Andrew Wiens– Andrew.wiens@gatech.edu Andrew Carek Omar T. Inan Georgia Institute of Technology Electrical and Computer Engineering
Popular version of poster 3aBA12 “Sternal vibrations reflect hemodynamic changes during immersion: underwater ballistocardiography.” Presented Wednesday, May 19, 2015, 11:30 am, Kings 2 169th ASA Meeting, Pittsburgh
In 2014, one out of every four internet users in the United States wore a wearable device such as a smart watch or fitness monitor. As more people incorporate wearable devices into their daily lives, better techniques are needed to enable real, accurate health measurements.
Currently, wearable devices can make simple measurements of various metrics such as heart rate, general activity level, and sleep cycles. Heart rate is usually measured from small changes in the intensity of the light reflected from light-emitting diodes, or LEDs, that are placed on the surface of the skin. In medical parlance, this technique is known as photoplethysmography. Activity level and sleep cycles, on the other hand, are usually measured from relatively large motions of the human body using small sensors called accelerometers.
Recently, researchers have improved a technique called ballistocardiography, or BCG, that uses one or more mechanical sensors, such as an accelerometer worn on the body, to measure very small vibrations originating from the beating heart. Using this technique, changes in the heart’s time intervals and the volume of pumped blood, or cardiac output, have been measured. These are capabilities that other types of noninvasive wearable sensors currently cannot provide from a single point on the body, such as the wrist or chest wall. This method could become crucial for blood pressure measurement via pulse-transit time, a promising noninvasive, cuffless method that measures blood pressure using the time interval from when blood is ejected from the heart to when it arrives at the end of a main artery.
Figure. 1. The underwater BCG recorded at rest.
The goal of the preliminary study reported here was to demonstrate similar measurements recorded during immersion in an aquatic environment. Three volunteers wore a waterproof accelerometer on the chest while immersed in water up to the neck. An example of these vibrations recorded at rest appear in Figure 1. The subjects performed a physiologic exercise called a Valsalva maneuver to temporarily modulate the cardiovascular system. Two water temperatures and three body postures were tested as well to discover differences in the signal morphology that could arise under different conditions.
Measurements of the vibrations that occurred during single heart beats appear in Figure 2. Investigation of the recorded signals shows that the amplitude of the signal increased during immersion compared to standing in air. In addition, the median frequency of the vibrations also decreased substantially.
Figure. 2. Single heart beats of the underwater BCG from three subjects in three different environments and body postures.
One remaining question is, why did these changes occur? It is known that a significant volume of blood shifts toward the thorax, or chest, during immersion, leading to changes in the mechanical loading of the heart. It is possible that this phenomenon wholly or partially explains the changes in the vibrations observed during immersion. Finally, how can we make accurate physiologic measurements from the underwater wearable BCG? These are open questions, and further investigation is needed.
Irene van Kamp, (irene.van.kamp@rivm.nl) Elise van Kempen, Hanneke Kruize, Wim Swart National Institute for Public Health and the Environment Netherlands Pobox 1 Postvak 10 3720 BA BILTHOVEN Netherlands Phone +31629555704
Popular version of paper in session 2aNSa, “Soundscapes and human restoration in green urban areas” Presented Tuesday morning, May 19, 2015, 9:35 AM, Commonwealth 1 169th ASA Meeting, Pittsburgh
Worldwide there is a revival of interest in the positive effect of landscapes, green and blue space, open countryside on human well-being, quality of life, and health especially for urban dwellers. However, most studies do not account for the influence of the acoustic environment in these spaces both in a negative and positive way. One of the few studies in the field, which was done by Kang and Zhang (2010) identified relaxation, communication, dynamics and spatiality as the key factors in the evaluation of urban soundscapes. Remarkable is their finding that the general public and urban designers clearly value public space very different. The latter had a much stronger preference for natural sounds and green spaces than the lay-observers. Do we as professionals tend to exaggerate the value of green and what characteristics of urban green space are key to health, wellbeing and restoration? And what role does the acoustic quality and accompanying social quality play in this? In his famous studies on livable streets Donald Appleyard concluded that in heavy traffic streets the number of contacts with friends, acquaintances and the amount of social interaction in general was much lower. Also people in busy streets had a tendency to describe their environment as being much smaller than their counterparts in quiet streets did. In other words, the acoustic quality affects not only our wellbeing and behavior but also our sense of territory, social cohesion and social interactions. And this concerns all of us: citing Appleyard “nearly everyone in the world lives in a street”.
