## 3 Open Loop Administration of an Insulin
### Continuous Subcutaneous Insulin Therapy  
Insulin pump therapy also known as continuous subcutaneous insulin infusion (CSII) is a way of providing intensive insulin therapy which consistently leads to enhances glucose and reduced hypoglycemia. CSII was developed about 40 years ago. CSII systems are portable pump therapy devices that are generally constructed as a combination of an onboard insulin reservoir, an infusion apparatus  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Type of Insulin** & **Time Action Profile** & **Dose** \\ \hline Short acting & Begins from the 30-min after the subcutaneous & 3 times in a day, 30 min before \\  & with reaching peak action in 2–4 h & taking a meal \\ \hline Long acting & Beyond 24 h and up to 36 h & Once daily subcutaneous, at the same time with at least 8h interval \\  & & between consecutive doses \\ \hline Rapid acting & Generally, 4–20 min after subcutaneous injection & Three times a day up to 15 min \\  & with peak at 20–30 min. & before food intake \\ \hline Intermediate acting & Peak onset from 4–6 h, with the duration of action & 1 or 2 time daily subcutaneous \\  & until 14–16 h & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Description about distinct types of the insulin available in medicine for T1 DM treatment.  
(tubing and cannula), and an electromechanical infusion pump [94; 95]. According to numerous studies, these systems can be operated easily using the synthetic human insulin or rapid-acting insulin analogs (RAIA), with the help of RAIA, it provides superior performance to the synthetic human insulin [94]. In most cases, CSII uses the same basal dosage as MDI, with the basal insulin dosage applied more consistently over the day in CSII [95].  
The CSII is an efficient self-management tool for T1 DM patients. It is recommended that insulin therapy should initiate at the start of the week, it is because patient has access to the clinical help for the rest of the week [96]. In fact, across Europe, there are less than 30% T1 DM patients which are using insulin pumps, while in the USA, the use of insulin pump is relatively higher [97]. The key dominance of insulin pumps is the additional flexibility, allowing patients to adjust basal insulin in response to the requirement changes due to illness, alcohol and exercise. Many pumps also provide on-board automated bolus calculators, allowing persistent boluses for corrections by the day. Moreover, wellbeing and increased flexibility using CSII in patients may increase their attachment to intensified therapy [98]. A short randomized trial revealed that increased glucose in the target but too short to report HbA1c levels [99]. Despite the fact that CSII is effective, it must be appropriately maintained and used, as device performance heavily depends on proper operation (i.e., timely replacement of consumables) to avoid failure modes such as impeded or clogged infusion pathways, which can lead to the insulin deficiency and hyperglycemia. The tools used by the T1 DM subjects for insulin dosing are summarized in Figure 6, and the detailed description about each method/tool, and their advantages and disadvantages are summarized by [PERSON] et al. [100].