Saroa Surgical System

Chronology

Posted Sep 21, 2026

Updated Sep 22, 2026

2026. Regulatory approval in Malaysia (June 12) and Thailand (June 18), marking its first expansion beyond Japan

Jul, 2023. First Saroa clinical case (thoracic surgery)

May 31, 2023. Saroa Surgical System receives Japanese manufacturing and marketing approval.

2019. ISO 13485:2016 certification obtained.

2018. RIVERFIELD selected for Japan’s J-Startup programme.

2015. EMARO endoscope-holder robot submitted for regulatory approval.

May 20, 2014. RIVERFIELD Inc. founded

2013. 6th prototype

2012. selected for Japan’s START program (Program for Creating STart-ups from Advanced Research and Technology)

2010. 5th prototype

2009. 4th prototype

2007. 3rd prototype

2004. 2nd prototype

2004. 1st prototype

2003. R&D at Tokyo Institute of Technology.

Saroa Surgical System is a Japanese robotic surgical platform developed at the Tokyo Institute of Technology from 2003. After several prototypes, RIVERFIELD Inc. was founded on May 20, 2014, as a university venture, originating from research at Tokyo Institute of Technology and Tokyo Medical and Dental University (later merged to form the Institute of Science Tokyo, October 1, 2024). Its defining feature the attempt to restore the sense of force that is largely lost in conventional soft-tissue robotic surgery.

Saroa uses pneumatic actuation to generate and estimate the force applied by its instruments and feeds this information back to the surgeon through the hand controllers. The force is also displayed quantitatively on the navigation monitor, in Newtons and as a bar graph.

A pneumatic approach to haptics

The principle behind Saroa is relatively straightforward. Pneumatic cylinders incorporated into the robotic arms actuate wires running through the instruments and connected to the grasping jaws. The pressure inside these cylinders is continuously monitored. This information is converted into electrical signals and transmitted to the surgeon’s hand controller, where the corresponding resistance is reproduced.

Designed around collaboration

The other unusual aspect of Saroa is its physical configuration. RIVERFIELD has deliberately developed a relatively compact robotic architecture, with space around the patient cart for surgical assistants to remain close to the operative field.

Saroa is also an open platform. It can be used with endoscopes, monitors and electrosurgical equipment from different manufacturers, allowing hospitals to incorporate equipment they may already have rather than replacing the entire surgical infrastructure.

Three arms and a different mechanical philosophy

Saroa is a three-arm system. Its pneumatic architecture also gives the robotic arms a degree of mechanical compliance that is different from the rigid, motor-driven architecture traditionally associated with surgical robots.

The instruments themselves remain conventional laparoscopic-style instruments.

Clinical experience

Saroa received Japanese manufacturing and marketing approval in May 2023. The first published clinical report described a sigmoidectomy for colorectal cancer and demonstrated the feasibility of performing oncological surgery using the platform with tactile feedback.

Clinical experience has subsequently expanded into several specialties. Published reports include prostatectomy, gynecological surgery, inguinal hernia repair and liver and pulmonary surgery. A 2025 report described the first robotic inguinal hernia repair using Saroa, while a 2026 series reported 23 anatomical pulmonary resections during early clinical adoption. The available evidence remains early and largely consists of initial clinical experiences and relatively small series.

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