Overview
The pulse editor is used to create and organize pulses used as stimuli in various programs. A standard type of a pulse consists of one or more steps in voltage or current, delivered through an analog output channel of the I/O board to a device such as a patch clamp amplifier, mirror galvonometer, etc. However, the pulses can also be used to control TTL devices, digital devices, or other types of devices. For example, pulses are designed in units of "percent transmission" for driving the Pockels cell used for mapping.
Note that the pulse parameters do not include a field for the duration -- the duration of stimuli is set in the 'Trace Length' windows of the programs that use the pulses. The 'Display Time' field in the pulseEditor gui only sets the trace length of the graphical representation of the currently selected pulse (see below).
Note that the user does not need to save any changes made to pulse sets, pulses, or pulse parameters; all edits are automatically saved.
File>Open
Use this to select the directory containing the pulse sets.
Pulse Sets Panel
Pulse sets are collections of pulses. The functions in this panel allow one to create, delete, and rename pulse sets. The listbox displays the pulse sets in the currently selected pulse directory.
Pulses Panel
The functions in this panel allow one to create, delete, rename, and order the pulses that are in the currently selected pulse set. The number of the currently selected pulse is displayed in the text window in the upper right corner of the panel, and the pulses can be browsed using the slider with arrows. The buttons with the up and down arrows allow one to move pulses up or down the list of pulses shown in the listbox. On hitting 'New' the user is prompted to choose between a normal and additive type of pulse. Additive pulses are pulses that add the parameters specified in other pulses to the parameters specified in the currently selected pulse. Normal pulses are simply pulses without additive components.
Pulse Parameters Panel
Windows show, and allow editing of, the pulse parameters for the currently selected pulse.
- Number: the number of steps.
- ISI: the interstimulus interval, in milliseconds. In other words, the time between the start of each step.
- Width: the pulse duration, in milliseconds.
- Amp: the step amplitude, in units appropriate for the device. For voltage steps, the units are mV; for current steps, the units are pA. For example, use "-5" to specify a step of -5 mV in a pulse that will be used for ephys acquisition. Use "5000" for TTL step amplitudes.
- Delay: the time in milliseconds of the start of the step.
- Additive: which trace to add.
Plot, Display Time
Parameter values are rounded!
Parameter values are rounded as appropriate for the sampling rate. In the case where a value is less than the sampling rate (for example, a pulse width of <0.1 msec with a sampling rate of 10,000 Hz), then the minimum value is applied (e.g. 0.1 in this example). Generally this is only an issue when using very short duration pulse parameters, (e.g. sub-millisecond stimuli for electrical stimulation).
Use this checkbox to toggle the display of the currently selected pulse in a separate plot window. The plot shows a pulse based on the parameters for the currently selected pulse, for a duration specified by the display time setting. As mentioned above, it is important to be aware that the duration of acquisition is not a pulse parameter but rather a property set by the acquiring/stimulating program(s).
Interface
For standard pulses use the Handicapped option. The Advanced option is under development.
Batch edit
This button brings up a gui that allows selected (checked) pulse parameters to be applied to all the pulses in the currently selected pulse set. For example:
NB: In addition to accepting single (scalar) values, the text boxes accept vectors. In this way, you can rapidly generate a family of pulses (i.e., a pulse set) varying in one (or more) parameters. For example, the following settings, when applied to a pulse set consisting of four traces, would yield pulses increasing in the number of steps from 1 to 4, and in the value of the steps from -5 to 10:
