Accepted Manuscripts

Sina Ameli, Fazel Naghdy, David Stirling, Golshah Naghdy, Morteza Aghmesheh, Ryan Anthony, Peter McLennan and Gregory Peoples
ASME J of Medical Diagnostics   doi: 10.1115/1.4039211
Objective: Exercise-induced fatigue evolves from the initiation of physical work. Nonetheless, the development of an objective method for detecting fatigue based on variation in ambulatory motion parameters measured during exercise is yet to be explored. Approach: In this study, the ambulatory motion parameters consisting of kinematic parameters of 23 body segments in addition to muscle tissue oxygen saturation (SmO2), heart rate and vertical work of 8 healthy male subjects during Stair Climbing Tests (SCT) were measured before and after a fatigue protocol utilizing Wingate cycling test. The impacts of fatigue on ambulatory motion and postural behaviors were analyzed using an unsupervised machine learning method classifying angular joint motions. Main results: The average of total distance travelled by subjects and the overall body postural behavior showed about 25% decline and 90% variation after fatigue protocol, respectively. Also, higher relative desaturation in SCT1 -64.0 (1.1) compared SCT2 -54.8 (1.1) was measured. Significance: Measurements of differences in metabolic indexes and motion postural states proved a strong correlation.
TOPICS: Fatigue, Machinery, Stairs, Biological tissues, Muscle, Oxygen, Kinematics
Brian Henry, Gardner Yost, Robert Molokie and Thomas J. Royston
ASME J of Medical Diagnostics   doi: 10.1115/1.4039177
Acute chest syndrome (ACS) is a leading cause of death for those with sickle cell disease (SCD). ACS is defined by the development of a new pulmonary infiltrate on chest x-ray, with fever and respiratory symptoms. Efforts have been made to apply various technologies in the hospital setting to provide earlier detection of ACS than x-ray, but they are expensive, increase radiation exposure to the patient, and are not technologies that are easily transferrable for home use to help with early diagnosis. We present preliminary studies on patients suggesting that acoustical measurements recorded quantitatively with contact sensors (electronic stethoscopes) and analyzed using advanced computational analysis methods may provide an earlier diagnostic indicator of the onset of ACS than is possible with current clinical practice. In silico models of respiratory acoustics utilizing image-based and algorithmically developed lungs with full conducting airway trees support and help explain measured acoustic trends and provide guidance on the next steps in developing and translating a potentially life-saving diagnostic approach. More broadly, the experimental and computational techniques introduced herein, while focused on monitoring and predicting the onset of ACS, could catalyze further advances in mobile health (mhealth)-enabled, computer-based auscultative diagnoses for a wide range of cardiopulmonary pathologies.
TOPICS: Acoustics, X-rays, Sensors, Radiation (Physics), Computers, Diseases, Lung
Lara A. Thompson, Csilla Haburcakova and Richard F. Lewis
ASME J of Medical Diagnostics   doi: 10.1115/1.4039140
The purpose of this paper is to describe novel experiments and methodology utilizing a distinctive balance platform-system to investigate postural responses for moderate to severe vestibular loss and invasive vestibular prosthesis-assisted non-human primates (rhesus monkeys). For several millions of vestibular loss sufferers in the United States, daily-living is severely affected in that common everyday tasks, such as getting out of bed at night, maintaining balance on a moving bus, or walking on an uneven surface, may cause loss of stability leading to falls and injury. Aside from loss of balance, blurred vision and vertigo (perceived spinning sensation) are also debilitating in vestibular impaired individuals. Although the need for vestibular rehabilitative solutions is apparent, postural responses for a broad range of peripheral vestibular function, and for various stationary and moving support conditions, have not been systematically investigated. For the investigation of implants and prostheses that are being developed towards implementation in humans, non-human primates are a key component. The measurement system used in this research was unique. Our platform-system facilitated the study of rhesus monkey posture for stationary support surface conditions (quiet stance and head turns) and for dynamic support surface conditions (pseudorandom roll-tilts of the support surface). Further, the platform-system was used to systematically study postural responses that will serve as baseline measures for future vestibular-focused human and non-human primate posture studies.
