9 research outputs found
A Construction of Multisender Authentication Codes with Sequential Model from Symplectic Geometry over Finite Fields
Multisender authentication codes allow a group of senders to construct an authenticated message for a receiver such that the receiver can verify authenticity of the received message. In this paper, we construct multisender authentication codes with sequential model from symplectic geometry over finite fields, and the parameters and the maximum probabilities of deceptions are also calculated
Filtering-induced changes of pulse transmit time across different ages:a neglected concern in photoplethysmography-based cuffless blood pressure measurement
Mini Review: Linkages between Essential Tremor and Parkinson\u27s Disease?
Essential tremor (ET) and Parkinson’s disease (PD) are two of the most common movement disorders. Tremors are the primary symptoms of ET and of some PD patients, the two are often mistaken for each other. Especially since there are no available differentiate tests for the tremor of ET or PD, the early diagnoses mainly based on clinical assessments of medical symptoms, family and medication history, and examination by physicians. There is increasing evidence suggesting an association between ET and PD, such as a similar tremor frequency, overlapping resting tremors (a typical PD tremor), postural tremors (mainly in ET patients) in both ET and PD patients, and many ET patients develop PD later in life. Although it is difficult to make a differential diagnosis of ET and tremor-dominant PD based on clinical assessment, recent developments of objective measurements, such as brain imaging, neuropathology, and genetic analysis, has opened a helpful window for distinguishing ET from PD. In this mini review, we included literatures of ET and PD studies and discussed various advanced methods for differential diagnosis between ET and PD such as neuroimaging, genetic markers, tremor intensity and frequency, and drug-responses
Assessing the Effects of Filtering Processing on Pulse Wave Transit Time Measured by Photoplethysmography from Earlobe
The waveform of a photoplethysmography (PPG) signal depends on individual physiological conditions. Pulse transition time (PTT), derived from electrocardiogram (ECG) and PPG waveform features, is an important physiological parameter for blood pressure estimation. Filtering can change PPG signal waveform and the timing of PPG feature points. This work aimed to quantitatively investigate the filtering-induced PTT changes at earlobe in healthy subjects of different ages and with different PTT definitions. The ECG and earlobe PPG signals were recorded simultaneously at a sample rate of 2500 Hz for 120 s from 100 healthy adults in 5 age groups (20-29, 30-39, 40-49, 50-59, and over 60 years). The PPG signals were preprocessed using band-pass filtering (pass and stop bands: >0.5 Hz and <0.2 Hz for high-pass filter, <20 Hz and >30 Hz for low-pass filter) and then low-pass filtered (pass and stop bands: <3 Hz and >5 Hz). The PTT difference between the preprocessed and filtered PPG signals was calculated and analyzed. Four pulse feature points were defined and extracted (i.e., maximum peak (MP), valley point (VP), maximal first derivative (M1D), and maximal second derivative (M2D)). The results showed significant effect of PTT definition on filtering-induced PTT relative difference (p<0.001). It was found that the age group (50-59) and the MP definition had the minimum filtering-induce PTT changes. This work suggested that the physiological factors including PTT definition and age should be considered in the PTT-based blood pressure estimation methods.</p