External magnetic forces can have an impact on programmable valve mechanisms and potentially alter the opening pressure. As wearable technology has begun to permeate mainstream living, there is a clear need to provide information regarding safety of these devices for use near a programmable valve (PV). The aim of this study was to evaluate the magnetic fields of reference devices using smartphone-integrated magnetometers and compare the results with published shunt tolerances.

Five smartphones from different manufacturers were used to evaluate the magnetic properties of various commonly used (n = 6) and newer-generation (n = 10) devices using measurements generated from the internal smartphone magnetometers. PV tolerance testing using calibrated magnets of varying field strengths was also performed by smartphone magnetometers.

All tested smartphone-integrated magnetometers had a factory sensor saturation point at around 5000 µT or 50 Gauss (G). This is well below the threshold at which a magnet can potentially deprogram a shunt, based on manufacturer reports as well as the authors’ experimental data with a threshold of more than 300 G. While many of the devices did saturate the smartphone sensors at the source, the magnetic flux density of the objects decreases significantly at 2 inches.

The existence of an upper limit on the magnetometers of all the smartphones used, although well below the published deprogramming threshold for modern programmable valves, does not allow us to give precise recommendations on those devices that saturate the sensor. Based on the authors’ experimental data using smartphone-integrated magnetometers, they concluded that devices that measure < 40 G can be used safely close to a PV.

外部磁力会对可编程阀门机构产生影响，并可能改变开启压力。随着可穿戴技术开始渗透到主流生活中，显然需要提供有关这些设备在可编程阀门 (PV) 附近使用的安全性的信息。本研究的目的是使用智能手机集成磁力计评估参考设备的磁场，并将结果与​​公布的分流容差进行比较。

来自不同制造商的五款智能手机用于评估各种常用（n = 6）和新一代（n = 10）设备的磁性能，使用内部智能手机磁力计生成的测量值。智能手机磁力计还使用不同场强的校准磁铁进行 PV 容差测试。

所有经过测试的智能手机集成磁力计的出厂传感器饱和点都在 5000 µT 或 50 高斯 (G) 左右。根据制造商报告以及作者的实验数据，这远低于磁铁可能对分流器进行解编程的阈值，阈值超过 300 G。虽然许多设备确实在源头上使智能手机传感器饱和，物体的磁通密度在 2 英寸处显着降低。

所有使用的智能手机的磁力计都存在上限，尽管远低于现代可编程阀门公布的解编程阈值，但我们无法对那些使传感器饱和的设备给出精确的建议。根据作者使用智能手机集成磁力计的实验数据，他们得出结论，测量 < 40 G 的设备可以在 PV 附近安全使用。