@article {286, title = {911 services and vital sign measurement utilizing mobile phone sensors and applications}, year = {2016}, month = {11/2016}, publisher = {University of North Texas}, address = {US}, abstract = {

Improved methods for utilizing 911 services, for implementing 911 dispatch protocols, and for measuring vital signs of a human, all by accessing mobile phone sensors and applications, are disclosed. Vital signs such as heart rate, breathing rate, breathing distress, and blood pressure can be measured using mobile phone sensors and applications. A method for differential estimation of blood pressure involves the synchronization of time between two mobile phones, locating an appropriate position for one cell phone and recording heart sounds, and recording video data from the finger tip of the subject using the other mobile phone.

}, keywords = {data, patient, rate, Remote, video}, issn = {US9485345B2}, url = {https://patents.google.com/patent/US9485345/en}, author = {Ram Dantu and Chandrasekaran, Vikram and Gupta, Neeraj} } @article {15, title = {Cuffless Differential Blood Pressure Estimation Using Smart Phones}, journal = {IEEE Transactions on Biomedical Engineering}, volume = {60}, year = {2013}, pages = {1080 - 1089}, abstract = {

Smart phones today have become increasingly popular with the general public for their diverse functionalities such as navigation, social networking, and multimedia facilities. These phones are equipped with high-end processors, high-resolution cameras, and built-in sensors such as accelerometer, orientation-sensor, and light-sensor. According to comScore survey, 26.2\% of U.S. adults use smart phones in their daily lives. Motivated by this statistic and the diverse capability of smart phones, we focus on utilizing them for biomedical applications. We present a new application of the smart phone with its built-in camera and microphone replacing the traditional stethoscope and cuff-based measurement technique, to quantify vital signs such as heart rate and blood pressure. We propose two differential blood pressure estimating techniques using the heartbeat and pulse data. The first method uses two smart phones whereas the second method replaces one of the phones with a customized external microphone. We estimate the systolic and diastolic pressure in the two techniques by computing the pulse pressure and the stroke volume from the data recorded. By comparing the estimated blood pressure values with those measured using a commercial blood pressure meter, we obtained encouraging results of 95{\textendash}100\% accuracy.

}, keywords = {Blood pressure, cuffless, Estimation, finger pulse, Heart, Microphones, mobile camera, Mobile communication, mobile phone, Synchronization, Valves, vascular transit time}, doi = {10.1109/TBME.2012.2211078}, author = {Chandrasekaran, Vikram and Ram Dantu and Jonnada, Srikanth and Thiyagaraja, Shanti and Subbu, Kalyan} } @article {82, title = {Socio-technical Aspects of Remote Media Control for a NG9-1-1 System}, journal = {Multimedia Tools Appl.}, volume = {62}, year = {2013}, pages = {733{\textendash}759}, abstract = {

9-1-1 emergency calls mostly involve distress situations that cause people to panic while trying to answer questions or follow instructions given by a dispatcher. To obtain precious information with the least user intervention and reduced stress on the user, there is a need for the dispatcher to have a better control and understanding of the condition or situation at the other end. The increasing growth of smartphones embedded with camera, speaker phone, GPS, microphone and various other sensors, extends their usage from merely making calls to life saving gadgets during critical situations. By integrating these sensor rich smartphones and the rapidly growing VoIP technology, we propose a VoIP based Next Generation 9-1-1 (NG9-1-1) system for remote media control. Specifically, we use Session Initiation Protocol (SIP) in the implementation of the system using a mobile and a PC client. The proposed system on the mobile client accounted for less than 25\% of CPU utilization even with video transmission. The average network utilization was about 10 and 72 kbps for audio and video, respectively. With these encouraging results, we believe the proposed remote media control system will facilitate information acquisition and decision making in emergency situations.

}, keywords = {Image transmission, Media control, NG9-1-1, PSAP, Remote, SIP, Voice quality, VoIP}, issn = {1380-7501}, doi = {10.1007/s11042-011-0875-1}, url = {http://dx.doi.org/10.1007/s11042-011-0875-1}, author = {Chandrasekaran, Vikram and Ram Dantu and Subbu, Kalyan} } @conference {68, title = {Efficiency of Social Connection-based Routing in P2P VoIP Networks}, booktitle = {Proceedings of the 2Nd International Conference on COMmunication Systems and NETworks}, year = {2010}, publisher = {IEEE Press}, organization = {IEEE Press}, address = {Piscataway, NJ, USA}, keywords = {P2P routing, P2P VoIP systems, Social networks, social-network based routing}, isbn = {978-1-4244-5487-7}, url = {http://dl.acm.org/citation.cfm?id=1831443.1831488}, author = {Chandrasekaran, Vikram and Ram Dantu and Gupta, Neeraj and Yang, Xiaohui and Wijesekera, Duminda} } @conference {237, title = {Socio-technical aspects of video phones}, booktitle = {2010 Second International Conference on COMmunication Systems and NETworks (COMSNETS 2010)}, year = {2010}, month = {Jan}, abstract = {

The widespread use of voice over Internet protocol has paved the way for video over Internet protocol. In the past, certain technical shortcomings have prevented the popularity of videophones in the market. With present-day technology, videophones have just about everything required for day-to-day functions. Under such circumstances, certain socio-technical aspects require attention so that videophones can become as widespread and as technically streamlined as a plain old telephone system (POTS) with its additional benefits. A frequently brushed-upon topic is optimum features in the video phone for day-to-day social interactions. We carried out several experiments on different kinds of codecs and video formats to address two issues: i) the size of a video screen and ii) perception of motion and distance. From the measurements, we observed that a small frame rate with low bandwidth is adequate and can result in satisfactory video quality. We also observed that H263 performs well for all the day-to-day social networking activities. Standing 4 feet from the camera can still give reasonably good video quality in the currently available codecs. We believe that socio-technical issues will emerge more clearly over the next several years and they are germane to deployment of PC-based soft phones as well as hard phones.

}, keywords = {Bandwidth, Cameras, Codecs, Computer science, Internet telephony, plain old telephone system, Protocols, social aspects of automation, Social factors, social interactions, social issues, Social network services, social networking activities, sociotechnical aspects, Streaming media, technical issues, video codecs, video coding, video phones, video quality, Videoconference, videophone quality, videophones, videotelephony, voice over Internet protocol}, doi = {10.1109/COMSNETS.2010.5431971}, author = {Chandrasekaran, Vikram and Dantu, Siva and Kadiyala, Priyanka and Ram Dantu and Phithakkitnukoon, Santi} }