Healthcare and Wearables

In the context of healthcare electronics, the advent of the wearable devices  and  the Internet of Things (IoTs) are going to revolutionize the age tested hospital system. The major challenge in modern healthcare services is to provide quality medical care  at affordable prices for the large number of seekers.  The emerging field of  low power electronics and the miniaturization of devices makes the wearable devices the best choice for personalized healthcare.

The concept level model for this system is to propagate the so called "health begins at home" . In other words this means to redistribute the load of the healthcare management to a wider community of health specialists, so that an equality of health related services is rendered. According to my broad (maybe vague) perception of medical field, each individual needs to undergo the three steps of Diagnosis (Prediction), Prescription and Prevention - which is easily remembered by the 3 P's. This is very similar to the analytics which our present day data scientists are familiar with. The model henceforth develops into a stronger hierarchy of medical institution, which now translates into home medicine, primary health centers,  general hospitals, speciality hospitals and research institutions in medicine. The goal in the mind of the IoT healthcare community is to come up with wearable systems (eg: gadgets) that may equip each individual to be better informed about their health status in tandem with the best in house medical doctors to be allocated 24 x 7. 

Vehicle automation towards self driving cars

In this age of machines, humans are going automatic.

Anyone who hears this is bound to believe, something is wrong. What is really meant by automation? The term automatic refers to an activity that is performed without a person to directly control it. So,  is the action performed really independent of the person who initiated the process? To analyse the scene further, what really is unknown in the automated system is the knowledge of the controller/ initiator. This is a game changer - how can one remove the knowledge of the controller and inscribe it on the product. These threads of questioning  suggests that in automation human involvement is hidden but not completely made invisible. The debate over automation being beneficial or not is present among many communities. The importance should thus focus upon whether a middle path between human resource and automated resource can be made. In the past we have witnessed technology playing a key role in changing human values and attitudes. The current attention in this post is to establish such a compromise approach to better utilize the current resources (human as well as machines/automated) to uphold the integral human values - viz - equality, environmental consciousness and human safety.

The current attention surrounding self driving cars is motivated by several human factors which makes the roads busy and unsafe. The reliability factor in such systems is the use of vehicular communication systems and efficient sensors. However, the main human factor in the cities is solo driving. So the natural question is if the effective use of the road real estate possible with vehicle automation. This needs not just automation, but some technology that can change the human attitude. One solution for this was given through the integrated transport app (in the blog post : Travelling that .. ). This article discusses one step ahead. The intend is to make possible  a system where the user can rely on his vehicle to reach the nearest public transport station and enable the car to self drive back home. In such a situation, people would be keen on better utilizing the existing infrastructure.

Travelling that goes smart

Travelling and transportation are posing as a main challenge in the face of  developing India. At one end we have wide classes of vehicles on the road - starting from four seated motor bikes to, small cars, medium cars, luxury cars to busses and trains. Still we experience the scenario of a passenger standing on the foot board of the public transport system. With these setbacks, India has the advantage that it is well connected  by cellular mobile phones. It is the right beginning to think about a integrated app which is a solution for all personal transport requirements. In this context it has become a possibility to use the pooling system of online cabs which is well developed.

The idea here is to provide a one place integrated transport solution, ie the user can get a comfortable hassle free travel from place A to place B. The integrated solution comes in the form of a mobile app. The app requires a social login, for instance Facebook or Gmail or Twitter. On completion of the signing in the user will be enquired about the start point and the destination. The choices present would be a public transport system a pool system or a private owned car. The map shall also come up showing the social friends in nearby locations who are willing to pool. The integrated solution for the public transport is  a door to door service which will be taking the needs of the passenger from the staring point to the final destination. The door service is to be available with help of Autorikshas and taxi cabs.

The integrated transport system is automated to collect the cash in the form of mobile wallet. The public transport system option is flexible as it allows for seat reservations. The possibility of seat reservation is possible by ensuring connectivity between the vehicle and the "transport" server.

