MEMS as In-Vivo Sensors and Actuators: Challenges and Opportunities

2000 ◽  
Author(s):  
Roop L. Mahajan

Abstract MicroElectroMechanical Systems (MEMS) is a developing field which promises to open up new fields of applications in such diverse areas as medical systems, wireless communications and space explorations. They are particularly attractive to the medical community for their consistent reproducibility, high levels of accuracy and reliability, and exceptional stability. This is achieved through silicon micro-fabrication techniques conducive to high volume manufacturing at a low cost.

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2822
Author(s):  
Rocco Crescenzi ◽  
Giuseppe Vincenzo Castellito ◽  
Simone Quaranta ◽  
Marco Balucani

Gyroscopes are one of the next killer applications for the MEMS (Micro-Electro-Mechanical-Systems) sensors industry. Many mature applications have already been developed and produced in limited volumes for the automotive, consumer, industrial, medical, and military markets. Plenty of high-volume applications, over 100 million per year, have been calling for low-cost gyroscopes. Bulk silicon is a promising candidate for low-cost gyroscopes due to its large scale availability and maturity of its manufacturing industry. Nevertheless, it is not suitable for a real monolithic IC integration and requires a dedicated packaging. New designs are supposed to eliminate the need for magnets and metal case package, and allow for a real monolithic MEMS-IC (Integrated Circuit) electronic system. In addition, a drastic cost reduction could be achieved by utilizing off-the-shelf plastic packaging with lead frames for the final assembly. The present paper puts forward the design of a novel tri-axial gyroscope based on rotating comb-drives acting as both capacitive sensors and actuators. The comb-drives are comprised of a single monolithic moving component (rotor) and fixed parts (stators). The former is made out of different concentrated masses connected by curved silicon beams in order to decouple the motion signals. The sensor was devised to be fabricated through the PolyMUMPs® process and it is intended for working in air in order to semplify the MEMS-IC monolithic integration.


Nutrients ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 2169 ◽  
Author(s):  
Vollono Laura ◽  
Falconi Mattia ◽  
Gaziano Roberta ◽  
Iacovelli Federico ◽  
Dika Emi ◽  
...  

Curcumin is a compound isolated from turmeric, a plant known for its medicinal use. Recently, there is a growing interest in the medical community in identifying novel, low-cost, safe molecules that may be used in the treatment of inflammatory and neoplastic diseases. An increasing amount of evidence suggests that curcumin may represent an effective agent in the treatment of several skin conditions. We examined the most relevant in vitro and in vivo studies published to date regarding the use of curcumin in inflammatory, neoplastic, and infectious skin diseases, providing information on its bioavailability and safety profile. Moreover, we performed a computational analysis about curcumin’s interaction towards the major enzymatic targets identified in the literature. Our results suggest that curcumin may represent a low-cost, well-tolerated, effective agent in the treatment of skin diseases. However, bypass of limitations of its in vivo use (low oral bioavailability, metabolism) is essential in order to conduct larger clinical trials that could confirm these observations. The possible use of curcumin in combination with traditional drugs and the formulations of novel delivery systems represent a very promising field for future applicative research.


2019 ◽  
Vol 65 (3) ◽  
pp. 274
Author(s):  
F. S. Chiwo ◽  
And F.J. Gonzalez

Non-invasive medical diagnosis has become popular due to the possibility of detecting illnesses in vivo and in real time this technique, often referred to as "optical biopsy", comprises several optical techniques such as thermography, diffuse reflectance spectroscopy, optical coherence tomography and Raman spectroscopy among others. Particularly Raman spectroscopy is an optical technique based on the inelastic scattering of light that can detect disease markers, this technique has been successfully used to detect several types of diseases, however the high price of a Raman spectrometer makes it difficult for the medical community to adopt its use as a common diagnostic procedure. In this work a Raman spectroscopy system was designed and fabricated from low-cost readily available components. The system was characterized and the Raman spectra obtained was compared to commercial systems. Results show that it is possible to fabricate a custom Raman system with the desired optical configuration for non-invasive optical diagnosis at low costs and portable size.


