Artificial Cardiac Pacemaker - Coursework Example

Pacemaker By: Introduction The pacemaker is an essential gadget derived from polymer that has highly impacted the medical sector and the human race in totality. The device entails a combined case of electronic and intense polymer material application to generate eventually the elegant device applied in the medical sector (Khandpur, 2003, p63). The entailment of electronic, biomedical apparatus that can control a person’s heartbeat when its ordinary regulating system breaks down is highly vital. It is a tiny box implanted surgically into the chest space cavity and possesses electrodes that are in unswerving contact with tissues of the heart. The device was originally developed around 1950s. The gadget has undergone massive design alterations and has found new use and applications following its invention. Currently, the device is extensively used, implanted in many thousands of patients yearly (Khandpur, 2003, p83). Background The polymer made pacemaker has mainly four chambers that have significant composition of made of two pumps. Normally, the pump at the right location receives the blood released from the entire body and finally forces it or pumps it up to the lungs. On contrary, the left segment pump collects blood coming from the lungs and eventually pumps it to the entire body. The designs of the pumps allow for every pump is derived from chambers having an atrium and an entailed ventricle segment. Typically, the designed atrium accumulates any incoming blood and usually when it contracts; it normally forces the blood to ventricle sections. Finally following the contraction of leads the blood to be pumped outside the heart. If the heart operates normally, the pumping process is characteristically synchronized by the entire pacemaker section of the heart or also the sinoatrial node that is found right atrium. The designed and natural pacemaker usually has the capability to create electrical power. The electrical signal and entailed impulse is conventionally caused by the diffusion of available calcium ions or potassium ions locate across the cell membrane in the pacemaker locale. Normally, the derived impulse generated by the movement of the ions is initially transferred to atria. The transfer causes them to contract and eventually pressure blood into entire ventricles sections. Rhythmically, after every 150 milliseconds, the generated impulse shifts to the ventricles. The action causes the ventricles to contract and push the blood out of the heart. Normally, as the generated impulse relocates or shifts from every hollow of the heart the segment relaxes. Usually, the designed electronic pacemakers are well-tailored to typically supplement the existent hearts ordinary controls and to control the beatings of the heart when there is break down or heart failure. The device is normally capable of undertaking this process since it is normally well equipped with attached sensors that frequently monitor the patient’s state of the heart. Normally, there is a battery that sends electrical power when wanted, through mainly lead wires to the entire heart and excite the heart to beat. While the artificial pacemakers have the outer units, it can also be properly and permanently implanted person’s chest. The process is usually conducted by initially guiding the esteemed lead through the vein and eventually into portions of the heart. The process is typically facilitated by fluoroscopic imaging. The pacemaker is usually placed in a pocket that is formed under surgical process above the upper part of the abdominal segment. The attached lead wire is also linked to the pacemaker, and the derived the pocket is eventually sewn thus shutting the hollow. This is normally vast improvement over original techniques and entailed methods, which compelled opening the entire chest space and essential attaching the lead wire to the external surface of the heart to facilitate optimum functioning of the heart. History The derived idea of entailing electronic apparatus to offer consistent guideline of the continuous beating heart was not originally obvious to the initial developers and designers of the pacemaker. The original pacemaker was invented and developed by Paul Zoll in the year 1952. The invented device was portable adaptation of an enhanced cardiac resuscitator. The apparatus had double lead wires that were usually attached to a located belt initially worn by a specific patient. It was again plugged on the closest wall socket, and a current or an electric shock was strategically passed to allow for stimulation of the heart of a person having an attack. The systematic stimulation was typically satisfactory and sufficient to generate normal functioning of the heart or even resumption of normal working process of the heart. While reasonably effectual, this original pacemaker was chiefly applied in emergency situations and cases. From 1957 to 1960 very noteworthy redesigns and entailed improvements were undertaken on Zoll’s initial invention. There was intensive urge and need to reduce the quantity of voltage desired to start over the heart and augment the length of moment electronic pacing steadily be appropriately accomplished. Walton Lillehei designed a new pacemaker that entailed redesigned features having leads linked on the exterior wall of the heart. Following, in 