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This paper describes the methodology for rapid prototyping of nitinol structures by heat setting. Nitinol is a shape memory alloy commonly used in implantable medical devices. The proposed technique, based on 3D printing, can be used to effectively iterate multiple nitinol designs for different types of medical devices. We describe a rapid and low-cost process of ceramic replica molding of standard 3D printed parts to create high-temperature resistant fixtures, suitable for heat setting of nitinol. The technique represents a low cost (

Carbon dioxide is the central ozone-harming substance that consequences from human workout routines and reasons a hazardous atmospheric deviation and climatic change. The ingesting of the herbal substances in non-renewable electricity sources produces vitality and discharges carbon dioxide and one-of-a-kind mixes into the world's climate. Ozone-harming materials can be radiated through vehicle, land freedom, introduction and utilization of nourishment, fills, made products, materials, wood, streets, constructions and administrations and so forth. A carbon footprint is the percentage of the measure of ozone-depleting substances, estimated in devices of carbon dioxide, delivered through human exercises. An automobile footprint shall be estimated of every individual or an association, and is many times given in massive amounts of carbon dioxide equally every year. Hence, this paper manages the examination on outflow of carbon dioxide from special emanation inventories in any or in a particular educational institute. The investigation has been embraced in the university campus so as to check the measure of carbon dioxide and to recommend the therapeutic measures which can be used to decrease the discharges as a piece of social responsibility.

Mould development in investment casting is time consuming process. In addition cost involved in preparation of die and other tooling justified when large volume production is required. Application of 3D printed pattern as an alternative of wax pattern enables faster production as well as provides design flexibility for complex parts. In present work, investigation is carried out on surface quality of 3D printed ABS and PLA patterns to replace conventional wax patterns. Post processing of 3D printed ABS and PLA patterns were carried out to improve surface finish as it removes line marks formed by layered fabrication on printed patterns. Acetone smoothing was applied to finish the ABS pattern and sanding was done to finish PLA pattern. Improvement in surface finish of mould is observed to greater extent with PLA and ABS patterns as compared to wax patterns. From the experiments it is concluded that primary slurry retention and slurry wetting is better with ABS and PLA patterns as compared to wax patterns that contributes to the improvement in surface finish of mould.

Background: Virtual functional assessment index (vFAI), an alternative approach for assessing hemodynamic significance of stenosis has been shown to enhance the diagnostic performance of coronary computed tomography angiography (CCTA) based on evaluating the area under pressure drop-flow curve for a stenosis. Previously, this was assessed via computational fluid dynamics. We investigated the evaluation of vFAI from CCTA images using 3D printing and an in vitro flow loop and its efficacy as compared to the invasively measured fractional flow reserve (FFR). Methods and Results: Eighteen patients with varying degrees of coronary artery disease who underwent non-invasive CCTA scans and invasive FFR of their left anterior descending coronary artery (LAD) were included. The LAD artery was segmented and reconstructed using Mimics (Materialise inc.,). The segmented models were then 3D printed using Carbon 3D printer (Carbon Inc.,) with rigid resins. An in vitro flow circulation system representative of invasive measurements in a cardiac catheterization laboratory was developed to experimentally evaluate the hemodynamic parameters of pressure and flow (Fig A). For each model, a range of physiological flow rates was applied by a peristaltic steady flow pump and titrated by a flow sensor. The pressure drop and the pressure ratio (Pd/Pa) were assessed for patient-specific aortic pressure and differing flow rates. vFAI was evaluated as the normalized area under the P d /P a vs Q curve from 0 to 240 mL/min. There was a strong correlation between vFAI and FFR, (R = 0.83, p < 0.001; Fig B) and a very good agreement between the two parameters by Bland-Altman analysis. The mean difference of measurements from the two methods was 0.06 (SD = 0.08, p=0.0063; Fig C), indicating a small systematic overestimation of the FFR by vFAI. Conclusions: vFAI can be effectively derived from 3D CTCA datasets using 3D-printed in vitro models, based on evaluation over a range of hemodynamic conditions.