Author(s):  
J. Mallon ◽  
J. Bryzek ◽  
J. Ramsey ◽  
G. Tomblin ◽  
F. Pourahmadi

Author(s):  
R.J. Mount ◽  
R.V. Harrison

The sensory end organ of the ear, the organ of Corti, rests on a thin basilar membrane which lies between the bone of the central modiolus and the bony wall of the cochlea. In vivo, the organ of Corti is protected by the bony wall which totally surrounds it. In order to examine the sensory epithelium by scanning electron microscopy it is necessary to dissect away the protective bone and expose the region of interest (Fig. 1). This leaves the fragile organ of Corti susceptible to physical damage during subsequent handling. In our laboratory cochlear specimens, after dissection, are routinely prepared by the O-T- O-T-O technique, critical point dried and then lightly sputter coated with gold. This processing involves considerable specimen handling including several hours on a rotator during which the organ of Corti is at risk of being physically damaged. The following procedure uses low cost, readily available materials to hold the specimen during processing ,preventing physical damage while allowing an unhindered exchange of fluids.Following fixation, the cochlea is dehydrated to 70% ethanol then dissected under ethanol to prevent air drying. The holder is prepared by punching a hole in the flexible snap cap of a Wheaton vial with a paper hole punch. A small amount of two component epoxy putty is well mixed then pushed through the hole in the cap. The putty on the inner cap is formed into a “cup” to hold the specimen (Fig. 2), the putty on the outside is smoothed into a “button” to give good attachment even when the cap is flexed during handling (Fig. 3). The cap is submerged in the 70% ethanol, the bone at the base of the cochlea is seated into the cup and the sides of the cup squeezed with forceps to grip it (Fig.4). Several types of epoxy putty have been tried, most are either soluble in ethanol to some degree or do not set in ethanol. The only putty we find successful is “DUROtm MASTERMENDtm Epoxy Extra Strength Ribbon” (Loctite Corp., Cleveland, Ohio), this is a blue and yellow ribbon which is kneaded to form a green putty, it is available at many hardware stores.


Author(s):  
Pavani C H

Hyperlipidemia is the immediate results of the excessive fat intake in food. This results in the elevated levels of cholesterol and triglycerides in the blood. This leads to heart conditions like CAD, hypertension, congestive heart failure as risk factors which can be lethal. There are many drugs to treat and control the lipids levels in the body. These drugs are either designed to prevent LDL accumulation and VLDL synthesis. Some drugs also lower the elevated levels of saturated lipids in the body. But many drugs are known to cause side effects and adverse effects; therefore, alternatives to the drugs are the subjects for current investigations. Herbs and medicinal plants are used as treatment sources for many years. They have been used in the Indian medical systems like Ayurveda, Siddha etc. As the application of herbs in the treatment is growing, there is an urgent need for the establishment of Pharmacological reasoning and standardization of the activity of the medicinal plants. Chloris paraguaiensis Steud. is Poyaceae member that is called locally as Uppugaddi. Traditionally it is used to treat Rheumatism, Diabetes, fever and diarrhoea. The chemical constituents are known to have anti-oxidant properties and most of the anti-oxidants have anti-hyperlipidemic activity too. Since the plant has abundant flavonoid and phenol content, the current research focusses on the investigation of the anti-hyperlipidemic activity of the plant Chloris extracts. Extracts of Chloris at 200mg/kg showed a comparably similar anti hyperlipidemia activity to that of the standard drug. The extracts showed a dose based increase in the activity at 100 and 200mg/kg body weight.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guanhua Xun ◽  
Stephan Thomas Lane ◽  
Vassily Andrew Petrov ◽  
Brandon Elliott Pepa ◽  
Huimin Zhao

