电容式力感知牙周探针设计建模与实验研究

Aimed at overcoming the shortcomings of the current periodontal probes in probing force control, this paper put forward a product scheme based on a differential capacitive force sensing periodontal probe prototype, which takes advantage of the flexure effect of a cantilever. We designed the periodontal probe prototype, constructed the flexure model of the irregularly shaped probe tip, derived the equation between the probing force and the differential electric capacitance. The model and the equation are verified by simulation and experiment respectively. The results show that, firstly, the relative errors between the flexure model of the prove tip and static stress simulation are less than±4.5%; secondly, the force sensing standard deviation of the periodontal probe prototype under repeated measurements is less than 0.1% of the mean value; finally, the solutions of the equation and the experimental data have the same tendency, which was modified then by coefficients weighted by the probing force, so that a mean error of 2.49% is achieved in the full measuring range. So, the prototype has the feasibility for further product development.