Second derivative photoplethysmographic signal analysis of differences between fingers in healthy subjects

2018 ◽  
Author(s):  
Kristjan Pilt ◽  
Sandra Silluta ◽  
Merlin Palmar ◽  
Deniss Karai ◽  
Kalju Meigas ◽  
...  
Keyword(s):  
Signal Analysis ◽  
Healthy Subjects ◽  
Second Derivative

Assessment of the Vascular Effects of PC6 (Neiguan) Using the Second Derivative of the Finger Photoplethysmogram in Healthy and Hypertensive Subjects

2007 ◽  
Vol 35 (03) ◽  
pp. 427-436 ◽  
Author(s):  
José F. Rivas-Vilchis ◽  
Fernando Hernández-Sánchez ◽  
Ramón González-Camarena ◽  
Luis D. Suárez-Rodríguez ◽  
Ricardo Escorcia-Gaona ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Light Transmission ◽  
Infrared Light ◽  
Second Derivative ◽  
Large Artery ◽  
Vascular Aging ◽  
Acute Effects ◽  
Vascular Effects ◽  
Artery Stiffness ◽  
Volume Pulse

Indices obtained from the second derivative of the digital volume pulse waveform have been proposed to characterize vascular aging, arterial rigidity, and the effects of vasoactive drugs. The purpose of this study was to assess the effects of manual needling of PC6 on SDDVP indices in healthy and untreated hypertensive subjects. AI, B:A, and D:A indices, based on the height of the wave components of SDDVP, in 40 healthy subjects and 25 untreated hypertensive subjects were compared. DVP was obtained by measuring infrared light transmission through the finger. For each subject, 20-min-long DVP registration was obtained. PC6 was stimulated unilaterally by manual needling for 5 min (1–6 min). In each subject, pre-acupuncture DVP indices were compared to those of during acupuncture (1 vs. 4 min) and post-acupuncture (1 vs. 18 min). In healthy subjects, AI was significantly improved when comparing the pre- to the post-acupuncture values. In hypertensive subjects, the SDDVP indices improved significantly as follows: the AI index when the value of pre-acupuncture comparing to that of during acupuncture and post-acupuncture values; B:A and D:A indices when the pre-comparing to post-acupuncture values. There were significant differences between healthy and hypertensive subjects in AI, B:A, and D:A at baseline and in B:A in the during acupuncture period; there were no significant differences at post-acupuncture. These results indicate that manual needling of PC6 produced acute effects on vascular pathophysiology. Moreover, PC6 needling produced changes in SDDVP indices related to both large artery stiffness and the reflected wave originating in small arteries.

The venous thromboembolic risk and the clot wave analysis: a useful relationship?

2018 ◽  
Vol 56 (3) ◽  
pp. 448-453 ◽  
Author(s):  
Maria Filomena Ruberto ◽  
Francesco Marongiu ◽  
Antonella Mandas ◽  
Antonella Mameli ◽  
Mariagrazia Porru ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Waveform Analysis ◽  
Second Derivative ◽  
Medical Patients ◽  
Wave Analysis ◽  
Thromboembolic Risk ◽  
Antithrombotic Prophylaxis ◽  
First Derivative ◽  
Venous Thromboembolic ◽  
D Dimer

AbstractBackground:Hospitalized patients with acute medical conditions have higher venous thromboembolism (VTE) risk. A patient with a final Padua Prediction Score (PPS) of ≥4 is considered to be at high risk for VTE. The aim of this study was to investigate on a possible relationship between PPS, the dynamics of the clot formation, i.e. the clot waveform analysis (CWA) of aPTT, fibrinogen and D-Dimer in a large group of medical patients.Methods:CWA in terms of velocity (first derivative), acceleration (second derivative), density (Delta) of aPTT, fibrinogen, D-Dimer and PPS for VTE were determined in 801 medical patients divided in three groups (without antithrombotic prophylaxis and high PPS, without antithrombotic prophylaxis and low PPS, with antithrombotic prophylaxis and high PPS) and a group of healthy subjects.Results:CWA, fibrinogen and D-Dimer values were higher in the medical patients with high PPS with or without antithrombotic prophylaxis when compared with patients without antithrombotic prophylaxis with low PPS and healthy subjects. The second derivative, fibrinogen and D-Dimer were significantly associated with a high PPS score (≥4): odds ratio (OR) = 1.53, 95% confidence interval (CI) = 1.03–2.28; OR = 1.91, 95% CI = 1.3–2.79; OR = 3.16, 95% CI = 2.29–4.36, respectively. Interactions between first derivative and D-Dimer (OR = 2.14, 95% CI = 1.23–3.72) and first derivative and fibrinogen (OR = 1.75, 95% CI = 1.02–2.98) were found.Conclusions:CWA could give useful information to recognize a hypercoagulable state in patients admitted to a medical ward with high and low PPS. First and second derivative aPTT, D-Dimer and fibrinogen levels could be added to PPS to better assess the global thromboembolic risk of these patients.

