It has been proposed that a portable unit which can be worn on a patient's head to provide a lightweight, low cost unit can conduct AM-PET (Ambulatory Micro-dose Positron Emission Tomography) scans in diverse locations. This is also conducive to the testing of patients while performing selected activities that stimulate certain brain regions such as walking, playing a game, clapping, and other such tasks; this unit is specifically intended for those with Alzheimer's, cancer, drug addiction, or any kind of brain injury to learn more about the condition for findings of a cure and treatment options. The need for this type of device has led to the design of a portable head held unit that currently uses twelve PET module sensors in specific locations around the head. Current PET scanners need a patient to remain still for several minutes, whereas this unit you can see defined parts of the brain working. This manuscript is focused on the engineering design aspects of the Am-PET project. The goal of this work is to further design this portable head unit to alleviate weight of the current head unit, improve comfort for the patient, and diversify its application amongst research activities. Specific gains include the design and manufacture of a system that reduces the relative movement of head and helmet significantly and does not restrict the user's head motion. The continuation of this work includes design review of the current model, design improvements based on the identified project requirements, and development of a working prototype. The success of this work will be measured by comparing the developed prototype to the original device and the newly developed metrics.