(возможности_Open-APS-DynamicISF)=
# DynamicISF (DynISF)
**Dynamic ISF** was added in **AAPS** version 3.2 and requires Objective 11 to be started before **Dynamic ISF** can be activated. Select **Dynamic ISF** in the Config Builder > **AAPS** to activate. **Dynamic ISF** is recommended only for advanced users that have a good handle on their **AAPS'** controls and monitoring.

To use **Dynamic ISF** effectively, **AAPS'** database requires a minimum of five (5) days of the user's **AAPS** data.

**Dynamic ISF** adapts the user's insulin sensitivity factor (**ISF**) dynamically based on the user's:

- Total Daily Dose of insulin (**TDD**); and
- current and predicted blood glucose values.

**Dynamic ISF** uses Chris Wilson’s model to determine **ISF** instead of a user's static **Profile's** settings for **ISF**.

The **Dynamic ISF**  equation implemented is: ISF = 1800 / (TDD * Ln (( glucose / insulin divisor) +1 ))

SMB/AMA - an example of a user's **Profile** with static **ISF** as set by the user and utilized by **SMB** and **AMA**.

![Static ISF](../images/DynISF1.png)

Dynamic ISF - an example of a user's **ISF** subject to change as determined by **Dynamic ISF**.

![Dyn ISF](../images/DynISF2.png)

The implementation uses the above equation to calculate current **ISF** and in the oref1 predictions for **IOB**, **ZT** and **UAM**. It is not used for **COB**.  Further discussion can be found here: https://www.youtube.com/watch?v=oL49FhOts3c.

## TDD (Total Daily Dose)
TDD will use a combination of the following values:
1.  7 day average **TDD**;
2.  the previous day’s **TDD**; and
3.  a weighted average of the last eight (8) hours of insulin use extrapolated out for 24 hours.

The **TDD** used in the above equation is weighted one third to each of the above values.

## Insulin Divisor
Делитель инсулина зависит от пика используемого инсулина и обратно пропорционален времени до пика. Для Люмжева его значение 75, для Фиаспа 65 и для обычных быстрых инсулинов 55.

## Dynamic ISF Adjustment Factor
The Adjustment Factor allows the user to specify a value between 1% and 300%. This acts as a multiplier on the **TDD** value and results in the **ISF** values becoming *smaller* (i.e. more insulin required to move glucose levels a small amount) as the value is increased above 100% and *larger* (i.e. less insulin required to move glucose levels a small amount) as the value is decreased below 100%.

The Adjustment Factor can be located in ‘Preferences’ > **AAPS**:

![Factor ISF](../images/DynISF3.png)


## Future ISF

Future **ISF** is used in the dosing decisions that oref1 makes.  Future **ISF** uses the same **TDD** value as generated above, taking the Adjustment Factor (discussed above) into account. Далее в расчет берутся различные значения ГК, в зависимости от ситуации:

* If levels are flat, within +/- 3 mg/dl, and predicted **BG** is above target, a combination of 50% minimum predicted **BG** and 50% current **BG** is used.

* If eventual **BG** is above target and glucose levels are increasing, or eventual **BG** is above current **BG**, current **BG** is used.

Otherwise, minimum predicted **BG** is used.

## Enable TDD based sensitivity ratio for basal and glucose target modification

This setting replaces Autosens, and uses the last 24h **TDD**/7D **TDD** as the basis for increasing and decreasing basal rate, in the same way that standard Autosens does. Эта вычисляемая величина также применяется для подстройки цели, если включены опции подстройки целей в зависимости от чувствительности. Unlike Autosens, this option does not adjust **ISF** values.

## CAUTION - Automations or Profile Percentage Increase
**Automations** should always be used with care. This is particularly so with **Dynamic ISF**.

If **Dynamic ISF** is in operation, users should reconsider enabling any temporary **Profile** increase as an **Automation** rule or similarly activating a **Profile Percentage** which may create **Dynamic ISF** to be overly aggressive in correction bolusing and could cause hypoglycemia.