Study of the measurement of halitosis by thin film semi-conductor sensor

目前，在一般口腔临床中，口臭患者的判断主要是由牙医的嗅觉决定的。但评审团成员的嗅觉会因他们的身体状况或年龄而改变。为了避免这些麻烦，评审团成员必须用标准的方法进行嗅觉测试，并需要多名评审员。由于这些局限性，期望有可靠的分析方法。我们报道了用气相色谱分析挥发性硫化物(VSC)的浓度与专家组对口臭的判断很好地一致。但在一般牙科临床中，由于需要特殊的技术和较高的成本，制备气相色谱是非常困难的。我们的目标是研制一种由薄膜氧化锌半导体传感器组成的对VSC具有高选择性的便捷嗅觉仪。我们做了第一次和第二次试验嗅觉仪，并测试了他们的e…效率更高。研究结果如下。该传感器的灵敏度足以检测到VSC的明显口臭。该传感器对口腔空气中典型的有机成分丙酮和乙醇的灵敏度比VSC低1/10，表明该传感器具有良好的选择性。对标准口臭空气的重复测量试验具有足够的重现性，通过使用酸性吸附过滤器提高了选择性。该嗅觉仪对口腔进行了实际测量，预热时间约为3分钟，测量时间约为1.5分钟，下一次测量需要约3分钟。但对同一人的重复测量与通过时间显示出相当大的差异。这种差异是由口腔气味随时间的变化引起的，还是由口腔空气的采样方法引起的，还有待进一步研究。较少

The present time, in general dental clinic, the judgment of halitosis of the patients who complaining bad breath is due to the olfactory sense of dentists. But the olfactory sense of panelists is changed by their physical condition or aging. For avoiding these troubles, the panelists must be tested of their olfactory sense by standard method and plural panelists are needed. Because of these many limitations, reliable analytical method was expected.We reported that the concentration of volatile sulfur compounds(VSC) analyzed by gas chromatography is well correspond to the judgement of halitosis by panel. But in general dental clinic, it is very hard to prepare the gas chromatography, for needed special techniques and high cost. So, the development of convenient olfactometer was expected.We aimed to develop a convenient olfactometer composed of thin film zinc oxide semi-conductor sensor which is high selective to VSC. We made the first and the second trial olfactometer and tested their e … More fficiency. The result are as follows. The sensitivity of this sensor is sufficient to detect noticeable halitosis revel of VSC. The sensitivity revel of acetone and ethylalcohol, the typical organic contents in mouth air, are 1/10 fold lower than VSC which shows good selectivity of this sensor. Repeating measuring test to standard halitosis air is sufficient reproducibility.The selectivity is improved by using acidic absorbent filter. A mouth air chamber which accumulate a certain volume of mouth air, is useful to decreasing the detective variance and is also useful to protect the contamination of saliva into the detective path.The practice measuring was done to mouths, using this olfactometer, and the time for preheat is about 3 minutes, measuring time is one and half minutes and about 3 minutes is necessary for the next measuring. But repeating measurements to same person with passage time showed considerable variance. Further study is necessary whether this variance was caused by the changes of mouth odor with passage of time or whether by the sampling methods of mouth air. Less