Subcutaneous device with leak prevention

A medical device comprising:

• a base having a needle channel and a first surface configured to be secured to a patient's skin, the first surface attached to the patient's skin by an adhesive material layer attached to the first surface, wherein a width of the adhesive material layer is greater than a width of the first surface, wherein the adhesive material layer defines an opening;
• an annular substrate located in the opening, the annular substrate defining an opening aligned with the needle channel;
• an insertable member comprising a length portion extending through the needle channel, the first surface, and the opening of the annular substrate for insertion through the patient's skin at an insertion site;
• and
• a septum extending across the needle channel and perpendicular to the length portion, the septum providing a liquid seal across the needle channel, wherein the needle channel and the septum provide a sealed volume in which a limited amount of blood or other fluid from the insertion site may be held.

A method of making a medical device, the method comprising:

• providing a base having a needle channel and a first surface configured to be secured to a patient's skin;
• providing one or more sensors located in the base;
• attaching an adhesive material layer to the first surface of the base;
• securing the base to the patient's skin via the adhesive material layer;
• securing an insertable member to the base comprising a first portion and a second portion contiguous with the first portion, the first portion coupled to the one or more sensors and the second portion extending through the needle channel and the first surface for insertion through the patient's skin at an insertion site;
• and
• extending a septum across the needle channel and perpendicular to the second portion, the septum providing a liquid seal across the needle channel;
• wherein the needle channel and the septum provide a sealed volume in which a limited amount of blood or other fluid from the insertion site may be held.