An implantable apparatus for measuring intracranial pressure in a brain housed within a skull, comprising: an implant body having a first internal cavity and a second internal cavity, a cap that hermetically seals the first internal cavity on one end and a hermetic feedthrough that seals the first internal cavity on the other end, an electronics assembly housed inside the first internal cavity, a power source housed inside the first internal cavity, and a pressure conduction catheter having a proximal end and a distal end, wherein the distal end is configured to extend into the brain through a burr hole in the skull and includes a plurality of ports (53, 55), and wherein the implant body is configured to be implanted on the outer table of the skull but underneath the skin; a diaphragm coupled to the proximal end of the pressure conduction catheter, the diaphragm configured to deform in response to changes in ICP; wherein the pressure conduction catheter couples the diaphragm to a region targeted for pressure measurement, wherein pressure is conducted from a measured region of tissue through the ports (53, 55) at the distal end of the catheter through gas, liquid, gel or solid media within an inner lumen of the catheter up to the diaphragm, and wherein the diaphragm is integrated into the implant body and such integration forms a unibody construction between the implant body and the diaphragm; at least one sensor disposed in the second internal cavity, the at least one sensor being configured to obtain data indicative of deformation of the diaphragm, wherein the sensor includes a strain gauge, and wherein a physiological pressure is measured by detecting deflection of the diaphragm when an external pressure is experienced against a reference pressure within the second internal cavity; and a processor, configured to receive said obtained data and determine the ICP based at least in part on the obtained data. an implant body having a first internal cavity and a second internal cavity, a cap that hermetically seals the first internal cavity on one end and a hermetic feedthrough that seals the first internal cavity on the other end, an electronics assembly housed inside the first internal cavity, a power source housed inside the first internal cavity, and a pressure conduction catheter having a proximal end and a distal end, wherein the distal end is configured to extend into the brain through a burr hole in the skull and includes a plurality of ports (53, 55), and wherein the implant body is configured to be implanted on the outer table of the skull but underneath the skin; a diaphragm coupled to the proximal end of the pressure conduction catheter, the diaphragm configured to deform in response to changes in ICP; wherein the pressure conduction catheter couples the diaphragm to a region targeted for pressure measurement, wherein pressure is conducted from a measured region of tissue through the ports (53, 55) at the distal end of the catheter through gas, liquid, gel or solid media within an inner lumen of the catheter up to the diaphragm, and wherein the diaphragm is integrated into the implant body and such integration forms a unibody construction between the implant body and the diaphragm; at least one sensor disposed in the second internal cavity, the at least one sensor being configured to obtain data indicative of deformation of the diaphragm, wherein the sensor includes a strain gauge, and wherein a physiological pressure is measured by detecting deflection of the diaphragm when an external pressure is experienced against a reference pressure within the second internal cavity; and a processor, configured to receive said obtained data and determine the ICP based at least in part on the obtained data.