There is evidence that green or natural areas/wilderness/ or urban environments with natural elements as well as areas with a high sound quality can intrinsically provide restoration through spending time there. Also merely the knowledge that such quiet and green places are available seems to work as a buffer effect between stress and health (Van Kamp, Klaeboe, Brown, and Lercher, 2015 : in Jian Kang and Brigitte Schulte-Fortkamp (Eds) in press).
Recently a European study was performed into the health effect of access and use of green area in four European cities of varying size in Spain, the UK, Netherlands and Lithuania)
At the four study centers people were selected from neighborhoods with varying levels of socioeconomic status and green and blue space. By means of a structured interview information was gathered about availability, use and importance of green space in the immediate environment as well as the sound quality of favorite green areas used for physical activity, social encounters and relaxation. Data are also available about perceived mental/physical health and medication use. This allowed for analyzing the association between indicators of green, restoration and health, while accounting for perceived soundscapes in more detail. In general there are four mechanisms assumed that lead from green and tranquil space to health: via physical activity, via social interactions and relaxation and finally via reduced levels of traffic related air and noise pollution. This paper will explore the role of sound in the process which leads from access and use of green space to restoration and health. So far this aspect has been understudied. There is some indication that certain areas contribute to restoration more than others. Most studies address the restorative effects of natural recreational areas outside the urban environment. The question is whether natural areas within, and in the vicinity of, urban areas contribute to psycho-physiological and mental restoration after stress as well. Does restoration require the absence of urban noise?
Example of an acoustic environment – a New York City Park – with potential restorative outcomes (Photo: A.L. Brown)
Chucri A. Kardous – ckardous@cdc.gov Peter B. Shaw – pbs3@cdc.gov National Institute for Occupational Safety and Health Centers for Disease Control and Prevention 1090 Tusculum Avenue Cincinnati, Ohio 45226
Popular version of paper 2pNSb, “Use of smartphone sound measurement apps for occupational noise assessments” Presented Tuesday May 19, 2015, 3:55 PM, Ballroom 1 169th ASA Meeting, Pittsburgh, PA See also: Evaluation of smartphone sound measurement applications
Our world is getting louder. Excessive noise is a public health problem and can cause a range of health issues; noise exposure can induce hearing impairment, cardiovascular disease, hypertension, sleep disturbance, and a host of other psychological and social behavior problems. The World Health Organization (WHO) estimates that there are 360 million people with disabling hearing loss. Occupational hearing loss is the most common work-related illness in the United States; the National Institute for Occupational Safety and Health (NIOSH) estimates that approximately 22 million U.S. workers are exposed to hazardous noise.
Smartphones users are expected to hit the 2 billion mark in 2015. The ubiquity of smartphones and the sophistication of current sound measurement applications (apps) present a great opportunity to revolutionize the way we look at noise and its effects on our hearing and overall health. Through the use of crowdsourcing techniques, people around the world may be able to collect and share noise exposure data using their smartphones. Scientists and public health professionals could rely on such shared data to promote better hearing health and prevention efforts. In addition, the ability to acquire and display real-time noise exposure data raises people’s awareness about their work (and off-work) environment and allows them to make informed decisions about hazards to their hearing and overall well-being. For instance, the European Environment Agency (EEA) developed the Noise Watch app that allows citizens around the world to make noise measurements whether at their work or during their leisure activities, and upload that data to a database in real time and using the smartphone GPS capabilities to construct a map of the noisiest places and sources in their environment.
However, not all smartphone sound measurements apps are equal. Some are basic and not very accurate while some are much more sophisticated. NIOSH researchers conducted a study of 192 smartphone sound measurement apps to examine the accuracy and functionality of such apps. We conducted the study in our acoustics laboratory and compared the results to a professional sound level meter. Only 10 apps met our selection criteria, and of those only 4 met our accuracy requirements of being within ±2 decibels (dB) of type 1 professional sound level meter. Apps developed for the iOS platform were more advanced, functionality and performance wise, than Android apps. You can read more about our original study on our NIOSH Science Blog at: http://blogs.cdc.gov/niosh-science-blog/2014/04/09/sound-apps/ or download our JASA paper at: http://scitation.aip.org/content/asa/journal/jasa/135/4/10.1121/1.4865269.
