A fluid medicament delivery device comprising: a patient attachment unit comprising: a housing and a fluid channel, which is a basal flowpath, located therein, wherein at least a portion of the fluid channel comprises a flexible member substantially coterminous with the housing; and a separate indicator unit adapted to be detachably coupled to the housing of the patient attachment unit, the indicator unit comprising a first sensing element configured to contact the flexible member when the indicator unit is coupled to the housing, that comprises a first pressure sensor adapted to detect pressure in the fluid channel via pressure transmitted through at least one of a fluid and a gel due to deflection of the flexible member, wherein the patient attachment unit comprises the following fluid flow control components in the medicament delivery device: a reservoir, a fillport for introducing insulin into the reservoir, a bolus flowpath for the flow of insulin from the reservoir to the patient via a cannula upon activation of a bolus button, and the basal flowpath for the flow of insulin through a pressure sensor chamber, which includes the flexible member, to the patient via the cannula. a patient attachment unit comprising: a housing and a fluid channel, which is a basal flowpath, located therein, wherein at least a portion of the fluid channel comprises a flexible member substantially coterminous with the housing; and a separate indicator unit adapted to be detachably coupled to the housing of the patient attachment unit, the indicator unit comprising a first sensing element configured to contact the flexible member when the indicator unit is coupled to the housing, that comprises a first pressure sensor adapted to detect pressure in the fluid channel via pressure transmitted through at least one of a fluid and a gel due to deflection of the flexible member, wherein the patient attachment unit comprises the following fluid flow control components in the medicament delivery device: a reservoir, a fillport for introducing insulin into the reservoir, a bolus flowpath for the flow of insulin from the reservoir to the patient via a cannula upon activation of a bolus button, and the basal flowpath for the flow of insulin through a pressure sensor chamber, which includes the flexible member, to the patient via the cannula. a housing and a fluid channel, which is a basal flowpath, located therein, wherein at least a portion of the fluid channel comprises a flexible member substantially coterminous with the housing; and a separate indicator unit adapted to be detachably coupled to the housing of the patient attachment unit, the indicator unit comprising a first sensing element configured to contact the flexible member when the indicator unit is coupled to the housing, that comprises a first pressure sensor adapted to detect pressure in the fluid channel via pressure transmitted through at least one of a fluid and a gel due to deflection of the flexible member, wherein the patient attachment unit comprises the following fluid flow control components in the medicament delivery device: a reservoir, a fillport for introducing insulin into the reservoir, a bolus flowpath for the flow of insulin from the reservoir to the patient via a cannula upon activation of a bolus button, and the basal flowpath for the flow of insulin through a pressure sensor chamber, which includes the flexible member, to the patient via the cannula.