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1.
Artigo em Inglês | MEDLINE | ID: mdl-33806377

RESUMO

BACKGROUND: Online education became mandatory for many students during the Coronavirus disease 2019 (COVID-19) pandemic and blurred the distinction between settings where processes of stress and restoration used to take place. The lockdown also likely changed perceptions of the indoor acoustic environment (i.e., soundscape) and raised its importance. In the present study, we seek to understand how indoor soundscape related to university students' self-rated health in Bulgaria around the time that the country was under a state of emergency declaration caused by the COVID-19 pandemic. METHODS: Between 17 May and 10 June 2020, we conducted a cross-sectional online survey among 323 students (median age 21 years; 31% male) from two universities in the city of Plovdiv, Bulgaria. Self-rated health (SRH) was measured with a single-item. Participants were asked how frequently they heard different types of sounds while at home and how pleasant they considered each of those sounds to be. Restorative quality of the home (the "being away" dimension of the Perceived Restorativeness Scale) was measured with a single-item. A priori confounders and effect modifiers included sociodemographics, house-related characteristics, general sensitivity to environmental influences, and mental health. Our analysis strategy involved sequential exploratory factor analysis (EFA), multivariate linear and ordinal regressions, effect modification tests, and structural equation modeling (SEM). RESULTS: EFA supported grouping perceived sounds into three distinct factors-mechanical, human, and nature sounds. Regression analyses revealed that greater exposure to mechanical sounds was consistently associated with worse SRH, whereas no significant associations were found for human and nature sounds. In SEM, exposure to mechanical sounds related to lower restorative quality of the home, and then to poorer SRH, whereas nature sounds correlated with higher restorative quality, and in turn with better SRH. CONCLUSIONS: These findings suggest a role of positive indoor soundscape and restorative quality for promoting self-rated health in times of social distancing.


Assuntos
Quarentena , Acústica , Adulto , Bulgária , Cidades , Controle de Doenças Transmissíveis , Estudos Transversais , Feminino , Humanos , Masculino , Pandemias , Estudantes , Universidades , Adulto Jovem
2.
Zootaxa ; 4908(1): zootaxa.4908.1.1, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33756630

RESUMO

Three new species of the Asian genus Mata Distant, 1906 (Hemiptera: Cicadidae) viz. Mata lenonia sp.nov.; Mata ruffordii sp.nov. and Mata meghalayana sp.nov. are described from Indian state of Meghalaya. Keys and taxonomic descriptions of these species are provided with detailed accounts of their natural history and acoustics.


Assuntos
Hemípteros , Acústica , Animais , Índia , Répteis
3.
Zootaxa ; 4948(2): zootaxa.4948.2.8, 2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33757030

RESUMO

The southernmost record of the neotropical genus Xenicola is documented. An apparently tiny population of X. dohrni, a species described long ago from southern Brazil without other published records, lives at the shore of the Río de la Plata, 1000 km further south. Perhaps it has been established there by means of floating vegetation. The acoustic communication of this species is also very interesting: The male produces with its minuscule tegmina brief signals with a carrier frequency range between 80 and 100 kHz. The female responds, and the male modifies its song when engaged in a duet. It modifies it further, when the female responds from very close. The paper includes a review of the records of Xenicola species on biodiversity observation platforms.


Assuntos
Ortópteros , Acústica , Animais , Argentina , Comunicação , Feminino , Masculino
4.
Ying Yong Sheng Tai Xue Bao ; 32(3): 1119-1128, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33754580

RESUMO

Sound is an important way of communication among organisms. The monitoring and analy-sis of biological sound is an emerging method to describe and evaluate biodiversity. This method does not invade or damage the natural environment. By recording ecological information through sound, it can effectively reflect the relevant characteristics of biodiversity. The sound-based exploration of biodiversity change has broadened the interdisciplinary approach and has been increasingly applied to ecological research. Here, we expounded on the main theoretical foundations and research methods of using acoustic monitoring to assess biodiversity. We introduced related research fields from two aspects, namely the biodiversity of vocal animals and the temporal and spatial diversity of soundscape. We presented examples of the application of acoustic monitoring to assess the impact of land-use change, climate change and urbanization on biodiversity. Finally, we proposed the future direction of development, and hope that the potential of sound surveys could be further explored to provide an effective reference for biodiversity monitoring and assessment.