Figure 1. Testing the SoundMeter app on the iPhone 5 and iPhone 4S against a ½” Larson-Davis 2559 random incidence reference microphone Today, we will present on our additional efforts to examine the accuracy of smartphone sound measurement apps using external microphones that can be calibrated. There are several external microphones available mostly for the consumer market, and although they vary greatly in price, they all possess similar acoustical specifications and have performed similarly in our laboratory tests. Preliminary results showed even greater agreement with professional sound measurement instruments (± 1 dB) over our testing range.
Figure 2. Calibrating the SPLnFFT app with MicW i436 external microphone using the Larson-Davis CAL250 acoustic calibrator (114 dB SPL @ 250Hz)
Figure 3. Laboratory testing of 4 iOS devices using MicW i436 and comparing the measurements to a Larson-Davis type 831 sound level meter (pink noise at 75 dBA)
We will also discuss our plans to develop and distribute a free NIOSH Sound Level Meter app in an effort to facilitate future occupational research efforts and build an noise job exposure database.
Challenges remain with using smartphones to collect and document noise exposure data. Some of the main issues encountered in recent studies relate to privacy and collection of personal data, sustained motivation to participate in such studies, bad or corrupted data, and mechanisms for storing and accessing such data.
Brigitte Schulte-Fortkamp – b.schulte-fortkamp@tu-berlin.de Technical University Berlin Institute of Fluid Mechanics and Engineering Acoustics -Psychoacoustics and Noise effects – Einsteinufer 25 10587 Berlin -Germany
Popular version of paper 2aNSa1, “Soundscape as a resource to balance the quality of an acoustic environment” Tuesday morning, May 19, 2015, 8:35 AM, Commonwealth 1 169th ASA Meeting, Pittsburgh Pennsylvania
Preface Soundscape studies investigate and find increasingly better ways to measure and hone the acoustic environment. Soundscape offers the opportunity for multidisciplinary working, bringing together science, medicine, social studies and the arts – combined, crucially, with analysis, advice and feedback from the ‘users of the space’ as the primary ‘experts’ of any environment – to find creative and responsive solutions for protection of living places and to enhance the quality of life.
The Soundscape concept was introduced as a scope to rethink the evaluation of “noise” and its effects. The challenge was to consider the limits of acoustic measurements and to account for its cultural dimension.
The recent international standard ISO 12913-1 Acoustics — Soundscape —Part 1: Definition and conceptual framework Acoustique – Paysage sonore -Partie 1: Définition et cadre conceptual clarifies soundscape as an “acoustic environment as perceived or experienced and/or understood by a person or people, in context”
Figure 1 — Elements in the perceptual construct of soundscape
Soundscape suggests exploring noise in its complexity and its ambivalence and its approach towards sound to consider the conditions and purposes of its production, perception, and evaluation, to understand evaluation of noise/ sound as a holistic approach.
To discuss the contribution of Soundscape research into the area of Community noise research means to focus on the meaning of sounds and its implicit assessments to contribute to the understanding that the evaluation through perceptual effects is a key issue.
Using the resources – an example- Soundscape Approach Public Space Perception and Enhancement Drawing on Experience in Berlin Figure 2 – Soundscape Nauener Platz
The concept of development of the open pace relies on the understanding that people living in the chosen are the “real” experts concerning the evaluation of this place according to their expectations and experiences in the respective area. The intention of scientific research here is to learn about the meaning of the noise with respect to people’s living situation and to implement the adequate procedure to open the “black box” of people’s mind.
Therefore, the aim was to get residents involved through workshops to get access to the different social groups. Figure 3 – Participation and Collaboration Figure 4 – The concept of evaluation
Interdisciplinarity is considered as a must in the soundscape approach. In this case it was concerned with the collaboration of architects, acoustics engineers, environmental health specialists, psychologists, social scientists, and urban developers. The tasks are related to the local individual needs and are open to noise sensitive and other vulnerable groups. It is also concerned with cultural aspects and the relevance of natural soundscapes – sometimes referred to as quiet areas – which is obviously related to the highest level of needs. Figure 5 – Soundscape – an interactive approach using the resources
Improving local soundscape quality? Obviously, these new approaches and methods make it possible to learn about the process of perception and evaluation sufficiently as they take into account the context, ambiance, the usual interaction between noise and listener and the multidimensionality of noise perception.
