Biotechnology is used for the compatibility with a device to work in the organic structure without the organic structure seeing it as a foreign component and assailing it. When the organic structure notices a foreign component in the organic structure it sends white blood cells to assail it. The device needs to be seen as portion of the organic structure so the devices packaging demands to be biocompatible. This happens by the proteins and fibers in the organic structure get down to attach to the devices lodging and finally it wholly encapsulates the device in the organic structure and this is called hempen encapsulation.

Nanotechnology is used in the electronics and sensor country of the device. For engrafting a device in the organic structure it has to be little no bigger than a pacesetter would be a good regulation of pollex. The detector bed is little in devices normally a piezoelectric detector, which notices the minimum alteration in a construction.

Information engineering is used in the information processing bed of a device. The computing machine systems are being used to analysis information and give feedback. This besides comes in if a device is being wirelessly powered and it is the engineering being used to power the device besides falls under information engineering.

Cognitive scientific discipline is the single personi??s ability and cognize how for analyzing and treating the informations coming from the system.

Implantable Medical Device

A merchandise or device that is manufactured is defined as a medical device if it is used to:

* Cope with human disease

o Prevent human disease.

o Diagnose human disease.

o Treat human disease.

o Alleviate human disease.

o Monitor human disease.

* Care for human hurts

o Diagnose human hurts.

o Treat human hurts.

o Alleviate homo hurts.

o Monitor human hurts.

o Compensate for human hurts.

* Meet human anatomical demands

o Investigate human anatomical issues.

o Replace human anatomical constructions.

o Modify human anatomical constructions.

o Support human anatomical constructions.

* Maintain human physiological maps

o Investigate human physiological maps.

o Replace human physiological maps.

o Modify human physiological maps.

o Support human physiological maps.

* Support or prolong human life

* Control human construct

* Disinfect human medical devices

* Examine specimens taken from human organic structures

Medical devices can include the undermentioned:

* Instruments

* Appliances

* Implants

* Machines

* Software

* Materials

* Calibrators

* Apparatuss

* In vitro reagents

* Related articles

( praxiom 2011 )

Atrial Fibrillation

Atrial fibrillation is frequently referred to as i??afibi?? , this is an irregular pulse, a rapid pulse, and besides a shaking of the upper Chamberss of the bosom, this is called the atria. Atrial fibrillation is caused by a malfunction in the hearti??s electrical system, and is the most common bosom abnormality, or cardiac arrhythmia. The two most normally used methods of commanding atrial fibrillation are electrical and pharmaceutical. ( Stopafib 2011 )

Pharmaceutical

The first measure that is taken on in pull offing atrial fibrillation is to typically handle it with medicines, get downing off with a rate controlled drug to decelerate down the bosom rate in combination with anticoagulation by a blood dilutant to cut down the hazard of a shot.

If this first procedure fails to work, so the afib is treated with a beat control drug that restores the bosom rate to normal, this is called i??normal fistula rhythmi?? .

Some patients have success with electrical cardio version, which is used to floor the bosom back into normal sinus beat ; this is so followed by beats control drugs to keep that normal fistula beat.

There are three types of medicines used in handling and pull offing afib:

* Rate control medicine to command the bosom rate

* Rhythm control medicine which is sometimes called drug cardio version, to assist set the bosom back into normal fistula beat.

* Anticoagulant medicine, such as Warfarin or Coumadin, used to command blood thickness and avoid blood coagulums and shots. ( Stopafib 2011 )

Advantages

* Rapid oncoming of consequence

* Short continuances of consequence for endovenous signifiers

* Heart rate control at remainder and with activity

* Oral signifiers available with changing continuances of effects

Disadvantages

* May decline bosom failure in decompensated patient

* May worsen reactive air passage diseases

* Can do weariness

* Depression

* Abrupt backdown may do recoil tachycardia

* Hypertension ( Dresing and Schweikert 2011 )