The Indian Scenario

The Indian transportation planning is quiet distinct from the ones that are addressed in the West. The major drawback is the lack of viable real estate and infrastructure to cater to the needs of the population. In many a places, the public transport exceeds its "capacity"(if there is one) and literally there is not a piece of land where one can put his/her feet. The incorporation of the integrated app is to benefit the commuters in atleast two folds. Firstly, the commuters  becomes aware that the world is a place where one has to live and let live. Public consciousness is the key attitude shift that can be brought. Since the app can make personalized suggestion on choosing the fastest, cheapest or the greenest routes - she/ he is made to think twice before using her/his own private vehicle.  Second, the system can be used for accurate and real time survey. This means that we can replace the present system where the bus conductors note down the number of passengers who covered  a certain distance,  The data set obtained from the app is a boon for the transport coorporation for the city or the state since the real data is available, while planning for additional routes or on optimizing the trips or even in efficient budgetary allotment. 

A Final Note

The number of people who owns a private car does not tell anything about the development of a country, but what matters is the productivity that is derived by the public transport network. This is the right eye opener for many of the nation planners to invest more on optimizing the available resources rather than to build expressways and fly overs.

Elements in the pedagogy for the future IoT revolution

The internet of things is going to transform the way we perceive the objective world. The world is getting more and more connected with multiple devices available.  This post is a reflection on my recent encounter with the the use cases of the Internet of Things (IoTs) in education and academia There a pressing need for us to invest on the human resources for developing the current IoT. If there is lot of potential in IoT, then the need to train our younger generations is also high.

The IoT mania is more hyped than reality. In reality, we are not trying to do something that is entirely new. But IoT is just another way of getting things done in a smarter, simplified and user friendly manner. The whole jargon blinds us of many things that we can/have fundamentally deal/dealt with. For instance, has anyone thought about the number of multimedia content that gets transferred across the internet and the cloud. Is there that theoretical "infinite" storage that is available to us to store this on the clouds? Here comes the savior in the form of Wavelet and Time-Frequency transforms. A fundamental theory that has developed more than a 50 years back, comes into action in a beautiful coincidence to solve a Big Data issue. Looking at the various layers of the communication stack in the current, IoT can back on a huge legacy network if it gets focused on the specific constraints. The IoT is going to make access to every possible sensed data at any place. In a nutshell, it becomes an all pervasive network.

The key drivers in IoT is surely the ability to handle data. Are we prepared for that ? Some key anticipations in the industry goes in the areas of low power, storage and integration of the hardware software peripherals. The answers to all these are open as of today. The 50 billion or the a trillion devices by 2020 .. how can one possibly give a network address to each of these.

If the technologists claim it to be the next biggest revolution after the industrial revolution in the early 18th century, then we better get ready. - the earlier the better. There are a variety of starter kits for students to pick up early. Specifically, there needs to be training in the following aspects : sensing, networking and actuation. An undergraduate IoT lab facility is strongly required.


Navigate to IoT Lab.

Switch or Stay

One thing that is often reiterated, is that one should keep up to the pace of the world around. If you stay, you will miss somethings, but there is always an advantage in switching. Consider this classical example called the "Monty Hall" problem in probability theory:

The "Monty Hall" problem relates to a popular TV show, where the participant of the game is allowed to win a Bentley (most expensive car!) or has to be satisfied with a goat (most sort after domestic animal!). The problem is stated as a conversation between Monty and the participant Mr. P

Monty : Welcome, Mr P to this game. Before we begin let me explain. You can see 3 closed doors,     behind one of the doors is the most priced Bentley, and behind the others are the useful goats. Choose one and you will be prized with the gift behind the door. You can either go with a shiny, new expensive Bentley or be satisfied with the goat. So are you ready?

Mr. P  : Okay let me choose Door __ .

Monty : Okay let us see if the luck supports you. (Pause) Maybe I can give you another chance. I shall open a second door and see if you want to change the choice.

Monty opens a second door and shows that it is a goat.

Monty :  Do you wish to stay or switch?

Think that you are Mr. P and write your choice... Stay or Switch!

Figure showing the illustration of the Monty Hall Problem. (Drawn using MetaMoji Note App)

Solution : Mr. P would wish to switch in order to win the Bentley. The reasoning is as follows.

We contrast the chance of winning on switching vs the chance of winning on staying with the previous decision

$\mathbb{P} (win|switch) = \mathbb{P}(I = G, III = B) = \frac 23$ and $\mathbb{P} (win|stay) = \mathbb{P}(I = B, III = G) = \frac 13$.

The chances of winning is more while one switches. The solution to the problem seems to be very counter intuitive. Hence this is regarded as a good example problem for learning elementary probability.

