Parameter Determination; Setting The Pulse Width; Adjusting The Energy Per Pulse - COOK Medical Rhapsody H-30 User Manual

Enter Button
• Function: Sets various options as directed by instructions in the information bar.
• Operation: Button is active when the button text and icon are white. The button text and icon
will be gray when inactive.

Parameter Determination

Choosing the ideal laser fiber
Cook Medical's holmium laser fibers for use with the Rhapsody H-30 Holmium Laser System come
in 150, 200, 273, 365, 550, and 940 μm core diameters for single-use fibers and 273, 365, 550, and
940 μm core diameters for multi-use fibers. Larger-core fibers will allow the use of higher power
but are less flexible. Higher pulse energy and larger fibers result in larger ablation volumes.
core fibers will also be consumed less during procedures because of their greater thermal mass
and their ability to dissipate parasitic thermal energy faster. Users are encouraged to select the
largest core size feasible considering the flexibility needed to reach the target and the size of the
endoscope's working channel.
Kang HW, Lee H, Teichman JMH, et al. Dependence of calculus retropulsion on pulse duration during Ho: YAG laser lithotripsy. Lasers Surg Med.
1
2006;38(8):762-772.

Setting the Pulse Width

(via the toggle button on the main screen) (See Figure 6, page 1-32.)
Lithotripsy
• Short pulse width will cause larger fragmentation particulates ("busting" the stone) but will
also cause greater retropulsion.
• Long pulse width will cause smaller fragmentation particulates ("dusting" the stone) and will
cause less retropulsion.
Soft Tissue
• Use the Short pulse width if you want to minimize coagulation or create a large, thick cut or
vaporization area.
• Use the Long pulse width if you want to increase coagulation and decrease bleeding.
NOTE
: Most soft tissue cases will benefit from using the Long pulse width mode.
NOTE
: If conditions have changed, such as a piece of an impacted stone breaks off or the soft
tissue is bleeding more than expected, the pulse width mode can easily be switched with the tap
of a toggle button.

Adjusting the Energy per Pulse

Adjust the energy per pulse to match the desired clinical effect.
Lithotripsy
• Lower pulse energy will cause the particulate size to be smaller ("dusting" the stone) and cause
less retropulsion.
• Higher pulse energy will create larger fragments ("busting" or "drilling" the stone) but will also
cause more retropulsion.
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Chapter 5
Operation
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