Isoelastic implants with improved anchorage means

Isoelastic implants are provided with a surface roughness for anchorage in and load transmission to the surrounding tissue. The surface roughness is formed of one or more of the structures including undulations, or grooves, or pores, or lacunae, or gaps and protrusions. The roughness is located at two separate and confined regions along the surfaces of the implant which are intended for transmitting loads from the surrounding tissue into the implant or vice versa. The regions for containing the roughness are confined to two small areas at the opposite ends of the implant\u27s surface. The ends are defined in relation to the direction of the load to be transmitted through the surfaces

Soft tissue implant with micron-scale surface texture to optimize anchorage

A soft tissue implant device such as a catheter, heart valve, or plastic or reconstructive surgical material, to be at least partially embedded in an implantation site in soft organic tissue of a living organism includes a body defining a surface layer extending over the portion of the body contacting the organic tissue. The surface layer defines a three-dimensional pattern with an exterior surface defining a plurality of spaces and a plurality of solid surface portions. The spaces have a mean bridging distance ranging from greater than 1.0 micron to less than 4.0 microns and the solid surface portions have mean breadths ranging from 0.10 micron to 2.0 microns. The mean bridging distance is preferably greater than 1.4 microns and less than 1.9 microns. The exterior surface is substantially free of indentations having a bridging distance measuring in a range from between 10.0 microns and 1,000 microns

Intraocular lens with integrated means of fixation

An intraocular lens has an optic body with at least a posterior surface defining a roughness portion disposed close to the periphery of the optic body wherein the roughness portion further defines an attachment configuration specified by parameters falling within certain specific ranges determined statistically using a profilometer. The parameters measure on the order of micrometers. The attachment configuration holds the lens in place without the use of spiral shaped fibrous arms

die Bedeutung und Anwendbarkeit von Multimarkerstrategien und Point-of-Care Diagnostik zur schnellen Behandlung akuter kardiovaskulärer Erkrankungen in der Notaufnahme