Physical Layer Security Using Energy Harvesting Models

This article has appeared in the Technical Article Board of ECE Department, SSET - June 2016

Abstract

A point to point communication with a receiver and a single transmitter is the system under study. We consider the security aspect at the physical layer of the wireless communication transmission in the presence of an eavesdropper. A combination of techniques involving the channel state information(CSI) and energy harvesting information(EHI) is used to ensure the security. The experimentation is performed using the NI USRP 2920 hardware.

Extended Abstract

ireless communication systems consists of a transmitter and many distributed receivers. The eavesdropper is an unintended node that tries to know what the wireless transmitter sends. The eavesdropper can cause security hazards to the intended receiver by causing leakage of the message and causing intentional manipulations. These manipulations can in turn, lead to wrong message being delivered. The wireless physical layer is the lowermost level of the 7 layer OSI (Open System Interconnection) model. In many existing systems the security aspects are dealt mostly at the link layer and the network layer. These schemes have their drawbacks like, complex cryptographic cyphering, power consumption, hardware cost to name a few. Physical  layer security is destined to be the future, where systems can be implemented in low battery power devices using improved simplicity. 

The physical layer security is dealt with the help of the CSI information available at the transmitter and receiver[1]. The CSI information is independent at the eavesdropper and receiver. This helps us to manipulate the order of the interleaving bits. The scheme of the interleaver requires that the channel state observed by the receiver and the eavesdropper are both independent. This prompts us to look for methods that are statistically independent with the users, but at the same time observable. In this context we try to provide a scheme that is a combination of the CSI and the proposed scheme of Energy Harvesting Information.

Courtesy : https://arxiv.org/pdf/1505.07929.pdf
Fig 1: Communication and Security Model

Harvested Energy Model 

We consider the case of a device that is capable of harvesting/collecting renewable energy from sources such as solar, wind, piezo, etc. In general as energy impinges on the photo sensors(in the case of a solar panel) some part is lost in the conversion process to electrical energy. Thus, the harvested energy at any given time is high or low, ie a Bernouli random process. Depending on the position of the device the amount of energy harvested (say in a block interval) is an independent sequence. So the interleaving pattern can be made a function of the random energy harvested.

Fig 2 : The Block diagram of the OFDM scheme using the Energy Harvesting Information (EHI)

The schematic for the physical layer security using the OFDM scheme is described. The channel is estimated and used as an input to the interleaver along with the energy harvesting input. The combined inputs fed to the interleaver will allow for an improvement in the security and decoding performance. The system has been tested under the USRP test condition with the the eavesdropper being placed in a separation. Initially channel measurements are performed using perfect channel knowledge. Later it is modified to the case where in the absence of the perfect channel state information, an estimation is performed at both the transmitter and receiver.

Reference

[1] H. Li, X. Wang and Y. Zou, "Dynamic Subcarrier Coordinate Interleaving for Eavesdropping Prevention in OFDM Systems," in IEEE Communications Letters, vol. 18, no. 6, pp. 1059-1062, June 2014

[2] Universally near-optimal online power control for energy harvesting nodes
D Shaviv, A Özgür - arXiv preprint arXiv:1511.00353, 2015

This is joint work with a M.Tech student at the Wireless Communication Lab, SSET

Qualifying vs Quantifying

In this article we look into the duality of the two words, quality and quantity. The nature around us provides a good witness to make this duality precise. All the objects in the eyes of an observer are the same in the elements of composition while they are different in their nature, form and properties. The quality of an 'Engineering' product sets a standard whereas its quantity is only and (measuring) analysis tool.

Courtesy : http://thoughtprocess101.wordpress.com

It is often retold that Quality matters more than the Quantity. The reason for such a statement is recognized to be the connection and the duality of the two terms. The process of measurement comes into play, while one quantifies, whereas qualifying would require certain inferences or analysis from the measure. Look at the question "How old are you?". When this question is asked many of us has certain inherent doubts. But one knows that age is just another number. Look at this perspective into the matter. Can you think about it from the "half filled" angle of the age being a quantity that describes your physical strength, attitude, responsibility, or the like. The point being emphasized here is that quantification only leads to a sense of comparison, while qualifying brings around a sense of positive security(which in fact is the truth).

How do you measure your food habits? Is it dependent on the quality, quantity or both? Unless a desirable quality is derived from the measure being performed the exercise of measurement seems to be fruitless. In Engineering and Scientific study this stands out to a great extent. A sense of scientific enquiry, begins from the limited nature of our measuring tools, while the ability to draw useful interpretations (if not conclusions) would extend the possibility to expand our domain of knowledge.