Assuntos
Acústica , Biodiversidade , Animais , Conservação dos Recursos Naturais , Urbanização
5.
Sensors (Basel) ; 21(5)2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33668776

RESUMO

Red palm weevil (RPW) is a detrimental pest, which has wiped out many palm tree farms worldwide. Early detection of RPW is challenging, especially in large-scale farms. Here, we introduce the combination of machine learning and fiber optic distributed acoustic sensing (DAS) techniques as a solution for the early detection of RPW in vast farms. Within the laboratory environment, we reconstructed the conditions of a farm that includes an infested tree with ∼12 day old weevil larvae and another healthy tree. Meanwhile, some noise sources are introduced, including wind and bird sounds around the trees. After training with the experimental time- and frequency-domain data provided by the fiber optic DAS system, a fully-connected artificial neural network (ANN) and a convolutional neural network (CNN) can efficiently recognize the healthy and infested trees with high classification accuracy values (99.9% by ANN with temporal data and 99.7% by CNN with spectral data, in reasonable noise conditions). This work paves the way for deploying the high efficiency and cost-effective fiber optic DAS to monitor RPW in open-air and large-scale farms containing thousands of trees.


Assuntos
Tecnologia de Fibra Óptica , Aprendizado de Máquina , Gorgulhos , Acústica , Animais , Larva
6.
Sensors (Basel) ; 21(4)2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33670096

RESUMO

Acoustic event detection and analysis has been widely developed in the last few years for its valuable application in monitoring elderly or dependant people, for surveillance issues, for multimedia retrieval, or even for biodiversity metrics in natural environments. For this purpose, sound source identification is a key issue to give a smart technological answer to all the aforementioned applications. Diverse types of sounds and variate environments, together with a number of challenges in terms of application, widen the choice of artificial intelligence algorithm proposal. This paper presents a comparative study on combining several feature extraction algorithms (Mel Frequency Cepstrum Coefficients (MFCC), Gammatone Cepstrum Coefficients (GTCC), and Narrow Band (NB)) with a group of machine learning algorithms (k-Nearest Neighbor (kNN), Neural Networks (NN), and Gaussian Mixture Model (GMM)), tested over five different acoustic environments. This work has the goal of detailing a best practice method and evaluate the reliability of this general-purpose algorithm for all the classes. Preliminary results show that most of the combinations of feature extraction and machine learning present acceptable results in most of the described corpora. Nevertheless, there is a combination that outperforms the others: the use of GTCC together with kNN, and its results are further analyzed for all the corpora.


Assuntos
Acústica , Algoritmos , Inteligência Artificial , Aprendizado de Máquina , Humanos , Redes Neurais de Computação , Distribuição Normal , Reprodutibilidade dos Testes
7.
Sensors (Basel) ; 21(4)2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33671202

RESUMO

Respiratory activity is an important vital sign of life that can indicate health status. Diseases such as bronchitis, emphysema, pneumonia and coronavirus cause respiratory disorders that affect the respiratory systems. Typically, the diagnosis of these diseases is facilitated by pulmonary auscultation using a stethoscope. We present a new attempt to develop a lightweight, comprehensive wearable sensor system to monitor respiration using a multi-sensor approach. We employed new wearable sensor technology using a novel integration of acoustics and biopotentials to monitor various vital signs on two volunteers. In this study, a new method to monitor lung function, such as respiration rate and tidal volume, is presented using the multi-sensor approach. Using the new sensor, we obtained lung sound, electrocardiogram (ECG), and electromyogram (EMG) measurements at the external intercostal muscles (EIM) and at the diaphragm during breathing cycles with 500 mL, 625 mL, 750 mL, 875 mL, and 1000 mL tidal volume. The tidal volumes were controlled with a spirometer. The duration of each breathing cycle was 8 s and was timed using a metronome. For each of the different tidal volumes, the EMG data was plotted against time and the area under the curve (AUC) was calculated. The AUC calculated from EMG data obtained at the diaphragm and EIM represent the expansion of the diaphragm and EIM respectively. AUC obtained from EMG data collected at the diaphragm had a lower variance between samples per tidal volume compared to those monitored at the EIM. Using cubic spline interpolation, we built a model for computing tidal volume from EMG data at the diaphragm. Our findings show that the new sensor can be used to measure respiration rate and variations thereof and holds potential to estimate tidal lung volume from EMG measurements obtained from the diaphragm.


