Medical device: Defibrillator - Essay Example

Medical device: Defibrillator A Defibrillator refers to an electronic device that is applied to address the fibrillation heart problem, through delivering a therapeutic dose of a brief electric shock, to the areas of the heart that is affected by the problem (Hayes, Fallon & Noble, 2002 p757). The therapeutic dose of electrical energy applied serves to counteract the fibrillation of the heart muscles, and thus allow for the restoration of the normal heartbeat. History of device development, the clinical problem it addresses and its therapeutic function History of Defibrillator development The history of heart problem dates as back as the history of man. Nevertheless, the heart problems are so diverse, that they cannot be categorized into a single disease. The same applies for their causes, with many cardiovascular problems being associated with different causative agents. However, Ventricular fibrillation refers to a heart condition where the cardiac muscles of the ventricles in the heart experiences uncoordinated contractions, which pose a fatal medical emergency, that must be addressed within seconds, lest the condition degenerates into carcinogenic shock (Paradis, 2007 p500). This degeneration may in turn affect the blood circulation into the heart by causing a cessation of effective blood flow into the heart muscles, which may result to cardiac death (American Association of Cardiovascular, 2004 p202). It is this condition of the heart that caused two physiologists from the University of Geneva, Prevost and Batelli, to carry out experimentation on Ventricular fibrillation with a dog, which indicated that small shocks would induce Ventricular fibrillation in dogs, and the application of higher charges of the shocks would reverse the condition (Pacifico, 2002 p21). They first demonstrated this concept in 1889, after which many other scholars delved into similar studies, to understand how the Ventricular fibrillation could be reversed, and thus allow normal blood circulation in the heart. The studies in this respect continued until the first application of therapeutic dose of a brief electric shock was undertaken in human by Claude Beck, who was a professor of surgery, in 1947 (Chow & Buxton, 2006 p11). He developed a theory which postulated that Ventricular fibrillation occurred in hearts that were too good to be allowed to die. Beck applied the technique successfully on a 14 year old boy, through applying brief electric shocks on both sides of the heart, which had experienced fibrillation, and the result proved to have helped the boy regain his normal sinus rhythm (ECG facts made incredibly quick, 2009 p104). However the technique was first applied through surgically opening the chest and applying the brief electric shocks directly on the heart, through using two electric shock pedals on either side of the heart. Having been proved to be a viable technique that could help address the problem of Ventricular fibrillation, it was now time to address the problems that were noted to arise out of the direct application of the shocks on the heart. The post mortem investigations showed that there was a damage of the cells of the heart muscles. The trend continued until the 1950s, when the Defibrillator was used through an open heart cavity, where the shock pedals were applied directly on the sides of the heart, applying alternating voltage of between 300 and 100 volts (Jance, 2012 p33). In the mid 1950s, Dr V. Eskin pioneered an external Defibrillator device, which applied external electrodes through the chest cavity into the heart, with an alternating voltage of more than 1000 volts (American Association of Cardiovascular, 2004 p207). The advancement in the field was further made by Bernard Lown, who pioneered the development of Defibrillator devices that used direct current in 1959, which was then followed by the breakthrough of introducing portable Defibrillators, which was done by Prof. Pantridge, in 1960 (World Health Organization, 2010 p62). From then onwards, Defibrillators have remained the single most important devices for addressing the Ventricular fibrillation condition of the heart. The clinical problem the Defibrillator addresses The Defibrillator is used to address the heart problem of Ventricular fibrillation and arrhythmia, which are both heart conditions that are associated with irregular heartbeat (Kroll, 1996 p77). The device is used to help patients who have abnormal electrical heart activities, which may range from heartbeats that are too fast, to the ones that too slow. Whenever such problems are experienced in the heart, there are higher chances that the heart may experience cardiac arrest, which in turn may result to cardiac death (World Health Organization, 2010 p62). Therefore, the Defibrillator is used to apply brief electric shocks oh the muscles of the heart, which could have uncoordinated contractions, that threatens to stall the heart beat completely, while stopping the heart from pumping blood. Therefore, the Defibrillator is used to reset the hearts rhythm, and thus help the heart resume its normal heartbeat and rate (Jordaens & Theuns, 2007 p44). A brief description of the therapeutic function The therapeutic function of the Defibrillator device occurs through the process of placing the electrodes of the device, which can either be pads or peddles, on the chest of the patient by a medical technician. However, considering that the area between the skin and the electrode, affects the transmission of the electrical charge to the heart, apple gel is applied on the skin area where the electrode pads or peddles are to be placed, to direct the electrical pulse into the heart (Hayes, Fallon & Noble, 2002 p762). After the Defibrillator is placed on the chest cavity, it sends the electrical pulse into the heart, through the chest cavity. Depending on the type of the Defibrillator being used, the voltage is either measured directly by the device, or the medical technician sets it manually, depending on the monitored heart rate (American Association of Cardiovascular, 2004 p210). Once the electrical shock reaches the heart, the heart stops momentarily, for the pace maker of the heart to regain control of the heart functionality, after which the heart regains its normal rhythm, which then allows the heart regain its usual heartbeat and rate, and thus continues to pump blood throughout the body (Khandpur, 2003 p715). A description of the functional components of the device A Defibrillator is made up of several component parts, which are very essential for its therapeutic application, to help the heart regain its normal heartbeat and rate. While there could be various components which may run into tens of numbers, there are some four fundamental components of the Defibrillator, which interacts to allow the device restore the normal heart rhythm. The Defibrillator ECG front end These refers to the anterior components of the Defibrillator, which are the parts used to make contact with the body of the patient, thus transferring the electrical shock from the Defibrillator device, into the body of the patient, and directly to the heart. These parts of the device have the electrode components, which are provided with electricity conductive gel that allows the electric shock charge to be transferred from the device into the heart of the patient, through the chest cavity (ECG facts made incredibly quick, 2009 p105). However, peddles are highly preferred compared to the pads, due to the high speed with which they can be applied, considering that saving the life of a patient experiencing Ventricular fibrillation is a matter of life and death, which requires that the condition be addressed within few seconds. The modern Defibrillator have been designed to monitor the heart beat and rhythm, and then transmit the information back to the device, which then sets the voltage that is suitable to address the degree of Ventricular fibrillation that is discovered by the pedals. These components of the device are re-usable, and they only require cleaning and storage, until the next time, when the gel is applied on them, and then used to deliver the electric shock charge to a patient (Prutchi, 2005 p417). Controllers/Capacitors This is yet another vital component of the Defibrillator, which is used for storage. A Capacitor is the component of the Defibrillator that is used to store the energy required to address the Ventricular fibrillation condition of the heart, which is normally stored in form of electrical charge (Liem, 2001 p94). The electrical energy is stored in terms of electrical voltages that are transmitted to the heart when the device is used to revive the heartbeat of a patient, and the energy is normally released occasionally from the capacitor. Inside the Controller, there are other vital components of the device such as the conductor plates and the insulators, which are vital components during the process of device application. The insulator serves to protect against any loss of electrons from the storage component of the device, while the conductor is applied to lose the electrons, thus promoting current flow (How it works, 2000 p8). Infrared Communications/Inductors This refer to coils of wires that are found within the device, which are used to ensure that the electric charge that is released into the heart lasts for a reasonable duration, to help the heart stop momentarily, then regain its normal heart rhythm, through making the pace makers of the heart to regain control of the heartbeat functionality (Gambling, Douglas & McKay, 2008 p53). The Defibrillator is a device which is meant to deliver some shock into the heart, which then allows the heart to regain its normal heartbeat. However, this can only be achieved through sustaining the electric shock transmitted to the heart for a reasonable duration of time, so that the shock can re-activate the peace maker to regain control of the heart rhythm. Considering that the Defibrillator delivers the electric charge to the heart at a very high speed, the shock cannot reactivate the pacemaker, since it allows the electric charge to last for several milliseconds (Hayes, Fallon & Noble, 2002 p757). The prolonged electric charge by the inductors is achieved through the generation of electricity, which opposes the motion of the current that passes through them, allowing the electric charge to remain present for a while, which in turn gives time for the pacemakers to be reactivated and thus controls the heart rhythm back to the normal rate. Power source This is the last of the major components of the Defibrillator device, which consists of set-up transformers that increases the voltage (American Association of Cardiovascular, 2004 p212). The set-up transformers are used to convert a minute 240 volts of alternating current into massive 5000 VAC volts, allowing the Defibrillator to have sufficient electrical energy that can be applied to help the heart regain its normal heartbeat. While the open and direct application of the electrical shock into the heart muscles required between 300 and 1000 volts, the application of the electrical charge through the chest cavity requires more than 1000 volts, in order to deliver substantial electric shock to the heart (Lippincott, 2004 p242). Additionally, the application of step-up transformers allows for the opportunity for the medical technicians to choose among different