Term
| What is the symbol for a capacitor? |
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Definition
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Term
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Definition
| An electrical device that stores an electrical charge. It is constructed from two parallel conductive plates that are separated by an isulator called the dielectric. |
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Term
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Definition
| An electrical insulator that can be polarized by an applied electric field. |
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Term
| What could be said about the capacitor when it is in a neutral state? |
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Definition
| Both plates separated by the dielectric have an equal number of free electrons (charge). |
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Term
| What could be said about the capacitor when it is in a charged state? |
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Definition
| When voltage is applied, electrons are pulled off one of the plates and deposited on the other plate making a difference in potential. |
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Term
| When voltage is applied to a capacitor, when does the transfer of electrons stop? |
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Definition
| When the potential of the capacitor equal the potential of the voltage source. |
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Term
| What are the units for capacitance? |
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Definition
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Term
| How many coulombs are stored if you use a 1F capacitor connected to a 1V power supply? |
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Definition
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Term
| How many electrons are in 1 coulomb? |
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Definition
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Term
| How many electrons are in 1 Farad? |
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Definition
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Term
| What type of circuit are capacitors tyically used in? |
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Definition
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Term
| What is the capacitance equation in a parallel circuit? |
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Definition
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Term
| What is the capacitance equation in a series circuit? |
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Definition
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Term
| Can a capacitor store energy when disconnected from its voltage source? |
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Definition
| YES, essentially making it a temporary battery |
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Term
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Definition
| Commonly used in electronic devices to maintain power while batteries are being change, to prevent loss of information in volatile memory. |
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Term
| When would you use a defibrillator? |
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Definition
| Life-threatening arrhythmias only |
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Term
| When would you not use a defibrillator? |
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Definition
| Life-altering arrhythmias or asystole |
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Term
| What is the typical wattage for a defibrillator? |
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Definition
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Term
| What is the typical joules ouput from a defibrillator? |
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Definition
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Term
| What does "ABG" stand for? |
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Definition
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Term
| Who usually performs an ABG test? |
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Definition
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Term
| What does an ABG exam determine? |
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Definition
| Contents for carbon dioxide, oxygen and biarbonate in arterial blood. Also determines the pH level. |
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Term
| Why is the need to determine the pH level in arterial blood? |
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Definition
| To evalute metabolic disorders such as acidosis and alkalosis. |
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Term
| What is the main use for ABG numbers? |
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Definition
Pulmonology: To determine gas exhange levels related to lung function.
Nephrology: To determine that toxins in the blood are being filtered out as not to contaminate the blood pH levels. |
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Term
| When determining the pH level in arterial blood, what is really being determined? |
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Definition
| The amount of hydrogen ions (H+) in the blood |
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Term
| What is normal pH level for human blood? |
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Definition
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Term
| What is neutral on the pH scale? |
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Definition
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Term
| What is considered acidic on the pH scale? |
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Definition
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Term
| What is considered alkaline on the pH scale? |
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Definition
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Term
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Definition
| Arterial blood oxygen (partial) pressure |
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Term
| What is the normal range for PaO2? |
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Definition
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Term
| What are you determining with a PaO2 value? |
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Definition
| How much oxygen is dissolved in the arterial blood. |
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Term
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Definition
| Arterial blood oxygen saturation |
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Term
| What is the normal range for SaO2 |
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Definition
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Term
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Definition
| Arterial carbon dioxide pressure |
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Term
| What are you determining with a PaCO2value? |
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Definition
| How much carbon dioxide is dissolved in arterial blood. |
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Term
| What is the normal range for PaCO2? |
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Definition
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Term
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Definition
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Term
| What is the normal range of HCO3in arterial blood? |
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Definition
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Term
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Definition
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Term
| What does a B.E value signify? |
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Definition
| Indicates the amount of excess or insufficient levels of HCO3 |
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Term
| What does a negative B.E. signify? |
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Definition
| Indicates a "base" deficit in the blood |
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Term
| What does a positive B.E. signify? |
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Definition
| Indicates a "base" excess in the blood |
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Term
| What is the Intrumentation Chain? |
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Definition
1. Detect the biological signal
2. Amplify, filter, and process the signal
3. Display the signal
4. Store the signal |
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Term
| What does a transducer do? |
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Definition
| The first tage in the instrument chain; detects a specific biological signal then converts the signal to some other form of energy, usually electrical. It must be fairly sensive to pick up both low and high frequencies. It is subject to also picking up unwanted noise (external and internal) called artifact. |
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Definition
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Term
| Name the transducible properties. |
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Definition
1. Specificity: The ability of a signal detector to distinguish one biological signal from another.
2. Applicability: Measure without limiting the production of the signal.
3. Errors: Detectors must have linearity and adequate bandwidth, with very little distortion. |
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Term
| Define "Frequency Response" |
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Definition
| The quantitative measure of the output spectrum of a system or device in response to a stimulus, and is used to characterize the dynamics of the system. It is a measure of magnitude and phase of the output as a function of frequency, in comparison to the input. |
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Term
| What is a frequency response curve? |
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Definition
| Indicates the accuracy of an electronic component or system. |
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Term
| How do you know if you have a high or good frquency response? |
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Definition
| When a system or component reproduces all desired input signals with no emphasis or attenuation. |
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Term
| How do you know if you have a high frequency response at one end of the scale (0-50 Hz) with low or poor frequency response at the othe other (60-100 Hz)? |
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Definition
| When a system or component reproduces all desired input signals but with emphasis then attenuation. |
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Term
| How do you know when you have a poor frequency response? |
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Definition
| When a system or component fails to reproduce the desire input signal with high attenuation. |
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Term
| What is passive sensing and give an example of a passive sensing transducer? |
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Definition
Passive sensing is no additional energy is required to pick up a signal.
