The use of an inertially stabilized platform (ISP) as a key component in electro-optical tracking instruments to control the sensor's line of sight (LOS) has been investigated for over decades. Its aim is to achieve an accurate tracking for a target and isolate the LOS from the carrier vibrations. A typical assumption in such a system is that the mass distribution of the ISP is symmetrical with respect to the frame axes under consideration. This assumption is rarely satisfied in practice. This paper explores the development of an output feedback controller for an ISP while considering dynamic mass unbalance, where the controller derivation is based on the assumption that all parameters used in the system modeling are unknown, but bounded in size. This assumption implies that the ISP is affected by both matched and unmatched uncertainties. The research, in this paper, illustrates how an indirect robust control can be incorporated with a modified extended state observer-based feedforward term to achieve a high performance on the tracking in the presence of uncertainties, mass imbalance, kinematic coupling, carrier vibrations, and external disturbances. Simulation results are presented to confirm the effectiveness of the proposed scheme.

In this paper, an output feedback position tracking control problem relevant for a linear piezoelectric ceramic motor (LPCM) is studied. The main goals of the control design include achieving extremely high resolution, accuracy, stability, and improved transient performance when system uncertainties, unknown dynamics, and external disturbances act on the system. The proposed control approach is designed in such a way that the implementation of the high-precision micro/nanopositioning is possible. An adaptive sliding mode-based scheme is adopted to synthesize a robust controller. Stability analysis of the control approach is performed and it is analytically shown that the position tracking error asymptotically converges to zero. The important advantages of this control approach are 1) designing a controller without the requirement of prior knowledge about uncertainty/disturbance bounds, 2) having a chattering-free control input, and 3) obtaining a fast response without overshoot. The proposed control strategy was experimentally validated and compared to the existing control approaches.

This paper presents an initial prototype of an in-vivo robotic laparoscopic camera that features optimized illumination to address the problems, i.e. inferior lighting uniformity and low optical efficiency, in the state-of-the-art designs of in-vivo laparoscopic cameras. Benefiting from the transformable structure of the robotic camera, sufficient on-board space is created without sacrificing the camera's compactness to carry three dedicatedly-designed freeform optical lenses for achieving the optimized illumination requirements. Designing miniature freeform optical lenses for extended light sources, such as LEDs, is a very challenging task which usually involves solving a non-standard Monge-Ampere equation. In this paper, we approach the illumination optical design based on a ray-mapping method that is governed by a standard Monge-Ampere equation. We propose an effective numerical solver to compute the ray-mapping solution for constructing freeform lens surfaces. Experimental results prove the predicted performance of the illumination system design: greater than 97% illuminance uniformity, greater than 80% optical efficiency, and greater than 14,323 lx illuminance on a target plane with a distance of 100 mm. The effectiveness of this prototype is also experimentally verified by performing a suturing task in a simulated abdomen.

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${}^{\circ }$ and +180${}^{\circ }$, and pan in the range of 0${}^{\circ }$∼360${}^{\circ }$. The s-CAM has brought robotic laparoscopic imaging one step further toward less invasiveness and more dexterity.

Background: Insertable laparoscopic camera systems were developed to improve the minimally invasive surgeries. Robotic degrees of freedom for an insertable laparoscopic camera are required to adjust the camera's orientation and position inside an abdominal cavity.Methods: This paper demonstrates an insertable magnetic actuated robotic camera system with two‐degree‐of‐freedom (2‐DoF) orientation control for single incision laparoscopic surgery. The camera system design consists of an external magnetic control unit and a fully insertable camera capsule. This system features a unified mechanism for anchoring, navigating, and rotating the insertable camera capsule by externally generated rotational magnetic field from the control unit. The motor‐free camera capsule is encapsulated in an one‐piece housing with two ring‐shaped tail‐end magnets and one cylindrical central magnet. The control unit that positioned externally consists of both permanent magnets and electromagnetic coils to generate rotational magnetic field and control the camera capsule.Results: The experimental investigations indicated that the camera control system can achieve less than 1° control accuracies with average errors 0.594° and 0.524° for tilt motion and pan motion, respectively.Conclusion: The designed control system provides fine orientation control for the insertable camera capsule which guarantees proper vision for the surgeon during single incision laparoscopic surgery.