amounts of charge, depending on the response of the heart monitors, which determines the amount of charge required to activate a patient’s pacemaker, and enable it to control the heartbeat back to normalcy (Chow & Buxton, 2006 p12). Usability and safety aspects of the device in terms of human factors engineering The usability of Defibrillator device is not without some safety challenges, which may render its application even more dangerous, if certain safety aspects of the device use are not adhered to (Jance, 2012 p77). Therefore, in terms of human factors engineering, the device has been designed with various aspects that allows for the safety of the users, as well as that of the patients. First, the Defibrillator device is designed with a patient interface that requires the application of surgical gel, to reduce the resistance of the electric current that flows through the skin to the heart, while also ensuring the impediment of chest burn (Aronfeld, 2013 n.p.). The standards and codes of regulations applicable in the medical procedures, for example the California AED Code of Regulations, require that such a gel shall be applied on the device at all times of its use (California Code of Regulations, 2009 p2). The other aspect of the safety aspect of the device in terms of human factor engineering is the inclusion of the paddle electrodes as the anterior face of the device, which allows for the transmission of the electric shock from the Defibrillator to the heart of the patient (Walker, n.p.). The paddles are designed in a way that makes them work as monitors, which is a safety precautionary measure for ensuring that the medical technician do not apply an electric voltage charge that is greater than necessary, which serves to protect the patient from the side effects of high voltage electrocution. The other design aspect that is focused on human factor engineering safety is the design of modern automated and semi-automated Defibrillators, with Self-adhesive electrodes (California Code of Regulations, 2009 p3). This design aspect is meant to ensure that such electrodes are readily installed with the surgical gel that helps in the transmission of the electric shock to the heart as well as in preventing burning of the chest, which is a safety precautionary measure, especially for the lay users who are not trained to use the Defibrillators. Since the lay-users may just apply the device on a patient without applying the necessary gel, the Self-adhesive electrodes serves to ensure that the patient is not burnt, since the electrodes automatically applies the gel and then transmits the electric charge (Kroll, 1996 p42). The standards and regulations for the use of Defibrillators provides that an untrained individual, who may not be licensed or qualified is granted the immunity, if he/she caused harm to the individual patient, while trying to save his/her life. The Cardiac Arrest Survival Act of the State of Florida provides that a lay man who is untrained in the use of Defibrillators should not be charged for any harm, on the event that he/she was trying to reasonably help someone who is in emergency (Aronfeld, 2013 n.p.). Thus, considering that people who are not trained are also allowed to administer the electric charge on an individual experiencing a Ventricular fibrillation, the provision of Self-adhesive electrodes on modern Defibrillators ensures the safety of the patient in case a lay man uses the devise, since the lay man may not apply the required gel before applying the device on the patient, which may cause great harm. According to Article 4 of the California Code of Regulations, covering the operational AED Service Provider and Vendor Requirements of the medical practitioners and other professionals applying the Defibrillators, provides that they should observe several guidelines while applying the device on patients. The standards of Defibrillators application requires that by the time of the device application on the patient, the patient must not be already in a state of sinus rhythm (California Code of Regulations, 2009 p5). The standards also provide that placement of the Defibrillators pedals should follow certain guidelines. While applying the device on the patient, a medical technician is supposed to place the pedals of the Defibrillators along the axis of the heart, and should avoid touching the transdermal patches, because they are flammable (Sanders, Lewis, Quick & McKenna, 2012 708.). Additionally, the regulations require that such device should not be allowed to touch any metallic object while being applied, since currents are likely to travel through the metal and cause burning (California Code of Regulations, 2009 p4). The regulations also provide that all oxygen supplying devices should be disconnected during the application of the device, considering that oxygen is a gas that supports combustion. The medical staff applying the Defibrillators are also prohibited from touching the patient, the bed or any other equipment that could be connected to the patient at the time of the device application, since the medical staff might also be affected by the electric current (Walker, n.p.). Finally, the regulations require that the device shall not be place directly on a woman’s breast and that the Defibrillator pedals should not have any charge at the time of application on the patient, to avoid injury (Walker, n.p.). References American Association of Cardiovascular & Pulmonary Rehabilitation. (2004). Guidelines for cardiac rehabilitation and secondary prevention programs. Champaign, Ill: Human Kinetics. Aronfeld, S. (2013). The Shocking Truth -- Florida's Defibrillator Law. The Huffing Post. 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