Development of scalable finite element models based on knee laxity tests on cadavers

Aim of the study: The aim of the project was to use the results of laxity tests on cadaver knees to create scalable, subject-specific finite element (FE) models. The models were used to improve the surface geometry of unicondylar knee prostheses using optimization techniques. Material and methods: For the experimental tests, the alignment of the knee and the robot was defined by inserting carbon rods through the bones, recording CT data and then designing bone- and subject-specific 3D prints. As the FE-models rely on MRI images while the experiments use CT coordinate systems, there are differences in their positions. Therefore, a transformation matrix was used to correct the offset of the FE-model. With MeshLab the bones were aligned and then the position offsets calculated. The FE-model was built based on segmented MRI data using Mimics (Materialise NV) with the FE-program Ansys® Academic Research Mechanical (ANSYS Inc.). A multilinear elastic material model was selected as the material model for the ligaments with a uniaxial tensile test of a lateral collateral ligament as input. An initial area and length were assigned to calculate a stress-strain curve. In addition, a strain offset parameter was introduced to handle different strains. An additional internal/external stiffness was added. An important feature of the FE-model was to assign an initial strain to the ligaments. This maintains the actual geometry segmented from the MRI and helps to keep the ligament in tension. The level of detail chosen for the model also meant that there was only one principal ligament per laxity test. Results: This scalable parameter model of knee ligaments build was applied to six knees that had a native geometry and three different unicompartmental knee joint replacement geometries. The difference in position between the experiments and the FE-model could be offset. With knowledge of the transformation matrix, the FE-model could include the same implant position as implanted by the surgeon. Discussion: A reliable framework for the development of knee FE-models based on cadaver laxity testing was demonstrated. An improvement for future FE-models would be to provide fixation so that the MRI and CT scans are taken at the same position or by using fixed bone markers in both scans. Finally, initial stretching could be fixed to a certain strain value; however, the challenge is whether this solution remains scalable

Optimal Clinical Time for Reliable Measurement of Transcutaneous CO2 with Ear Probes: Counterbalancing Overshoot and the Vasodilatation Effect

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Disease expression in juvenile polyposis syndrome : a retrospective survey on a cohort of 221 European patients and comparison with a literature-derived cohort of 473 SMAD4/BMPR1A pathogenic variant carriers

Purpose Juvenile polyposis syndrome (JPS) is a rare, autosomal-dominantly inherited cancer predisposition caused in approximately 50% of cases by pathogenic germline variants in SMAD4 and BMPR1A. We aimed to gather detailed clinical and molecular genetic information on JPS disease expression to provide a basis for management guidelines and establish open access variant databases. Methods We performed a retrospective, questionnaire-based European multicenter survey on and established a cohort of SMAD4/BMPR1A pathogenic variant carriers from the medical literature. Results We analyzed questionnaire-based data on 221 JPS patients (126 kindreds) from ten European centers and retrieved literature-based information on 473 patients. Compared with BMPR1A carriers, SMAD4 carriers displayed anemia twice as often (58% vs. 26%), and exclusively showed overlap symptoms with hemorrhagic telangiectasia (32%) and an increased prevalence (39% vs. 13%) of gastric juvenile polyps. Cancer, reported in 15% of JPS patients (median age 41 years), mainly occurred in the colorectum (overall: 62%, SMAD4: 58%, BMPR1A: 88%) and the stomach (overall: 21%; SMAD4: 27%, BMPR1A: 0%). Conclusion This comprehensive retrospective study on genotype-phenotype correlations in 694 JPS patients corroborates previous observations on JPS in general and SMAD4 carriers in particular, facilitates recommendations for clinical management, and provides the basis for open access variant SMAD4 and BMPR1A databases.Peer reviewe

State-of-the-Art Sensor Technology in Spain: Invasive and Non-Invasive Techniques for Monitoring Respiratory Variables

The interest in measuring physiological parameters (especially arterial blood gases) has grown progressively in parallel to the development of new technologies. Physiological parameters were first measured invasively and at discrete time points; however, it was clearly desirable to measure them continuously and non-invasively. The development of intensive care units promoted the use of ventilators via oral intubation ventilators via oral intubation and mechanical respiratory variables were progressively studied. Later, the knowledge gained in the hospital was applied to out-of-hospital management. In the present paper we review the invasive and non-invasive techniques for monitoring respiratory variables

