DIA:CONN P8(Smart Insulin Pen) Study in Diabetes Patients

\[Blind CGM Period\] All eligible participants who voluntarily provide informed consent to participate in this clinical trial and are determined suitable for trial inclusion/exclusion criteria undergo a blind CGM before the baseline visit (randomization). During this period, every subjects is provided with two DIA:CONN P8 devices for continuous glucose monitoring (CGM), basal insulin, and bolus insulin administration.

Throughout this period, subjects receive training on fundamental insulin pen usage and CGM operation. They use the DIA:CONN P8 specifically for insulin dosage entry and administration, functioning similarly to a conventional insulin pen, only utilizing the injection and injection recording function.

Insulin injection dosages and timing (time stamps) recorded on the DIA:CONN P8 and the participant's blood glucose data logged in the CGM app are collected.

\[Application Period\] The subject allocated to the intervention or control group through randomization will visit hospital maximun 5 times during the 12-week application period, including the baseline visit, in the following process.

1. Treatment Group: For the treatment group, education sessions will be conducted during the baseline visit on carb counting and bolus calculator methods, installation, and usage instructions for DIA:CONN P8 and DIA:CONN app, as well as CGM and CGM app. 2. Control Group: The control group will receive education on insulin pen and CGM usage, maintaining their conventional multiple dose insulin therapy while implementing CGM.