Control system software, simulation, and robotic applications

All essential existing capabilities needed to create a man-machine interaction dynamics and performance (MMIDAP) capability are reviewed. The multibody system dynamics software program Order N DISCOS will be used for machine and musculo-skeletal dynamics modeling. The program JACK will be used for estimating and animating whole body human response to given loading situations and motion constraints. The basic elements of performance (BEP) task decomposition methodologies associated with the Human Performance Institute database will be used for performance assessment. Techniques for resolving the statically indeterminant muscular load sharing problem will be used for a detailed understanding of potential musculotendon or ligamentous fatigue, pain, discomfort, and trauma. The envisioned capacity is to be used for mechanical system design, human performance assessment, extrapolation of man/machine interaction test data, biomedical engineering, and soft prototyping within a concurrent engineering (CE) system

Enhancement of plastic surgery training by including simulation in education and training programmes

Background. This research investigated the possibility of integrating simulation in plastic surgery residency training. The problem addressed was the lack of knowledge about using simulation as a teaching method to enhance the training of plastic surgeons. There was a lack of empirical evidence regarding learning outcomes that could be mastered by simulation-based education and training and their specific cognitive levels.Objectives. To identify and describe: (i) learning outcomes for plastic surgery education and training for which simulation might be an important (essential and useful) training method; and (ii) simulation modalities, linked to specific cognitive levels, to establish the influence of simulation on plastic surgery education and training. The objectives entail determining the importance of simulation in plastic surgery training and identifying simulation modalities most suited to attain specific outcomes.Methods. Data were collected by means of a Delphi survey to obtain consensus from an expert panel comprising 9 plastic surgeons, supplemented by semi-structured interviews conducted with 8 national and international role players in simulation and postgraduate education.Results. Learning outcomes, levels of training, possible simulation modalities, cognitive levels and descriptive verbs and phrases were described, as these pertain to learning. Participants agreed that simulation in medical education can be used to enhance postgraduate plastic surgery training, with special reference to specific outcomes and cognitive levels. Participants made recommendations for the planning and support of the implementation, aimed at ensuring the quality of training.Conclusion. The objectives set were achieved and the results of the study serve as encouragement and guidance in the striving for the enhancement of postgraduate plastic surgery education and training, and in other medical disciplines

Assessment of surgical performance

Surgical patient outcomes are related to technical and non-technical skills of the surgeon. Trauma patient operative and management experience has declined since trainee duty-hour restrictions were mandated in 2003 resulting in less experience in technical surgical skills. The Advanced Surgical Skills for Exposure in Trauma (ASSET) cadaver-based course, teaching vascular exposure and haemorrhage control, was developed to fill this training gap. The aim of this Thesis is to develop surgeon performance metrics and to test surgeons before and after taking the ASSET course to determine whether such training improves performance of peripheral vascular control. The importance of training in surgical vascular control in both civilian and military practice, and a description of current surgical training for trauma are described in Chapter 1. Reviews of existing trauma training courses and surgical performance metrics are provided in Chapters 2 and 3, and show limited testing of training courses and lack of trauma surgical performance metrics. Data collection methods, evaluator training and analysis are described in Chapter 4. Chapter 5 evaluates self-confidence of surgeons performing the vascular control procedures in cadavers compared to the performance evaluated by trained evaluators. Preliminary validation of vascular-control performance metrics and testing of a standardized script with item analysis and inter-rater reliability are discussed in Chapter 6. Testing 40 surgeons performing 3 extremity vascular control procedures before and after training is reported in Chapter 7. ASSET training improves performance, but large performance variability, repeated errors and no improvements were found in some surgeons. Chapter 8 reports how blind video analysis checklist, global rating metrics, error occurrence and recovery show convergent validity with co-located evaluators. Chapter 9 identifies the key findings and implications, innovation of the work described in the Thesis and concludes with the potential impact on military readiness and my personal reflection on what I learnt.  Open Acces

The Development and Application of a Forearm Simulator to Investigate Radial Head Biomechanics

The forearm is a complex articular unit, with poorly understood biomechanics. A novel forearm simulator to facilitate physiologic testing of cadavers for multiple clinical scenarios was designed, manufactured and validated. A number of outcome measurements were potentiated including the forearm’s resistance to rotation, radiocapitellar contact pressure and area as well as IOM loads. Testing of changes to forearm biomechanics due to radial head excision and variations of radial head arthroplasty dimensions was conducted. Radial head arthroplasty using the correct radial head length and diameter recreated the biomechanics of an intact forearm. Radial head excision as well an implant of non-anatomic length or diameter created abnormal radiocapitellar joint properties and load transfer within the forearm. The simulator had good repeatability and reproducibility. If radial head arthroplasty is clinically required, an implant that is similar in dimensions to the native radial head maintains native forearm biomechanics

