scholarly journals Miniaturized wireless gastric pacing via inductive power transfer with non-invasive monitoring using cutaneous Electrogastrography

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Andrew Perley ◽  
Mehrdad Roustaei ◽  
Marcelo Aguilar-Rivera ◽  
David C. Kunkel ◽  
Tzung K. Hsiai ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Slow Wave ◽  
Spectral Power ◽  
Wave Direction ◽  
Electrode Arrays ◽  
Statistical Parameters ◽  
Invasive Approach ◽  
Non Invasive ◽  
Increased Strength

Abstract Background Gastroparesis is a debilitating disease that is often refractory to pharmacotherapy. While gastric electrical stimulation has been studied as a potential treatment, current devices are limited by surgical complications and an incomplete understanding of the mechanism by which electrical stimulation affects physiology. Methods A leadless inductively-powered pacemaker was implanted on the gastric serosa in an anesthetized pig. Wireless pacing was performed at transmitter-to-receiver distances up to 20 mm, frequency of 0.05 Hz, and pulse width of 400 ms. Electrogastrogram (EGG) recordings using cutaneous and serosal electrode arrays were analyzed to compute spectral and spatial statistical parameters associated with the slow wave. Results Our data demonstrated evident change in EGG signal patterns upon initiation of pacing. A buffer period was noted before a pattern of entrainment appeared with consistent and low variability in slow wave direction. A spectral power increase in the EGG frequency band during entrainment also suggested that pacing increased strength of the slow wave. Conclusion Our preliminary in vivo study using wireless pacing and concurrent EGG recording established the foundations for a minimally invasive approach to understand and optimize the effect of pacing on gastric motor activity as a means to treat conditions of gastric dysmotility.

A single-step multi-level supramolecular system for cancer sonotheranostics

2019 ◽  
Vol 4 (1) ◽  
pp. 190-195 ◽  
Author(s):  
Huirong Lin ◽  
Shuang Li ◽  
Junqing Wang ◽  
Chengchao Chu ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Self Assembly ◽  
Single Step ◽  
Supramolecular System ◽  
Therapeutic Effects ◽  
Invasive Approach ◽  
Non Invasive ◽  
Ionic Crosslinking ◽  
Critical Issues ◽  
Multi Level

A multi-level supramolecular system produced by single-step Fe3+-mediated ionic crosslinking self-assembly can overcome the critical issues of current sonodynamic therapy (SDT) and address the need to monitor therapeutic effects in vivo with a non-invasive approach.

scholarly journals Optogenetic activation of muscle contraction in vivo

2020 ◽  
Author(s):  
Elahe Ganji ◽  
C. Savio Chan ◽  
Christopher W. Ward ◽  
Megan L. Killian
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Muscle Contraction ◽  
Fluorescent Imaging ◽  
Triceps Surae ◽  
Light Activation ◽  
Non Invasive ◽  
Optogenetic Stimulation ◽  
Stimulation Of

AbstractOptogenetics is an emerging alternative to traditional electrical stimulation to initiate action potentials in activatable cells both ex vivo and in vivo. Optogenetics has been commonly used in mammalian neurons and more recently, it has been adapted for activation of cardiomyocytes and skeletal muscle. Therefore, the aim of this study was to evaluate the stimulation feasibility and sustain isometric muscle contraction and limit decay for an extended period of time (1s), using non-invasive transdermal light activation of skeletal muscle (triceps surae) in vivo. We used inducible Cre recombination to target expression of Channelrhodopsin-2 (ChR2(H134R)-EYFP) in skeletal muscle (Acta1-Cre) in mice. Fluorescent imaging confirmed that ChR2 expression is localized in skeletal muscle and does not have specific expression in sciatic nerve branch, therefore, allowing for non-nerve mediated optical stimulation of skeletal muscle. We induced muscle contraction using transdermal exposure to blue light and selected 10Hz stimulation after controlled optimization experiments to sustain prolonged muscle contraction. Increasing the stimulation frequency from 10Hz to 40Hz increased the muscle contraction decay during prolonged 1s stimulation, highlighting frequency dependency and importance of membrane repolarization for effective light activation. Finally, we showed that optimized pulsed optogenetic stimulation of 10 Hz resulted in comparable ankle torque and contractile functionality to that of electrical stimulation. Our results demonstrate the feasibility and repeatability of non-invasive optogenetic stimulation of muscle in vivo and highlight optogenetic stimulation as a powerful tool for non-invasive in vivo direct activation of skeletal muscle.

