Neck myoelectric signal control-type speaking valve with low flow resistance: Proposal of asymmetric type baffle plate

We aimed to develop some welfare devices for phonation disorder patients. One of them is the electrical control type speaking valve system. The conventional speaking valve have the one-way valve mechanism, they open when the user breaths in, and close when user breaths out and produce the voice. This type is very simple and tough, but some users feel closeness in case of exhalation. This problem is caused by its mechanism that can't be controlled by user's will. Therefore, we proposed an electrical control-type speaking valve system. This valve is opening and closing controlled by the myoelectric signal of user's sternohyoid muscle. In our previous report, it was clarified that this controllable valve had better performance from the viewpoint of easy breathing than the conventional valve. Furthermore, we proposed the compact myoelectric control-type speaking valve system. This compact valve was enough small to attach the user's body, and its opening area was larger than conventional type. However, some vortex flow was seen inside of this valve from the FEM analysis of this valve. Then, we tried to extinguish the vortex flow by the baffle plates. In this report, the result of FEM analysis about the effectiveness of the various shape baffle plate. From the result of the analysis, it was clarified that the asymmetric type baffle plate had better characteristic than the symmetric type.