Einleitung: Hochsensitive Troponin-Tests (hsTn) werden in der kardiovaskulären Diagnostik zunehmend eingesetzt, zum frühen Infarktausschluss ist jedoch wegen der zeitversetzten Freisetzung immer ein zweiter Wert erforderlich. Copeptin ist ein Marker der Vasopressinfreisetzung, der komplementär zum Troponin bereits unmittelbar nach Beginn eines Myokardinfarkts (MI) erhöht ist. Im Bereich der cerebrovaskulären Akutdiagnostik ist bisher kein Biomarker fest etabliert. Retrospektive Analysen haben gezeigt, daß die Bestimmung von Copeptin in Kombination mit Troponin insbesondere den Ausschluss eines Myokardinfarkts beschleunigen kann. Der Nutzen des hsTn in der klinischen Routine der Notaufnahme mit zahlreichen Patienten, die aus anderen Gründen als dem MI erhöhte Werte aufweisen, wird noch kontrovers diskutiert. Methodik und Ergebnisse: In zwei unabhängigen prospektiven Studien wurde die Verwendbarkeit von Copeptin für die Akutdiagnostik des Akuten Koronarsyndroms (ACS) und den sicheren Ausschluss eines Myokardinfarktes (Publikation 1), sowie eine Eignung zur Differenzierung des akuten Schlaganfalls und seiner Differentialdiagnosen insbesondere „stroke mimics“ (Publikation 2) evaluiert. Die sichere Verwendung bei Patienten mit niedrigem bis mittelhohem Risiko und Verdacht auf MI konnte unter Realbedingungen in der Notaufnahme gezeigt werden. Eine Eignung für die sichere Differenzierung beim V. a. Schlaganfall konnte allerdings nicht bestätigt werden. In einer dritten Studie (Publikation 3) wurde in einer unselektierten Population von Notfallpatienten mit Troponin-Anforderung ein Troponin-Test auf Point of Care (PoC)-Basis verglichen mit einem laborbasierten hochsensitiven Troponin-Assay. In der Studie konnte eine vergleichbare diagnostische Wertigkeit der verschiedenen Systeme gezeigt werden, sowie keine signifikanten Unterschiede bezüglich eines sicheren Nicht-ST-Hebungsinfarkt-Ausschlusses (NSTEMI). Bei Verwendung der 99. Perzentilen zeigt der PoC-Assay eine höhere Genauigkeit, die höchste Sensitivität hingegen konnte für den hsTnT-Assay an der 99. Perzentile berechnet werden. Schlussfolgerung: Die klinische Sicherheit und Machbarkeit einer Multimarkerstrategie von Copeptin und Troponin für die ACS-Akut-Diagnostik und die Gleichwertigkeit von PoC-Geräten im notfallmedizinischen Alltag konnte gezeigt werden und bieten im zeitkritischen Kontext der Notfallmedizin eine sichere Alternative zum gegenwärtig definierten Standard serieller Troponinmessungen. Die zuverlässige Differenzierung zwischen Schlaganfall, Transitorische Ischämische Attacke (TIA) und stroke mimics gelingt mittels Copeptin nicht.Introduction: The use of high-sensitive troponin testing (hsTn) in cardiovascular diagnostics is increasing but due to time-dependent release of troponin a second measurement is needed for early rule-out of myocardial infarction (MI). Copeptin is a marker of Vasopressin release and correlates to rising troponin levels immediately after the start of MI. Regarding diagnostics of acute cerebrovascular diseases, no such biomarker could be established yet. Retrospective analyses have shown that the combined use of copeptin and troponin-testing led to reduced turnaround times in the rule-out of MI. The use of hsTn in the clinical emergency routine in patients with elevated values based on other reasons than MI is still discussed controversially. Methods and Results: In two independent prospective studies the usability of Copeptin was evaluated regarding the diagnosis of Acute Coronary Syndrome (ACS) and myocardial infarction (publication 1) and the value of Copeptin in differentiating ischemic stroke and its differential diagnoses including stroke mimics (publication 2). The safety utilizing Copeptin in suspected ACS and MI patients with low to intermediate risk could be shown under real life conditions in the Emergency Department. The safe use of copeptin in differentiating suspected acute stroke could not be confirmed. In a third study (publication 3) a Point of Care-based (PoC) troponin assay was compared to a lab-based high-sensitive troponin assay in regards to diagnostic performance in an unselected population of acute patients with a troponin testing order. The study results showed a comparable diagnostic accuracy of the different systems used. No significant differences were detected in the safe rule-out of Non-ST-elevation myocardial infarction (NSTEMI). Looking at the 99th percentile, the highest Negative Predictive Value (NPV) and sensitivity were achieved using hsTnT while PoC-TnT showed higher accuracy. Conclusion: The safe use of a multimarker-strategy of Copeptin and Troponin in ACS diagnosis and the equivalence of PoC-testing in the acute setting was successfully shown under routine and real-life conditions. Facing the time-critical conditions of an emergency, the new process can be seen as a safe alternative to the current standard of serial troponin testing. The safe differentiation of suspected ischemic stroke, Transitoric Ischemic Attack (TIA) and its differential diagnoses using copeptin failed

Graphene-based chemiresistive gas sensors

Gas sensors allow the monitoring of the chemical environment of humans, which is often crucial for their wellbeing or even survival. Miniaturization, reversibility, and selectivity are some of the key challenges for serial use of chemical sensors. This tutorial review describes critical aspects when using nanomaterials as sensing substrates for the application in chemiresistive gas sensors. Graphene has been shown to be a promising candidate, as it allows gas sensors to be operated at room temperature, possibly saving large amounts of energy. In this review, an overview is given on the general mechanisms for gas-sensitive semiconducting materials and the implications of doping and functionalization on the sensing parameters of chemiresistive devices. It shows in detail how different challenges, like sensitivity, response time, reversibility and selectivity have been approached by material development and operation modes. In addition, perspectives from the area of data analysis and intelligent algorithms are presented, which can further enhance these sensors' usability in the field