scholarly journals IMAGING TECHNIQUES FOR THE EVALUATION OF GRAPES IN WITHERING FOR AMARONE WINE PRODUCTION

2018 ◽  
Author(s):  
Barbara Cisterna ◽  
Federico Boschi ◽  
Anna Cleta Croce ◽  
Rachele Podda ◽  
Serena Zanzoni ◽  
...  
Keyword(s):  
Optical Properties ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Wine Production ◽  
Invasive Approach ◽  
Non Invasive ◽  
Innovative Materials ◽  
Amarone Wine

Optical Imaging (OI) is an emerging field developed in recent years which can be a very versatile, fast and non-invasive approach for the acquisition of images of  small (few centimetres) sized samples, such as layers of cells (in vitro), small animals (in vivo), animal organs (ex vivo) and innovative materials. OI was primarily developed for biomedical applications to study the progression of some pathologies and to assess the efficacy of new pharmaceutical compounds. Here we applied the OI technique to a completely new field: the study of food optical properties. In this case we exploited the optical properties of endogenous molecules, which are generally considered responsible of a background noise affecting the investigation. Here we used this sort of “noise”, named autofluorescence, to obtain information on the drying of Corvinone grapes employed for Amarone wine production. OI can provide interesting information and, inserted in a multimodal approach, it may be a real support to other techniques in the description of a biological phenomenon.

scholarly journals In vivo measurement of pH and CO2 levels in the uterus of sows through the estrous cycle and after insemination

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Octavio López-Albors ◽  
Pedro José Llamas-López ◽  
Joaquín Ángel Ortuño ◽  
Rafael Latorre ◽  
Francisco Alberto García-Vázquez
Keyword(s):  
Estrous Cycle ◽  
Assisted Reproductive Technologies ◽  
Reproductive Technologies ◽  
Invasive Approach ◽  
Vitro Fertilization ◽  
Non Invasive ◽  
Physiological Values

AbstractThe pH–CO2–HCO3− system is a ubiquitous biological regulator with important functional implications for reproduction. Knowledge of the physiological values of its components is relevant for reproductive biology and the optimization of Assisted Reproductive Technologies (ARTs). However, in situ measurements of these parameters in the uterus are scarce or null. This study describes a non-invasive method for in situ time-lapse recording of pH and CO2 within the uterus of non-anesthetized sows. Animals were at three different reproductive conditions, estrous with no insemination and two hours after insemination, and diestrous. From pH and CO2 data, HCO3− concentration was estimated. The non-invasive approach to the porcine uterus with novel optical probes allowed the obtaining of in situ physiological values of pH, CO2, and HCO3−. Variable oscillatory patterns of pH, CO2 and HCO3− were found independently of the estrous condition. Insemination did not immediately change the levels of uterine pH, CO2 (%) and HCO3− concentration, but all the values were affected by the estrous cycle decreasing significantly at diestrous condition. This study contributes to a better understanding of the in vivo regulation of the pH-CO2-HCO3− system in the uterus and may help to optimize the protocols of sperm treatment for in vitro fertilization.

scholarly journals Foregut organ progenitors and their niche display distinct viscoelastic properties in vivo during early morphogenesis stages

2021 ◽  
Author(s):  
Aliaksandr Dzementsei ◽  
Younes F. A Barooji ◽  
Elke A Ober ◽  
Lene Broeng Oddershede
Keyword(s):  
Optical Tweezers ◽  
Material Properties ◽  
Biological Function ◽  
Living Matter ◽  
Internal Organs ◽  
Neighboring Cell ◽  
Invasive Approach ◽  
Non Invasive

Material properties of living matter play an important role for biological function and development. Yet, quantification of material properties of internal organs in vivo, without causing physiological damage, remains challenging. Here, we present a non-invasive approach based on modified optical tweezers for quantifying sub-cellular material properties deep inside living zebrafish. Material properties of cells within the gut region of living zebrafish are quantified as deep as 150 μ into the biological tissue. The measurements demonstrate differential mechanical properties of the developing foregut organs progenitors: Gut progenitors are more elastic than any of the neighboring cell populations at the time when the developing organs undergo substantial displacements during morphogenesis. The higher elasticity of gut progenitors correlates with an increased cellular concentration of microtubules. The results infer a role of material properties during morphogenesis and the approach paves the way for quantitative material investigations in vivo of embryos, explants, or organoids.

scholarly journals In vivo measurement of pH, CO2 and HCO3- levels in the uterus of non-anesthetized sows through the estrous cycle and after insemination

2020 ◽  
Author(s):  
Octavio López Albors ◽  
Pedro José Llamas-López ◽  
Joaquín Ortuño ◽  
Rafael Latorre ◽  
Francisco Alberto García Vázquez
Keyword(s):  
Estrous Cycle ◽  
Time Lapse ◽  
Invasive Approach ◽  
In Vivo Measurement ◽  
Non Invasive ◽  
Reproductive Techniques ◽  
Physiological Values

