Pagnacco G, Oggero E, Morr D R, Berme N
Mechanical Engineering Department, Ohio State University, Columbus 43210, USA.
Biomed Sci Instrum. 1997;34:137-42.
The ability to capture analog signals in a digital format suitable for subsequent storage, processing and analysis by a computer has revolutionized many scientific fields, including biomechanics. In the process of going from the analog signal to its digital representation, it is essential to maintain as much of the original signal content as possible. There is always a loss of information associated with the conversion from analog to digital, independently of how it is actually performed. The only possibility to reduce the loss of information is to increase the number of states or the resolution of the digital signal. The method presented here, based on the same theory used in oversampling analog to digital converters, is applicable to digital signals acquired using any converter. In most situations this method provides a feasible and inexpensive technique to significantly improve the amplitude resolution of the analog to digital conversion. This can be of fundamental importance when the information of interest is small in amplitude compared to the overall signal, or when subsequent ill-conditioned operations, like the computation of the derivatives of the signal, are to be performed.
以适合计算机后续存储、处理和分析的数字格式捕获模拟信号的能力,已经彻底改变了包括生物力学在内的许多科学领域。在从模拟信号转换为其数字表示的过程中,尽可能多地保留原始信号内容至关重要。从模拟到数字的转换总会伴随着信息丢失,无论实际是如何进行转换的。减少信息丢失的唯一方法是增加数字信号的状态数量或分辨率。这里介绍的方法基于过采样模数转换器所使用的相同理论,适用于使用任何转换器采集的数字信号。在大多数情况下,这种方法提供了一种可行且廉价的技术,可显著提高模数转换的幅度分辨率。当感兴趣的信息在幅度上相对于整体信号较小时,或者当要执行后续的病态操作(如信号导数的计算)时,这可能具有至关重要的意义。