University of California, San Diego, CA 92103-8465, USA.
Clin Neurophysiol. 2012 Mar;123(3):621-5. doi: 10.1016/j.clinph.2011.08.009. Epub 2011 Sep 7.
Motor unit action potentials (MUAPs) recorded by needle electrode reflect the functional state of the motor unit and its force-generating capacity, and are usually described morphologically (e.g. amplitude, duration). However, since the purpose of motor unit activation is force generation, MUAP energy seems a more physically meaningful measurement.
MUAPs were obtained by multi-MUAP decomposition of real interference patterns taken from human patients with neurological diseases. The energy content of each MUAP was measured from a time-frequency representation (TFR), specifically the Choi-Williams distribution, and compared with the standard MUAP morphological measure, the Size Index. The sample included normal, neurogenic, and myopathic MUAPs, from 11 patients.
There is an exponential distribution of energy within a sample of MUAPs and a strong exponential relationship between the Size Index and MUAP energy was observed.
The energy content of a MUAP can be quantified and corresponds very well with the current quantitative standard. Energy is a possible addition to MUAP quantification.
MUAPs could be classified as having normal, large (neurogenic), or low (myopathic) energy. MUAP energy has direct physical and physiological meaning that reflects the force-generating capacity of the motor unit. Time-frequency analysis could also be used to study the specific frequency content of MUAPs and the energy of MUAPs within an interference pattern, without the need for decomposition.
通过针电极记录的运动单位动作电位（MUAPs）反映运动单位的功能状态及其产生力的能力，通常从形态学上进行描述（例如，幅度、持续时间）。然而，由于运动单位激活的目的是产生力，MUAP 能量似乎是一种更具物理意义的测量方法。
通过对来自患有神经疾病的人类患者的真实干扰图案进行多 MUAP 分解来获得 MUAP。从时频表示（TFR），特别是 Choi-Williams 分布中测量每个 MUAP 的能量含量，并将其与标准 MUAP 形态测量（大小指数）进行比较。该样本包括正常、神经源性和肌源性 MUAP，来自 11 名患者。
MUAP 样本中存在能量的指数分布，并且观察到大小指数和 MUAP 能量之间存在很强的指数关系。
MUAP 的能量含量可以量化，并且与当前的定量标准非常吻合。能量可能是 MUAP 量化的一个补充。
MUAP 可以分类为具有正常、大（神经源性）或低（肌源性）能量。MUAP 能量具有直接的物理和生理意义，反映了运动单位的产生力的能力。时频分析也可以用于研究 MUAP 的特定频率内容以及干扰图案中的 MUAP 能量，而无需进行分解。