AbstractThe need for rapid, accurate, and scalable testing systems for COVID-19 diagnosis is clear and urgent. Here, we report a rapid Scalable and Portable Testing (SPOT) system consisting of a rapid, highly sensitive, and accurate assay and a battery-powered portable device for COVID-19 diagnosis. The SPOT assay comprises a one-pot reverse transcriptase-loop-mediated isothermal amplification (RT-LAMP) followed by PfAgo-based target sequence detection. It is capable of detecting the N gene and E gene in a multiplexed reaction with the limit of detection (LoD) of 0.44 copies/μL and 1.09 copies/μL, respectively, in SARS-CoV-2 virus-spiked saliva samples within 30 min. Moreover, the SPOT system is used to analyze 104 clinical saliva samples and identified 28/30 (93.3% sensitivity) SARS-CoV-2 positive samples (100% sensitivity if LoD is considered) and 73/74 (98.6% specificity) SARS-CoV-2 negative samples. This combination of speed, accuracy, sensitivity, and portability will enable high-volume, low-cost access to areas in need of urgent COVID-19 testing capabilities.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S586-S587
Author(s):  
Caroline G Coleman ◽  
Timothy T Daugherty ◽  
Yooree G Chung ◽  
Angel X Xiao ◽  
Amy C Sherman ◽  
...  

Abstract Background The medical community has used Twitter as a learning tool during the COVID-19 pandemic to digest the high volume of rapidly evolving literature. However, Twitter contains educational content of varying quality and accuracy. To address this issue, we created and disseminated visual abstracts of COVID-19 literature on Twitter to educate health professionals. Methods Fellows and faculty members from multiple institutions collaborated with Emory University medical students to create visual abstracts of published COVID-19 literature (Figure 1). ID fellows and faculty identified and summarized 10-15 high-impact COVID-19 articles each week. Medical students created visual abstracts for each article, which fellows or faculty reviewed for accuracy. We disseminated them on Twitter (@JenniferSpicer4, 4,373 followers) and our website (Figure 2). We measured engagement with tweets using Twitter Analytics. Figure 1: COVID-19 Visual Abstract Example Figure 2: Website hosting COVID-19 weekly literature summaries and visual abstracts (https://med.emory.edu/departments/medicine/divisions/infectious-diseases/covid19-roundup/) Results Since March 2020, we have created, reviewed, and disseminated 139 graphics with 116 student authors and 33 fellow/faculty reviewers across three academic institutions (Table 1). Topics included public health & prevention, virology & basic science, epidemiology, transmission & infection control, clinical syndrome, diagnostics, therapeutics, vaccinology, and ethics & policy. Tweets had a median of 9,300 impressions (interquartile range [IQR] 5,432-13,233) with 766 engagements (IQR 432-1,288) and an engagement rate of 8.6% (IQR 7.1%-10.0%) (Table 2). Each tweet had a median of 25 retweets (IQR 17-38) and 55 likes (IQR 34-81). A few tweets had significantly higher metrics; maximum values were 84,257 impressions, 9,758 engagements, 19.0% engagement rate, 239 retweets, and 381 likes. In addition to disseminating graphics on Twitter, we received requests to use them as teaching aids from multiple health professionals worldwide, and the visual abstracts have been translated into Spanish and disseminated on Twitter and Instagram via @MEdSinFrontera. Table 1: Descriptive Statistics of COVID-19 Visual Series Table 2: Twitter Metrics for COVID-19 Visual Series (as of 6/10/2020) Conclusion Engagement rates with our visual abstracts were high, demonstrating the power of Twitter. ID educators can use visual abstracts to summarize and disseminate accurate information to a large audience on social media, which is especially important in the setting of an emerging infection. Disclosures All Authors: No reported disclosures


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Woo Seok Kim ◽  
Sungcheol Hong ◽  
Milenka Gamero ◽  
Vivekanand Jeevakumar ◽  
Clay M. Smithhart ◽  
...  

AbstractThe vagus nerve supports diverse autonomic functions and behaviors important for health and survival. To understand how specific components of the vagus contribute to behaviors and long-term physiological effects, it is critical to modulate their activity with anatomical specificity in awake, freely behaving conditions using reliable methods. Here, we introduce an organ-specific scalable, multimodal, wireless optoelectronic device for precise and chronic optogenetic manipulations in vivo. When combined with an advanced, coil-antenna system and a multiplexing strategy for powering 8 individual homecages using a single RF transmitter, the proposed wireless telemetry enables low cost, high-throughput, and precise functional mapping of peripheral neural circuits, including long-term behavioral and physiological measurements. Deployment of these technologies reveals an unexpected role for stomach, non-stretch vagal sensory fibers in suppressing appetite and demonstrates the durability of the miniature wireless device inside harsh gastric conditions.


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