Skotak Maciej, Alay Eren, Chandra Namas
Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States.
Front Neurol. 2018 Feb 6;9:52. doi: 10.3389/fneur.2018.00052. eCollection 2018.
Measurement issues leading to the acquisition of artifact-free shock wave pressure-time profiles are discussed. We address the importance of in-house sensor calibration and data acquisition sampling rate. Sensor calibration takes into account possible differences between calibration methodology in a manufacturing facility, and those used in the specific laboratory. We found in-house calibration factors of brand new sensors differ by less than 10% from their manufacturer supplied data. Larger differences were noticeable for sensors that have been used for hundreds of experiments and were as high as 30% for sensors close to the end of their useful lifetime. These observations were despite the fact that typical overpressures in our experiments do not exceed 50 psi for sensors that are rated at 1,000 psi maximum pressure. We demonstrate that sampling rate of 1,000 kHz is necessary to capture the correct rise time values, but there were no statistically significant differences between peak overpressure and impulse values for low-intensity shock waves (Mach number <2) at lower rates. We discuss two sources of experimental errors originating from mechanical vibration and electromagnetic interference on the quality of a waveform recorded using state-of-the-art high-frequency pressure sensors. The implementation of preventive measures, pressure acquisition artifacts, and data interpretation with examples, are provided in this paper that will help the community at large to avoid these mistakes. In order to facilitate inter-laboratory data comparison, common reporting standards should be developed by the blast TBI research community. We noticed the majority of published literature on the subject limits reporting to peak overpressure; with much less attention directed toward other important parameters, i.e., duration, impulse, and dynamic pressure. These parameters should be included as a mandatory requirement in publications so the results can be properly compared with others.
讨论了导致获取无伪影冲击波压力-时间曲线的测量问题。我们阐述了内部传感器校准和数据采集采样率的重要性。传感器校准考虑了制造工厂的校准方法与特定实验室所使用方法之间可能存在的差异。我们发现全新传感器的内部校准因子与制造商提供的数据相差不到10%。对于已用于数百次实验的传感器，差异更为明显，而对于接近使用寿命末期的传感器，差异高达30%。尽管我们实验中的典型超压对于额定最大压力为1000 psi的传感器不超过50 psi，但仍出现了这些差异。我们证明，为了捕捉正确的上升时间值，采样率为1000 kHz是必要的，但对于低强度冲击波（马赫数<2），在较低采样率下，峰值超压和冲量值之间没有统计学上的显著差异。我们讨论了源于机械振动和电磁干扰的两个实验误差源，它们会影响使用最先进的高频压力传感器记录的波形质量。本文提供了预防措施的实施、压力采集伪影以及示例数据解释，这将有助于广大研究群体避免这些错误。为了便于实验室间的数据比较，爆炸性创伤性脑损伤研究群体应制定通用的报告标准。我们注意到，关于该主题的大多数已发表文献将报告局限于峰值超压；而对其他重要参数，即持续时间、冲量和动态压力的关注则少得多。这些参数应作为出版物中的强制性要求纳入，以便结果能够与其他结果进行适当比较。