Math as a Language for Signal Processing

[This article has appeared in the Technical Article Board April 2016, Also appeared in annual magazine of the Electronics and Communication Engg Department : Explora 2016]

Mathematics and its applications pervades in all engineering systems. Today, an aspiring engineering student can easily get demotivated by the traditional methods of instruction adopted in many of the technical institutes. In many countries, the student community across academia are in a dilemma on their inability to see any usefulness in the rote teaching-learning mechanism happening. The rising drop out rates, lack of reflection, rising unemployable population are clear indicators on the need for a change in the learning approach. With the penetration of the internet and the immense compute power brought by the electronics, one can re-invent the  math classroom to become more engaging, practical and mastery oriented.  The advent of online classes and the flipped approach of lecturing alongside with the availability of low cost electronics can trigger a rapid change in the attitude and approach towards the subject. The objective of the article is to enlighten both teachers and learners on the novel methods that are available in absorbing mathematics rather that swallowing. 


To read the complete article click the link below
Document

Energy Harvesting Communication - Why, How and Where?

This article is a part of the technical article board at SSET

Abstract

The recent trends in communication and signal processing looks for low energy circuits and algorithms. In this article we look into some of the practical schemes of implementing a network of sensors using renewable sources of energy. An effi cient computation between the sensor nodes is also presented.

Introduction

Hand held devices are battery operated and is often drained o frequently in day to day applications.
There is a provision to recharge these cells as and when needed, using power sockets. But in applications such as environment monitoring or deep space observation where there are multiple sensor nodes, this "scheme" is not possible. Li-ion batteries are being replaced with supercapacitors, which has the ability to store charges from renewable sources. The intermittent availability of the energy packets, makes the energy available at any point to be random according to some 'probability distribution'.

A Working Example

Consider a communication system having one transmitter and a receiver - called as a 'point to point'

channel. A transmitter requires energy to transmit bits to the receiver and needs to 'obey' the channel

rules for end to end reliability.

The Energy harvester block is a solar panel wind turbine, a piezo electric or bio-mechanical gear, which is capable of converting various energy sources to electrical energy. The charge gets stored in the supercapacitor, where it is available for usage while transmitting. The transmission is an adaptive scheme, where the power disbursed on each packet/bit is controlled with respect to the energy available within the storage device. The power also needs to be decided by the channel condition - i.e in low SNR regime send at a lower rate and at higher SNR send at a larger rate.

Make Your Own Harvester

• Solar : Easily available and can be applied to almost all sensors. But its e ciency is less than 10%
• Piezo : Useful in converting natural movements to storable form. Advantage that no other storage medium is required.
• Bio-Mechanical : Converts periodic regular movements to electricity using mechnical pronciples of gear.

Can we get energy for free?

Neodymium magnets when placed near the CPU fans can act as a dynamo to run an LED bulb!

Reference

[1] Shaviv, Dor, and Ayfer zgr. "Universally Near-Optimal Online Power Control for Energy Harvesting Nodes." arXiv preprint arXiv:1511.00353 (2015).

[2] Marjan Aslani, "Electrochemical Double Layer Capacitors (Supercapacitors)", 2012, Web link : http://large.stanford.edu/courses/2012/ph240/aslani1/

On the Realization of Photo-conductive Paints

In a country like India where the sunlight is available throughout the year, a large opportunity awaits in realizing it to the full potential. Very large scale projects are being undertaken by the Government to realize this goal, and the electrification of the Cochin Airport through solar cells is the finest example.

When it comes to solar power, the main challenge lies in the cost of installation. People seldom look into its long time value and are often caught in huge investment they have to make. In this scenario, it is vital, that some cost cutting technology come to help. And one proposal here is to develop a photo-conductive paint. The idea here is to develop a paint, with a chemical composition such that, it can absorb the ambient sunlight. The paint shall be composed of nano-particles which will in directly help in the conduction of the electricity.

A proposed idea helps you to apply the paint such that it can supplement the power line to your home.

Courtesy : http://www.stewmac.com/

eNose - Design, Applications and Challenges

This article is a republished version of the Technical Article Board at SSET

Abstract

Sensors are widely used today to collect local databases on various parameters. In this article, a sensor which can measure olfactory(smell) signals is presented. The eNose or the Electronic Nose is a biologically inspired sensor, having origins in the functioning of the mammalian olfactory system. A review of the various sensing techniques along with the classification methods and applications are presented.

