Science Of Energy Flashcards
Advanced bipolar instruments incorporate the following improvements over traditional bipolar instruments:
Impedance sensing, increased compression, mechanical cutting, 7mm vessel seal
“Energy always seeks the path of least resistance.” This principle relates to which important tissue effect?
Lateral thermal spread
What are the controllable factors that impact tissue sealing? (Select all that apply)
Heat, time, compression
What surgeons sometimes do to coagulate vessels> 1mm with a monopolar pencil?
Use a metal instrument (forceps or hemostat) to apply compression while using intentional direct coupling
Which of the following is NOT benefit of harmonic technology?
Faster than monopolar
Vessel Sealing up to and including 7mm is a benefit of increasing the physical factor in advanced bipolar devices.
Compression
Ohm’s law states that voltage is equal to current times _____.
Resistance
As tissue dedicates (dries out), the ____ within the tissue ______, causing energy to move to a new path outside of the intended area.
Resistance, increases
What is NOT true about monopolar devices?
Monopolar devices require longer time on tissue, compared to bipolar or ultrasonic devices
When using monopolar pencils, which action below may decrease the risk of a surgeon getting burned when intentionally using direct coupling (“buzzing” a metal instrument to add compression”)
Holding the instrument in a way that provides more surface area and contact, to minimize concentration
Nerve and muscle stimulation ceases at ____ kHz, because the _____ is so rapid across the body’s neurons that the brain doesn’t recognize it.
100 kHz, frequency
Which statement below is FALSE?
Monopolar devices use direct current and bipolar devices use alternating current
Which of the following energy modalities requires a return pad?
Monopolar
The smaller the area of contact, the greater the current concentration, resulting in greater tissue effect. TRUE OR FALSE
TRUE
What is the relationship between current concentration and time on the tissue?
Higher current concentration and longer time on tissue means more thermal tissue damage
What is the relationship between voltage and power?
Voltage and power are directly related, meaning if the voltage is lower , the power is less
In terms of electrical current, smaller areas of contact result in _____ higher current density (or current concentration), creating a ____ substantial tissue effect (tissue damage)
Higher, more
What is NOT a basic principle of electricity?
Follows the path of greatest resistance
This monopolar waveform has higher volatiles and is only approx. 6% of the time.
Coagulation
Patients don’t get electrocuted during the electrosurgery because electro surgical generators operate safely at frequencies of 200kHz or above, which is too high to cause neuromuscular stimulation. TRUE OR FALSE
True
In what way could the PURE CUT setting be beneficial to the patient?
Lower voltages can minimize lateral thermal damage
Potential risks of monopolar electrosurgery are:
All of the above
Which monopolar waveform produces the least lateral thermal damage?
Pure cut
Which statement below is FALSE?
Power is the driving force that pushes electrons, measured in watts
______ _______ and _____ are uncontrollable factors that impact tissue sealing.
Collagen, elastin, water
Which is NOT a reason why surgeons may choose to use Monopolar devices?
Large vessel sealing
