A Study on Electro-Magnetic Interferences for ICD cause of Dental Electric Equipments

植入式心律转复除颤器（ICD）用于在心律失常时人工刺激心脏。随着老年人口的增加，ICD患者数量也在增加。ICD可能受到电气设备的影响，即电磁干扰（EMI）。在牙科治疗中，使用电动牙科设备是必要的，但这些设备对ICD的影响尚不清楚，只有少数报道。因此，最近的ICD只在必要时才起作用。我们评估了最近的电子牙科设备，目的是系统化的安全性和积极的牙科治疗。材料与方法对鹤见大学口腔医学院医院正在使用的12台24型电动牙科设备进行了试验。初步试验：采用磁通门磁强计测量磁通密度。如果磁通密度值较大，则在仿真模型中对这些设备进行测试。模拟模型：按照人体大小设计一个水箱，里面装满生理盐溶液。ICD放置在溶液12mm下，通过遥测系统与编程器连接。结果：少量电动口腔器械的电磁干扰对ICD有抑制作用。根据产生电磁干扰的原因，将这些装置分为两类。在类型1的情况下，某些设备的供电单元的电气设备抑制到27厘米的起搏距离。该数值足以影响牙科治疗的实际情况。在类型2的情况下，一些电根测量装置仅在电源开/关定时使用时才抑制起搏。所有数据由程序员打印出来，存储和分析。我们建议在使用电动牙科器械时必须采取预防措施。这项检查是在有限的条件下进行的。我们的设置是在最恶劣的条件下。我们必须认识到ICD和电动牙科装置的特点，所以牙科治疗本身没有限制。

ICD(implantable cardioverter-defibrillator) are used to artificially stimulate the heart in case of arrhythmia. As the population of elderly increases, number of patients with ICD increase. ICD can be affected by electrical equipment, known as electromagnetic interference (EMI).In dental treatment, it is necessary to use electrical dental equipments, but influences of these devices to ICD are unknown and reported only a few. Recent ICD therefore only functions when necessary.We evaluated recent electrical dental equipment aimed to systematize safety and positive dental treatment.Material and methodsWe tested 12 type 24 devices of electrical dental equipments that are being used in Tsurumi Univ. School of Dental Medicine hospital..Preliminary examination : Used flux-gate magneto-meter to measurement of flux density. If the value of flux density was high, these equipments were tested in simulation model.Simulation model : A water tank designed as the same size of the human body was filled with physiological salt solution. ICD was placed under the solution 12mm, connected by telemetric system to programmer.Results : ICD were inhibited by EMI of few electrical dental devices.These device were classified into two categories, according to cause of EMI.In case of type 1, some devices power supply unit of electrical device inhibit to pacing distance of 27 cm. This value was enough to influence to actual state of dental treatment.In case of type 2, some electrical root measurement device inhibit to pacing only when power on/off timing usage.All data was printed out by programmer, stored and analyzed.We suggest that precaution must be taken with the usage of electrical dental devices.This examination was done in limited conditions. Our settings were placed on most severe conditions.We must recognize the characteristics of ICD and electrical dental devices, so there are no limitation of dental treatment itself.