1958, a feature of the battery was included into the system as a power source thus allowing the pacemaker to be accurately portable device which also permitted the patients having them to be mobile. The feature also allowed the patients to utilize the pacemaker incessantly instead of barely for emergencies cases alone. This new design also was placed outside the body. Afterwards, designers Wilson Greatbatch and William Chardack discovered the initial implantable pacemaker and it was first implanted in a breathing or living patient in 1960. The contemporary system for lodging a pacemaker into a person’s heart was later nurtured and developed by Seymour Furman to make it more efficient process. As an alternative of cutting a small cavity into the chest cavity, he applied technique of inserting the certain leads into the vein. The leads were then threaded up into the attached ventricles. Since the leads were now low into the heart small voltages were required to regulate the process of heartbeat. This attachment case typically increased the span of point a pacemaker could take a while inside a patient. The new method was not hugely applied as in the late 1960s majority of cardiac specialists had moved to Furmans endocardia pacemakers. Years afterwards, improvements have been steadily incorporated to the pacemaker design. The improvements entail smaller pacemaker devices and improving the duration and time lasting of the battery of even the entailed computer controls process (Tranquillo, 2014, p98). Fig (a): first pacemaker designed in 1958 Main Raw Materials According to (Bronzino, 2000, p67), the inclusion of polymer in the process of designing is very significant. To improve the efficiency of the instrument, several materials are included in the construction and design of the pacemaker. Most of these portions are pharnacologically inert or inactive components which are mostly non-toxic. In addition, they are easily sterilizable, and even capable of working or functioning in the ecological conditions eminent in the human body (Tranquillo, 2014, p92). An assortment of parts of the pacemaker, counting the casing, entailed microelectronics, and the essential leads are usually designed and made with excellent biocompatible materials or incorporated bodies. Usually, the entire casing is usually designed from titanium or even incorporated titanium alloy material, and the lead is also precisely designed and made from a metal alloy. Fig (b): an x-ray image showing early pacemaker inserted in human chest cavity The entire body hence insulated by entailing the polymer which in most cases are polyurethane, but barely the metal end point or tip of the lead is normally exposed. The classification of Polyurethane noted the resilience, flexibility and enhanced durability it presents to the material engineering space. The polymer can usually assume the roles of paint, rubber, cotton, or even metal in varying range of applications found in most cases across practically all fields. The material can usually be hard comparable to fiberglass or even squishy typical to upholstery foam and can also take the protective quality varnish. In most cases, the material is usually bouncy typical to rubber, and it has been the using since 1940s and has been applied in a wide range of items. The polymer molecule which contains a series of repeating minor units referred to as monomers and these bases on based on the chemical structure of the substance. The material is usually prepared and manufactured by incorporating or combining double types of entailed compounds. The compounds are usually diisocyanate combined with a diol, which usually basic monomers in an enhanced chemical reaction. The resultant material is usually the basic material whose product whose alterations or variations can be be stretched intensively, scratched and normally remained moderately indestructible. With regards to the varying and different diisocyanates, diol and polyol compositions, the product polyurethane can usually be informed of liquid, solid or foam. For the manufacture of pacemaker, solid product is usually desired. Some polyurethane is normally grouped as an elastomer since most of them have the elastic properties and qualities. Apart from making pacemaker, polyurethane is also applied in deriving other beneficial for parts and items like wheels of dollies that are designed to absorb shock in the absence of compressing extensively. The material can be extremely elastic when entailed in use while in foam insulator or even be in construction for enhancement of cushioning or upholstery purpose. In some cases, it is deformed to recurrently but still it maintains the original shape a property that is widely called maintaining the structural memory. The combined and varying qualities are attached to eventual provide an essential combination of qualities desirable for the derivation of pacemaker device (Baran, Kiani & Samuel, 2013, p92). With reference to (Tranquillo, 2014, p98), the other entailed and significant circuitry is frequently made of customized from conventional silicon semiconductors. Currently, many versions and types of pacemakers are available due to varying applications of designs in the market. The establishment a society NASPE has extensively classified the devices according to the categories on which the heart parts and segments or chamber