A non-invasive, low frequency resonant method to detect bubbles in liquid media

2021 ◽  
Vol 179 ◽  
pp. 108044
Author(s):  
Manuel Rivera ◽  
Edwin López ◽  
Silvina Cancelos
Keyword(s):  
Low Frequency ◽  
Liquid Media ◽  
Non Invasive ◽  
Resonant Method

HEART RATE VARIABILITY RELATED TO N95 RESPIRATOR USE IN INTERNS DURING COVID-19 PANDEMIC

2021 ◽  
pp. 69-70
Author(s):  
Pakanati Sujana ◽  
Venkata Mahesh Gandhavalla ◽  
K. Prabhakara Rao
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Low Frequency ◽  
Protective Equipment ◽  
Short Term ◽  
Non Invasive ◽  
Critical Components ◽  
The Individual ◽  
N95 Respirators ◽  
Respiratory Droplets

Introduction: COVID19 is caused by SARS-CoV-2 which is primarily transmitted through respiratory droplets and contact routes. WHO recommended the use of personal protective equipment (PPE) for prevention and N95 respirators are critical components of PPE. Breathing through N95 respirator will impart stress in the individual and that can be assessed by heart rate variability (HRV). HRV measures the variation in time between each heartbeat controlled by autonomic nervous system (ANS), which is a non invasive reliable index to identify the ANS imbalances. Aims And Objectives: This study is aimed at assessing the HRV of Interns working in COVID19 wards using N95 respirators. Methodology: This study included 100 interns in whom short term HRV was recorded using the standard protocol. Lead II of ECG was recorded using AD instruments (ADI) 8channel polygraph and HRV was analysed using Labchart 8pro software. The recordings were taken before and 1hour after wearing N95 respirator. Results: Overall HRV (SDRR) was found to decrease signicantly after wearing N95 respirator for 1hr (p=0.000). Similarly, indices representing the parasympathetic component ( RMSSD and HF ) were also found to decrease signicantly with the use of N95 respirator. Low frequency (LF) power and LF/HF ratio increased signicantly with N95 respirator use (p=0.000). Conclusion: We conclude that using N95 respirator increased sympathetic activity reecting decreased HRV in our subjects Hence we recommend that it is better to change the duty pattern for interns.

scholarly journals Natural Sensations Evoked in Distal Extremities Using Surface Electrical Stimulation

2018 ◽  
Vol 12 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Julia P. Slopsema ◽  
John M. Boss ◽  
Lane A. Heyboer ◽  
Carson M. Tobias ◽  
Brooke P. Draggoo ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Low Frequency ◽  
Pulse Amplitude ◽  
Neural Stimulation ◽  
Phantom Limb ◽  
Neural Function ◽  
Medical Treatments ◽  
Non Invasive ◽  
Knee Strength ◽  
Better Than

Background: Electrical stimulation is increasingly relevant in a variety of medical treatments. In this study, surface electrical stimulation was evaluated as a method to non-invasively target a neural function, specifically natural sensation in the distal limbs. Method: Electrodes were placed over the median and ulnar nerves at the elbow and the common peroneal and lateral sural cutaneous nerves at the knee. Strength-duration curves for sensation were compared between nerves. The location, modality, and intensity of each sensation were also analyzed. In an effort to evoke natural sensations, several patterned waveforms were evaluated. Results: Distal sensation was obtained in all but one of the 48 nerves tested in able-bodied subjects and in the two nerves from subjects with an amputation. Increasing the pulse amplitude of the stimulus caused an increase in the area and magnitude of the sensation in a majority of subjects. A low frequency waveform evoked a tapping or tapping-like sensation in 29 out of the 31 able-bodied subjects and a sensation that could be considered natural in two subjects with an amputation. This waveform performed better than other patterned waveforms that had proven effective during implanted extra-neural stimulation. Conclusion: Surface electrical stimulation has the potential to be a powerful, non-invasive tool for activation of the nervous system. These results suggest that a tapping sensation in the distal extremity can be evoked in most able-bodied individuals and that targeting the nerve trunk from the surface is a valid method to evoke sensation in the phantom limb of individuals with an amputation for short term applications.

