In many robotic applications, such as humanoids, wearable robots or supernumerary limbs, there is a growing shift from rigid, traditional mechanisms toward softer, more compliant systems. This trend is driven by the need for safer physical human-robot interaction and the ability to operate in unstructured environments. In this work, we present a hybrid approach to controlling a single-degree-of-freedom robotic joint that combines a rigid frame with soft pneumatic actuators to enable both precise and versatile interaction. The joint is bioinspired, as it is powered by a couple of actuators mounted in an antagonist configuration, such as the human elbow. A key innovation is the design of pneumatic artificial muscles using thermoplastic polyurethane (TPU), which achieve high isometric force (400 N at 240 kPa), significant stretchability (80 mm), and low density (0.3 g/cm³), making them competitive with state-of-the-art alternatives. Two model-free controllers were developed to independently regulate joint position and stiffness. Angle control achieved high precision (< 2°RMSE) with minimal overshoot (< 1%) and fast response (rise time < 1.3 s). Stiffness control modulated joint compliance across a range of 0.054-0.076 Nm/deg, with the expected trade-off of reduced workspace. A final proof-of-concept demonstrated the concurrent use of both controllers to modulate the joint's dynamic behavior in response to external disturbances. While future work will address multi-DOF coordination and wearable integration, this study represents a foundational step toward safe, adaptable robotic actuation through the combination of rigid structures and soft actuation.

Coronary artery bypass grafting is frequently performed in combination with valve surgery; however, minimally invasive approaches for such combined procedures remain limited due to challenges in exposure and access. While bilateral minimally invasive strategies have been described in selected cases, standardized access concepts for concomitant procedures are not well defined. This study aimed to assess the anatomical accessibility and procedural workflow of a minimally invasive biaxillary access strategy for combined coronary and valve surgery in a human cadaver model. Combined coronary artery bypass grafting and valve procedures were performed in nine Thiel/ethanol-fixed human cadavers using a biaxillary access approach. Anatomical exposure, conduit length, graft harvesting and anastomosis times, and valve positioning were evaluated by macroscopic inspection and postprocedural three-dimensional computed tomography imaging. All planned procedural steps were completed in all nine cadavers. The mean left and right internal thoracic artery lengths were 18.1 ± 1.8 cm and 18.9 ± 1.9 cm, respectively. The average bilateral internal thoracic artery harvest and anastomosis times were 52.0 ± 17.6 min and 46.6 ± 12.6 min, respectively. Postprocedural three-dimensional computed tomography imaging and macroscopic inspection demonstrated consistent graft positioning and anatomical valve seating across all specimens. This cadaveric study demonstrates that a minimally invasive biaxillary access strategy allows anatomical exposure and supports a conceptual procedural workflow for combined coronary and valve interventions. These findings represent an early-stage technical proof-of-concept and require further validation before clinical application can be considered.