Determination of Thin NiTi Wires' Mechanical Properties during Phase Transformations.

The modern industrial and consumer applications in accordance with the concepts of Industry 4.0 and the Internet of Things are characterized by autonomy and self-sufficiency. This has led to an increase in the interest for the so-called smart materials, capable of combining the functionalities of sensors, actuators and, in some applications, control systems. An important group of smart materials are shape-memory alloys, among which nickel-titanium (NiTi) alloys are the most known. In this article, the influence of phase transformation on the mechanical properties of thin NiTi alloy wires was investigated. During the test, the influence of the heating currents on the displacement and the force generated by the thin NiTi wires were analyzed. The temperature of the wires during heating was measured by a thermographic camera. This study proved the maximum value of the wires' displacement was related to the value of the heating current. During the research, the dependence of the transformation dynamics on the value of the heating currents was also proved. In addition, the influence of the surface inhomogeneity of the thin NiTi alloy wires on the accuracy of the thermographic measurements was analyzed. For the experimental research described in this article, we used the NiTi alloy whose trade name is Flexinol, produced by DYNALLOY (Inc. 2801 McGaw Ave. Irvine, CA, USA).

Determination of the Kinematic Excitation Originating from the Irregular Envelope of an Omnidirectional Wheel.

This paper describes a test stand for determining the kinematic excitation originating from the contact between a vehicle's wheel and the ground, thus acting on the single suspension upright of the vehicle. This excitation is unique to the movement of omnidirectional wheels and originates from the irregular envelope of the wheel. The presented attitude enables the vertical displacement of the wheel's axis rolling on a horizontal surface to be determined. This work includes experimental results considering different wheel orientations against the direction of movement.

Control System Design of an Underactuated Dynamic Body Weight Support System Using Its Stability.

This paper discusses the stability of systems controlling patient body weight support systems which are used in gait re-education. These devices belong to the class of underactuated mechanical systems. This is due to the application of elastic shock-absorbing connections between the active part of the system and the passive part which impacts the patient. The model takes into account properties of the system, such as inertia, attenuation and susceptibility to the elements. Stability is an essential property of the system due to human-device interaction. In order to demonstrate stability, Lyapunov's theory of stability, which is based on the model of system dynamics, was applied. The stability of the control system based on a model that requires knowledge of the structure and parameters of the equations of motion was demonstrated. Due to inaccuracies in the modeling of the rope (one of the basic elements of the device), an adaptive control system was introduced and its stability was also proved. The authors conducted simulation and experimental tests that illustrate the functionality of the analyzed control systems.

Inter-observer and intra-observer reliability in the radiographic measurements of paediatric forefoot alignment.

BACKGROUND: Foot bones in children have more rounded shapes in radiograms than adults. Thus, the goal of this work was assessing inter- and intra-observer reliability in paediatric forefoot angle measurements. MATERIAL AND METHODS: Six forefoot angles in 34 AP standing paediatric foot radiographs were measured by 5 researchers. A classic statistical analysis with use of IBM SPSS Statistics 25 was performed and a new method with two-way analysis of variance was applied. RESULTS: Results of statistical analysis revealed the properties of a subjective assessment related to specific angles. Kilmartin's angle, calcaneus-fifth metatarsal angle and first ray angle are the most reliable; metatarsus adductus angle should be used with great caution in pediatric population. Engel's angle is the most difficult for measuring and measurement error is the highest. CONCLUSION: The power of paediatric forefoot measurements is various. Several angles are reliable, while Engle's angle is the most doubtful.

Upper Limb after Forearm Lengthening in Patients' and Physicians' Perspective.

BACKGROUND: The goal of this study was to perform a functional (subjective) and radiological evaluation of patients who had undergone forearm lengthening by distraction osteogenesis years before. MATERIAL AND METHODS: Eleven patients with forearm shortening of various etiology were enrolled. They had undergone a total of 21 lengthening procedures. A retrospective analysis of radiological data was conducted and a subjective evaluation was accomplished by using a modified QuickDASH-9 questionnaire. RESULTS: Average bone lengthening was 3.54cm, and mean lengthening index was 40.53day/cm. Eight pa-tients answered the questionnaire at a mean of 7.8yrs after the treatment. The mean questionnaire score was 9.75pts (of 36). Four patients rated the overall function of the affected limb as improved following distraction, while 3 patients were not able to see any improvement. One patient reported that the lengthening had impaired limb function. With regard to cosmetic aspects, 4 patients reported a worsening after the lengthening procedure while 3 patients reported improvement and 1 patient did not note any changes. CONCLUSIONS: 1. Despite deformities and functional limitations, patients after forearm lengthening only occasionally suffered from moderate intensity pain. 2. The radiological outcomes were positive and the rate of complications was low. 3. The radiological outcomes did not match patient-declared functional and cosmetic results.