Electrical

Electrical cardioversion is a procedure in which the bosom is shocked to change over it from an irregular beat bosom crush back into a normal fistula beat. For patients in relentless atrial fibrillation, electrical cardioversion can be done in two ways, first it can be done early in the procedure to halt the afib and put the bosom into normal fistula beat. Then for other patients, electrical cardioversion may non be tried until a ulterior phase, when medicine has stopped working. While electrical cardioversion may be effectual at change overing the bosom back to normal fistula beat, it does hold a low success rate of maintaining it there and therefore may necessitate multiple attempts. It besides doesni??t remedy atrial fibrillation. ( Stopafib 2011 )

Advantages

* Restore normal bosom beat

* Reduce and command the rapid bosom rate

* Reduce the hazard of shot

( Afanswers 2011 )

Disadvantages

* Some patients can hold hemorrhage, swelling or contusing where the catheters were inserted.

* Serious complications do sometimes happen which are infection, harm to the bosom or blood vass and blood coagulums.

* The hearti??s normal electrical system could be damaged during process.

* Although all types of anaesthesia involve some hazard, single side effects and complications from anaesthesia can change. Specific hazards can differ depending on assorted wellness factors. ( Afanswers 2011 )

Application Space

At the minute there are chiefly two methods to assist reconstruct the bosom back to normal fistula beat. These are long-run anti-arrhythmic drugs ( AAD ) and atrial fibrillation catheter extirpation.

What is being used presently

AAD

AAD interventions are used to seek and barricade or modulate the electrical activities of the bosom as to avoid the happening and continuance of arrhythmia. This method is effectual for 60 per centum for patients, and it requires a long-run intervention procedure. While there are many side effects of drug therapy, some drugs are prohibited to portion of patients. Although, most drugs are executable. When the consequence of merely utilizing one sort of drug, patients can see a assortment of different drugs to be used in combination. ( Problems 2009 )

Catheter Ablation

The Catheter extirpation can assist portion of patients with atrial fibrillation to obtain a normal fistula beat. It has been confirmed that the beginnings of most atrial fibrillation incidences are located around the left atrial pneumonic vena because of this the efficiency of circumferential pneumonic vena stop deading extirpation to bring around atrial fibrillation is about 70 per centum. The chief complications of this technique are cardiac tamponage, thrombosis or AV fistulous withers. Patients after holding successful interventions do non necessitate to go on taking anti- jerking drugs, therefore the atrial fibrillation has been cured. It is estimated that there are 10 thousand units atrial fibrillation radiofrequency extirpation each twelvemonth in Europe. ( Problems 2009 )

New Thinking

There are many new engineerings coming about utilizing the usage of convergent engineerings to develop these devices. One peculiar device being developed is a low-priced microelectronic platform for wireless enablement of implantable medical devices. In this work, a battery free radio enabled implantable microelectronic platform architecture for in-vivo tissue electric resistance measuring is proposed. The platform has specifically been designed to use low-priced regulative compliant trade good engineerings ; using near field magnetic yoke at HF-RFID frequences for power bringing and a far-field MedRadio transceiver for high-velocity low-power informations transportation. For construct presentation, the platform was ab initio adapted to ease in-vivo tissue electric resistance measuring. However, the design remains suited for integrating with a broad scope of pre-existing and emerging implantable detector engineerings. ( P.R.Walsh 2009 )

Historical tendencies

Closed-chest Method

Until the early 1950s, defibrillation of the bosom could merely be performed when the chest pit was unfastened during surgery. The technique used an jumping current from a 300 or even greater V beginning delivered to both sides of the open bosom by paddle electrodes where each electrode was a level or somewhat concave metal home base of 20mm in radius.

The closed- thorax defibrillator device which applied an jumping current of greater than 1,000 Vs. This was conducted by agencies of externally applied electrodes through the chest coop to the bosom. ( news-medical 2010 )

Move to Direct Current

In the late 1950s Bernard Lown commenced research into an option technique which involved charging of a bank of capacitances to about 1,000 Vs with an energy content of 100 to 200 Js so presenting the charge through an induction to bring forth a to a great extent damped sinusoidal moving ridge of finite continuance to the bosom by utilizing paddle electrodes. The work of Lown was taken to clinical application by an applied scientist Barouh Berkovits with his cardioverter.