Print-Light-Synthesis of Platinum Nanostructured Indium-Tin-Oxide Electrodes for Energy Research

Print-light-synthesis is a new concept for the large-scale in situ fabrication of nanoparticles and structures on large substrates. Here, Pt nanoparticles are synthesized on indium tin oxide (ITO) coated glass slides by using combined inkjet printing and photonic curing operated under ambient conditions and with low material usage. A formulated chloroplatinic acid based ink provides stable and reproducible jetting, optimized ink–substrate interaction and fast ink drying to create well-defined thin precursor films acting as nanoreactors. The precursor loading is precisely controlled by the printing parameters. Then, a short light pulse from a Xe flash lamp fully converts the printed Pt precursor containing film into pure Pt nanoparticles. The optimum precursor coverage is ≈1 µg mm−2 Pt consuming as less as ≈50 nL mm−2 of ink. Neither reducing nor capping agents are used resulting in pure Pt nanoparticles (30 nm average size) and micrometer-size aggregates. The nanostructures are well-adhered to the ITO substrate and show a stable electrochemical performance for the oxygen reduction reaction. The fast and cost-effective process optimization in terms of ink formulation, substrate pre-treatment, inkjet printing resolution, and post-processing for the rapid fabrication of Pt nano- and microparticle-coated ITO electrodes is presented and discussed

A combined ear sensor for pulse oximetry and carbon dioxide tension monitoring: accuracy in critically ill children.

IMPLICATIONS: A new combined ear sensor was tested for accuracy in 20 critically ill children. It provides noninvasive and continuous monitoring of arterial oxygen saturation, arterial carbon dioxide tension, and pulse rate. The sensor proved to be clinically accurate in the tested range

Accuracy of a new transmittance-reflectance pulse oximetry sensor in critically ill neonates.

OBJECTIVE: To test the accuracy of a new pulse oximeter sensor based on transmittance and reflectance. This sensor makes transillumination of tissue unnecessary and allows measurements on the hand, forearm, foot, and lower limb. DESIGN: Prospective, open, nonrandomized criterion standard study. SETTING: Neonatal intensive care unit, tertiary care center. PATIENTS: Sequential sample of 54 critically ill neonates (gestational age 27 to 42 wks; postnatal age 1 to 28 days) with arterial catheters in place. MEASUREMENTS AND MAIN RESULTS: A total of 99 comparisons between pulse oximetry and arterial saturation were obtained. Comparison of femoral or umbilical arterial blood with transcutaneous measurements on the lower limb (n = 66) demonstrated an excellent correlation (r2 = .96). The mean difference was +1.44% +/- 3.51 (SD) % (range -11% to +8%). Comparison of the transcutaneous values with the radial artery saturation from the corresponding upper limb (n = 33) revealed a correlation coefficient of 0.94 with a mean error of +0.66% +/- 3.34% (range -6% to +7%). The mean difference between noninvasive and invasive measurements was least with the test sensor on the hand, intermediate on the calf and arm, and greatest on the foot. The mean error and its standard deviation were slightly larger for arterial saturation values < 90% than for values > or = 90%. CONCLUSION: Accurate pulse oximetry saturation can be acquired from the hand, forearm, foot, and calf of critically ill newborns using this new sensor

Die Früherkennung von axialer Spondyloarthritis

In der Schweiz verstreichen nach den ersten Symptomen durchschnittlich drei Jahre, bis eine axiale Spondyloarthritis (M. Bechterew) erkannt wird. PhysiotherapeutInnen können mit einem sorgfältigen Clinical Reasoning zur Früherkennung beitragen

Qvaestiones Theologicae Ex Verbi Incarnati Delicioso Mysterio Delibatæ

Svb Præsidio Admodvm Reverendi Atqve Doctissimi P. Bonifacii Tschupp ... Disputatio expositæ A Rev. Rel. Et Doctissimi DD. Mariano Scoto, Et Adelrico Suter ...Dreiseitiger GoldschnittDissertation Einsiedeln 1664Aus dem Vorbesitz des Klosters Rheina