“Applications: Change in Biomed Imaging” by Gary Pitre, Toshiba Imaging Systems

Advances in high-definition (HD) imaging technology and the development of ultracompact camera systems have brought rapid changes to biomedical imaging. More detail and richer color provide medical professionals valuable information for examinations, diagnoses and surgical procedures. Whether the diagnostician is searching for cancerous cells on a pathology slide, analyzing vibratory characteristics of vocal cords or repairing torn tissue, the clarity of the video image is crucial for making sound decisions.

If you have HDTV at home, you are aware of the difference between that and standard-definition transmission mode. Now the high-quality images that once were reserved for the professional broadcast market are available as an important scientific tool. Real-time images taken at 30 frames per second can provide physicians and clinicians the necessary information to diagnose, examine or perform the surgical procedure more effectively, and even to save lives.

High definition is a term that has often been misunderstood or misinterpreted. True high definition means a pixel resolution of 1920 × 1080. To get the best HD image quality and detail, both the camera and the display must be in “true” high definition. If you use an HD camera with a lower-resolution monitor, it defeats the purpose of capturing the imagery in HD. If you use a lower-resolution camera on an HD monitor, the image data can be up-converted to HD, but the pixel interpolation will not provide the most accurate information. Recent advances in imaging technology also include miniaturization and microelectronics.

Cameras, for example, are smaller and lighter than ever before. A new generation of HD cameras with a compact head and a lightweight control unit is now available and feature three-chip technology that can be integrated easily into new or existing systems. These more portable devices provide comfort, control and convenience for the physician, who, during certain exams and procedures, must stabilize the camera head while positioning it with precision.

Figure 1. Three-chip camera technology provides three image sensors within a prism block assembly.
Figure 1. Three-chip camera technology provides three image sensors within a prism block assembly.

In the scientific HD imaging world, two types of chip technology are offered: the single-chip and the three-chip camera. The less sophisticated single-chip camera consists of one sensor with a Bayer color filter between the sensor and the optics. In this setup, color information is interpolated from neighboring pixels, providing a complete color image. The three-chip camera technology, on the other hand, provides three separate image sensors within a prism block assembly. The prism divides the incoming light rays into their red, green and blue components, and each sensor receives a single color at full resolution, providing the best color reproduction available. Mainly because of the lower price, the majority of cameras on the market use single-chip technology, but the most complex scientific imaging applications rely on the precision of three-chip color cameras.

Figure 2. A Bayer color filter is situated between the optics and the sensor.
Figure 2. A Bayer color filter is situated between the optics and the sensor.

Most laboratories and scientific research facilities are equipped with standard-definition displays, but to take full advantage of the new technology, hospitals, clinics and labs soon will need to make the conversion to high-definition. One factor that will affect this transition is cost, but the consumer market continues to drive the price down.

The HD world is rapidly changing in the consumer market, and now, with affordable products available for the biomedical imaging market from companies like Toshiba Imaging Systems, medical diagnostic equipment manufacturers are introducing HD to provide health care professionals better tools to accurately and effectively perform their analyses, diagnoses and procedures.

Pitre, Gary (2009, January). Applications: Change in Biomed Imaging. Photonics Spectra Magazine. Retrieved on March 2, 2009 from http://www.photonics.com/Content/ReadArticle.aspx?ArticleID=36216.

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