The Lown wave form, as it was known became the criterion for defibrillation until the late eightiess when legion surveies showed that biphasic truncated wave form ( BTE ) was every bit as efficient while necessitating the bringing of lower degrees of energy to bring forth defibrillation. A side consequence was the important decrease in weight of the machine. The BTE wave form, combined with automatic measuring of transthoracic electric resistance is the footing for modern defibrillators. ( news-medical 2010 )

Portable units become available

A major discovery was the debut of portable defibrillators used out of the infirmary. This was pioneered in the early 1960s by Frank Pantridge in Belfast. Today the portable defibrillators are among the many of import tools carried by ambulances. Using this device is the lone proved manner to revive a individual who has had a cardiac apprehension un-witnessed by EMS who is still in relentless ventricular fibrillation or ventricular tachycardia at the reaching of pre-hospital suppliers. There have been gradual betterments in the design of defibrillators, partially based on the work in developing implantable versions, which have led to the handiness of machine-controlled external defibrillators. These devices can analyze the bosom beat by themselves, name the shock-able beat, and charge to handle. This means that there are no clinical accomplishments required to utilize the device and this allows for ballad people to react to emergencies efficaciously. ( news-medical 2010 )

Change to a Biphasic Waveform

Until the late eightiess, external defibrillators delivered a Lown type wave form which was a to a great extent damped sinusoidal impulse holding a chiefly uniphasic feature. Biphasic defribrillation, nevertheless, alternates the way of the pulsations, finishing one rhythm in about 10 msecs. Biphasic defibrillation was originally developed and used for implantable cardioverter-defibrillator. When applied to external defibrillators, biphasic defibrillation significantly decreases the energy degree that is necessary for successful defibrillation. In bend, this decreases hazard of Burnss and myocardial harm.

Ventricular fibrillation ( VF ) could be returned to normal fistula beat in 60 % of cardiac arresti??patients treated with a individual daze from a monophasic defibrillator. Most biphasic defibrillators have a first daze success rate of greater than 90 % . ( news-medical 2010 )

Implantable devices

A farther development in defibrillation came with the innovation of the implantable device, known as an implantable cardioverter-defibrillator ( or ICD ) . This was pioneered at Sinai Hospital in Baltimore by a squad that included Stephen Heilman, Alois Langer, Jack Lattuca, Morton Mower, Michel Mirowski, and Mir Imran, with the aid of industrial confederate Intec Systems of Pittsburgh. Mirowski so teamed up with Mower and Staewen, and by working together they commenced their research in 1969 but it was 11 old ages before they treated their first patient. Similar developmental work was carried out by Schuder and co-workers at the University of Missouri.

The work was commenced, despite uncertainties amongst taking experts in the field of arrhythmias and sudden decease. There was uncertainty that their thoughts would of all time go a clinical world. In 1962 Bernard Lown introduced the external DC defibrillator. This device applied a direct current from a discharging capacitance through the chest wall into the bosom to halt bosom fibrillation. In 1972, Lown stated in the diary ”Circulation ” , “ The really rare patient who has frequent turns of ventricular fibrillation is best treated in a coronary attention unit and is better served by an effectual antiarrhythmic plan or surgical rectification of unequal coronary blood flow or ventricular malfunction. In fact, the implanted defibrillator system represents an imperfect solution in hunt of a plausible and practical application. ”

The jobs to be overcome were the design of a system which would let sensing of ventricular fibrillation or ventricular tachycardia. Despite the deficiency of fiscal backup and grants, they persisted and the first device was implanted in February 1980 at Johns Hopkins Hospital by Dr. Levi Watkins, Jr. Modern ICDs do non necessitate a thoracotomy and possess tempo, cardioversion, and defibrillation capablenesss.

