Week 9 Flashcards by Alyssa Powell

True or False: The fundamental electrical building block is the transistor?

False

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A prosthesis that uses an additional energy supply for motion and control over and above that provided by muscle power from the user is known as?

Active

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True or False: Switches are the devices that control the flow of current in a binary (on-off) manner?

True

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Please notate the correct examples of toggle switch configuration…

DPDT
SPDT
SPST

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True or False: Rotary switches consist of a number of open contact mounted wafers containing many poles operated by a spindle that passes through the center of each wafer?

False

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True or False: Optical switches consist of an infrared light-emitting diode (IR LED) and a phototransistor sensitive to a similar optical wavelength mounted into the same plastic holder?

True

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Relays are?

Electrically controlled switches

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True or False: Solid-state relays (SSRs) generally have an opto-isolated high-voltage input that controls low current-handling transistors or thyristors?

False

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What is a MOSFET?

Metal-oxide-semiconductor field-effect transistors

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True or False: Most portable rechargeable batteries are wet cell types, which are hermetically sealed?

False

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These are primary battery types that are available for different applications:

Zinc Carbon
Zinc Air
Mercury

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True or False: The main advantages of primary batteries are their high energy density, long storage life, and ease of disposal

True

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True or False: One convenient alternative from to the lead-acid battery is the gel cell, which contains a semisolid electrolyte that prevents spillage.

True

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True or False: In regards to a Wheatstone bridge, temperature changes can result in resistance changes of the same order as those caused by strain, so temperature compensation is not essential if good accuracy is required.

False

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Rotary Optical, Absolute, Optical Disk, and Incremental are all examples of:

Encoders

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True of False: Small displacements can be measured using precision potentiometers.

False

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Rate Gyros, Accelerometers, Tilt Sensors, and Switches are all examples of:

Transducers

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True or False: Potentiometers made from conductive plastic film are the components of choice. They are low friction and low noise and have a long operational life. Unfortunately, they are sensitive to temperature and other environmental factors.

True

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What sensor can be manufactured from accelerometers mounted on three orthogonal axes and equating the relative gravity vector in each?

Tilt Sensor

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True of False: From a mechanical perspective, potentiometers add inertia and friction to the moving parts of the system they are measuring. As a result, a conductive plastic potentiometer will not last hundreds of million of cycles even if the conditions are good. Wire-wound pots last much longer.

False

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What are the types of pressure?

Absolute, gauge, and differential

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The most common inductive device for measuring linear displacement is

Linear variable differential transformer

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kPa, psi, cm H2O, in HG, and mbar are all units of measure for what?

Pressure

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True or False: Linear encoders are more sensitive to variations in temperature than the other types of encoders, but their main disadvantage is a limited frequency response.

False

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In traditional methods of measuring blood pressure, the "lub-dub" sound is called:

Korotkoff

Magnetic field strength is most commonly measured using:

magnetoresistance (MR) and the Hall effect

The most commonly used piezoelectric material that is very sensitive and flexible is called:

PVF2

MR is a property of most magnetic materials. A decrease in electrical resistance occurs when a magnet field is applied __________________ to the direction of the current flow.

perpendicular

True or False: All organs in the body generate some voltage.

True

True or False: MR and GMR sensors are often incorporated into a Wheatstone bridge configuration to increase temperature dependance and to reduce sensitivity.

False

Electrodes that do not use externally applied electrolyte gels are known as:

Dry

"The capacitance of parallel plate capacitor is ______________ proportional to the area of the two plates and ______________ proportional to the distance between them."

directly; indirectly

True or False: Electrical devices that produce or trigger a physical or physiological response by stimulating the body's musculature or nerves are also considered to be actuators.

True

Capacitance is _________________ proportional to the dielectric constant of the material between the plates.

Directly

The equations that describe how electrical building blocks are combined are known as:

Kirchoff's law

True or False: Capacitance-based sensors use a pair of coaxial capacitors with a movable dielectric sleeve that fits between the outer and inner electrode of the one capacitor. The proportion of the area between the two electrodes that is filled with dielectric determines the capacitance.

True

The most common of all the sensors used for angle and angular rate measurement are:

Digital optical encoder

The encoder that consists of a light source and a number of photo transistors separated by a rotating mask made from alternating opaque and transparent radial bands is consistent with a(n):

digital optical encoders

In Biomechatronics, signals obtained directly from the organism include:

Electrical, chemical, and pressure signals

Which encoder can be made from glass or plastic onto which has been deposited a radial pattern organized into tracks, or metal disks through which holes have been cut?

