In the previous logs we talked about the problem statement in general and about technical aspects of breathing sensing technology. I wanted to use this build log to document the various design decisions we had to make and the core rationale behind the approaches we are taking.
Our goal with NeuroCuddl is to build a wearable VR system that combines of breath sensing and audiovisual, thermal, vibrotactile and muscle stimulation haptics. Through these sensors and haptics we aim to deliver a VR experience that would provide users with an immersive and blissful mindfulness training session.

While designing NeuroCuddl we have to ensure a balance in design between functionality and user comfort while remaining compact. The design should ensure proper biofeedback stimuli is delivered while being unobtrusive to the user during usage. User immersion during regular VR activity should be unaffected. The first decision along the process was to decide between NeuroCuddl being developed as either a desktop VR accessory or a mobile based VR accessory. Due financial constraints at this moment we are unable to purchase a desktop VR headset like Vive or Oculus Rift. 
This alone however is not the main reason for us not building for desktop VR headsets at this moment, our decision was driven by the amazing growth of mobile VR with Google's daydream to Samsung GearVR to Oculus Go. This we envision as being the first point of contact for average consumers to the amazing world of VR. With better mobile processors like Snapdragon XR and more inexpensive displays and the dawn of Augumented Reality headsets we see this space as being highly interesting to explore through the use of an accessory to extend haptic feedback and physiological sensing. We thus chose a route of building battery powered wearable accessory for mobile VR headsets. 

Existing research in the use of haptics for VR have explored various sites for thermal haptics and found that a significant amount of people preferred the neck as a site for thermal stimulation. Further the commonly reported pain point in people with work stress is in the upper back muscles. Thus making the ideal location to wear NeuroCuddl be in the neck. We thus envision NeuroCuddl being a neck worn wearable VR accessory that can provide multimodal stimulation.

NeuroCuddl system should be designed to require only minimal modification to any compatible mobile based VR headset. The neck worn wearable have to have an appropriate coupling mechanism to adhere to the neck and ensure appropriate weight distribution. Further the system would need to be highly intuitive for a stressed user to use and require only minor user engagement to set up.  The respiration sensor too would have to be housed away from the nose while still being able to sense the breathing parameters. Here is the design we hope to accomplish.

Below image shows the conceptual design of the neckband for sensing and feedback..