The innovation of implantable units is priceless to some regular sick persons of bosom jobs, although they are by and large merely given to those people who have already had a cardiac episode. ( news-medical 2010 )

Chapter 2

Regulatory personal businesss

Radio

Radio Frequency

EMC

Medical intervention Device

Testing

Quality Management System

ISO 13485

Boxing

Pacesetter

Sensor Layer

Electric resistance Spectroscopy

Electric resistance Spectroscopy ( IS ) is a general term used for a little signal measuring of the additive electrical response of a stuff and the subsequent analysis of the response to give utile information about the physicochemical belongingss of a system. The analysis of this system is by and large carried out in the frequence sphere, although the measurings are sometimes made in the clip sphere and so the Fourier transformed to the frequence sphere. Impedance spectrometry is non limited to measurement and analysis of informations at the electric resistance degree ( e.g. , electric resistance vs. frequence ) but may besides include any of the four basic immittance degrees. Most by and large impedance spectrometry by and large stands for immittance spectrometry ( Donald 1992 ) .

There are two chief classs of electric resistance spectrometry: Electrochemical IS ( EIS ) and everything else. EIS involves the measuring and analysis of stuffs in which ionic conductivity strongly predominates. Examples of these stuffs are solid and liquid electrolytes, fused salts, ionically carry oning spectacless and polymers. EIS is besides valuable into the survey of fuel cells, rechargeable batteries and corrosion.

The staying class of electric resistance spectrometry applies to the dielectric stuffs: solid or liquid non music directors whose electrical features involve dipolar rotary motion, and to stuffs with preponderantly electronic conductivity. Examples of these are individual crystal or formless semiconducting materials, spectacless and polymers. It is deserving observing that although EIS is the most quickly turning country of electric resistance spectrometry ; non-electrochemical electric resistance spectrometry measurings came foremost and are still an built-in portion in both basic and applied countries. ( Donald 1992 )

Data and Control Layer

AD5933 Impedance bit

The AD5933 is a high preciseness electric resistance convertor system solution that combines an on-board frequence generator with a 12-bit, 1 MSPS, analog-to-digital convertor ( ADC ) . The frequence generator allows an external complex electric resistance to be excited with a known frequence. The response signal from the electric resistance is sampled by the on-board ADC and a distinct Fourier transform ( DFT ) is processed by an on-board DSP engine. The DFT algorithm returns a existent and fanciful data-word at each end product frequence.

Once calibrated, the magnitude of the electric resistance and comparative stage of the electric resistance at each frequence point along the expanse is easy calculated. This is done off bit utilizing the existent and fanciful registry contents, which can be read from the consecutive I2C interface ( Analog 2010 ) .

Figure 4 AD5933 Impedance Chip ( Analog 2010 )

Microcontroller

A microcontroller is a computing machine. All computing machines, whether speaking about persomal desktop computing machines or a big mainframe computing machine in a company or a microcontroller, all have several things in common:

1. All computing machines have a cardinal processing unit ( CPU ) that executes plans. When utilizing the computing machine to look up a web browser the CPU is put to deathing a plan to open this web browser and show it on screen.

2. The CPU loads the plan. On the desktop, the browser plan is loaded from the difficult disc.

3. The computing machine has random entree memory ( RAM ) where variables can be stored.

4. The computing machine has some input and end product devices so it can interact with people. On a desktop machine, the keyboard and mouse are input devices and the proctor and pressman are end product devices. The difficult disc is an I/O device that can manage both inputs and end products.

The desktop computing machines being used are general purpose computing machines that can run any of 1000s of plans. Microcontrollers are particular purpose computing machines. Microcontrollers perform one undertaking good. There are plentifulness of other features that define microcontrollers. If a computing machine matches a bulk of these features, so it can be called a microcontroller. Microcontrollers are embedded inside some other devices so they can command the characteristics and actions of the merchandise.

1. Microcontrollers are dedicated to one specific undertaking and run one plan. The plan is stored in read merely memory ( ROM ) and normally does non alter.