Validation of a statistical shape model-based 2D/3D reconstruction method for determination of cup orientation after THA

Purpose: The aim of this study was to validate the accuracy and reproducibility of a statistical shape model-based 2D/3D reconstruction method for determining cup orientation after total hip arthroplasty. With a statistical shape model, this method allows reconstructing a patient-specific 3D-model of the pelvis from a standard AP X-ray radiograph. Cup orientation (inclination and anteversion) is then calculated with respect to the anterior pelvic plane that is derived from the reconstructed model. Materials and methods: The validation study was conducted retrospectively on datasets of 29 patients (31 hips). Among them, there were 15 men (15 hips) and 14 women (16 hips). The average age of the patients was 69.4±8.5(49−82) years. Each dataset has one postoperative X-ray radiograph and one postoperative CT scan. The postoperative CT scan for each patient was used to establish the ground truth for the cup orientation. The cup anteversion and inclination that were calculated from the 2D/3D reconstruction method were compared to the associated ground truth. To validate reproducibility and reliability, two observers performed measurements for each dataset twice in order to measure the reproducibility and the reliability of the 2D/3D reconstruction method. Results: Our validation study demonstrated a mean accuracy of 0.4 ± 1.8°(−2.6° to 3.3°) for inclination and a mean accuracy of 0.6±1.5°(−2.0° to 3.9°) for anteversion. Through the Bland-Altman analysis, no systematic errors in accuracy were detected. The method showed very good consistency for both parameters. Conclusions: Our validation results demonstrate that the statistical shape model-based 2D/3D reconstruction-based method is an accurate, consistent, and reproducible technique to measure cup orientation from postoperative X-ray radiographs. The best results were achieved with radiographs including the bilateral anterior superior iliac spines and the cranial part of non-fractured pelvise

Continuous Delivery of Biomaterials to the Skin–Percutaneous Device Interface Using a Fluid Pump

We have developed an in vitro culture system composed of organotypic human skin explants interfaced with titanium rods attached to a fluid pump. This device was designed to mimic the process of natural mucosa delivery at the point where a rigid, permanent object penetrates living skin. Full thickness human breast skin explants discarded from surgeries were cultured at different time points at the air-liquid interface. The skin specimens were punctured to fit at the bottom of hollow cylindrical titanium rods. Sodium lauryl sulfate (SLS) was delivered continuously to the specimens through the rods by using an attached fluid pump. Histological analysis of the skin explants as well as no-pump controls was then performed. Our results show substantial differences between controls, where no material was pumped at the interface of rod–skin, and specimens treated with SLS, indicating that the technique of pumping the material is effective in producing observable epithelial changes. These results suggest that an adaptation of this type of device may be useful for the treatment of complications arising from the contact between tissues and percutaneous devices in vivo.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78629/1/j.1525-1594.2009.00931.x.pd

Characteristics of two different locking compression plates in the volar fixation of complex articular distal radius fractures

Objectives: To investigate the differences of open reduction and internal fixation (ORIF) of complex AO Type C distal radius fractures between two different models of a single implant type. Methods: A total of 136 patients who received either a 2.4 mm (n = 61) or 3.5 mm (n = 75) distal radius locking compression plate (LCP DR) using a volar approach were followed over two years. The main outcome measurements included motion, grip strength, pain, and the scores of Gartland and Werley, the Short-Form 36 (SF-36) and the Disabilities of the Arm, Shoulder, and Hand (DASH). Differences between the treatment groups were evaluated using regression analysis and the likelihood ratio test with significance based on the Bonferroni corrected p-value of 0.052) and grip strength measurements relative to the contralateral healthy side (p = 0.583). In addition, DASH and SF-36 component scores as well as pain were not significantly different between the treatment groups throughout the two-year period (all p ≥ 0.005). No patient from either treatment group had a step-off > 2 mm. Conclusions: Differences in plate design do not influence the overall final outcome of fracture fixation using LCP