TOPICS: Prostheses, Measurement systems, Wounds, Stability, Spinning (Textile), Spin (Aerodynamics)
Dilip DE
ASME J of Medical Diagnostics   doi: 10.1115/1.4039100
We have obtained from the Bloch NMR equations the correct dependence of the single component My and Mz at resonnance (NMR/MRI) on relaxation times, rf B1 field (pulsed or continuous), blood(nuclear spin) flow velocity, etc. in the rotating frame of reference. We find that the new formulation for the first time uniquely describes the true relationship between individual single component My, Mz of magnetization of flowing nuclear spin with the above quantities (excluding diffusion and gradient fields) during NMR/MRI excitation. The equations are applicable for both CW and pulsed NMR experiments with or without flow of spins. Our approaches can be extended easily to include gradient fields and diffusion of spins, if needed in NMR/MRI experiments. We also discuss the application of our equations to a specific case of MR excitation scheme: Free induction decay. The new equations and further equations that can be derived with the methodlogies used here, can advance the techniques of non-invasive blood flow estimation by MR and also accurate extraction of paramaters of clinical importance by enabling accurate simulation of the MR images ( of blood flow and tissue) and comparison with experimental MR images. The detailed simulations from the equations will be published in the next article.
TOPICS: Nuclear magnetic resonance, Nuclear spin, Magnetization, Magnetic resonance imaging, Excitation, Blood flow, Flow (Dynamics), Diffusion (Physics), Simulation, Relaxation (Physics), Electromagnetic induction, Biological tissues, Blood
Ronald S. LaFleur and Laura S. Goshko
ASME J of Medical Diagnostics   doi: 10.1115/1.4039103
Cardiovascular disease (CVD) continues to be a leading cause of death. Accordingly, risk models attempt to predict an individual's probability of developing the disease. These risk models are incorporated into calculators to determine the risk for a number of clinical conditions, including the 10-year risk of developing CVD. There is significant variability in the published models in terms of how the clinical measurements are converted to risk factors as well as the specific population used to determine b-weights of these risk factors. Adding to model variability is the fact that numbers are an imperfect representation of a person's health status. Acknowledgement of uncertainty must be addressed for reliable clinical decision making. This paper analyzes thirty-five published risk calculators and then generalizes them into one 'Super Risk Formula' to form a common basis for uncertainty calculations to determine the best risk model to use for an individual. Special error arithmetic, the duals method, is used to faithfully propagate error from model parameters, population averages and patient specific clinical measures to one risk number and its relative uncertainty. A set of sample patients show that the 'best model' is specific to the individual and no one model is appropriate for every patient.
TOPICS: Uncertainty, Risk, Diseases, Errors, Probability, Cardiovascular system, Decision making
Review Article  
Andrii Maryniak, Brock Laschowski and Jan Andrysek
ASME J of Medical Diagnostics   doi: 10.1115/1.4039105
Bone-anchored prostheses represent a promising solution to numerous medical complications associated with conventional socket-suspended prostheses. The following technical overview was constructed for prospective engineers and orthopaedic surgeons interested in osseointegrated implants for transfemoral prosthesis-residuum interfacing. Existing osseointegrated implants comprise different biomaterial compositions (i.e., titanium alloy vs. cobalt-chromium-molybdenum alloy) and mechanical designs (i.e., screw-fixated vs. press-fixated devices). Perioperative systems of osseointegration surgery include: preoperative assessments (i.e., alongside inclusion and exclusion criteria); intraoperative procedures; and postoperative rehabilitation (i.e., static loading and dynamic gait rehabilitation). The intraoperative procedures involve: transecting and reorganizing the residual musculature; embedding the implant into the femoral intramedullary cavity; and coupling the osseointegrated implant to an external prosthesis (e.g., robotic device). Postoperative clinical evaluations have demonstrated significant biomechanical, psychological, and physiological improvements in patients using bone-anchored prostheses compared to conventional socket-suspended prostheses. Nevertheless, bacterial infections surrounding the skin-implant biointerface, often resulting from Staphylococcus aureus or other coagulase-negative staphylococci, remain a relatively frequent medical complication, which can culminate in periprosthetic osteomyelitis and/or implant extraction. The technical overview concludes with discussions of: the recent FDA Humanitarian Use Device designations; financial analyses between bone-anchored and socket-suspended prostheses; and applications of vibrotactile osseoperception for augmenting walking and balance feedback control.
TOPICS: Surgery, Design, Prostheses, Orthopedics, Bone, Biomedicine, Food and Drug Administration, Skin, Physiology, Robotics, Cavities, Economic analysis, Feedback, Frequency-domain analysis, molybdenum, Muscle, Cobalt, Alloys, Engineers, Screws, Biomaterials, Titanium alloys, Biomechanics

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