2. Microcontrollers are frequently low power devices. A desktop computing machine is about ever plugged into a wall socket and consumes 50 Watts of electricity. As an option a battery powered microcontroller might devour 50 milliwatts.

3. Microcontrollers have a dedicated input device and frequently but non ever have a little LED or LCD show for end product. A microcontroller takes input from the device it is commanding and controls the device by directing different signals to different parts in the device.

4. Microcontrollers are frequently little and low cost. The constituents are chosen to understate size and to be every bit cheap as possible ( Works 2010 )

ATmega128L

The ATmega128L provides the followers:

* 128Kbytes of In-System Programmable Flash with Read-While-Write capablenesss

* 4Kbytes EEPROM,

* 4Kbytes SRAM,

* 53 general intent I/O lines,

* 32 general intent working registries,

* Real Time Counter ( RTC ) ,

* Four flexible Timer/Counters with comparison manners and PWM,

* 2 USARTs,

* Byte oriented Two-wire Serial Interface,

* 8-channel, 10-bit ADC with optional differential input phase with programmable addition

* Programmable Watchdog Timer with Internal Oscillator

* SPI consecutive port,

* IEEE venereal disease. 1149.1 compliant

* JTAG trial interface, besides used for accessing the On-chip Debug system and scheduling and six package selectable power salvaging manners ( ATmel 2011 ) .

Figure 6 ATmega128L Block Diagram ( Atmel 2011 )

Power Delivery and Control Layer

RFID

RFID ( radio frequence designation ) this is a engineering that is similar to that of the barcode designation system. With RFID, the electromagnetic or electrostatic yoke in the wireless frequence part of the electromagnetic spectrum is used to convey signals. This system works by holding both a sender and an aerial, which will read the wireless frequence and reassign the information to a processing device, and a transponder, or ticket, which is an incorporate circuit incorporating the wireless frequence circuitry and information to be transmitted. The RFID systems can be used in a scope of applications from one extreme to the other such as vesture tickets to missiles to pet tickets to nutrient, anyplace where a alone designation system is needed. Some auto fabrication installations use RFID systems to travel autos through an assembly line. At each phase of production, the RFID ticket tells the computing machines what the following phase of automated assembly is.

One of the chief differences that exist between RFID and the barcode system is that RFID eliminates the demand for in-of-line sight reading that saloon coding depends on. Besides, RFID scanning can be done at a greater distance than that of saloon cryptography. High frequence RFID systems ( 850 MHz to 950 MHZ and 2.4 GHz to 2.5 GHz ) offer transmittal scopes of more than 90 pess, although wavelengths in the 2.4 GHz scope are absorbed by H2O and hence have restrictions. ( Webopedia 2011 )

Beginning: hypertext transfer protocol: //www.insystems.de/eng/Produkte/rfid.html

Medical Use of Radio Frequency Energy

Radio frequence is a signifier of electrical energy that has been used in medical applications for decennaries. One of the interventions that RF is used for in medical applications is rapid heartbeat syndrome. RF extirpation is used to handle some types of rapid bosom whipping, particularly that of Wolff Parkinson White syndrome. A catheter, with an electrode at its tip, transmits RF energy through an accessary tract to the bosom musculus, doing cells in a really little country to decease. That stops the country from carry oning the excess urges doing the rapid pulses. The chief ground it is being used today is because RF is absorbed by the organic structure and this can be used for the most advanced surgical techniques, and for this ground it is replacing optical masers in everything from prostatic malignant neoplastic disease to cardiovascular processs. ( locateadoc 2010 )

Chapter 3

Overview

The new device being purposed is extremely based on two documents, Escalano ( 2004 ) into wireless atrial powered defibrillation and electric resistance spectrometry to find a wellness variable status by Walsh ( 2010 ) . With the usage of the two documents a new engineering utilizing a low cost radio enabled implantable microelectronic platform for tissue electric resistance monitoring in medical applications can be utilised. The device will be implanted into the organic structure mensurating the current province of the atrium and utilizing this information to make up one’s mind the best class of action of the device in the organic structure, i.e. utilizing the device to defibrillate the patient or for the device to power down and utilize some medicine on the patient.

