Embedded Files
Wireless Health Mobile System (Mask Design)
Wireless Health Mobile System (Mask Design)
Winter 2015 MAE 156B SPONSORED PROJECT - Team 6
Aaron Lineback, Rose Forcier, Phuoc Le, Yuqi Ouyang
UNIVERSITY OF CALIFORNIA SAN DIEGO
SPONSORED BY: Dr. Erik Viirre (Ph.D.), UC San Diego Health System
Background:
Background:
The wireless health mobile system is an idea developed by Dr. Viirre to examine and analyze eye movements. The system consists of a mobile chassis with advanced electronics inspired by the Star Trek Tricorder and mask with infra-red optode and active electrode sensors. Together, the system records real-time eye movements to examine diseases related to vertigo and inner ear balance disorder. The wireless health system will compete in the Qualcomm Tricorder XPRIZE competition for $10M in prize.
Figure 1: Conceptual Design By Dr. Virre
BPPV is a disorder in the inner ear resulting in involuntary eye movement. It makes compensating for sudden changes in motion difficult resulting in positional vertigo or a spinning dizzy sensation due to changes in head orientation. It lasts anywhere from a few seconds to minutes and is often associated with nausea. There are different forms of the condition, meaning the specific head movement associated with the vertigo sensation can vary. Rolling to an individual's right side may be normal while rolling to the left can induce vertigo.
Figure 2: BPPV: Inner Ear Anatomy
(www.dizziness-and-balance.com)
Ultimately, diagnosis of BPPV comes from a test called the Dix-Hallpike. During this test the examiner quickly moves the patient’s head in an attempt to induce vertigo. Based on which inner ear canal contains the calcium crystals, the eyes will respond in a specific way. The eye is controlled by six muscles, two muscles for each direction of motion: side to side, up and down, and torsional.
Figure 3: Eye Muscles
(http://www.improveeyesighthq.com/eye-muscles.html)
Figure 4: Video of Dix-Hallpike Test
The mask design will use the electrodes for a method called electrooculography (EOG), which is the resulting signal from the potential voltage difference between the poles of the eye. Based on the eye position the electrode signal will be more positive or more negative. This measures the side to side and up and down motion. The optode is made up of two separate components; the emitter and the detector. The emitter is an LED light which is placed over the lateral rectus muscle. This muscle changes position in conjunction with eye movement. The detector is a photodiode which receives any reflected light from the emitter. The reflected light obtained by the detector allows the torsional movement of the eyes to be observed. Specifically the varying muscle position will vary the intensity of light reflected.
Diagnosing which canal contains displaced crystals is the difficult part that requires a specialist doctor. The sensors on the mask track the movement of the eye muscles in order to gather data from multiple patients with a known condition. This data can be used to create a database of recognizable muscle patterns correlating to the disease.
Project Objectives:
The primary objective of this project is to design the mask to be used with the wireless health mobile system. Electrodes and optodes are to be mounted on mask in a certain array that produces high quality signals. The mask are going to be used to help doctors perform the Dix-Hallpike test by providing accurate eye movement measurements. The masks are health devices worn by patients for periods up to 30 minutes and needs to be safe and comfortable. The mask also need to have a futuristic look inspired by Star Trek to complement the Tricorder chassis.
Project Goals:
Active electrodes from Biosemi and optodes from Nirx are to be mounted on the mask device. The main goal of the project is to pair mask with an advanced mounting system for the various sensors. The mounting system must provide the doctors the ability to adjust each of the sensors individually so the points of the sensors have as much contact with the skin as possible. By doing this, the quality of the sensor readings will increase and produce clearer, more precise results.
Functional Requirements:
Minimum of 6 electrodes per eye (Biosemi)
Minimum of 1 pair of optodes per eye (Nirx)
Fully adjustable sensors mount
Secured (Dix-Hallpike test)
Safe (Medical device)
Comfortable (for up to 30 minutes)
See thru (iris visible for doctor)
Cords conveniently routed
Patentable
Design Solution:
Mask
a.) Large mask allows for additional sensors being added.
b.) Adjustable nose piece and headband allow the doctors to adjust the piece for each patient
c.) Iron-man like appearance (WOW factor)
Figure 5: CAD model of the mask
Mounting Mechanism
a.) 3 part system allows pivoting in the x and y direction, as well as translation in the z direction
b.) Replaceable, 3D printed parts
c.) Removable sensors for maintenance
Figure 6: CAD model of the mounting mechanism
Final Design:
Figure 7: Electrode Mask
Figure 8: Optode Mask
Figure 9: Dr. Viirre with Optode Mask
Page updated
Report abuse