Design of a Magnetically Anchored Laparoscope Using Miniature Ultrasonic Motors

Images taken by an endoscope in single-port-access surgery are the most important information for directing surgeons to operate, so acquiring images taken at better position and a more desired perspective has profound significance for improving the efficiency and safety of surgery. The magnetically anchored laparoscope can help to realize this goal compared with the traditional laparoscope used in single-port-access surgery. In this paper, we propose the concept of applying ultrasonic motors in the magnetically anchored laparoscope. Two types of ultrasonic motors used for driving the laparoscope, namely a miniature traveling wave-rotating ultrasonic motor and a miniature traveling wave-tilt ultrasonic motor, are designed. The prototype of the magnetically anchored laparoscope using these two types of ultrasonic motors is fabricated and evaluated by experiments. The results show that the maximum output torque of the miniature traveling wave-rotating ultrasonic motor is 1.2 mN·m, and that of the miniature traveling wave-tilt ultrasonic motor is 1.4 mN·m, which is enough to actuate the magnetically anchored laparoscope. Additionally, it is proven that the two designed ultrasonic motors can be applied successfully in the laparoscope.

s-CAM: An Untethered Insertable Laparoscopic Surgical Camera Robot with Non-Contact Actuation

Fully insertable robotic imaging devices represent a promising future of minimally invasive laparoscopic vision. Emerging research efforts in this field have resulted in several proof-of-concept prototypes. One common drawback of these designs derives from their clumsy tethering wires which not only cause operational interference but also reduce camera mobility. In this paper, a tetherless insertable surgical camera (s-CAM) robot with non-contact transabdominal actuation is presented for single-incision laparoscopic vision. Wireless video transmission and control communication using onboard power help eliminate cumbersome tethering wires. Furthermore, magnetic based camera actuation gets rid of intrinsic physical constraints of mechanical driving mechanisms, thereby improving camera mobility and reducing operational interference. In addition, a custom Bluetooth low energy (BLE) application profile and a real-time operating system (RTOS) based multitask programming framework are also proposed to facilitate embedded software design for insertable medical devices. Initial ex vivo test results of the s-CAM design have demonstrated technical feasibility of a tetherless insertable laparoscopic camera. Effective imaging is confirmed at as low as 500 lx illumination. Wireless laparoscopic vision is accessible within a distance of more than 10 m. Transabdominal BLE communication is stable at over −52 dBm and shows its potential for wireless control of insertable medical devices. RTOS based sfotware event response is bounded within 1 ms while the CPU usage is at 3∼5%. The device is able to work for 50 min with its onboard power. For the mobility, the robot can translate against the interior abdominal wall to reach full abdomen quadrants, tilt between −180∘ and +180∘, and pan in the range of 0∘∼360∘. The s-CAM has brought robotic laparoscopic imaging one step further toward less invasiveness and more dexterity.

Miniature Pump for Treatment of Refractory Ascites Based on Local Magnetic Actuation

This paper presents the design, fabrication, and experimental validation of a novel low-cost implantable pump for the treatment of refractory ascites (RA) based on local magnetic actuation (LMA). A reciprocating positive displacement pump displaces liquid unidirectionally through magnetic coupling with a magnetic controller placed on the outside of the patient's body. The proposed solution is intuitive to use given an alignment algorithm that exploits externally placed magnetic field sensors (MFS). The implantable device has a catheter-like shape, is electronic free (no on-board battery), has low fabrication cost (<8 USD), and is able to generate a flow-rate of 3.65 L/h while effectively pumping fluids with various viscosity (1–5.5 cP). RA is commonly treated via costly paracentesis or invasive surgical placement of a transjugular portosystemic shunt (TIPS). The proposed solution can be implanted with minimally invasive techniques and can be used on a daily basis to drain a set amount of liquid, without requiring recurrent hospital visits.