which the freedom to move becomes increasingly restricted with increasing foetal size and decreasing amniotic fluid. Therefore, the mechanical environment experienced by the foetus affects its ability to move freely. Secondly, the mechanical forces induced by foetal movements are crucial for normal skeletal development, as evidenced by a number of conditions and syndromes for which reduced or abnormal foetal movements are implicated, such as developmental dysplasia of the hip, arthrogryposis and foetal akinesia deformation sequence. This review examines both the biomechanical effects of the physical environment on foetal movements through discussion of intrauterine factors, such as space, foetal positioning and volume of amniotic fluid, and the biomechanical role of gross foetal movements in human skeletal development through investigation of the effects of abnormal movement on the bones and joints. This review also highlights computational simulations of foetal movements that attempt to determine the mechanical forces acting on the foetus as it moves. Finally, avenues for future research into foetal movement biomechanics are highlighted, which have potential impact for a diverse range of fields including foetal medicine, musculoskeletal disorders and tissue engineering