NSK Develops “Spherical Parallel Link Actuator” for Echocardiography Robots


  • Free range of motion enables precise reproduction of a skilled medical technician’s movements.
  • Enables remote-controlled manipulation of echocardiography ultrasound probe, contributing to development of telemedicine systems of the future

The “spherical parallel link actuator” developed by NSK has been adopted in the world’s first remote echocardiography robot “Orizuru,” which performs echocardiography in a seated position, developed by Waseda University (Shinjuku-ku, Tokyo). The robot was exhibited at Yokohama Robot World 2021 at Pacifico Yokohama (Yokohama City, Kanagawa Prefecture) from November 10-11.

Spherical Parallel Link Actuator
                                Spherical Parallel Link Actuator

Development Background

Early detection and treatment are important to combat heart disease, which is one of the leading causes of death in Japan and abroad. With the aim of early detection of cardiac diseases, the Hiroyasu Iwata Laboratory at Waseda University is developing robots that can easily perform echocardiographic examinations in familiar places (e.g., convenience stores) where specialized equipment is not available, using a telemedicine (remote controlled) system integrated with AI technology.

In the development of this robot, one of the major challenges was to reproduce the smooth movements of an echocardiography technician when acquiring echocardiographic images.


NSK’s spherical parallel link actuator is used to move and manipulate the Orizuru ultrasound probe, and contributes to precise echocardiographic image acquisition by reproducing the smooth movement of the probe as operated by the technician by remote control.


Echocardiographic measurements are taken from various angles without moving the probe tip. The spherical parallel link actuator is the mechanism that enables this motion, and the probe posture angle can be controlled more easily than with conventional technology. This will improve image accuracy, contribute to the miniaturization of the device, and also shorten the imaging time.


NSK will continue to contribute to a safe and smooth society through Motion & Control technology.