Robotic fetal ultrasonography platform with a passive scan mechanism

Purpose: The shortage of obstetricians and gynecologists has intensified in developed countries. Our long-term goal is to develop a robotic prenatal care platform for automatic ultrasound (US) scanning to improve the workflow efficiency of obstetricians and gynecologists. This paper develops a hardware platform for the positioning of the US probe to obtain diagnostic US images while satisfying safety requirements of the fetus and pregnant woman. Method: The proposed system includes a mechanism that maintains the contact force in a certain range and passively adjusts the US probe posture relative to the body surface. The system is designed according to clinical survey data. For proof of concept, we conducted a robotic US scan with an agar phantom and three pregnant women under the operation of a physician. Results: Experimental results show the passive US scan motion followed the phantom surface with an acceptable contact force (< 15 N). Clinical trials were safely carried out with observations of fetal body parts. Conclusion: Our proposed platform acquired US images with satisfactory contact forces in the phantom study. The feasibility of the platform was demonstrated in a clinical study.