Precision Low-Cost Compact Micro-Displacement Sensors Based on a New Arrangement of Cascaded Levers with Flexural Joints.

Existing displacement sensors of micrometers to sub-micron precision are expensive and have various limitations. This paper reports the design and development of a new contact type compact micro-displacement sensor of sub-micron precision for a fraction of the cost of commercial devices. The basic concept of the new sensor system applies a mechanical magnifying mechanism to magnify a displacement at sub-micron to micron level and uses a low-cost Hall sensor to measure the magnified displacement. Various conceptual designs for the mechanical magnifying mechanism based on cascaded levers with flexural joints were studied and a final design, featuring side-by-side placement of lever structures in a multi-planar layout with adjacent levers coupled by L-shaped coupling foils, was devised. Prototypes of two different sizes and constructions with mechanical magnification ratios over 100 were made and tested. Measurement repeatability and accuracy to sub-micrometer level and a resolution down to hundredths of a micrometer were demonstrated by a compact Alpha Model prototype. Design modification of parts and a corresponding small lot size production procedure were devised to provide an estimated bill of material cost per unit under US$100.

Safety Assessment of the Auto Manipulation Device for Acupuncture in Sprague-Dawley Rats: Preclinical Evaluation of the Prototype.

BACKGROUND: The Auto Manipulation Device for Acupuncture (AMDA) is designed for providing stable, quantified effects and higher frequency when doing lifting and thrusting manipulation. The purpose of this study is to investigate the safety of manipulation by AMDA in different frequency and duration in healthy rats. METHODS: The study was divided into two parts: single intervention and once a day for a week. 12 rats and 15 rats were randomly allocated to different groups: Control (needle insertion only), AMDA (2Hz/10Mins), AMDA (2Hz/20Mins), AMDA (20Hz/10Mins), and AMDA (20Hz/20Mins) for single and repeated interventions. Real-time physiological functions, laboratory data, and the bilateral muscle tissue of acupoint (ST 36) were obtained after the intervention. RESULTS: We found neither real-time physiological functions nor laboratory data differences between control group and AMDA groups in both parts. In the muscle tissue samples, the slight damage had been observed in the AMDA group with a frequency of 2 Hz for 20 minutes after once intervention, and the repeated session groups noted more obvious tissue damage with fibrotic change. Although the period was shorter, higher frequency manipulation caused more damage that fibroblast nuclei became more slender and obvious. However, no significant adverse effect was noted such as crippled and molting in the whole process. CONCLUSION: Our study suggested that the safety issue of AMDA operation in rats is feasible because there was no difference between control group and AMDA groups among real-time physiological functions and laboratory data. However, manipulation with higher frequency should be more preserved.

Spirometric prediction equations and the relationship between metabolic syndrome and spirometric parameters from an island in Fujian, China.

BACKGROUND: We investigated risk factors for decreased lung function among Chinese island residents (≥30 years) to determine the relationship between metabolic syndrome (MS) and decreased lung function. METHODS: From October 17, 2011 to November 1, 2011, 2607 residents aged ≥30 years who lived on the Huangqi Peninsula of Fujian were enlisted by random cluster sampling. They completed a questionnaire designed according to the Burden of Obstructive Lung Disease (BOLD) questionnaire, and underwent physical examination, blood test, and lung function evaluation. We constructed spirometric prediction equations for forced vital capacity (FVC) and forced expiratory volume in one second (FEV1), determined the lower limits of normal for FVC, FEV1 and FEV1/FVC, and examined the relationship between lung function and MS. RESULTS: Prediction equations for normal island residents were as follows: FVC (L) = -0.023 × age (years) + 0.042 × height (cm) + 0.641 × weight (kg) - 3.607 (males); FVC (L) = -0.017 × age (years) + 0.030 × height (cm) + 0.009 × weight (kg) - 1.741 (females); FEV1 (L) = -0.023 × age (years) + 0.040 × height (cm) + 0.010 × weight (kg) - 2.999 (males); FEV1 (L) = -0.017 × age (years) + 0.026 × height (cm) + 0.007 × weight (kg) -1.135 (females). The odds ratio for MS for increased risk of decreased FVC was 4.623 (95%CI =3.626-5.894, P<0.001), and for increased risk of decreased FEV1 was 3.043 (95%CI =2.447-3.785, P<0.001). CONCLUSIONS: MS is a risk factor for decreased lung function in island residents ≥30 years old.

Colloid chitin azure is a dispersible, low-cost substrate for chitinase measurements in a sensitive, fast, reproducible assay.

Chitin and its derivatives are widely used as biomedical materials because of their versatility and biocompatibility. Chitinases are enzymes that produce chito-oligosaccharides from chitin. The assay of chitinase activity is difficult because few appropriate substrates are available. In this study, the authors developed an efficient and low-cost chitinase assay using colloidal chitin azure. The assay feasibility is evaluated and compared with traditional assays employing colloidal chitin and chitin azure. The authors found that the optimum pH for determining chitinase activity using colloid chitin azure was pH 5 or 8. The method was sensitive, and the assay was complete within 30 min. When the assay was used to measure chitinase activities produced by 2 strains of chitinolytic bacteria, BCTS (an Escherichia coli BL21 [DE3] expressing a secretory recombinant chitinase) and AS1 (a chitinolytic bacterium with low levels of chitinase), it was shown that cultivation in Bushnell-Haas selection medium caused AS1 to secrete a higher level of chitinase than was secreted when the bacterium grew in other media. In summary, colloid chitin azure is a sensitive, feasible, reproducible, and low-cost substrate for the assay of chitinase activity.