Reversal of Renal Insufficiency in an Aging Cat: A 5-year Multi-Crossover Case Study

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Robert Dennis ◽  
John Dennis
Keyword(s):  
Palliative Care ◽  
Renal Insufficiency ◽  
Treatment Options ◽  
Low Frequency ◽  
Standard Of Care ◽  
Omega 3 ◽  
Current Standard ◽  
Invasive Treatment ◽  
Non Invasive ◽  
Electro Magnetic

Renal failure is a leading cause of suffering and death in domestic cats, with approximately 1 in 3 cats affected.  Current standard-of-care treatment usually involves palliative care, diets restricted in protein and phosphorus, plenty of fluids, and sometimes vitamin D and Omega-3.  But even with early detection, which is difficult, treatment options are limited and often are not very effective.  Dietary restrictions and palliative care are often the best that can be offered, but the creatinine levels tend to inexorably creep upward toward eventual kidney failure and death.  We report the effectiveness of the use of a low-frequency, low-intensity, non-invasive treatment using Pulsed Electro-Magnetic Fields, specifically tuned to inductively generate micro-electric currents in deep tissues (ICES®-PEMF).  This report chronicles the return to normal and then reversion to renal insufficiency in a single cat, when ICES®-PEMF was applied, then withheld, then applied again, over three cycles of application and non-application, over a 5-year period. A return to normal creatinine levels, with a subsequent return to renal insufficiency as indicated by loss of control of creatinine, correlated precisely with the application and non-application of ICES®-PEMF.  The pattern observed during each cycle was as follows:  when applied 2 to 3 times weekly for 20-60 minutes each treatment, creatinine levels declined to normal range within 2-3 months.  During periods when treatment was discontinued, creatinine levels began to climb to high levels again.  We suggest the further study and potential use of ICES®-PEMF as an effective, inexpensive, safe, non-invasive treatment for feline kidney disease.

Non-invasive determination of the irradiation dose in fingers using low-frequency EPR

2004 ◽  
Vol 49 (13) ◽  
pp. 2891-2898 ◽  
Author(s):  
M Zdravkova ◽  
N Crokart ◽  
F Trompier ◽  
N Beghein ◽  
B Gallez ◽  
...  
Keyword(s):  
Irradiation Dose ◽  
Low Frequency ◽  
Non Invasive

Synergism of Aspirin and Heparin with a Low-Frequency Non-Invasive Ultrasound System for Augmentation of In-Vitro Clot Lysis

2003 ◽  
Vol 15 (3) ◽  
pp. 165-169 ◽  
Author(s):  
Shaul Atar ◽  
Yoram Neuman ◽  
Takashi Miyamoto ◽  
Ming Chen ◽  
Yochai Birnbaum ◽  
...  
Keyword(s):  
Low Frequency ◽  
Clot Lysis ◽  
Non Invasive ◽  
Ultrasound System

scholarly journals A Novel Broadband Forcecardiography Sensor for Simultaneous Monitoring of Respiration, Infrasonic Cardiac Vibrations and Heart Sounds

2021 ◽  
Vol 12 ◽  
Author(s):  
Emilio Andreozzi ◽  
Gaetano D. Gargiulo ◽  
Daniele Esposito ◽  
Paolo Bifulco
Keyword(s):  
Low Frequency ◽  
Piezoelectric Sensor ◽  
Heart Sounds ◽  
Invasive Technique ◽  
Electronic Stethoscope ◽  
Ecg Signals ◽  
Non Invasive ◽  
Wide Range ◽  
Potential Applications ◽  
Electrocardiogram Ecg