Cardiac and Vascular Responses to Thigh Cuffs and Respiratory Maneuvers on Crewmembers of the International Space Station

The transition to microgravity eliminates the hydrostatic gradients in the vascular system. The resulting fluid redistribution commonly manifests as facial edema, engorgement of the external neck veins, and a decrease in leg diameter. This experiment examined the responses to modified Valsalva and Mueller maneuvers measured by cardiac and vascular ultrasound (ECHO) in a baseline steady state and during preload reduction introduced with thigh occlusion cuffs used as a counter-measure device (Braslet cuffs) measured by cardiac and vascular ultrasound examinations. Methods: Nine International Space Station crewmember subjects (Expeditions 16 - 20) were examined in 15 experiment sessions 101 +/- 46.days after launch (mean +/- SD; 33 - 185). Twenty Seven cardiac and vascular parameters were obtained with/without respiratory maneuvers before and after tightening of the Braslet cuffs. Results: Non-physicians performed diagnostic-quality cardiac and vascular ultrasound examinations using remote guidance. Three of 27 combinations of maneuvers and Braslet or Braslet alone were identified as being significant changed when compared to baseline. Eleven of 81 differences between combinations of Mueller, Valsalva or baseline were significant and related to cardiac preload reduction or increase in lower extremity venous volume. Conclusions: Acute application of Braslet occlusion cuffs causes lower extremity fluid sequestration and exerts commensurate measurable effects on cardiac performance in microgravity. Ultrasound techniques to measure the hemodynamic effects of thigh cuffs in combination with respiratory maneuvers may serve as an invaluable tool in determining the volume status of the cardiac patient at the 'microgravity bedside'

An investigation of the forces within the tibiae at typical blast loading rates : with different boots

Includes bibliographical references.Anti-Vehicular Landmines (AVLs), underbelly Improvised Explosive Devices (IEDs) or side-attack IEDs are some of the major threats to military vehicles and their occupants (Ramasamy et al., 2011). The lower extremities of the occupants are very prone to injury, mostly caused by underbelly detonation of AVLs or IEDs due to their spatial proximity to the rapidly deforming floor of a vehicle in response to the threat mechanism. Lower limb surrogate legs, such as a Hybrid III or Military Lower Extremity (MiL-Lx) legs, are used to quantify the impulse loading on the lower extremities when subjected to the forces of the rapidly deforming floor. These surrogate legs are also used in laboratories for simulated blast loading tests and scaled field tests to evaluate protection measures for the lower extremities. In this study, the responses of the HIII and MiL-Lx surrogate legs were evaluated at several blast loading conditions using the Modified Lower Limb Impactor. The impact tests were conducted using a lower limb impactor with the leg mounted vertically and attached to the knee of the Anthropomorphic Test Device (ATD). The MiL-Lx leg is a recently developed surrogate which has limited evaluation across the loading conditions. This work evaluated the MiL-Lx leg across a range of velocities from 2.7 – 10.2 m/s. The study also included the evaluation of the response of the surrogate legs when fitted with two different types of combat boot. The current study shows that the response of the MiL-Lx leg compares satisfactorily with a previous study of a simulated blast at 7.2 m/s and the Post Mortem Human Subject (PMHS) corridors conducted at Wayne State University (WSU), Michigan, U.S.A. The MiL-Lx leg force-time trajectories from both the lower and upper tibia load cell were found to have distinct features that can be related to the impactor dynamics. This observation implies that the response of the legs can be used to deduce the dynamics of the impactor or deforming floor. The MiL-Lx leg results measured by the lower tibia load cell shows that the combat boots mitigate the peak tibia force and delay the time to peak force. However, the results from the upper tibia load cell show that the boots did not reduce high-severity force, but only the delays the time-to-peak force. The upper tibia load cell did not show any potential mitigation capability of the combat boots. The HIII leg force-time trajectories from both the lower and upper load cells showed a similar bell shape and duration but different magnitudes. Both the lower and upper tibia load cells of the HIII leg showed that the combat boots had mitigation capabilities. This is the first time that the lower tibia response of the MiL-Lx leg has been tested and analysed at a range of loading conditions. This has resulted in better understanding of the response of the MiL-Lx leg and will ultimately lead to better protection measures of the lower extremities