ACQUISITION AND CHARACTERIZATION OF BOWEL SOUNDS USING LabVIEW SOFTWARE

2018 ◽  
Vol 30 (02) ◽  
pp. 1850006
Author(s):  
Oinam Robita Chanu ◽  
V. Karthik Raj
Keyword(s):  
Signal Analysis ◽  
Healthy Subjects ◽  
Low Cost ◽  
Bowel Sounds ◽  
Electronic Stethoscope ◽  
Epigastric Region ◽  
Labview Software ◽  
Traditional Technique

Bowel sounds (BSs) are defined as the sounds when contractions of the lower intestines propel forward. It is simple, but empirical and too subjective. Auscultation is the traditional technique for determining gastrointestinal functioning. The most physicians and nurses carry out a cursory listen for BS resulting in misinterpretation. The aim and objective of this project are to design a low-cost prototype of an electronic stethoscope to acquire the BSs and analyzing its characteristics using LabVIEW software. The developed prototype is interfaced with the software, and the BSs are recorded from the epigastric region and the umbilical region. The characteristics of recorded BSs are analyzed in the LabVIEW software with the available tool like signal analysis and sound analysis. For this study, a total number of 17 subjects are included. Around 1[Formula: see text]min BS recordings are performed on 12 healthy subjects and 5 abnormal subjects. The result showed that the BSs are recorded from the designed prototype. The frequencies of detected BS vary for each person in different areas of the abdomen. Based on the frequency of detected BS for a particular subject, the classification of BS is made into hypoactive, hyperactive and absent (no sounds).

scholarly journals Assessment of the Dysautonomia Presence in Parkinson disease through Cardiovascular Signal Analysis

2017 ◽  
Author(s):  
◽  
S. Alvarado-Jalomo
Keyword(s):  
Parkinson Disease ◽  
Signal Analysis ◽  
Healthy Subjects ◽  
Pulse Transit Time ◽  
Approximate Entropy ◽  
Sensitivity Index ◽  
Baroreflex Control ◽  
Non Invasive ◽  
Sympathetic Modulation ◽  
Controlled Breathing

The goal of this work is to assess and to compare the autonomic nervous system (SNA) response in Parkinson’s disease (EP) patients and healthy subjects in order to evaluate the possible dysautonomia presence. Electrocardiogram and photoplethysmography signals were acquired during the following maneuvers: rest, orthostatic change (Post-CP), controlled breathing (RC) and hyperventilation (Hip.). The signal processing was carried out by means of linear and no linear indices of heart rate variability (VFC), indices of pulse transit time (PTT) and baroreflex sensitivity (– index). Parkinson disease patients showed an attenuated sympathetic modulation mainly during Post-CP and the cardiovagal response resulted blunted during RC. Approximate entropy was significantly decreased in healthy subjects with respect to EP subjects during RC. In addition, the index – resulted in lower values in EP patients with respect to healthy subjects during the complete protocol, this result suggests that the baroreflex control in EP patients is blunted. However, is necessary to increase the number of subjects with the objective of determining levels of dysautonomia. The protocol designed to evaluate the dysautonomia presence in mexicans with EP through non invasive signals provides information about the SNA behavior.

scholarly journals Assessment of the Dysautonomia Presence in Parkinson disease through Cardiovascular Signal Analysis

2017 ◽  
Author(s):  
◽  
S. Alvarado-Jalomo
Keyword(s):  
Parkinson Disease ◽  
Signal Analysis ◽  
Healthy Subjects ◽  
Pulse Transit Time ◽  
Approximate Entropy ◽  
Sensitivity Index ◽  
Baroreflex Control ◽  
Non Invasive ◽  
Sympathetic Modulation ◽  
Controlled Breathing

The goal of this work is to assess and to compare the autonomic nervous system (SNA) response in Parkinson’s disease (EP) patients and healthy subjects in order to evaluate the possible dysautonomia presence. Electrocardiogram and photoplethysmography signals were acquired during the following maneuvers: rest, orthostatic change (Post-CP), controlled breathing (RC) and hyperventilation (Hip.). The signal processing was carried out by means of linear and no linear indices of heart rate variability (VFC), indices of pulse transit time (PTT) and baroreflex sensitivity (– index). Parkinson disease patients showed an attenuated sympathetic modulation mainly during Post-CP and the cardiovagal response resulted blunted during RC. Approximate entropy was significantly decreased in healthy subjects with respect to EP subjects during RC. In addition, the index – resulted in lower values in EP patients with respect to healthy subjects during the complete protocol, this result suggests that the baroreflex control in EP patients is blunted. However, is necessary to increase the number of subjects with the objective of determining levels of dysautonomia. The protocol designed to evaluate the dysautonomia presence in mexicans with EP through non invasive signals provides information about the SNA behavior.

Reflex Responses in Upper Limb Muscles to Cutaneous Stimuli

1993 ◽  
Vol 20 (04) ◽  
pp. 271-278 ◽  
Author(s):  
R. Chen
Keyword(s):  
Stimulus Intensity ◽  
Upper Limb ◽  
Healthy Subjects ◽  
Voluntary Contraction ◽  
Cutaneous Reflexes ◽  
Focal Lesions ◽  
Normal Ranges ◽  
Conduction Velocities ◽  
Limb Muscles ◽  
Biphasic Responses

ABSTRACT:Cutaneous reflexes in the upper limb were elicited by stimulating digital nerves and recorded by averaging rectified EMG from proximal and distal upper limb muscles during voluntary contraction. Distal muscles often showed a triphasic response: an inhibition with onset about 50 ms (Il) followed by a facilitation with onset about 60 ms (E2) followed by another inhibition with onset about 80 ms (12). Proximal muscles generally showed biphasic responses beginning with facilitation or inhibition with onset at about 40 ms. Normal ranges for the amplitude of these components were established from recordings on 22 arms of 11 healthy subjects. An attempt was made to determine the alterent fibers responsible for the various components by varying the stimulus intensity, by causing ischemic block of larger fibers and by estimating the afferent conduction velocities. The central pathways mediating these reflexes were examined by estimating central delays and by studying patients with focal lesions

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