Automated Optical Comparator Technology for Medical Implant Inspection

Why Consider Our Technology?

This technology offers positive impacts on the costs and results of your inspection process.robotpc

  • An inexpensive robot takes the place of a human in the inspection process.
  • The machine operator never touches the parts under inspection.
  • Our software corrects for mechanical misalignment (i.e., robot positioning error) and eliminates costly fixturing
  • The system accurately measures defects. It is far more than a Go/No Go Gauge. Our software can perform calculations that cannot be done with current optical comparator systems, resulting in a higher degree of inspection validity.
  • The speed of the system allows inspection of every part. Your quality control methodology does not rely on sampling and statistics.
  • Our software makes two, independent inspections to minimize the risk of a defective part passing inspection.
  • We can provide an automated, controlled and repeatable path from inspection to packaging.
  • Our technology conforms to FDA best practices.

The Inspection Technology

LVR Automated Optical Comparator for Bone Screw Inspection

Inspection System Rendering

Our technology controls a robot arm to position a part — in this case, a bone screw — between a light source and high resolution digital camera. As the robot rotates the screw, the software makes 18 images (every 20 degrees) to create a two-dimensional representation of the screw and compare them to a previously imaged reference, or “golden” screw. As the images are processed, it displays an easy to interpret visual comparison of the reference and part under inspection.

The same images are compared against part overlays in an independent inspection step for parts that pass the golden image comparison.  As a result, the defect miss rate is the product of the probability of a miss on the golden image comparison and the probability of a miss on the overlay comparison.  Our dual-inspection software offers an extremely small probability of passing a defect.

Our inspection accuracy is +/- 10 pixels with the standard 5 megapixel camera, resulting in a measurement accuracy of .0198mm (.00078″).  An auto-calibration cycle can be configured as part of the normal inspection or performed at the discretion of the operator.

data073-lightThe hand labor required for current inspection and measurement technologies, and their associated costs, are significantly reduced using the inspection technology.  For screws, calculations based on pitch, flank angles, and major/minor diameters can replace separate gauging as a measure of pull-out strength.

Integrated measurement means your quality control engineers can make accurate, on screen measurements and include these measurements in the automated inspection protocol.

We plan enhancements in three areas: Measurement, matching, and calculation.

What size parts can we inspect?  Our current system’s parameters are here.  We can customize for large or heavier parts.

Featured Measurements

Future versions of the bone screw inspection system will be engineered extract these measures from our imaging:

  • Pitch Diameter
  • Circularity
  • Major Diameter
  • Minor Diameter
  • Flank Angles
  • Length
  • Head Inspection


Manufacturers mark each part with a tracking code that can be read like a bar code. Our software can use the bar code to extract the correct “golden” part from a library of previously scanned parts and to load ideal parameters to verify both the “golden” part and each part under inspection.


Where parts are uniquely coded, we can use that code to store images and the results of the scan in a database, creating an inspection history for each part.  The history can be reported through the manufacturer’s own ERP system to create a permanent record of the inspection.


  • Given the measurements, the software can also determine the holding power of the screw.
  • Trend analysis of deviations from the golden screw can help to detect wear on the tooling of threading machines and to more accurately predict maintenance intervals.

The System

All hardware is included: We supply a computer, camera, robot, turntable (for longer parts), and all necessary components. When we quote a system, we will work with you to design an appropriate enclosure. The system can be packaged for installation in a sterile environment.

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