An anchor for a rectangular tube employs a wedge assembly, whereby rotation of an adjustment bolt of the wedge assembly moves an upper and lower wedge member together, and the wedge engagement with a central wedge member causes said central wedge member to move toward engagement with the tube, thereby securing the tube within a base body. An example medical devices includes a core member and a tubular member disposed over a portion of the core member. The hybrid SPI processing module makes the RX SPI performs the data transmission process as well when the RX SPI idles and the data transmission process proceeds at the same time and makes the TX SPI to performs the data receiving process as well when the TX SPI idles and the data receiving process proceeds at the same time. The microsphere also includes a polymer layer surrounding the magnetic material and the core microsphere.