Assuntos
Diafragma , Respiração , Volume de Ventilação Pulmonar , Dispositivos Eletrônicos Vestíveis , Acústica , Eletrocardiografia , Humanos , Sons Respiratórios
8.
J Acoust Soc Am ; 149(3): 1796, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33765803

RESUMO

While studies of urban acoustics are typically restricted to the audio range, anthropogenic activity also generates infrasound (<20 Hz, roughly at the lower end of the range of human hearing). Shutdowns related to the COVID-19 pandemic unintentionally created ideal conditions for the study of urban infrasound and low frequency audio (20-500 Hz), as closures reduced human-generated ambient noise, while natural signals remained relatively unaffected. An array of infrasound sensors deployed in Las Vegas, NV, provides data for a case study in monitoring human activity during the pandemic through urban acoustics. The array records a sharp decline in acoustic power following the temporary shutdown of businesses deemed nonessential by the state of Nevada. This decline varies spatially across the array, with stations close to McCarran International Airport generally recording the greatest declines in acoustic power. Further, declines in acoustic power fluctuate with the time of day. As only signals associated with anthropogenic activity are expected to decline, this gives a rough indication of periodicities in urban acoustics throughout Las Vegas. The results of this study reflect the city's response to the pandemic and suggest spatiotemporal trends in acoustics outside of shutdowns.


Assuntos
Acústica/instrumentação , Monitoramento Ambiental , Atividades Humanas , Cidades , Controle de Doenças Transmissíveis , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Humanos , Nevada , Ruído , Pandemias
9.
Food Chem ; 351: 129287, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-33640765

RESUMO

Broadband acoustic resonance dissolution spectroscopy (BARDS) is a novel method that can be used for the analysis of food-based powders, which are mainly characterized by their composition and particle morphology. This study aimed to evaluate BARDS for the compositional analysis of food powders. The changes in the BARDS spectra due to the changes in composition and particle morphology of fifteen salt mixtures (constituting of NaCl, KCl, and MgCl2) in five particle size ranges were comprehensively studied. Moreover, different regression methods were utilized to estimate each mixture component content. The results revealed that the average time-frequency spectra of each mixture in a certain particle size class were highly distinct and allowed discrimination from others. The unique spectra of each salt mixture originated from the specific dissolution rate and degassing effect of each constitutive compound. Finally, the accurate prediction of each mixture component content confirmed the consistency and efficiency of the method.


Assuntos
Análise de Alimentos/métodos , Pós/química , Sais/análise , Acústica , Análise dos Mínimos Quadrados , Tamanho da Partícula , Análise de Componente Principal , Solubilidade , Espectrofotometria
10.
Waste Manag ; 124: 1-7, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33592320

RESUMO

Massive quantities of fly ash are produced worldwide from thermal power plants, posing a serious environmental threat due to their storage and disposal problems. In this study, for the first time, fly ash is converted into an advanced and novel aerogel through a green and eco-friendly process. The developed aerogel has a low density of 0.10-0.19 g cm-3, a high porosity of up to 90%, a low thermal conductivity of 0.042-0.050 W/mK, and a good sound absorption coefficient (noise reduction coefficient [NRC] value of 0.20-0.30). It also shows a high compressive Young's modulus of up to 150 kPa. Therefore, the newly developed fly ash aerogel is a potential material for thermal and acoustic insulation applications, along with lightweight composites in automotive and aerospace applications.


