Toolkits

Patient Exam Cameras - Summary

Exam cameras have been a topic of much discussion and debate within the telehealth community.  On the one hand, clinicians have acknowledged that the well-lit photos from patient exam cameras are remarkably bright and clear.  On the other hand, the high-cost and lack of competitors in the patient exam camera market have caused some of these same clinicians to wonder if there are any other alternatives available.

Camcorders and, to a lesser extent, digital cameras have been looked at as possible options to use in lieu of the more expensive patient exam cameras.  Questions still existed when looking at the feasibility of camcorders and digital cameras – would the devices prove as reliable as exam cameras?  Could they offer the same ease of use?  How would they compare on functionality?  Were the images similar?

UPDATE: The TTAC is refraining from publishing scores from its evaluation and testing of Patient Exam Cameras and other technologies.  The raw data, including images for review and feature-based comparisons of products, are still available, but all references comparing product performance will be removed until further notice.

Reliability and Mechanics

Patient exam cameras are designed to be durable, easily cleaned, and comfortable to use.  Both AMD and GlobalMedia provide devices that have minimal configuration options, buttons, or settings in comparison to the more complex camcorders and digital cameras.

Ease of Use

The simplicity of patient exam cameras is a strong suit.  The single-purpose design of the devices makes them easy to connect, configure, and use in a patient examination.  Camcorders and digital cameras typically require 2-4 additional steps when attempting to view a paused or “frozen” image, have cables that interfere with holding or using the camera while sending out live video feeds, and require the use of additional lighting for macro or intraoral imaging.  However, despite these concerns, both camcorders and digital cameras were mostly viewed as acceptable in the category of ease-of-use. 

Functionality

Patient exam cameras, camcorders, and digital cameras all had different strengths and weaknesses in the area of functionality.  Overall, patient exam cameras could do fewer things; however, those things that they do are done very well.  Image freezing, manual focusing options, and proper lighting were the primary functions that patient exam cameras have.  The AMD-2500 had the additional benefit of a polarizing filter that could eliminate the glare of light on moist or reflective surfaces.

Camcorders and digital cameras have the benefit of being able to record images and video, capture audio, and support in-camera zooming on images.  This in-camera zooming can provide the devices with clarity and resolution that rivals that of patient exam cameras.  However, accessing those features requires additional steps by the user and can be more difficult to use.  The recorded images and videos also support transfer via store-and-forward systems through USB connections or media readers.  This is an improvement in available resolution in comparison to exam cameras that are recorded through a capture card.

Image Quality - Color and Detail

Overall, images from the patient exam cameras were superior to images from camcorders and digital cameras when viewed through live feeds.  In some contexts, however, camcorders and digital cameras provided images that were comparable to general exam cameras.  This is especially true when comparing images that have been captured to internal media and then reviewed and enlarged.  The extra resolution of these images allow for images with great detail.

Images for review were captured at the same resolution of 640x480 pixels.  This best simulates a "live feed" of video input, with each image captured onto a PCMCIA card that supports capturing through an S-Video connection.

All of the cameras had a struggle with color balance in at least one image.  Mixed-lighting environments could make all camera models reproduce skin tones that were uneven or inaccurate.   

Color accuracy evaluations were conducted with a specialized software tool that allows simultaneous side-by-side comparisons of all images.  The accuracy of the colors were measured against a Macbeth color chart and against live review of the subject's skin tone.  

Detail evaluations were similarly conducted with the specialized software tool that allows simultaneous side-by-side comparisons of all images.  The area of sharpest detail was used in the evaluation of each image; this allows operator error when focusing to be taken into consideration, rather than judging each device on a singular area of focus.  Images were simultaneously viewed at a zoom ranging from 50-400%. 

Note that, as these images were captured in "live" mode, there was no use of the digital camera or camcorder zoom functionality.  Please see these comparison images to see the differences that exist when using zoom functionality during image review.

Results

Depending on the exact make, model, and configuration of the patient exam cameras and some of the camcorders and cameras, useful and clinically relevant images can be captured and sent through existing videoconferencing or store-and-forward applications.  Additional review of the captured images with clinicians possessing a broader set of perspectives will ensure that a more thorough evaluation of the TTAC results can be published.

More information about the review process and results can be found elsewhere in this toolkit.

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