Clinical and Radiological Evaluation of Results of Surgical Correction of Forefoot Adduction by Cuneiform and Cuboid Osteotomy Using Radiological Forefoot Measurements.

BACKGROUND: Forefoot adduction is a relatively common problem. It is usually mild or it can be effectively managed conservatively. Severe deformities may require surgical treatment. The aim of the study was to perform a clinical and radiologic evaluation of forefoot adduction correction using medial cuboid and cuneiform osteotomy with a transposed wedge. MATERIAL AND METHODS: This is a retrospective study involving 16 patients who underwent 20 procedures. Mean age at surgery was 6 years (3-13). Clinical evaluation was based on measurements of forefoot deviation and patients'/care-givers' subjective opinion. The radiologic parameters assessed comprised the first ray angle, talar-first metatarsal angle, calcaneal-fifth metatarsal angle, talocalcaneal angle, metatarsus adductus angle, and Kilmartin's angle. Results were then compared in children below and above 6 years of age. The mean duration of follow-up was 4.6 years (2-9). RESULTS: The clinical and subjective outcome was rated as good in 16 procedures and satisfactory in 4. The talar-first metatarsal angle, calcaneal-fifth metatarsal angle, metatarsus adductus angle, and Kilmartin's angle were significantly reduced, while the talocalcaneal and first ray angle remained unchanged. A significantly better correction of metatarsus adductus and talar-first metatarsal angle was achieved In children below 6 years of age compared to older patients. CONCLUSIONS: 1. Medial cuneiform and cuboid osteotomy with a transposed wedge improves both clinical and radiological parameters, especially in children under the age of 6. 2. Besides the metatarsus adductus angle, the talar-first meta-tarsal, calcaneal-fifth metatarsal and Kilmartin's angles appear to be good radiologic indicators of correction.

Spine duplication or split notochord syndrome - case report and literature review.

Context: Spine duplication is a rare condition, with various extents and severe additional anomalies. The goal of this study was to describe a unique case of a boy with split notochord syndrome who was followed up from birth until maturity. Findings: Physical examination at birth showed defects of the abdominal wall and cloacal exstrophy with visible urether outlets. A transposed anus was present in the perineal region. Split bony elements of the spine with nonpalpable sacral bone were noted. A soft, skin-covered lump, with the consistency of a lipoma, was present in the sacral area. There was asymmetry of the lower limbs: the left was hypoplastic, with a deformed foot and hip. Computed tomography revealed a normal shape of the Th12 and L1 vertebrae, whereas the L2 was split. Downward from L3, there were two vertebrae at each level, with two spinal canals. The spinal cord divided into two "semicords" at the level of L1. Neurologic status and the shape of the spine remained unchanged during puberty. The last follow-up was performed at the age of 18 years. He managed to walk independently in prosthesis with visible limping. Conclusion: Spine deformities are always suspected in neonates with lipoma in the sacral region, which may sometimes be serious. Walking ability and quality of life depend on neurologic deficits; even with long duplication and double sacrum, walking can be a feasible option.

Quantitative Analysis of Foot Plantar Pressure During Walking.