Assuntos
Cinza de Carvão , Centrais Elétricas , Acústica , Porosidade , Condutividade Térmica
11.
Sensors (Basel) ; 21(4)2021 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-33572208

RESUMO

The overlaying rib cage is a major hindrance in treating liver tumors with high intensity focused ultrasound (HIFU). The problems caused are overheating of the ribs due to its high ultrasonic absorption capability and degradation of the ultrasound intensity distribution in the target plane. In this work, a correction method based on binarized apodization and geometric ray tracing approach was employed to avoid heating the ribs. A detailed calculation of the intensity distribution in the focus plane was undertaken to quantify and avoid the effect on HIFU beam generated by a 1-MHz 256-element random phased array after the ultrasonic beam passes through the rib cage. Focusing through the ribs was simulated for 18 different idealized ribs-array configurations and 10 anatomically correct ribs-array configurations, to show the effect of width of the ribs, intercostal spacing and the relative position of ribs and array on the quality of focus, and to identify the positions that are more effective for HIFU applications in the presence of ribs. Acoustic simulations showed that for a single focus without beam steering and for the same total acoustic power, the peak intensity at the target varies from a minimum of 211 W/cm2 to a maximum of 293 W/cm2 for a nominal acoustic input power of 15 W, whereas the side lobe level varies from 0.07 Ipeak to 0.28 Ipeak and the separation between the main lobe and side lobes varies from 2.5 mm to 6.3 mm, depending on the relative positioning of the array and ribs and the beam alignment. An increase in the side lobe level was observed by increasing the distance between the array and the ribs. The parameters of focus splitting and the deterioration of focus quality caused by the ultrasonic propagation through the ribs were quantified in various possible different clinical scenarios. In addition to idealized rib topology, anatomical realistic ribs were used to determine the focus quality of the HIFU beam when the beam is steered both in axial and transverse directions and when the transducer is positioned at different depths from the rib cage.


Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade , Costelas , Acústica , Humanos , Transdutores , Ultrassonografia
12.
Behav Processes ; 185: 104345, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33545319

RESUMO

Although the contact calls of birds have been studied for their acoustic properties, limited research has investigated their repetitive nature. The rate of contact calls could be related to movement, with recruiting birds signalling their location, or it could help maintaining spacing between group mates, or give information about the environment where both signaller and receiver are located. If maintaining spacing, higher call rates would be expected in denser vegetation; alternatively, if birds gain information about predation risk from the cessation of contact calling, then open areas might elicit higher call rate. We studied how contact call rate in groups of Swinhoe's White-eyes (Zosterops simplex) was influenced by vegetation, collecting a total of 800 recordings. After statistically controlling for group size, the vegetation effect was weak and inconsistent. However, flying individuals produced a distinct flight call consisting of repeated notes similar to contact calls, and group-level contact call rate increased before flights, particularly when birds flew into the group. Therefore, we believe that contact call rate indicates information about individual or group movements, and could function as a continuous signal about the need for recruitment. We encourage further studies investigating how habitat, risk and audience influence contact call rate.


Assuntos
Passeriformes , Vocalização Animal , Acústica , Animais , Ecossistema , Humanos
13.
Behav Processes ; 185: 104357, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33592283

RESUMO

Synchronous behaviours occur when two or more animals display the same behaviour at the same time. However, the mechanisms underlying this synchrony are not well understood. In this study, we carried out an experiment to determine whether or not Bottlenose dolphins use acoustic cues when performing a known synchronised exercise. For this, we recorded three dolphins while they performed requested aerial jumps both individually or synchronously in pairs, with a hydrophone array and a 360° underwater video camera allowing the identification of the subject emitting vocalisations. Results indicated that in pairs, dolphins synchronised their jumps 100% of the time. Whether they jumped alone or in pairs, they produced click trains before and after 92% of jumps. No whistles or burst-pulsed sounds were emitted by the animals during the exercise. The acoustic localisation process allowed the successful identification of the vocalising subject in 19.8% of all cases (N = 141). Our study showed that in all (n = 28) but one successful localisations, the click trains were produced by the same individual. It is worth noting that this individual was the oldest female of the group. This paper provides evidence suggesting that during synchronous behaviours, dolphins use acoustic cues, and more particularly click trains, to coordinate their movements; possibly by eavesdropping on the clicks or echoes produced by one individual leading the navigation.


