Rapid detection and classification of bacteria colonies ( Escherichia coli, Listeria monocytogens and Staphylococcus aureus) were investigated by using hyperspectral imaging. The hyperspectral reflectance images (390-1040 nm ) of bacterial colonies on agar plates were collected. Bacterial spectra were extracted automatically based on the masks produced by segmenting a band difference image using the OTSU method. Full wavelength and simplified PLS-DA models were established for classification of bacterial colonies. For the full wavelength model, the overall correct classification rate ( OCCR) and confident OCCR for the prediction set were 100% and 95. 9%, respectively. Besides, competitive adaptive reweighted sampling ( CARS), genetic algorithm ( GA ) and least angle regression-least absolute shrinkage and selection operator ( LARS-Lasso) were used to select feature wavelengths for the development of simplified models. Among them, the CARS-model outperformed the other two in terms of precision, stability and classification accuracy with OCCR and confident OCCR of 100% and 98. 0% for the prediction set, respectively. It was demonstrated that hyperspectral imaging was an effective technology for nondestructive detection of bacterial colonies with high accuracy and high speed. The allocated feature wavelengths by CARS could lay theoretical basis for developing low cost multispectral imaging systems for bacterial colony detection.

Complex and huge wound closure is a key step in pre hospital emergency care. Wound closure can effectively reduce the loss of blood and fluid inpatients before arriving hospital. Also, it has important significance to save the lives of patients. In this paper, a new type of wound closure device is developed, which is used for the rapid closure of complex and huge wound. Firstly, based on the detailed introduction of the structure working principle, the finite element simulation technology is adopted to analyze the stress of the structure. The results show that the stress of the structure has not beyond the allowable stress of the material. On the basis of this, the experiment was carried out in vitro. Test results show that the closure device operating time is 18.24 s and the minimum penetration of the skin force is 4.08 kg. The closure device can resist the horizontal tension of 1.53 kg and vertical tension of 2.25 kg. It also has good sealing performance and meets the design requirements. The results show that the device designed is reasonable, which can be quickly and effectively to achieve closure of the wound.