By contrast, conventional methods often reduce the complexity of reality on controllable variables, which supposedly represent the scrutinized object. Furthermore, traditional tests neglect frequently the context-dependency of human perception; they only provide artificial realities and diminish the complexity of perception on merely predetermined values, which do not completely correspond with perceptual authenticity. However, perception and evaluations entirely depend on the respective influences of the acoustic and non-acoustic modifiers.
Following the comments and group discussion and also the results from the narrative interviews it could be defined why people prefer some places over the public place and why not. It also became clear how people experience the noise in the distance from the road and also with respect to social life and social control. One of the most important findings here is how people react to low frequency noise at the public place and how experiences and expectations work together. It becomes obvious that the most wanted sound in this area is based on wishes to escape the road traffic noise through natural sounds. Figure 6 – Selected sounds for audio islands
Reshaping the place based on people’s expertise Relying on the combined evaluation procedures the place was reshaped installing a gabion wall along one of the main roads and further more audio islands like have been built that integrated the sounds people would like to enjoy when using the place. While the gabion wall protects against noise around the playground, the new installed audio islands provide nature sounds as selected by the people involved in the Soundscape approach. Figure 7 – Installation of the sounds
Conclusions Figure 8 – The new place
The process of tuning of urban areas with respect to the expertise of people’s mind and quality of life is related to the strategy of triangulation and provides the theoretical frame with regard to the solution of e.g. the change in an area. In other words: Approaching the field in this holistic manner is generally needed.
An effective and sustainable reduction of the number of highly annoyed people caused by noise is only possible with further scientific endeavors in the area of methods development and research of noise effects. Noise maps providing further information can help to obtain a deeper understanding of noise reactions and can help to reliably identify perception-related hot spots. Psychoacoustic maps are particularly interesting in areas where the noise levels are marginal below the noise level limits and offer an additional interpretation help with respect to the identification of required noise abatement measures.
But, the expertise of people involved will provide meaningful information. Soundwalks as an eligibly instrument for exploring urban areas by minds of the “local experts” as measuring device open a field of data for triangulation. These techniques in combination allow giving meaning to the numbers and values of recordings and their analysis to understand the significance of sound and noise as well as the perception of Soundscapes by its resources. tags: soundscape, acoustics, people, health
REFERENCES J. Kang, B. Schulte-Fortkamp (editors) Soundscape and the Built Environment CRC Press | Taylor & Francis Group, in print B. Schulte-Fortkamp, J. Kang (editors) Special Issue on Soundscape, JASA 2012 R. M. Schafer, “The Soundscape. Our sonic environment and the tuning of the world.” Rochester, Vermont: Destiny Books, (1977). B. Hollstein, “Qualitative approaches to social reality: the search for meaning” in: John Scott & Peter J. Carrington (Eds.): Sage handbook of social network analysis. London/Newe Dehli: Sage. (2012) R. M. Schafer, “The Book of Noise” (Price Milburn Co., Lee, Wellington, NZ, (1973). B. Truax, (ed.) „Handbook for Acoustic Ecology” (A.R.C. Publication, Vancouver, (1978). K. Hiramatsu, “Soundscape: The Concept and Its Significance in Acoustics,” Proc. ICA, Kyoto, 2004. A. Fiebig, B. Schulte-Fortkamp, K. Genuit, „New options for the determination of environmental noise quality”, 35th International Congress and Exposition on Noise Control Engineering INTER-NOISE 2006, 04.-06.December 2006, Honolulu, HI. P. Lercher, B. Schulte-Fortkamp, “Soundscape and community noise annoyance in the context of environmental impact assessments,” Proc. INTER-NOISE 2003, 2815-2824, (2003). B. Schulte-Fortkamp, D. Dubois: (editors) Acta Acustica united with Acustica, Special Issue, Recent advances in Soundscape research, Vol 92 (6), (2006). R. Klaboe, et. al. „Änderungen in der Klang- und Stadtlandschaft nach Änderung von Straßenverkehrsstraßen im Stadtteil Oslo-Ost“, Fortschritte der Akustik, Oldenburg, (2000).