Assuntos
Golfinho Nariz-de-Garrafa , Ecolocação , Acústica , Animais , Feminino , Humanos , Som , Espectrografia do Som , Vocalização Animal
14.
J Vis Exp ; (167)2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33554963

RESUMO

Efficient intracellular delivery of biomolecules is required for a broad range of biomedical research and cell-based therapeutic applications. Ultrasound-mediated sonoporation is an emerging technique for rapid intracellular delivery of biomolecules. Sonoporation occurs when cavitation of gas-filled microbubbles forms transient pores in nearby cell membranes, which enables rapid uptake of biomolecules from the surrounding fluid. Current techniques for in vitro sonoporation of cells in suspension are limited by slow throughput, variability in the ultrasound exposure conditions for each cell, and high cost. To address these limitations, a low-cost acoustofluidic device has been developed which integrates an ultrasound transducer in a PDMS-based fluidic device to induce consistent sonoporation of cells as they flow through the channels in combination with ultrasound contrast agents. The device is fabricated using standard photolithography techniques to produce the PDMS-based fluidic chip. An ultrasound piezo disk transducer is attached to the device and driven by a microcontroller. The assembly can be integrated inside a 3D-printed case for added protection. Cells and microbubbles are pushed through the device using a syringe pump or a peristaltic pump connected to PVC tubing. Enhanced delivery of biomolecules to human T cells and lung cancer cells is demonstrated with this acoustofluidic system. Compared to bulk treatment approaches, this acoustofluidic system increases throughput and reduces variability, which can improve cell processing methods for biomedical research applications and manufacturing of cell-based therapeutics.


Assuntos
Acústica/instrumentação , Células/metabolismo , Fluoresceína/metabolismo , Trealose/metabolismo , Células A549 , Células Cultivadas , Meios de Contraste/química , Humanos , Microbolhas , Linfócitos T/citologia , Ultrassom
15.
Science ; 371(6530): 731-735, 2021 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-33574212

RESUMO

Fin whale calls are among the strongest animal vocalizations that are detectable over great distances in the oceans. We analyze fin whale songs recorded at ocean-bottom seismometers in the northeast Pacific Ocean and show that in addition to the waterborne signal, the song recordings also contain signals reflected and refracted from crustal interfaces beneath the stations. With these data, we constrain the thickness and seismic velocity of the oceanic sediment and basaltic basement and the P-wave velocity of the gabbroic lower crust beneath and around the ocean bottom seismic stations. The abundant and globally available fin whale calls may be used to complement seismic studies in situations where conventional air-gun surveys are not available.


Assuntos
Baleia Comum/fisiologia , Sedimentos Geológicos , Vocalização Animal , Acústica , Animais , Fenômenos Geológicos , Oceano Pacífico
16.
Nat Commun ; 12(1): 968, 2021 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-33579910

RESUMO

How can deceptive communication signals exist in an evolutionarily stable signalling system? To resolve this age-old honest signalling paradox, researchers must first establish whether deception benefits deceivers. However, while vocal exaggeration is widespread in the animal kingdom and assumably adaptive, its effectiveness in biasing listeners has not been established. Here, we show that human listeners can detect deceptive vocal signals produced by vocalisers who volitionally shift their voice frequencies to exaggerate or attenuate their perceived size. Listeners can also judge the relative heights of cheaters, whose deceptive signals retain reliable acoustic cues to interindividual height. Importantly, although vocal deception biases listeners' absolute height judgments, listeners recalibrate their height assessments for vocalisers they correctly and concurrently identify as deceptive, particularly men judging men. Thus, while size exaggeration can fool listeners, benefiting the deceiver, its detection can reduce bias and mitigate costs for listeners, underscoring an unremitting arms-race between signallers and receivers in animal communication.


Assuntos
Tamanho Corporal , Decepção , Voz/fisiologia , Acústica , Adolescente , Adulto , Comunicação Animal , Animais , Percepção Auditiva , Evolução Biológica , Sinais (Psicologia) , Feminino , Humanos , Julgamento , Masculino , Pessoa de Meia-Idade , Adulto Jovem
17.
Mar Pollut Bull ; 165: 112144, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33611230

RESUMO

From the mid-June to mid-July 2020, there was a massive bloom of Creseise acicula nearby the waters of Daya Bay Nuclear Power Plant Base (DNPP base). In order to find out the spatiotemporal dynamic characteristics of C. acicula and the main factors related to its outbreak and extinction, acoustic surveys and in-situ observations were performed. The results showed that the average abundance of C. acicula at the in-situ observation site fluctuated with the tidal rhythm. Furthermore, a horizontal migration pattern during ebb tide and a vertical subsidence trend of C. acicula was found. The outbreak of C. acicula bloom nearby the waters of DNPP base was the result of the joint action of water temperature, salinity and food availability etc. The extinction of C. acicula was mainly related to the adhesion of Licmophora, predation pressure from phytoplanktivorous fishes (such as Sardinella lemuru and Dussumieria elopsoides) and human intervention.


