Circadian assistant

The circadian assistant is an artificial body part that slows the rate at which pawns get tired.
== Acquisition ==
Pawns from ancient shrines may have this implant installed.
== Summary ==
An installed circadian assistant decreases Sleep Fall Rate by . This does not equal 20% less sleep. See Sleep Saved for the exact details. This modifier is applied before genes and drugs, so in most situations it is equivalent to a simple factor.
The circadian assistant also renders a pawn vulnerable to EMP. Taking EMP damage from any source will inflict brain shock on the pawn, capping their consciousness at and downing them for between and .
=== Installation ===
Installing the part requires of work, 2x medicine of herbal quality or better, and a Medical skill of 5.
Removing the part requires of work, 1x medicine of herbal quality or better, and a Medical skill of 5.
If the operation fails, the part will be destroyed.
== Analysis ==
The circadian assistant increases work hours without impacting Consciousness like the half-cycler. However, this implant is virtually always worse for productivity than either a bionic arm or bionic leg, depending on the type of work the colonist focuses on. The brain shock makes using EMP against mechs more difficult, but gives a way to safely down the pawn in case of mental break, prison break, or slave rebellion.
With high quality beds, and/or other positive modifiers to rest, consider setting a pawn's schedule entirely to Anything. A pawn with greatly enhanced sleep will go beyond a 24 hour sleep schedule, which means that pawns will spend less time moving to/from their bed. Remember that being in darkness will reduce work speed by a significant percentage, unless there is something mitigating this.
=== Sleep saved ===
In essence, the circadian assistant only has an effect while the pawn is awake. Therefore, actual sleep saving will always be lower than expected values. 
For example, a baseline pawn in a normal bed would spend 18.19 hours awake per 7.56 hours sleeping, to avoid being Drowsy. The assistant increases awake time to (18.19/0.8), or 22.74 hours awake, without impacting the sleep needed.
* A baseline pawn in a normal bed spends (18.19 hr awake) / (7.56 + 18.19 hr total) = 70.6% of a day awake. Equal to 16.95 hr awake per 24 hour cycle, or 7.05 hours sleeping.
* With the circadian assistant, this becomes (22.74 hr awake) / (7.56 + 22.74 hr total) = 75.04% of a day awake. Equal to 18.01 hr awake per 24 hour cycle, or 5.99 hours sleeping.
This means that, in a normal bed, the circadian assistant actually reduces sleep time by roughly , or about 1.06 hours per day, rather than the expected -20%.
Alternatively, you could say that the circadian assistant increases awake time by . Increasing Rest Effectiveness or Rest Rate Multiplier will actually lower the time savings of this implant. For example, a quick sleeper installing a circadian assistant would end up increasing awake time by , saving about 0.853 hours per 24-hour day compared to quick sleeper on its own.
=== Comparison to other bionics ===
With a rough baseline of actual sleep saved calculated above, it is possible to compare the ciradian assistant to other bionics.
Bionic arms and bionic legs increase Manipulation or Moving by +12.5%, per part, which increase work speed / travel speed by that amount. While "awake time" would increase both time working and travel time, the other parts are more specialized and thus are generally better at increasing a specific work's speed. In addition, both bionic arms and legs have some functional benefit in combat. Rest does not impact combat until 0% rest, where exhausted pawns will collapse on the ground. 
If 2 bionic arms and/or 2 legs have already been installed, then the assistant offers a decent functional benefit. Bionic hearts offer Moving and an approximate 0.3 hour per day sleep reduction, so the circadian assistant would be better for work. However, it still confers an EMP weakness.
== Notes ==
Despite its description, it does nothing to mitigate toxic buildup.
Category:Medical Item Category:Body Part Category:Implant