Time-normalization Techniques for Gait Data
نویسندگان
چکیده
A method commonly used to “time-normalize” gait data (here referred to as linear length normalization [LLN]) is to linearly convert the trajectory’s time axis from the experimentally-recorded time units to an axis representing percentage of the gait cycle. However, other time-normalization techniques are also possible, such as dynamic time warping [DTW] and derivative dynamic time warping [DDTW]. DTW shifts the time index of each data point in a test trajectory to minimize the distance between the test and consensus trajectories. DDTW is a modification of DTW that minimizes the difference in the first derivatives of the trajectories.
منابع مشابه
Methods to temporally align gait cycle data.
The need for the temporal alignment of gait cycle data is well known; however, there is little consensus concerning which alignment method to use. In this paper, we discuss the pros and cons of some methods commonly applied to temporally align gait cycle data (normalization to percent gait cycle, dynamic time warping, derivative dynamic time warping, and piecewise alignment methods). In additio...
متن کاملNormalization of qPCR array data: a novel method based on procrustes superimposition
MicroRNAs (miRNAs) are short, endogenous non-coding RNAs that function as guide molecules to regulate transcription of their target messenger RNAs. Several methods including low-density qPCR arrays are being increasingly used to profile the expression of these molecules in a variety of different biological conditions. Reliable analysis of expression profiles demands removal of technical variati...
متن کاملGait temporospatial parameters: assessment tools for post- surgical recovery in patient with different anatomo- topographic types of lumbar disc herniation
The development in technology and informatics in the last decades enables integrated analysis of biomechanical and clinical data and facilitates the understanding of relations between human gait characteristic and different medical conditions of a patient. The aim of the study was to demonstrate the importance of gait temporospatial parameters analysis [opposite foot off, opposite foot contact,...
متن کاملNormalization of joint moments during gait: a comparison of two techniques.
Joint moments are commonly used to characterize gait. Factors like height and weight influence these moments. This study determined which of two commonly used normalization methods, body mass or body weight times height, most reduced the effects of height and weight on peak hip, knee, and ankle external moments during walking. The effectiveness of each normalization method in reducing gender di...
متن کاملGait Recognition using Encodings with Flexible Similarity Metrics
Gait signals detectable by sensors on ubiquitous personal devices such as smartphones can reveal characteristics unique to each individual, and thereby offer a new approach to recognizing users. Conventional pattern matching approaches use inner-product based distance measures which are not robust to common variations in time-series analysis (e.g., shifts and stretching). This is unfortunate gi...
متن کامل