Assuntos
Baías , Centrais Nucleares , Acústica , China , Surtos de Doenças , Monitoramento Ambiental , Humanos
18.
Mar Pollut Bull ; 165: 112171, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33621906

RESUMO

Acoustic Deterrent Devices (ADDs) are used worldwide to deter pinnipeds from predating fish-aquaculture facilities. Desk-based noise-propagation modelling of six commercial ADD models, and a 'fictional' ADD was performed, the latter involving alternating source level, frequency, duty cycle, noise-exposure duration, and number of ADDs active simultaneously. Potential auditory impacts on marine mammals were explored using the Southall et al. (2019) criteria. Depending on operational characteristics, real ADDs were predicted to cause Temporary Threshold Shift (TTS) to Very High Frequency (VHF) cetaceans at ranges of 4-31 km, and a single fictional device operating at the highest outputs tested was predicted to cause TTS to VHF cetaceans at up to 32 km. Cumulative effects of 23 real fish-farm ADDs produced noise across large swathes of the Inner-Hebrides. The single variable causing greatest reduction in potential impact to marine mammals from fictional ADDs was SL.


Assuntos
Cetáceos , Ruído , Estimulação Acústica , Acústica , Animais , Aquicultura , Escócia
19.
Nat Commun ; 12(1): 1118, 2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33602914

RESUMO

Modern biomedical research and preclinical pharmaceutical development rely heavily on the phenotyping of small vertebrate models for various diseases prior to human testing. In this article, we demonstrate an acoustofluidic rotational tweezing platform that enables contactless, high-speed, 3D multispectral imaging and digital reconstruction of zebrafish larvae for quantitative phenotypic analysis. The acoustic-induced polarized vortex streaming achieves contactless and rapid (~1 s/rotation) rotation of zebrafish larvae. This enables multispectral imaging of the zebrafish body and internal organs from different viewing perspectives. Moreover, we develop a 3D reconstruction pipeline that yields accurate 3D models based on the multi-view images for quantitative evaluation of basic morphological characteristics and advanced combinations of metrics. With its contactless nature and advantages in speed and automation, our acoustofluidic rotational tweezing system has the potential to be a valuable asset in numerous fields, especially for developmental biology, small molecule screening in biochemistry, and pre-clinical drug development in pharmacology.


Assuntos
Acústica , Rotação , Peixe-Zebra/anatomia & histologia , Animais , Etanol/farmacologia , Imageamento Tridimensional , Larva/anatomia & histologia , Larva/efeitos dos fármacos , Fígado/anatomia & histologia , Fígado/efeitos dos fármacos , Tamanho do Órgão/efeitos dos fármacos , Fenótipo , Transdutores
20.
Sensors (Basel) ; 21(2)2021 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-33435307

RESUMO

The aim of this work was to extend conventional medical implants by the possibility of communication between them. For reasons of data security and transmitting distances, this communication should be realized using ultrasound, which is generated and detected by capacitive micromachined ultrasonic transducers (CMUTs). These offer the advantage of an inherent high bandwidth and a high integration capability. To protect the surrounding tissue, it has to be encapsulated. In contrast to previous results of other research groups dealing with the encapsulation of CMUTs, the goal here is to integrate the CMUT into the housing of a medical implant. In this work, CMUTs were designed and fabricated for a center frequency of 2 MHz in water and experimentally tested on their characteristics for operation behind layers of Polyether ether ketone (PEEK) and titanium, two typical materials for the housings of medical implants. It could be shown that with silicone as a coupling layer it is possible to operate a CMUT behind the housing of an implant. Although it changes the characteristics of the CMUT, the setup is found to be well suited for communication between two transducers over a distance of at least 8 cm.


Assuntos
Transdutores , Ultrassom , Acústica , Comunicação , Desenho de Equipamento , Ultrassonografia
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