are paced or main sections on which chamber is factually sensed. Consistent with Baran, Kiani & Samuel (2013, p36), there are also extreme cases where the pacemaker is systematically placed in a position that are able to sense beats and the ability to entail significant extents of programs. Disregarding the varying models available in the market virtually all pacemakers are fundamentally comprised of a battery, attached lead wire circuitry. The main function of the pacemaker battery is to save sufficient energy to enhance properly and excite the heart with a shake of electrical power. The battery also supplies power to the attached sensors and entailed timing devices. The enhanced modern technology allows for the insertion of the devices into the human body and thus special regards are placed on the eventual categories of the special intrinsic portions of the battery. The initial requirement is that they must be able to generate approximately five volts of required power which is usually a level that is typically slightly above the total amount wanted to excite the heart. Another critical requirement is the need to retain their energy for many years which usually is minimum time outline of four years. The included batteries are also required to have very predictable life cycle which would allow the doctor denote replacement is a must. Lastly, the battery accessory must function hermetically referring to ability to work even in cases of airtight or even sealed. Furthermore, the entailed dual metal usually has anode and cathode points that work for the device. The batteries are mostly made from lithium /cadmium or even nuclear batteries. Normally, pacemaker typical leads are usually gaunt incorporating insulated wires that are also well designed to convey electricity along to the heart from the battery. Contemporarily, varying with the pacemaker, the instrument may contain a single lead on most single chamber pacemakers but it may usually have two leads, for dual section chamber pacemakers. Usually with entailed constant and timely beating of the heart the wires are unremittingly flexed and thus are compelled to be defiant to contemporary fracture. The market now has are many varying components and styles of leads accessible, with primary drawing differences times recognizable. Some of the leads have a well-built screw-in tips that aid in anchoring them to the inner placed wall of the heart. The entailment of the circuitry is the regulation center of the entire pacemaker. The center is normally entrenched in the heart and normally facilitates monitoring sensors, timing circuits and voltage regulators (Bronzino, 2000, p88). Fig (c): Pacemaker design parts and varying views According to (Baran, Kiani & Samuel, 2013, p32), the system’s circuitry is normally comprised of resistors, diodes, capacitors, and semiconductors. Conventional pacemaker circuitry design is a vast enhancement over the original models. After incorporation of semi-conductors, there has been extreme reduction in the size of circuit boards and energy requirements have also plummeted as this new device emits less heat and are exceedingly reliable. The complex manufacturing Process undergone by the pacemaker reveals the extreme levels of sophistications passed through to deliver the device into the market (Bronzino, 2000, p96). In many cases, manufacturers depend on external suppliers to supply many of the constituent parts. Normally the construction and manufacturing of a pacemaker is not a direct procedure but a properly integrated and combined model. Most of the assembled parts are constructed singly, but the battery, the circuitry and leads are usually constructed independently, and then pieced jointly to create the finishing product. During making of the battery for the pacemaker, mainly lithium and iodine cell is typically entailed. According to (Bronzino, 2000, p86), there is usually combining and mixing of the iodine an entailed polymer for instance poly2-vinyl pyridine (PVP) which heated mutually, creating a molten charge-transfer compound. The liquid is then conveyed into a half-moon-shaped, creating a preformed cell which usually is comprised of other parts of the battery. The cell helps in counting the lithium anode that adopts the part of positive charge and inclusion of a cathode that acts as the collector screen. Eventually, the included the iodine/polymer mixture usually solidifies and as it hence cools to generate the cathode. The finally the battery is normally hermetically entirely sealed to avoid moisture getting inside. On contrary, the leads are characteristically derived from of a metal alloy. The electrical conductor wire is normally made by incorporation of an extrusion process that allows the metal is heating to reach the melting point. The manufacturers undertake the heating process to the eventual case where the melt is collected and pushed through a definite size opening after which the component is normally bundled and treated with polymeric insulator for instance polyurethane. At one end of the derived lead wire is normally shaped into tip, and the other end is well fitted with a pacemaker link. The motherboard provides a platform where the device is placed (Tranquillo, 2014, p48). Fig (d): location of pacemaker implant in the heart other main components attached to the motherboard base includes