Wearable lumbar rehabilitation exoskeletons require body-size adaptability and deterministic kinematic modeling. Adjustable wearing structures may alter actuator anchor-point positions, creating inconsistencies in fixed-geometry inverse kinematic models. This study proposes a linear-actuator-driven parallel lumbar exoskeleton using a split semi-ring variable-width platform. Transverse opening increments, $h_1$ and $h_2$, are introduced into the anchor-point coordinates to reconstruct the worn geometry. A geometry-adaptive kinematic model is developed to map task-space motions to actuator-space commands. Multibody simulations indicate that compared with a fixed-geometry model, the proposed approach decreases the position RMSE from $1.30\mathrm{mm}$ to $0.32\mathrm{mm}$ and the orientation RMSE from ${0.62}^{\circ }$ to ${0.05}^{\circ }$. Human-worn experiments across three healthy adult male participants yielded a global actuator displacement RMSE of $0.08$–$0.09\mathrm{mm}$, a task-space position RMSE of $4.73$–$7.64\mathrm{mm}$, and an orientation RMSE of ${0.71}^{\circ }$–${1.09}^{\circ }$. These task-space errors characterize the exoskeleton-platform motion measured by optical marker clusters rather than directly measured anatomical lumbar-spine kinematics. Rigid testbench validation isolated the kinematic mechanism from human-interface compliance, reducing the testbench position RMSE from $3.07\mathrm{mm}$ to $1.86\mathrm{mm}$ and the orientation RMSE from ${0.78}^{\circ }$ to ${0.34}^{\circ }$ compared to the fixed-geometry assumption. These results provide a proof-of-concept validation for the feasibility of the architecture and model for lumbar exoskeletons with transverse width adjustability.

Robot-assisted gastrointestinal endoscopic surgery (RAGES) has emerged as a critical approach for minimally invasive procedures, including Endoscopic Submucosal Dissection, polypectomy, hemostasis, and therapeutic interventions. However, manual manipulation of flexible endoscopes remains technically demanding and limits surgical precision. To enhance surgical efficiency, this paper proposes a joystick-controlled Endoscopic Robotic System (ERS) comprising a Flexible Arm Delivery Device (FDD) and Main Body Driving Device (MDD). Through systematic structural design and validation, the ERS achieves stable four-DOF control: 360° circumferential rotation, 180° bending, 280–330 mm axial delivery, and ±15° rotational compensation. Key innovations include dual-encoder slippage detection in the FDD and a gripper assembly addressing circumferential angle loss through real-time torque sensing. Experimental results confirm compatibility with dual-channel endoscopes without custom modifications. The system demonstrates proof-of-concept for comprehensive endoscopic control while maintaining compact design (<0.2 m² per module) and low manufacturing cost. Although force-sensing capabilities require further refinement, this work establishes a foundation for accessible robotic platforms in gastrointestinal endoscopy, with identified limitations guiding future development toward clinical viability.