Abstract: A wearable surgical navigation system is developed for intraoperative imaging of surgical margin in cancer resection surgery. The system consists of an excitation light source, a monochromatic CCD camera, a host computer, and a wearable headset unit in either of the following two modes: head-mounted display (HMD) and Google glass. In the HMD mode, a CMOS camera is installed on a personal cinema system to capture the surgical scene in real-time and transmit the image to the host computer through a USB port. In the Google glass mode, a wireless connection is established between the glass and the host computer for image acquisition and data transport tasks. A software program is written in Python to call OpenCV functions for image calibration, co-registration, fusion, and display wi

Abstract: The performance of biomedical optical imaging devices heavily relies on appropriate calibration. However, many of existing calibration phantoms for biomedical optical devices are based on homogenous materials without considering the multi-layer heterogeneous structures observed in biological tissue. Using such a phantom for optical calibration may result in measurement bias. To overcome this problem, we propose a 3D printing method for freeform fabrication of tissue simulating phantoms with multilayer heterogeneous structure. The phantom simulates not only the morphologic characteristics of biological tissue but also absorption and scattering properties. The printing system is based on a 3D motion platform with coordinated control of the DC motors. A special jet nozzle is de

Abstract: The self-driven flow in microfluidic devices has attracted much attention due to its efficient, fast and convenient properties. We investigated the effect of femtosecond laser pulse overlap on the liquid flow characters in surface grooves both in experimental evidence and theoretical analysis. With the increase of the femtosecond laser pulse overlap, the speed of water flowing in grooves is increased. Both the surface granular protrusions microstructures and the surface chemical composition can influence the liquid dynamics in grooves. Femtosecond laser may have potential applications in self-driven microfluidic devices.Zhu Z, Li G, Li J, et al. Self-driven flow in surface grooves fabricated by femtosecond laser. Surface and Coatings Technology. 2014;242:246-250. doi:10.1016/j.su

Abstract: A novel method for forming steady cone-jet modes and multilayered droplets is developed based on capillary flow focusing geometry using tri-axial needles. The needles manufactured by a laser beam welding process can be readily cleaned, assembled and aligned. A tri-axial capillary flow focusing (TCFF) device is assembled in order to focus a combination of different liquids in the core of a high-speed gas stream co-flowing through a small orifice. The effects of main control process parameters on the characteristics of compound cone-jet mode are studied. Under appropriate working conditions, steady cone-jet configurations with three layers of liquids are obtained, resulting in multilayered droplets with outer shell, middle layer and inner core. The process can also produce monodisp

Abstract: The structural color originated from the nanoporous anodic alumina (NAA) film is related to the structural characteristics. This paper aimed to obtain different structural colors which can cover the whole visible range by widening the pore size of metalcoated NAA. First, we used the Finite Difference Time Domain (FDTD) method to analyze the relationship between the physical structure and optical properties. Then, we fabricated different colors and expected color pattern by widening the pore diameter of NAA. Numerical and experimental study shows that the colors can cover the whole visible range by widening the pore diameter. This work can not only lead to better understanding of the mechanism of tuning color on NAA film, but also help us to fabricate expected color in the whole l

Abstract: Temporal instability of an electrified liquid jet in the core of a high-speed gas stream is studied to better understand the electro-flow focusing (EFF) technique. Two types of physical models with and without viscosities of fluids are considered. One utilizes uniform basic flow and an axial electric field, while the other one considers both the axial and radial electric fields and employs appropriate velocity profiles based on the pipe flow for inner liquid and the error function for outer gas stream. Both models demonstrate that the axisymmetric instability and the helical instability are two most unstable modes in the EFF problem. The significance of free charge initially imposed on the interface is highlighted and the effects of surface tension and liquid viscosity on the jet