resistors, capacitors, semiconductor chips, and other incorporated devices. By entailing the process of hybridization, all the components are typically combined to create on solitary but complex circuit (Tranquillo, 2014, p92). The process of construction commences with a small board normally less than 0.32 sq in which reveals an electronic pattern mapped out. All the essential component and intricate parts are put in the correct place on the board. The portions are then properly fixed by applying a smallest number of entailed soldering welds. After going through the processes, the instrument is now usually ready for eventual compilation, assembly and eventual packaging (Tranquillo, 2014, p68). Final assembly and entailed packaging only take after collection of all the various components. The incorporated circuitry is linked to the device battery then both properly inserted into the prevailing metal casing. The metal casing applied in this case is classically made from titanium or even titanium alloy. According to (Ionescu, 2005, p57), the casing is constructed in manifold pieces that are sealed and packed together induction of the other pacemaker components and parts. Normally, affixed fitting is normally provided to the casing thus availing connecting points for the leads. Fig (e): modern pacemaker The complete devices packed into final packaging together with entailed accessories and usually followed exhaustive testing; they are normally sent out to other distributors and lastly to doctors. The manufacturing process has high levels of quality control measures. The excellence of every pacemaker is normally guaranteed by timely making visual or electrical inspections in the whole production process. The entailed assessments and tests typically detect most inherent flaws and threats to the eventual users (Tranquillo, 2014, p68). The incorporated batteries are also guaranteed of reliability and are specially manufactured and properly assessed or hence elevating associated costs. The entire functionality of the complete pacemaker is concurrently tested and assessed before it is left for sale. Most of the entailed tests are conducted under changeable environmental conditions, for instance, excessive humidity of even in very stressing states. Most eminent manufacturers usually establish their excellence standards for various pacemakers that they manufacture (Tranquillo, 2014, p08). These standards and corresponding outlines on performance recommendations and suggestions are needed and demanded by associated medical organizations or even the governmental agencies. Fig (f): placement of modern pacemaker Enhanced changes and advances in the application of the battery and generator technology have created improved changes in the Pacemaker technology comparing from the date of introduction in the 1958 to current era. This act has augmented extends of longevity of the device. The earliest devices applied a typical asynchronous pacing model that created imperative effect in reduction of rate of mortality conventional to most surgically induced heart block. Other typical changes are realizable on enhanced Ventricular oriented pacemakers defeating of predicaments relatable to asynchronous competitive pacing. The model also revealed pacemaker syndrome. Increased longevity of the battery enhanced the ability to program the device for entirely function for long period and become very independent as compared to the earlier model. The US has established standards for manufacturing of pacemaker and is usually classified according to class III biomedical devices. The main weaknesses fall quality checking of standards for the larger US markets considering that there is a collection of manufacturers available in the market. This categorization entails that they demand a pre-market consent from the United States body or organ. With concurrent growing numbers of the senior citizens in the US, the market anticipates that wider percentage of the entailed population will need a pacemaker It is worth noting that there are increased research are underway to develop excellent devices, very reliable devices. According to (Ionescu, 2005, p56), the entailed research also invests in increasing versatility and guarantee for long lasting life cycle duration. There are critical advances in new battery technology, for an instance, inclusion of radioactive isotopes for provision of power which with final incorporation shall outstandingly improve the durability of the implanted pacemaker types. In conclusion, the essence of pacemaker in the contemporary and modern world is very appreciative as it saves lives of a wide range of population especially the older generations who have predicaments with maintaining their normal life. Bibliography Baran, G. R., Kiani, M. F., & Samuel, S. P. (2013). Healthcare And Biomedical Technology In The 21st Century: An Introduction For Non-Science Majors. Http://Dx.Doi.Org/10.1007/978-1-4614-8541-4. Bronzino, J. D. (2000). The Biomedical Engineering Handbook. Boca Raton, Fl, Crc Press. Ionescu, M. (2005). Chemistry And Technology Of Polyols For Polyurethanes. Shrewsbury, Rapra Technology. Khandpur, R. S. (2003). Handbook Of Biomedical Instrumentation. New Delhi, Tata Mcgraw-Hill. Tranquillo, J. V. (2014). Biomedical Signals And Systems. Http://Www.Morganclaypool.Com/Doi/Pdf/10.2200/S00551ed1v01y201311bme052. Read More