Abstract Background The pH-CO2-HCO3− system is a ubiquitous biological regulator with important functional implications for reproduction. Knowledge of the physiological values of its components is relevant for reproductive biology and the optimization of Assistant Reproductive Techniques (ARTs). In vivo pH of the oviduct and uterus has been estimated by direct in situ measurements in a few species. However, regarding the levels of CO2 and HCO3−, information is very scarce and, when available, it comes from fluid samples instead of in vivo estimations. This study describes a non-invasive method to measure pH and % of CO2 in the uterus of sows with cutting-edge technology and no medication. Sows were at three different reproductive conditions, estrous with no insemination E(-)AI and after insemination E(+)AI, and diestrous (non-estrous, NE). From pH and CO2 data, HCO3− concentration was estimated. Results The designed methodology allowed for in situ time-lapse recording of pH and % of CO2 within the uterus of non-anesthetized sows. Variable oscillatory patterns of pH, CO2 and HCO3− were found independently of the estrous condition. Insemination did not changed the levels of uterine pH, % of CO2 and HCO3− concentration, -E(-)AI = E(+)AI-, but all the values were affected by the estrous cycle in a way that decreased significantly at diestrous condition - E(-)AI and E(+)AI > NE-. Conclusions A non-invasive approach to the porcine uterus with novel optical probes allowed the obtaining of in situ physiological values of pH, CO2, and HCO3− at different reproductive conditions. While the short-time presence of sperm in the uterus did not change the physiological milieu, the whole pH-CO2-HCO3− system was affected by the estrous cycle. This study contributes to a better understanding of the in vivo regulation of the pH/CO2/HCO3− system in the uterus and may help to optimize the protocols of sperm treatment for in vitro fertilization.

scholarly journals Electrophysiological investigation of intact retina with soft printed organic neural interface

2021 ◽  
Author(s):  
Ieva Vebraite-Adereth ◽  
Moshe David-Pur ◽  
David Rand ◽  
Eric Glowacki ◽  
Yael Hanein
Keyword(s):  
Electrical Stimulation ◽  
Ex Vivo ◽  
Electrode Array ◽  
Carbon Electrodes ◽  
Natural Image ◽  
Neural Firing ◽  
Electrode Arrays ◽  
Electrical Recording ◽  
Research Activities

Abstract Objective. Understanding how the retina converts a natural image or an electrically stimulated one into neural firing patterns is the focus of on-going research activities. Ex vivo, the retina can be readily investigated using multi electrode arrays. However, multi electrode array recording and stimulation from an intact retina (in the eye) has been so far insufficient. Approach. In the present study, we report new soft carbon electrode arrays suitable for recording and stimulating neural activity in an intact retina. Screen-printing of carbon ink on 20 µm polyurethane (PU) film was used to realize electrode arrays with electrodes as small as 40 µm in diameter. Passivation was achieved with a holey membrane, realized using laser drilling in a thin (50 µm) PU film. Plasma polymerized EDOT was used to coat the electrode array to improve the electrode specific capacitance. Chick retinas, embryonic stage day 13, both ex-planted and intact inside an enucleated eye, were used. Main results. A novel fabrication process based on printed carbon electrodes was developed and yielded high capacitance electrodes on a soft substrate. Ex vivo electrical recording of retina activity with carbon electrodes is demonstrated. With the addition of organic photo-capacitors, simultaneous photo-electrical stimulation and electrical recording was achieved. Finally, electrical activity recordings from an intact chick retina (inside enucleated eyes) were demonstrated. Both photosensitive retinal ganglion cell responses and spontaneous retina waves were recorded and their features analyzed. Significance. Results of this study demonstrated soft electrode arrays with unique properties, suitable for simultaneous recording and photo-electrical stimulation of the retina at high fidelity. This novel electrode technology opens up new frontiers in the study of neural tissue in vivo.

P4490Safety and feasibility of non invasive transthoracic pulsed cavitational ultrasound therapy (PCUT) on a swine aortic valve model

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
E Messas ◽  
M Remond ◽  
G Goudot ◽  
R Penot ◽  
D Ladarre ◽  
...  
Keyword(s):  
Side Effects ◽  
Aortic Valve ◽  
High Power ◽  
Ultrasound Therapy ◽  
Antithrombotic Treatment ◽  
Invasive Approach ◽  
Non Invasive ◽  
Valve Model