The virtual peripheral nerve academy: education for the identification and treatment of peripheral nerve disorders

Millions of people around the globe suffer peripheral nerve injuries caused by trauma and medical disorders. However, medical school curricula are profoundly deficient in peripheral nerve education. This lack of knowledge within the healthcare profession may cause inadequate patient care. We developed the Virtual Peripheral Nerve Academy (VPNA) as a reusable virtual learning environment to provide medical students with detailed education on the peripheral nervous system (PNS). Students are introduced to the PNS through virtual 3D rendering of the human body, wherein they visualize individual nerves through dissection and observe normal motor and sensory function associated with each nerve. PNS structures that are absent from traditional texts are included in this visualization, ranging from the innervation of joints to the normal anatomic variation required for differential diagnosis of pain after an injury. Detailed modules on peripheral nerve disorders allow students to observe pathophysiological mechanisms, associated symptomatology, and appropriate treatments. Students are briefed on a patient clinical case, then interact with a patient avatar to learn the appropriate diagnostics, including physical exam maneuvers and electrodiagnostic testing. Interactive modules on peripheral nerve surgeries detail surgical techniques. The VPNA data and analytics dashboards allow medical students and course instructors to assess skill improvement and identify specific learning needs. The built-in learner management system and availability on both computer-based and virtual reality platforms facilitate integration into any existing medical school curricula. Ultimately, this immersive technology enables every medical student to learn about the peripheral nervous system and gain competency in treating real-life nerve pathologies

The Kinematic and Biomechanical Effects of Bracing on the Rehabilitation of the LCL Injured Elbow

Lateral collateral ligament (LCL) injuries are often treated non-operatively or with surgical repair. If instability persists, hinged elbow orthoses (HEOs) are often recommended. However, these orthoses are designed as a straight hinge, which does not account for the native carrying angle of the elbow. A custom HEO was designed to adjust the orthosis valgus angulation to measure in vitro elbow kinematics and biomechanics. An in vitro study investigated the effect of HEO valgus angulation during simulated active and passive flexion, in the vertical dependent and varus positions, with the forearm pronated and supinated. In the vertical dependent position, the orthosis did not produce instability and in the varus position, greater HEO angles trended towards improving elbow stability. Passive flexion was not found to worsen instability. In a subsequent study, a novel LCL tensioning mechanism is introduced to examine the effects of orthosis valgus angulation on LCL loads. No significant differences were found, as the tension did not change much throughout the range of motion. Future work is proposed to further improve the understanding of elbow kinematics and biomechanics to optimize rehabilitation techniques, surgical protocols and orthosis designs

Development of an Active Elbow Motion Simulator and Coordinate Systems to Evaluate Kinematics in Multiple Positions

Elbow disorders are common as a consequence of both traumatic and degenerative conditions. Relative to disorders of the lower limb, there is comparatively little evidence to direct the treatment of many elbow disorders. Biomechanical studies are required to develop and validate the optimal treatment of elbow disorders prior to their application in patients. Clinically relevant simulation of elbow motion in the laboratory can be a powerful tool to advance our knowledge of elbow disorders. This work was undertaken with the rationale that simulation and quantification of elbow motion could be improved significantly. This treatise includes the development and evaluation of an in-vitro elbow motion simulator which, with the humerus horizontally positioned, is the first to achieve active flexion and extension in a vertical plane. Additionally, it is capable of operating in the vertical, varus and valgus positions, and while maintaining full forearm pronation or supination. The simulator controller employs a Cascade PID configuration with feedforward transfer functions, which achieves unified control of flexion angle and muscle tension for multiple muscles. Feedback of the elbow joint angle and muscle tension is utilized to achieve closed-loop control. A performance evaluation in a full series of specimens clearly demonstrated that the actual joint angle is not more than 5 degrees removed from the desired setpoint during flexion or extension in any position. Also, a new method for creating upper extremity bone segment coordinate systems which are derived from elbow flexion and forearm rotation was developed and tested. This produced joint kinematics with significantly less inter-subject variability than traditional anatomy-derived coordinate systems. This minimally-invasive method also provides increased statistical power for laboratory based studies and may prove useful for clinical applications. The new simulation techniques developed herein were applied to an in-vitro investigation of olecranon fracture repair with clinical significance. This study revealed valuable insights into a common repair procedure. This was made possible by the previously unattainable measurements that these new techniques now provide. These developments will assist surgeons and other investigators in the design and evaluation of treatments for elbow disorders, and contribute to the betterment of patient care