CASE STUDY

TearScience LipiView


Client: TearScience, Acquired by J&J in 2017
Project: LipiView and LipiView II Meibography


Diagnosing Meibomian Gland Dysfunction (MGD)

Meibomian Gland Disfunction (MGD) prevents the oil-producing meibomian glands in the eyelids from secreting oil when the eye blinks. Without a layer of oil to cover the tear film on the cornea, the tear film evaporates quickly, leaving eyes feeling itchy, red, and irritated. MGD is the leading cause of dry eye world-wide, and most recommended treatments, such as eye drops and warm compresses, only treat the symptoms to provide temporary relief. TearScience was created to find a pain-free, simple treatment solution to this worldwide and debilitating problem. The team soon learned that before treating the disease, we needed to create a device to accurately diagnosed it.

 

Dry eyes can be influenced by several factors, such as:

  • The thickness of the lipid layer
  • Improper blinking technique
  • Long hours staring at your computer or your phone
  • Blocked meibomian glands caused by MGD
  • Impaired or non-functional meibomian glands

 

To understand which, if any, of these factors is causing the patient’s ocular discomfort, we needed to create a device that could image the meibomian glands, analyze blinking technique, and measure the thickness of the lipid layer. In order to accomplish this, we created the LipiView with ocular surface interferometry and meibomian gland imaging

01


Interferometry

Visualizing and measuring the absolute thickness of the eye’s lipid layer with nanometer accuracy was a tough challenge. The LipiView operates on the principle of white light interferometry and provides an interferometry color assessment of the tear film by specular reflection. Along with the tear film assessment, we capture blink dynamics (detect patterns and partial blinks) and provide an assessment of factors that contribute to dry eye.

Optics - interferometry and specular reflection assessment

02


Analyzing the Disease State - Meibography Imaging

Analyzing the lipid layer thickness can only determine if a patient is lipid deficient, not if the patient has functioning glands able to create lipid. We capture still photos of the patient’s eyelids under infrared surface and retrograde illumination and use surface lighting originating from multiple light sources to minimize reflection. We also use changes to the light intensity across the surface of the illuminator to compensate for the lid thickness variations between patients. The result is a striking image of the meibomian glands and the current disease state. This image allows a physician to determine if a patient can be helped by the LipiFlow treatment.

03


Optics and Lighting

The breakthrough technology in the LipiView system was taking visual white light interferometry (which could be evaluated by a physician, but not repeatedly) and producing an image that could use algorithms to fit the resulted lipid colors to a theoretical curve representing thickness. We developed the camera and custom “tiled” lighting system to produce repeatable, predictable images that could accurately be analyzed with the theoretical color model. We proved the effectiveness of our algorithms using known nanometer thickness phantom models.

For meibography, we trans-illuminate a patient’s eyelid with an infrared (IR) light to provide a high contrast image of the meibomian glands that looks similar to an X-ray. We also capture an IR surface meibography image of the meibomian glands and combined with the trans-illumination image of the meibomian glands. This technique provides a higher contrast image of the meibomian glands, allowing for increased visibility of the disease state.

Theoretical meibomian lipid color palette
LipiView system patent

04


Designed for Use

Since physicians doing meibography need to operate one-handed (once hand is needed to flip the eyelid), our device needed to be controlled seamlessly with one hand. This meant the physician needed to be able to manipulate the camera system and lights, as well as capture the image, all while flipping the patient’s eyelid. To account for this, we designed controls on top of the LipiView for meibography imaging, and intuitive GUI Controls for taking images of the ocular surface.

05


Robust Mechanical Design

For LipiView, we had to create a robust, precision-moving, mechanical camera system that also reflected the high quality of the equipment.  Our motion systems were developed to be smooth and quiet; our details and finishes were in line with exotic sports cars. The mechanical engineering technology found in the LipiView Console encompasses:

  • A machined aluminum mechanical structure
  • Sheet metal design
  • Injection molded plastics
  • Motors and gears
  • Mechanically actuating systems
  • Rotating touchscreen integration
  • Device cooling
  • Aluminum alloy castings
  • Mechanism design

06


The Control System

We designed the LipiView to control the meibography lighting system (comprised of the illuminator, orange fixation LEDs, optional IR and blue LEDs, and the transilluminator lid flipper accessory), the camera, and a motorized three-axis system that positions the camera.

The illuminator and motion axes are driven by the lighting and motion control (LMC) circuit board, located in the head of the device. The LMC board is controlled by the LipiView computer via RS-232 serial protocol. The fixation LEDs are also controlled by the LMC board.

07


GUI Design and Software

Through continuous testing and human factors engineering, we developed an intuitive GUI and patient workflow, then executed the design in class B software written to IEC 62304.  The software contains items such as:

  • Positioning and focus of the camera system
  • Image analysis and presentation of results
  • Error handling and reporting
  • EMR connectivity
  • Printable reports for paper records
  • Entering and retention of patient data
  • HIPAA compliance
  • Cybersecurity

Medical device optics Intuitive GUI

08


The Regulatory Pathway

To achieve FDA clearance, we had to prove the science and safety of the LipiView.  Along with standard V&V testing to ensure the device operated safely as intended (IEC 60601-1 electrical safety testing and IEC 60601-1-2 EMC/EMI testing) we also had to test the light safety of the device and verify our thickness measurement to the nanometer.  We used phantoms for this verification and successfully proved that our system was as accurate as stated.

09


Manufacturing & Service

We developed the manufacturing systems to build and test the LipiView. This process evolved with several stages of controlled manufacturing.  From V&V units through pilot builds into full scale manufacturing, we evolved the process and quality at each stage. Part of this was designing and deployed light and calibration tests to be used in manufacturing. By doing the manufacturing internally, with our R&D engineers leading the charge, we increased our speed to market and were able to quickly work through those pesky start-up troubles, without delay and with solid solutions.

 

It takes an experienced team to quickly solve issues, to learn how to create efficiencies in the process and to reduce potential quality defects. This is our method at Blur. We creatively handle issues and learn as much as we can about the process and costs while we build, without chucking issues over the wall. And with Blur contract manufacturing, our learnings directly translate to improved ramp-up speeds, better costs for our customers, and a quick reduction of manufacturing defects.

10


A Note about Blur and TearScience

The Blur founders all originated from the successful ophthalmology start-up TearScience, which was acquired by Johnson & Johnson Vision in 2017. We were key members of the engineering team responsible for its commercially successful product line and J&J/TearScience remains our client today. We developed the science, engineering and manufacturing systems behind their diagnostic capital equipment imaging products and high-volume disposable treatment product. Many of Blur’s current employees, clients, and vendors were a result of the relationships we developed and fostered during our time there.