Abstract Background Aortic valve stenosis is associated with age and comorbidities, which require exploring less invasive therapeutic approach to improve patient outcome. We previously demonstrated in vitro and in vivo that pulsed cavitational ultrasound therapy (PCUT) can improve calcified bioprosthesis stenosis by softening leaflets remotely. To apply this technique noninvasively we aim to test PCUT transthoracicalyin a swine model targeting aortic valve. Because calcified aortic valve model doesn't exist, we tested this technique on a normal valve. Objective Primary objective was to estimate the feasibility and safety of PCUT. Secondary objectiveswere to evaluate occurrence, severity and evolution of cardiovascular side effects during therapy and within follow-up period (30±5 days) with and without double antithrombotic treatment. Methods All the experiments were performed on normal aortic valves (n=19) of swine. The system was composed of a high-power multi-element transducer with electronic steering and 2D echocardiographic probe embedded in the center. Swine were divided in three groups: one with PCUT and no anti thrombotic treatment (n=10), a second with PCUT and one-month treatment of aspirin and clopidogrel (n=5) and third group sham (n=4). All groups were followed up after 30 days. Results The primary feasibility endpoint was successful in 100% of tests performed (n=16). A maximal amplitude of 70 MPa and −19 MPa respectively for positive and negative peak pressure was found at the focus point. Survival at 30 days was 100% and no life-threatening arrhythmia was recorded and no sustained ventricular arrhythmia (SVT >30 s) was noticed. For the secondary safety objectives,we recorded acutely, at the time of procedure, NSVT in 7 pigs which corresponded to a cumulated duration of 2.1 out of the 485.3 min of the total US delivery (0.4% of time). Mean cycle of NSVT was slow 428.9 ms in average (139.6 bpm). The interruption or decrease of power of US delivery allowed immediate cessation of cardiac arrhythmia in all cases. There was no evidence of damage to the valve and no observation of impairment of valvular function by echocardiography. Only one animal showed side effects (RV dilatation) and the RV returned to normal after cessation of the therapy with no sequelae at follow up. At follow up no significant findings biology disturbance or valve thrombosis was observed (creatinine, CK MB, hemoglobin, hematocrit, haptoglobin or red blood cell numbers). Antithrombotic treatment didn't demonstrate any advantage at follow up. Conclusion We demonstrated in vivo feasibility and safety of transthoracic PCUT targeting aortic valve without any serious adverse event and no significant histopathology damage. We hope that this first-time transthoracic delivery of very focused ultrasound at high power will pave the way to new non invasive approach of valve softening in case of human aortic valve calcified stenosis.

scholarly journals One-shot tagging during wake and cueing during sleep with spatiotemporal patterns of transcranial electrical stimulation can boost long-term metamemory of individual episodes in humans

2019 ◽  
Author(s):  
Praveen K. Pilly ◽  
Steven W. Skorheim ◽  
Ryan J. Hubbard ◽  
Nicholas A. Ketz ◽  
Shane M. Roach ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Real World ◽  
Spectral Power ◽  
Memory Performance ◽  
Nrem Sleep ◽  
Transcranial Electrical Stimulation ◽  
Sensory Cues ◽  
Non Invasive ◽  
Episodic Memories ◽  
The One

AbstractTargeted memory reactivation (TMR) during slow-wave oscillations (SWOs) in non-rapid eye movement (NREM) sleep has been demonstrated with sensory cues to achieve about 5-12% improvement in post-nap memory performance on simple laboratory tasks. But prior work has neither addressed the one-shot aspect of episodic memory acquisition, nor dealt with the presence of interference from ambient environmental cues in real-world settings for the sensory cues. Moreover, TMR with sensory cues may not be scalable to the multitude of experiences over one’s lifetime. We designed a novel non-invasive paradigm that tags one-shot experiences of minute-long naturalistic episodes within immersive virtual reality (VR) with unique spatiotemporal amplitude-modulated patterns (STAMPs) of transcranial electrical stimulation (tES) and cues them during SWOs. In particular, we demonstrate that these STAMPs can be re-applied as brief pulses to temporally coincide with UP states of SWOs (0.4167 – 1 s) on two consecutive nights to achieve about 20% improvement in the metamemory of targeted episodes at 48 hours after the one-shot viewing, compared to the control episodes. Post-sleep metamemory of the targeted episodes was driven by an interaction between their pre-sleep metamemory and the number of STAMP applications for those episodes during sleep. Overnight metamemory improvements were mediated by spectral power increases from 6.18 to 6.7 s following the offset of STAMPs in the slow-spindle band (9-12 Hz) for left temporal areas in the scalp electroencephalography (EEG) during sleep. These results prescribe an optimal strategy to leverage STAMPs for boosting metamemory and suggest that real-world episodic memories can be modulated in a targeted manner even with coarser, non-invasive spatiotemporal stimulation.

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