BACKGROUND There are many methods of dynamic analysis of foot loading, however, we still need a simple, easily applicable system for foot plantar pressure analysis. In this study we asked the question: "Can a new system for foot evaluation, the ITE System, provide a good quantitative dynamic foot pressure analysis? Can it be used in clinical practice?". MATERIAL AND METHODS Twenty healthy volunteers, 8 females and 12 males, aged 20 to 25 years old took part in this study. Normal static foot loading was tested using a typical pedobarographic platform, followed by a dynamic analysis using the foot-pressure ITE System. A new algorithm for data analysis (from 8 sensors) was proposed. RESULTS The sum of all maximal values from sensors was 11.71 N mean, with relatively low standard deviation (SD) of 1.81. Loading of sensor 1 (heel) was the highest - on average 29.84%. Sensor 2 (medial midfoot) received the lowest loading - normal range for this segment would be 0-4%. The manner of loading heel/toes, dynamics of changes in loading during gait was quite diverse; when analyzing courses of changes on sensors, 4 gait patterns were observed. CONCLUSIONS Use of the ITE System creates a new possibility for dynamic foot evaluation, drawing from pedobarography and methods of gait analysis. The proposed data analysis algorithm is simple and can be applied in all cases. Normally, 30% of the sum of all pressures during stance phase falls on the rearfoot; 39% falls on forefoot.

Cervical spine surgery in patients with diastrophic dysplasia: Case report with long-term follow-up.

Cervical kyphosis in diastrophic dysplasia (DTD) is a very dangerous deformity which may lead to compression of neural structures resulting in tetraplegia or even. Treatment of this deformity is usually surgical, but no long-term follow-up studies are presented in the literature. Authors present a case of two children with DTD who underwent anterior corpectomy due to severe cervical kyphosis. The kyphotic deformity was corrected and the normal spinal canal width was restored. The effects of the correction remained stable for respectively 6 and 10 years of the follow-up period. The unique follow-up confirms that this type of intervention leads to an effective and long lasting results. Significant cervical kyphosis in patients suffering from DTD may be treated surgically using anterior approach even in young children with a favorable and lasting results.

Comparison of Postoperative Period in Patients with Pectus Excavatum Treated with Nuss Technique and Ravitch Technique.

BACKGROUND: Pectus excavatum (PE) is the most common defect of the chest wall. Surgery for PE can be performed with an open or endoscopic technique. The choice of the surgical approach influences the postoperative course. The aim of the paper is to analyze the postoperative period in two groups of patients treated for PE. Group 1 consisted of patients who underwent endoscopic surgery, and Group 2 was composed of patients who underwent open surgery. A secondary aim is to compare the surgical outcomes between the two groups. MATERIAL AND METHODS: The study group consisted of 40 patients treated in a single centre that uses a uniform postoperative analgesic protocol. The duration of surgery, blood loss, duration of hospital stay, complications, pain intensity and consumption of opioid and non-opioid analgesics were analyzed. The mean duration of follow-up was 9 months (6 -25 months). RESULTS: Age at surgery, weight and height did not differ between the groups. In Group 1 the duration of surgery and blood loss were lower than in Group 2. In Group 1 complications occurred in 25% of the patients. Pain intensity was higher in Group 1 (4.23 vs. 3.67), as was the consumption of strong opioids (0.52 mg/kg body weight vs. 0.25 mg/kg body weight). Subjective evaluation was satisfactory in 85% of the patients in Group 1 and 90% in Group 2. CONCLUSIONS: 1. Both techniques led to a satisfactory outcome. 2. The duration of surgery and blood loss were higher in the open surgery group, but pain intensity and consumption of strong analgesics were higher among the patients treated with the endoscopic technique. 3. Preparation for surgery should involve planning appropriate analgesic treatment in the post-operative period.

[Long-term consequences of resection of 1/3 proximal epiphysis of child's right tibia--a case study]. / Odlegle nastepstwa resekcji 1/3 nasady blizszej kosci piszczelowej prawej u dziecka--opis przypadku.

Authors report a case of a patient with varus deformity of right knee, caused by wide resection of proximal metaphysis and epiphysis of right tibia. Afore mentioned procedure led to loss of right knee joint integrity, with its lateral instability, shortening, and axis deviation of right tibia. Surgical treatment of this complications was performed in several stages and took about 5 years, starting from temporal, lateral hemiepiphysiodesis of proximal tibial epiphysis, subacute epiphysiolysis of proximal tibial epiphysis and high valgus tibia osteotomy, at the end finished with medial tibia condyle reconstruction with autogenic graft and osteoconductive substances. The proper mechanical and anatomical axis of the right limb, with full stability and movement of right knee was achieved after those surgeries. The process of treatment of lower extremity axis deviation takes long time, frequently involves several surgeries and needs firm cooperation between doctor and patient.