Appendix A  Technical Description 
Instructions for Use  A - 33 
Measurement Range and Accuracy 
The following tables describe the variability in accuracy for clinical measurements. 
Clinical Measurements: Range and Accuracy 
Direct 
Tolerance 
Tolerance Function or Value (Accuracy) 
Distance*  0 – 36 cm  Tol(D) 
3% of the distance or 1.5 mm; whichever is 
greater assuming 1,540 m/sec speed of sound. 
Does not apply to trace tool. Distance tolerance 
using trace tool is user-dependent. 
Distance using 
SieScape extended 
field of view 
0 – 60 cm  Tol(D) 
Linear transducer: 5% of the distance or 2.5 mm; 
whichever is greater assuming 1,540 m/sec 
speed of sound. 
Curved transducer: 8% of the distance or 
2.5 mm; whichever is greater assuming 
1,540 m/sec speed of sound. 
Trace Area*  0 – 560 cm
  Tol(A) 
6% of the area or 1.5 cm
; whichever is greater, 
assuming minimal operator error in tracing the 
desired object and assuming 1,540 m/sec speed 
of sound. 
Time @ 
0 – 9.4 sec  Tol(T) @  
15 msec 
Time @  
0 – 4.7 sec  Tol(T) @  
7.5 msec 
Time @  
0 – 2.4 sec  Tol(T) @  
3.8 msec 
Velocity  10 – 600 cm/sec  Tol(V) 
10% of the velocity or 5 cm/s; whichever is 
greater using a J J & A string phantom at 
45 degrees ±1 degree. 
* Also applies to measurements on MPR (slice) quadrants from acquired volumes. 
2D-Mode Measurements 
2D-mode 
Distance  0 – 34 cm  D-Tol(D)  D + Tol(D) 
Distance Ratio  D1/D2  (D1-Tol(D1))/(D2+Tol(D2))  (D1+Tol(D1))/(D2-Tol(D2)) 
Mean Distance  (D1+D2+D3)/3 
(D1-Tol(D1)+D2-Tol(D2)+ 
D3-Tol(D3))/3 
(D1+Tol(D1)+D2+ 
Tol(D2)+D3Tol(D3))/3 
Ellipse 
Circumference 
π{1/2[D1
2
+D2
2
]}
1/2
 
π{1/2[(D1-Tol(D1))
2
+ 
(D2-Tol(D2))
2
]}
1/2
 
π{1/2[(D1+Tol(D1))
2
+ 
(D2+Tol(D2))
2
]}
1/2
 
Ellipse Area 
π(D1)(D2)/4  π(D1-Tol(D1))(D2-Tol(D2))/4 
π(D1+Tol(D1)) 
(D2+Tol(D2))/4 
Ellipse Volume 
(D1 = axis of rotation) 
(π/6)(D1)(D2)
2
 
(π/6)(D1-Tol(D1))(D2-
Tol(D2))
2
 
(π/6)(D1+Tol(D1)) 
(D2+Tol(D2))
2
 
Trace Area  0 – 450 cm
  A-Tol(A)  A+Tol(A)