Diane Dalecki, Ph.D. Eric S. Comeau, M.S. Denise C. Hocking, Ph.D. Rochester Center for Biomedical Ultrasound University of Rochester Rochester, NY 14627
Popular version of paper 3aBA5, “Applications of acoustic radiation force for microvascular tissue engineering” Presented Wednesday morning May 20, 9:25 AM, in room Kings 2 169th ASA Meeting, Pittsburgh
Tissue engineering is the field of science dedicated to fabricating artificial tissues and organs that can be made available for patients in need of organ transplantation or tissue reconstructive surgery. Tissue engineers have successfully fabricated relatively thin tissues, such as skin substitutes, that can receive nutrients and oxygen by simple diffusion. However, recreating larger and/or more complex tissues and organs will require developing methods to fabricate functional microvascular networks to bring nutrients to all areas of the tissue for survival.
In the laboratories of Diane Dalecki, Ph.D. and Denise C. Hocking, Ph.D., research is underway to develop new ultrasound technologies to control and enhance the fabrication of artificial tissues1. Ultrasound fields are sound fields at frequencies higher than humans can hear (i.e., > 20 kHz). Dalecki and Hocking have developed a technology that uses a particular type of ultrasound field, called an ultrasound standing wave field, as a tool to non-invasively engineer complex spatial patterns of cells2 and fabricate microvessel networks3,4 within artificial tissue constructs.
When a solution of collagen and cells is exposed to an ultrasound standing wave field, the forces associated with the field lead to the alignment of the cells into planar bands (Figure 1). The distance between the bands of cells is controlled by the ultrasound frequency, and the density of cells within each band is controlled by the intensity of the sound field. The collagen polymerizes into a solid gel during the ultrasound exposure, thereby maintaining the spatial organization of the cells after the ultrasound is turned off. More complex patterning can be achieved by use of more than one ultrasound transducer.
Figure 1. Acoustic-patterning of microparticles (dark bands) using an ultrasound standing wave field. Distance between planar bands is 750 µm. Scale bar = 100 μm
An exciting application of this technology involves the fabrication of microvascular networks within artificial tissue constructs. Specifically, acoustic-patterning of endothelial cells into planar bands within collagen hydrogels leads to the rapid development of microvessel networks throughout the entire volume of the hydrogel. Interestingly, the structure of the resultant microvessel network can be controlled by choice of the ultrasound exposure parameters. As shown in Figure 2, ultrasound standing wave fields can be employed to fabricate microvessel networks with different physiologically relevant morphologies, including capillary-like networks (left panel), aligned non-branching vessels (center panel) or aligned vessels with hierarchically branching microvessels. Ultrasound fields provide an ideal technology for microvascular engineering; the technology is rapid, noninvasive, can be broadly applied to many types of cells and hydrogels, and can be adapted to commercial fabrication processes.
Figure 2. Ultrasound-fabricated microvessel networks within collagen hydrogels. The ultrasound pressure amplitude used for initial patterning determines the final microvessel morphology, which can resemble torturous capillary-like networks (left panel), aligned non-branching vessels (center panel) or aligned vessels with hierarchically branching microvessels. Scale bars = 100 μm.
[1] Dalecki D, Hocking DC. Ultrasound technologies for biomaterials fabrication and imaging. Annals of Biomedical Engineering 43:747-761; 2015.
[2] Garvin KA, Hocking DC, Dalecki D. Controlling the spatial organization of cells and extracellular matrix proteins in engineered tissues using ultrasound standing wave fields. Ultrasound Med. Biol. 36:1919-1932; 2010.
[3] Garvin KA, Dalecki D, Hocking DC. Vascularization of three-dimensional collagen hydrogels using ultrasound standing wave fields. Ultrasound Med. Biol. 37:1853-1864; 2011.
[4] Garvin KA, Dalecki D, Youssefhussien M, Helguera M, Hocking DC. Spatial patterning of endothelial cells and vascular network formation using ultrasound standing wave fields. J. Acoust. Soc. Am. 134:1483-1490; 2013.