Rotary encoders

True or False: Most absolute encorder discs are encoded with either binary or python codes.

False

The generic term for all electrical signals generated by nerve and muscle cells is called:

bioelectrical signals

True or False: A common application for those amazing absolute encoders is like ones found on a prosthetic arm.

True

True or False: Bioelectric potentials are ionic voltages produced as a result of electrochemical activity in some type of specialist cells.

True

Located at the joints or pivot points of an articulated prosthesis, which encoder can monitor exact angular position, direction and speed of arm travel?

Absolute Encoder

In a bioelectrical signal, the principal ions in solution are:

sodium, potassium, chloride

Tachogenerators are small AC or DC generators that output what in proportion to the rotational speed of a shaft?

Voltage

What does this circuit represent?http://upload.wikimedia.org/wikipedia/commons/9/93/Wheatstonebridge.svg

Wheatstone Bridge

What uses the conservation of angular momentum to keep one or more inertial axes pointed in one direction as the external frame translates and rotates?

Rate gyros

Most modern low-cost microelectromechanical systems (MEMSs) rate gyros operate using the ______________, which states that if an object is moving in a straight line and is subject to a rotation, its path will deviate from that straight line.

Coriolis force

The main advantages of MEMS rate gyros are their __________ size and the fact that they are ___________ power.

small; low

Another advantage of MEMS rate gyros are that they are ________________ reliable.

extremely

True or False: MEMS rate gyros are very sensitive to external environmental factors like shock, vibration, and acceleration due to the fact that the mass of the vibrating element is so small.

False

True or False: MEMS rate gyros suffer from drift and offset, and their sensitivity is lower than some of the other types.

True

True or False: In most applications, rate gyros are used in isolation, and not with other sensor modeling and filtering techniques.

False

True or False: Accelerometers are sensors designed to measure continuous mechanical vibrations such as bearing vibration from blasts or impacts, or the lower-frequency acceleration generated by bodies in motion.

True

True or False: More sophisticated tilt sensors can be manufactured from accelerometers mounted on two orthogonal axes and equating the relative gravity vector in each.

False

Pressure is defined as the normal force per unit area exerted by a(n) ________________ on any surface.

Fluid

Movement between the skin and the surface electrodes generates large electrical signals which can saturate any further stages of amplification. These movements are called:

Motion artifacts

True or False: The conventional sphygmomanometer is an indirect method of measuring blood pressure.

True

True or False: A thermocouple consists of a combination of different materials bonded together which will generate a potential difference, proportional to the temperature difference between the hot and cold terminals.

True

True or False: Materials such as gold, silver, and copper have high resistivity and also have high thermoelectric coefficients.

False

True or False: An Isolation Barrier is required to ensure that big voltages cannot be introduced into the patient/subject through electrodes attached to the body

True

True or False: Materials such as Bismuth (Bi) and Antimony (Sb) have high resistivities.

True

True or False: Tactile feedback is one of the critically important aspects of any successful hand prosthesis.

True

Tactile Feedback relies on contact-based effects including:

hardness Slippage Heat transfer

True or False: Personal computers (PCs) for display and analysis of medical data pose a major isolation problem.

True

True or False: Though tactile sensing requires sophisticated sensors, it is also reliant on the processes through which the device interacts with the explored object.

True

True or False: The design of power supplies in PCs permits high-leakage currents that are inadequate for medical environments. It is important to separate the patient from the PC by an isolation barrier which guarantees there is no risk of electrocution.

False

True or False: Resistive Tactile Sensors rely on materials whose resistance changes with increases in applied force.

True

True or False: If the row and column conductive strips are placed on either side of a compliant dielectric material, then the intersection of each forms a tiny capacitor.

True

Enzymes are remarkable because:

They are extremely selective to a given substance and are very effective in increasing the rate of chemical reactions

Electrochemical sensors are:

sensors that generally consist of a pair of electrodes as a part of a closed circuit The most versatile and are the best developed of all the chemical sensor type. Sensors that measure voltage, current, or resistivity

What does this circuit represent? | looks like an H

H-Bridge

What does this circuit represent? | Looks like a triangle person

Operational Amplifier