Table 2 Intraoperative network-connecting parameters and subjective evaluation investigated both from online experts and local urologists

Latency time, ms, median (IQR)

 Round-trip delay (t1)

13 (2)

 Robot servo-period delay (t2)

6 (0)

 Robot mechanical-response delay (t3)

121 (0)

 Ultrasound-imaging delay (t4)

19 (0)

 Video codec delay (t5)

18 (0)

 Total delay (T)^a

177 (2)

Data-transmission rate, Mb/s, median (IQR)

748 (107)

Packet loss rate, %, median (IQR)

1.4 (0.4)

Online experts’ evaluations, n (%)

 Satisfaction for doctor-side ultrasound image quality (4–5)^b

14 (93.3)

 Satisfaction for driving patient-side robot-arm (4–5)^b

 Satisfaction for total delay (4–5)^b

15 (100)

15 (100)

 Satisfaction for audio-visual communication (4–5)^b

15 (100)

 Confidence for completing tele-assistance (4–5)^c

15 (100)

Local urologists’ evaluations, n (%)

 Satisfaction for robot-arm probe guidance (4–5)^b

14 (93.3)

 Satisfaction for audio-visual communication (4–5)^b

15 (100)

 Satisfaction for total delay (4–5)^b

15 (100)

 Confidence for establishing accesses (4–5)^c

12 (80)

 Confidence for completing stone removal (4–5)^c

11 (73.3)