Hyper-redundantmanipulators (HRMs) are widely used in minimally invasive surgery (MIS) because of their flexibility, dexterity, and compactness. However, when an external load acts on an HRM, its bending motion is disturbed and the workspace decreases. In addition, the external load increases the cable tension, and thin cables may break due to their low breaking strengths. This article proposes a cable-movable rolling joint that increases the workspace for MIS under an external load and reduces the actuating cable tension through cable movement. Furthermore, it presents an optimized motion estimation analysis method that verifies the manipulator performance by finding the equilibrium position and predicting the shape and tip position. The simulated manipulator exhibited a shape similar to that of the prototype and an average tip position difference of 4.59% based on the prototype length. Under an external load of 150 g, the workspace and cable tension of the prototype were 27.32% larger and 1.79 N lower than those of the conventional rolling joint, respectively. The new cable-movable mechanism and estimation analysis method will help improve the bending performance and position accuracy of HRMs for MIS.

A multicolor fluorescence imaging device was recently developed for image-guided surgery. However, conventional systems are typically bulky and function with two cameras. To overcome these issues, we developed an economical home-built fluorescence imaging device based on a single RGB-IR sensor that can acquire both color and fluorescence images simultaneously. The technical feasibility of RGB-IR imaging was verified ex vivo in chicken breast tissue using fluorescein isothiocyanate (FITC), cyanine 5 (Cy5), and indocyanine green (ICG) as fluorescent agents. The minimum sensitivities for FITC, Cy5, and ICG were 0.200 µM, 0.130 µM, and 0.065 µM, respectively. In addition, we validated the fluorescence imaging of this device in vitro during a minimally invasive procedure using smURFP-labeled probiotics, which emit a spectrum similar to that of Cy5. Our preliminary study of the ex vivo tissue suggests that Cy5 and ICG are good candidates for deep tissue imaging. In addition, the tumor-specific amplification process was visualized using cancer cells incubated with probiotics that had been labeled with a fluorescent protein. Our approach indicates the potential for in vivo screening of tumors in rodent tumor models.

Current imaging techniques suffer from a lack of specificity and resolution, leading to inaccurate tumor imaging and limited applicability of targeted contrast agents, as they require cancer‐specific development. The need for enhanced contrast through improved tumor‐to‐background ratio (TBR) and the toxicity from repeated injections due to fading fluorescent signals further complicate the issue. Additionally, challenges in visualizing the entire 3D tumor with surface‐stained contrast agents highlight the demand for advanced imaging solutions for more precise surgical guidance. A novel approach is proposed utilizing Streptavidin Associated Salmonella (SAS) as a contrast agent for image‐guided surgeries. SAS selectively proliferates in cancerous tissues and secretes streptavidin upon induction, enabling the binding of subsequently injected biotin‐conjugated fluorescent dyes. This approach enhances tumor visualization with a TBR of up to 15.3, far surpassing conventional agents (TBR ∼ 2), while enabling prolonged 3‐day imaging, deep tumor penetration, and precise invasive margin delineation with a single contrast agent injection. Furthermore, biosafety evaluations confirmed efficient bacterial clearance, absence of systemic toxicity, and stable physiological responses, supporting its potential for safe clinical translation. This innovative method offers substantial improvements over existing fluorescent contrast agents and holds promise for both diagnostic and therapeutic applications in cancer surgery.