Introduction

The term ``electronic nose" was coined in 1988 by Gardner and Bartlett wherein they defined e-nose (EN) as ``an instrument which comprises an array of electronic chemical sensors with partial specificity and appropriate pattern recognition system, capable of recognizing simple, or complex odours". The design of the sensor replicates the functioning of the mammalian olfactory system, although it has some limitations. For instance, EN's are more application specific, that is the sensor available for bio-sensing cannot be employed for food testing or environment monitoring. Recently, chemical based sensors are employed in measuring food quality and in select beverages and fast foods. The figure below illustrates the broad parts of the eNose.

How it is done : Components that are used

The eNose consists of the following components :

• Multiple Sensor Array
• Data Acquisition System
• Pattern Recognition System

There are different sensing mechanisms for the functioning of the eNose, viz. Optical, Mass and Ion Mobility based, Gas Chromatography based, Infrared Spectroscopy based, Chemical Sensors. Of these the Chemical sensors are the most popular and widely employed, as it is possible to tailor various parameters and due to its close resemblance to mammalian olfaction. These are again classifies as MOS, MOSFET, surface and bulk acoustic wave, and conductive polymers.

Role of Nanomaterials

The preferred choice of sensor is to employ nano-structures which offer many advantages such as low cost, compact size, low power consumption, and faster response. With the advancement in microelectromechanical systems (MEMS), nanoelectromechanical systems (NEMS) very large-scale integration (VLSI), and nanoscience various novel nanostructures are successfully being employed in the fabrication of EN devices.

Reference : Ramgir, Niranjan S. "Electronic nose based on nanomaterials: Issues, challenges, and prospects." ISRN Nanomaterials 2013 (2013).

Going without a Jerk

This article is a republished version of the Technical Article Board at SSET

Abstract

Potholes on the road are a great threat to motorists using the highway. Currently there is very little infrastructure to locate these and repair them in a timely manner. This article presents a method to report the exact location of the portholes without any manual step. You just need to put a smartphone in your pocket.

Introduction

The article here discusses the use of the accelerometer in the phone for detecting the potholes and reporting them to the civil authorities through a database. The database can be used to locate the potholes on a map and take remedial measures quickly. The work explained here has been an extension of that developed in Nericell by Microsoft Research Bangalore. The Nericell gives a map view of the locations that and provides extension to accident detection due to abnormal braking.

Prelims of Accelerometer

The accelerometer is a device used in every smartphone and is capable of determining the acceleration along each perpendicular coordinates – X, Y and Z. The measurements are taken relative to the acceleration due to gravity, \(g (= 9.8 m/s^2).\) The directions are illustrated below. Using the X, Y components accelerometer can measure the abnormalities in the road plane. Along the Z direction, abnormalities due to level shifts can be detected- potholes or bumps for instance.

X, Y and Z directions of accelerometer

How It Works

It is possible to determine the following from the 3 reported acceleration graphs.

• Breaking Detection – accident reporting
• Pothole Detection
• Speed detection

If \(x\) is the distance, then \(\frac{dx}{dt}\) is the velocity, and \(\frac{d^2x}{dt^2}\) is the acceleration. If we look into the higher derivatives of \(x\), it is possible to detect the changes is acceleration corresponding to sudden changes in the accelerometer signal. It is possible to identify the sudden spiking of the signal along the \(x\) axis and translate it a jerk. Now the intensity of the jerk is dependent on the speed of the moving vehicle. At high speeds (ie > 25 kmph) , the jerk is prominent, while the jerk is less noticed for lower speeds (ie <25 kmph).

References

Mohan, Prashanth, Venkata N. Padmanabhan, and Ramachandran Ramjee. "Nericell: rich monitoring of road and traffic conditions using mobile smartphones." Proceedings of the 6th ACM conference on Embedded network sensor systems. ACM, 2008.

Is the Nyquist sampling rate a fundamental limiting rate in sampling ?

This post is an assessment of the key assumptions of the  conventional sampling paradigm.

The conventional sampling process applies to Bandlimited signals, or in other words, signal spreads in the time axis. The process assumes taking evenly spread samples of the signal at a spacing depending on the maximum frequency component of the signal.

We analyze the question, if localization of information is allowed , will the Nyquist rate be sub-optimal. For instance, consider the signal and its sampling method: