Page 319 - Control Theory in Biomedical Engineering

Continuum NasoXplorer manipulator with shape memory actuators 293

Fig. 1 The prototype, optical image (top), CAD model (middle) and illustrations
(bottom).

Table 1 NasoXplorer specifications.
NasoXplorer
Diameter (tip)/mm 3
Diameter (proximal end)/mm 8.4
Angulation range (deflection)/degrees 145
Working length (active)/cm 2
Working length (passive)/cm 9.8

2.3 Design components and design rationale
2.3.1 Optical zooming segment and camera
The camera we used is the IntroSpicio 110 micro CCD camera. It has a
diameter of 3.9mm and is threaded through the TangoBlack flexible seg-
ment, as well as the sole SMA spring in the NasoXplorer (Fig. 2). The distal
end of the NasoXplorer is the flexible tip, bending up to an angle of
100degrees. This is supported by the User and Technical Specification
Report. The NasoXplorer works using an SMA spring that extends and
contracts with the application of a small current. Fig. 3 shows part of the
NasoXplorer when relaxed and contracted, respectively. The spring used
in the NasoXplorer is 0.1in. in diameter and 0.6in. in length. Further details
are provided in Fig. 3. When the NasoXplorer enters the nasal inlet of the