Overview of the Medical Defibrillator.pptx

Overview of the Medical Defibrillator

1. DEFIBRILLATORS

2. CLINICAL APPLICATIONS OF A DEFIBRILLATOR Defibrillators are devices that send an electric shock to the heart, stopping extremely rapid or irregular heart beats and restoring them to normal. Defibrillators are common treatments used in correcting; Cardiac dysrhythmias Ventricular fibrillation pulse-less tachycardia ( heart contracts too fast. This prevents the ventricles from filling with blood and stops blood flow to the body. Ventricular fibrillation is converted into a more efficient rhythm by applying a high energy shock to the heart, the sudden surge across the heart causes all muscle fibers to contract simultaneously.

3. Types of defibrillators Implantable Cardioverter Defibrillators (ICD)- internal defibrillation Automated external defibrillator (AED) – external defibrillation

4. Internal defibrillators Implantable cardioverter defibrillators (ICD) are also known as pacemakers. It has 3 major Components; Generator : triggers impulses Lead wires: Transferring impulses to the electrodes Electrodes: picking impulses from the heart. I mplanted devices deliver much lower energies, around 1 to 40 Joules

5. External defibrillator (AED) An automated external defibrillator (AED) is a lightweight, portable device that delivers an electric shock through the chest to the heart. The shock can potentially stop an irregular heart beat (arrhythmia) and allow a normal rhythm to resume following sudden cardiac arrest (SCA). These are designed for laypeople and deliver a fixed, preset amount of energy for simplicity and effectiveness, typically between 150 and 200 Joules for adults.

6. AED Use in Children Use pediatric pads Smaller Produce lower-energy shocks Follow diagram on pads for placement Pediatric pads should not be used on adults If pediatric pads are not available, use adult pads

7. Internal Pacemaker/Defibrillator May see bulge beneath victim’s skin Do not place AED over area—place it at least one or more inches away If victim’s body is jerking Implanted defibrillator may be giving shocks Wait until jerking ends

8. How AEDs Work Automatically checks victim’s heart rhythm to detect fibrillation Advises whether victim needs a shock The shock (defibrillation) is an attempt to return heart to a more normal rhythm

9. Time is Important AEDs are easy and simple to use but must be used right away With every minute that goes by, survival drops by about 10%

10. Main internal parts

11. TYPES OF SENSORS IN THE MACHINE There are two main types of sensors in defibrillators namely; Electrodes These are the pads that are placed on the patient's chest. They detect the patient's heart rhythm and send this information to the defibrillator's computer. The electrodes are small and rectangular pads that are self adhesive, they have a conductive gel layer on one side that adheres to the patient’s chest and metal contacts on the other side that connect to the defibrillator.

12. Defibrillator electrodes

13. Positioning of the electrodes

14. Types of sensors cont ….. 2. Reed switches These are used in some defibrillators to detect when the high-voltage current has been reached and in turn allows the defibrillator to deliver the shock safely. Reed switches used in defibrillators are very small cylindrical devices with two metal reeds sealed inside a glass or plastic tube. The reeds are normally open but when a magnet is brought close to the switch, the reeds are attracted to each other and close the switch, hence completing the circuit. Reed switches control the flow of high-voltage electricity. When the switches closed, it allows the electricity flow to the paddles which are then used to deliver a shock to the patient’s heart

15. Reed switch

16. Other types of sensors…. ● Heart sounds sensors can detect the sound of the heart beating. This information can be used to help the defibrillator's computer diagnose the patient's heart condition. ● Temperature sensors can detect the patient's body temperature. This information can be used to help the defibrillator's computer determine whether the patient is stable enough to receive a shock. ● Motion sensors can detect if the patient is moving. This information can be used to prevent the defibrillator from delivering a shock if the patient is not in a safe position. The specific sensors that are used in a defibrillator will depend on the type of defibrillator and its intended use. For example, an implantable defibrillator (ICD) will have different sensors than an automated external defibrillator (AED).

17. THE WORKING PRINCIPLE Based on the principle of stored energy A high voltage electric current is applied to the Heart muscle either directly (Internal Defibrillator) thr ough the open chest or indirectly (External Defibrillator) through the chest wall to terminate ven tricular Fibrillation. An energy s torage capacitor is charged at relatively slow rate from AC line. The stored energy in the capacitor is then delivered at a relatively rapid rate to the chest of the patient

18. CHALLENGES ASSOCIATED WITH DEFIBRILLATORS Patients are prone to developing skin burns from prolonged use of defibrillator paddles. Other patients’ heart muscles weaken, develop abnormal heart rhythms and blood clots. Defibrillators are limited for ventricular tachycardia (without pulse) or for ventricular fibrillation. Using it in any other kinds of arrhythmia would give a patient ventricular fibrillation, cardiac arrest and in worst case scenarios; death.

19. MAINTAINANCE 1. Battery Use a multi-meter to check battery voltage and current and ensure they are in normal range Replace batteries after five years from date of installation or as instructed by manufacturer Use a defibrillator analyzer to test actual energy delivered by te defibrillator and compare it with the target value, recalibrate if the values displayed are out of range.

20. Maintenance……. 1. Paddles, pads and accessories cleaning Use pre-saturated alcohol wipes to clean the surface paddles and other accessories of conventional defibrillators Use dry microfiber cloth or alcohol wipes to clean the display and overall surface of the machine. Power off the defibrillators and use aerosol contact cleaners to clean the connectors and connection ports, insert the extension tube into the actuator to remove soil from tight areas. Allow the solvent to evaporate before connecting te defibrillator back to power.

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