This new device will be radical as there is more comfort given to the patient as they will non hold to travel for medical examination with the physician the whole clip and that they are invariably acquiring a signifier of intervention while the device is operation. This device will besides be wirelessly powered so no demand for batteries. The device will besides give feedback to a base station that a physician will be able to read this information to see if the device is working or to cognize if medicine is needed.

The device will be broken down into three beds and these beds will be discussed in item. These three beds are:

1. Front terminal detector bed

2. Datas managing bed

3. Wireless bed

Front End Sensor Technology

The device has to be able to mensurate and observe any alterations of the cardiac beat of the atrium. To be able to execute this undertaking the device will hold to be connected to the atrium wall. The method that is used to mensurate these alterations is impedance spectrometry. The device will be able to mensurate the electric resistance on the tissue whether the tissue is deceasing or there is an anomalousness to the regular rhythm. The tips of the device connected to the wall will mensurate this electric resistance. There is an ac current sent to prove these bing conditions in the atrium and consequences will be gathered. These consequences will be processed by an electric resistance bit.

The bit that was selected had to hold certain demands which are as follows:

* Low cost trade good portion

* Low power use

* Can run in legion environments

The bit chosen is developed Analogue Devices who manufacture the AD5933 illumination electric resistance french friess.

Data Handling Technology

Wireless Technology

Chapter 4

Chapter 5

Chapter 6

Mentions

Afanswers ( 2011 ) . “ Atrial fibrillation. ” from hypertext transfer protocol: //www.afanswers.com/treatment.html.

Analog ( 2010 ) . “ AD5933 Impedance Chip. ” from hypertext transfer protocol: //www.analog.com/en/rfif-components/direct-digital-synthesis-dds/ad5933/products/prodpopup.html? display=popup.

ATmel ( 2011 ) . “ ATmega128L. ”

Donald, R. M. ( 1992 ) . “ Impedance Spectroscopy. ” Annalss o f Biomedical Engineering 20.

Dresing, T. J. and R. A. Schweikert ( 2011 ) . “ Atrial fibrillation. ” from hypertext transfer protocol: //www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/cardiology/atrial-fibrillation/ .

locateadoc ( 2010 ) . “ Medical Use of Radiofrequency ( RF ) Energy. ” from hypertext transfer protocol: //www.locateadoc.com/articles/medical-use-of-radiofrequency-rf-energy-1224.html.

news-medical ( 2010 ) . “ Defibrillation. ” from hypertext transfer protocol: //www.news-medical.net/health/Defibrillator-What-is-a-Defibrillator.aspx.

P.R.Walsh, N. O. M. , O.J. Escalona ( 2009 ) . “ A LOW-COST MICROELECTRONIC PLATFORM FOR WIRELESS ENABLEMENT

OF IMPLANTABLE MEDICAL DEVICES. ”

praxiom ( 2011 ) . “ Implantable medical device. ” from hypertext transfer protocol: //www.praxiom.com/iso-13485-definitions.htm.

Problems, H. ( 2009 ) . “ Heart Problems. ” from hypertext transfer protocol: //www.heart-problems.net/arrhythmia/Medication_or_ablation_to_cure_atrial_fibrillation__71.html.

Stopafib ( 2011 ) . “ Atrial Fibrillation. ” from hypertext transfer protocol: //www.stopafib.org/ .

Webopedia ( 2011 ) . “ RFID. ” from hypertext transfer protocol: //www.webopedia.com/TERM/R/RFID.html.

Plants, H. S. ( 2010 ) . “ How Microcontrollers Work. ” from hypertext transfer protocol: //electronics.howstuffworks.com/microcontroller1.htm.

hypertext transfer protocol: //www.heart-problems.net/arrhythmia/Medication_or_ablation_to_cure_atrial_fibrillation__71.html