An example of a passive sensing transducer would be an EKG electrode. |
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Term
| What is active sensing and give an example of an active sensing transducer? |
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Definition
| Actice sensing is when an external energy source is required. An example of an active sensing transducer would be X-ray imaging. |
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Term
| How do EKG electrode transducers work passively? |
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Definition
| Electrical potentials are passively developed across cell membranes in the microvolt range. The electrode is linked to an ionic signal by an electrolyte, a conductive gel. |
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Term
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Definition
| A structure that contains a conductive electrode and a surrounding conductive electrolyte, separated by a naturally occurring "capacitor". The reaction (involving a metal ion) causes the electrolyte to acquire a net positive charge while the electrode acquires a net negative charge. The potential difference creates an electric field. |
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Term
| What is single-stage sensing? |
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Definition
| Biological signal to a electrical signal |
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Term
| What is multi-stage sensing? |
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Definition
| Biological signal goes through multiple processes before it is converted to an electrical signal. |
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Term
| What is an electronic pressure transducer? |
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Definition
| A multi-stage, active transducer device that converts physical pressure to electrical potential via a port in a Swans-Ganz catheter to a bedside monitor. Uses a Wheatstone bridge in the circuit in order to zero the pressure reading. |
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Term
| What are the pros and cons of a disposable blood pressure transducer? |
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Definition
Pros:
1. Single-piece, integrated, disposable unit.
2. Quick and easy set-up.
3. Fluid path visualization-3 cc or 30 cc per hour flow rates.
4. Design simplifies filling and de-bubbling.
5. With a variety of interface cables, can be connected to most types of bedside monitors.
Cons:
1. Calibration factor different for each manufacture. |
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Term
| What are the pros and cons of a domed blood pressure transducer? |
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Definition
Pros:
1. Initially expensive, but VERY accurate.
Cons:
1. Additional compnents must be added to operate, including stopcock, flush device, valve, tubings.
2. Design complicates filling and de-bubbling.
3. Cable to monitor is specific and dedicated.
4. MUST be sterilized between uses. |
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Term
| What information can you obtain with a Swanz-Ganz Catheter? |
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Definition
1. RA pressure
2. RV pressure
3. PA pressure
4. PAW pressure (LA pressure) |
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Term
| How do you float a Swanz-Ganz Catheter? |
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Definition
| Typically from a Femoral Vein, inflate the ballon end to 1cc that is hydroscopic, then float through the IVC into the RA, into the RV, into the PA, and wedge into a lung. |
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Term
| How many ports are on a basic Swanz-Ganz catheter? |
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Definition
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Term
| Up to how many ports can be available on a Swanz-Ganz cathether? |
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Definition
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Term
| What is a Wheatstone Bridge? |
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Definition
| An electrical circuit used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, one leg of which includes the unknown component. |
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Term
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Definition
| A resistor used to measure temperature. As temperature changes, resistance changes. The resistance change can be displayed as temperature. It is an active transducer. |
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Term
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Definition
| A bi-metallic strip of different metals. Each metal produces a unique small voltage in proportion to the temperature (relative difference). This device measure temperature difference not temperature. It is a passive transducer. |
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Term
| What is a pulse oximeter? |
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Definition
| A non-invasive device allowing the monitoring of the oxygenation of a patient's hemoglobin. |
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Term
| What are some things to consider with pulse oximetry? |
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Definition
| It may not be giving you the complete story. Patient may have hypoventilation, V/Q mismatch, or anemic and still have a reading WNL. |
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Term
| What causes respiratory failure? |
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Definition
| When the rate of gas exchange between the atmosphere and blood is unable to match the body's metabolic demands. |
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Term
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Definition
| Decreased partial pressure of oxygen in blood, sometimes specifically as less than 60 mmHg or causing hemoglobin oxygen saturation of less than 90%. |
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Term
| What can cause hypoxemia? |
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Definition
1. V/Q mismatch
2. Intrapulmonary shunt
3. Hypoventilation
4. Abnormal diffusion of gases at the alveolar-capillary interface
5. Reduction in inspired oxygen concentration
6. Increased venous desaturation with cardiac dysfunction plus one or more of the above 5 factors |
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Term
| What are the 3 most important abnormalities in gas exchange that lead to respiratory failure? |
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Definition
1. V/Q mismatch
2. Intrapulmonary shunt
3. Hypoventilation |
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Term
| What does V/Q ratio determine? |
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Definition
| The adequacy of gas exchange in the lung. |
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