Soft robotic sensor arrays for left-atrial mapping demonstrate highly conformal contact to complex patient anatomies., Devices that perform cardiac mapping and ablation to treat atrial fibrillation provide an effective means of treatment. Current devices, however, have limitations that either require tedious point-by-point mapping of a cardiac chamber or have limited ability to conform to the complex anatomy of a patient’s cardiac chamber. In this work, a detailed, scalable, and manufacturable technique is reported for fabrication of a multielectrode, soft robotic sensor array. These devices exhibit high conformability (~85 to 90%) and are equipped with an array of stretchable electronic sensors for voltage mapping. The form factor of the device is intended to match that of the entire left atrium and has a hydraulically actuated soft robotic structure whose profile facilitates deployment from a 13.5-Fr catheter. We anticipate that the methods described in this paper will serve a new generation of conformable medical devices that leverage the unique characteristics of stretchable electronics and soft robotics.

The main aim of this experiment is to study the effect of bacteria on the strength and durability properties of normal and GGBS concrete. Cement was replaced with 40% of GGBS by weight. Tests were performed for flexural, shear strength, water absorption, and water sorptivity. Flexural strength and Shear strength of GGBS bacterial concrete was found to be higher when compared to normal concrete and reduction in water absorption and water sorptivity was observed with concentration 105cells/ml of bacteria. The bacteria used in concrete is Pseudomonas Putida which improves the strength and durability of concrete through self-healing effect.

The main aim of this experiment is to study the effect of bacteria on the strength and durability properties of normal and silica fume (SF) concrete. The experiment is carried out to evaluate influence of Pseudomonas putida bacteria on the compressive strength, shear strength, sulphate attack and water sorptivity on concrete. Cement was replaced with 20% SF by weight. Three different cell concentrations (103, 105, 107cells/ml) of bacteria were used in making the concrete mixes. The tests were carried out on the strength and durability properties after complete curing of 28 days. The inclusion of Pseudomonas putida in SF based concrete has an ability to enhance strength and improve durability of concrete. The study showed that concrete having bacterial infusion in all cell concentrations have increment in strength in comparison to reference mix. From the test results, it was concluded that, optimum cell concentration for concrete was found to be 105 cells/ml. The strength and durability properties were enhanced due to addition of bacteria in SF concrete compared to plain concrete. The calcite precipitation in concrete was visualized through SEM and is the reason for improvement in properties of concrete due to filling of pores by the growth of filler materials resulting in denser concrete.

Objective To examine the association between subjective social status (SSS) and objective social status (OSS) and cardiovascular disease (CVD) risk factors in adults with type 2 diabetes. Methods Adult study participants ( N = 358) were recruited from 2 primary care settings. The CVD risk factors included hemoglobin A1c (HbA1c), systolic blood pressure and diastolic blood pressure (DBP) and low-density lipoprotein cholesterol (LDL-C). The OSS was assessed by income, education and employment. The SSS was measured using the validated MacArthur Scales of Subjective Social Status to demarcate self-reported perceptions of having the most money, education and respected job using a ladder scale (1 = rung 1, 10 = rung 10). Multiple linear regression was used to examine associations between CVD risk factors and SSC and OSS controlling for age, sex, race or ethnicity, marital status, employment status, income, study site, comorbidity, education and insurance status. Results Fully adjusted models showed that rung 2 ( P = 0.029), rung 3 ( P = 0.032), rung 8 ( P = 0.049) and rung 9 ( P = 0.032) of the SSS to be significantly associated with poorer DBP. Annual income ≥ $75,000 was significantly associated with lower LDL-C ( P = 0.021). Employment was associated with lower HbA1c ( P = 0.036), but higher LDL-C ( P = 0.002). Conclusions The SSS and OSSS levels are differentially associated with HbA1c, DBP and LDL-C. Findings provide new information about patients’ perspectives of the relationship between social status and diabetes-related outcomes.