The precordial mechanical vibrations generated by cardiac contractions have a rich frequency spectrum. While the lowest frequencies can be palpated, the higher infrasonic frequencies are usually captured by the seismocardiogram (SCG) signal and the audible ones correspond to heart sounds. Forcecardiography (FCG) is a non-invasive technique that measures these vibrations via force sensing resistors (FSR). This study presents a new piezoelectric sensor able to record all heart vibrations simultaneously, as well as a respiration signal. The new sensor was compared to the FSR-based one to assess its suitability for FCG. An electrocardiogram (ECG) lead and a signal from an electro-resistive respiration band (ERB) were synchronously acquired as references on six healthy volunteers (4 males, 2 females) at rest. The raw signals from the piezoelectric and the FSR-based sensors turned out to be very similar. The raw signals were divided into four components: Forcerespirogram (FRG), Low-Frequency FCG (LF-FCG), High-Frequency FCG (HF-FCG) and heart sounds (HS-FCG). A beat-by-beat comparison of FCG and ECG signals was carried out by means of regression, correlation and Bland–Altman analyses, and similarly for respiration signals (FRG and ERB). The results showed that the infrasonic FCG components are strongly related to the cardiac cycle (R2 > 0.999, null bias and Limits of Agreement (LoA) of ± 4.9 ms for HF-FCG; R2 > 0.99, null bias and LoA of ± 26.9 ms for LF-FCG) and the FRG inter-breath intervals are consistent with ERB ones (R2 > 0.99, non-significant bias and LoA of ± 0.46 s). Furthermore, the piezoelectric sensor was tested against an accelerometer and an electronic stethoscope: synchronous acquisitions were performed to quantify the similarity between the signals. ECG-triggered ensemble averages (synchronized with R-peaks) of HF-FCG and SCG showed a correlation greater than 0.81, while those of HS-FCG and PCG scored a correlation greater than 0.85. The piezoelectric sensor demonstrated superior performances as compared to the FSR, providing more accurate, beat-by-beat measurements. This is the first time that a single piezoelectric sensor demonstrated the ability to simultaneously capture respiration, heart sounds, an SCG-like signal (i.e., HF-FCG) and the LF-FCG signal, which may provide information on ventricular emptying and filling events. According to these preliminary results the novel piezoelectric FCG sensor stands as a promising device for accurate, unobtrusive, long-term monitoring of cardiorespiratory functions and paves the way for a wide range of potential applications, both in the research and clinical fields. However, these results should be confirmed by further analyses on a larger cohort of subjects, possibly including also pathological patients.

scholarly journals Efficacy and acceptability of non-invasive brain stimulation for the treatment of adult unipolar and bipolar depression: A systematic review and meta-analysis of randomised sham-controlled trials

2018 ◽  
Author(s):  
Julian Mutz ◽  
Daniel R. Edgcumbe ◽  
Andre R. Brunoni ◽  
Cynthia H.Y. Fu
Keyword(s):  
Brain Stimulation ◽  
High Frequency ◽  
Bipolar Depression ◽  
Meta Analysis ◽  
Low Frequency ◽  
Controlled Trials ◽  
Female Response ◽  
Non Invasive ◽  
Left Dlpfc ◽  
Severity Scores

AbstractWe examined the efficacy and acceptability of non-invasive brain stimulation in adult unipolar and bipolar depression. Randomised sham-controlled trials of transcranial direct current stimulation (tDCS), transcranial magnetic stimulation (TMS) and theta-burst stimulation (TBS), without co-initiation of another treatment, were included. We analysed response, remission and all-cause discontinuation rates, and depression severity scores. Fifty-four studies were included (N = 2,959, mean age = 44.94 years, 61.98% female). Response rates demonstrated efficacy of high-frequency rTMS over the left DLPFC (OR = 3.94, 95% CI [2.52; 6.15]), right-sided low-frequency rTMS (OR = 7.44, 95% CI [2.06; 26.83]) bilateral rTMS (OR = 3.68, 95% CI [1.66; 8.13]), deep TMS (OR = 1.69, 95% CI [1.003; 2.85]), intermittent TBS (OR = 4.70, 95% CI [1.14; 19.38]) and tDCS (OR = 4.32, 95% CI [2.02; 9.29]); but not for continuous TBS, bilateral TBS or synchronised TMS. There were no differences in all-cause discontinuation rates. The strongest evidence was for high-frequency rTMS over the left DLPFC. Intermittent TBS provides an advance in terms of reduced treatment duration. tDCS is a potential treatment for non-resistant depression.

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