All fish were anesthetized (60-ppm eugenol solution) measured (total length and girth at first dorsal insertion to the nearest mm), weighed (nearest g), and scanned with a Distell Fatmeter (Distell Industries, Ltd., Lothian, Scotland; Crossin and Hinch 2005).
This needle could measure the total insertion force and the needle tip force separately in real time.
To estimate the friction force, we proposed a method of estimating the change in the friction force by measuring the total insertion force during needle insertion using RLS and a disturbance observer.
Therefore, we proposed a method of estimating the change in the friction force by measuring the total insertion force during needle insertion using recursive least square method and a disturbance observer.
The needle tip force acting on the inner needle was measured by a load cell TL3B09-50 N, (Tec Gihan Co. Ltd., Japan), and the total insertion force was measured by another load cell (LMC-21023, Nissho electric works Co. Ltd., Japan).
Examples of the total insertion force, the friction force, and the needle tip force, as measured by the coaxial needle, are shown in Figure 5.
All measured losses at 1.95 GHz due to the connectors, cables, and attenuators amount to approximately 83 dB, and the total insertion losses of the bandstop and preselect filters at 1.95 GHz are measured to be 7 dB.
The total insertion force decreased with needle tip force.
Here, the input vector λ was the total insertion force f needle.
The needle tip force was a constant 0.5 N while the total insertion force increased.
