- Email: [email protected]
Simplifying video endoscopy: Inexpensive analog and digital video endoscopy in otolaryngology
CLINICAL TECHNIQUES AND TECHNOLOGY Simplifying video endoscopy: Inexpensive analog and digital video endoscopy in otolaryngology PATRICK C. MELDER,
MD,
Washington, DC
T
he addition of video to the practice of otolaryngology enhances patient care and serves as an educational tool; taping an examination or procedure further enhances these results and provides a means of dynamic medicolegal documentation. However, the equipment for accomplishing such a task can be quite expensive. In addition, commonly available VHS recorders are analog devices that limit editing and incorporation into other digital formats without additional equipment.1 New digital cameras and digital video recorders afford the otolaryngologist a varied means to perform video documentation (digital or analog). There are a variety of scaled applications for a digital camera in the clinical setting for capturing digital images. First, a digital still camera can be used as a single chip camera source for output to a standard TV or VHS recorder. The required equipment is: (1) a digital camera with audio/visual (AV) output capability and associated cables; (2) an endoscopic coupler; (3) a light source; (4) a TV and/or VHS recorder, depending on need; and (5) a flexible nasopharyngoscope or rigid nasal endoscope. The necessary equipment for digital endoscopy has previously been reported.1 Assuming any busy practice would already have appropriate scopes and light sources, the cost of this would range from $1000 to $1200. In this setup the digital camera acts as a direct video feed from the camera to the AV input for a VHS recorder/TV. This is accomplished by use of the AV output on the camera (inset, Fig 1). Necessary cables are usually provided with the camera and do not require additional cost. The intended purpose of these cables is to provide an output directly to a TV for review of photos on a large screen for a slide show. When the camera is configured for input rather than review, this provides a live camera feed to an input From the Department of Otolaryngology–Head and Neck Surgery, Walter Reed Army Medical Center. EBM rating: D. Reprint requests: Patrick C. Melder, MD, Department of Otolaryngology–Head and Neck Surgery, Walter Reed Army Medical Center, 6900 Georgia Ave. NW, Bldg 2 6BENT, Washington, DC 20012-0017; e-mail, [email protected]. Otolaryngol Head Neck Surg 2005;132:804-5. 0194-5998/$30.00 Copyright © 2005 by the American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. doi:10.1016/j.otohns.2004.03.047
804
source (TV/VCR). The output to a TV/VCR will be an analog video. The image can then be directly recorded onto the VHS tape. Since the image is passing through a single charged couple device, this is the equivalent to a single chip image (Fig 1). Second, the digital camera can be used to capture digital still images.1 Third, the camera can be used to capture short segment MPEG (Moving Picture Experts Group) video with audio. Depending on the camera, video of up to 30 seconds and longer can be captured on a digital media card. Multiple examinations can be captured on the memory card: limited only by the memory on the card. This simplified setup can be used in a mobile practice with a portable light source for mobile digital video documentation. An otolaryngologist in the ER or on the ward can easily perform video endoscopy with the ability to archive the examination. However, as the image is captured on the charge coupled device a moiré effect will be noted on review of the video. Many triple chip cameras offered by large endoscopy companies have embedded technology to “blur” the moiré to lessen the distortion of the image seen on a video. The moiré effect is not seen with straight output to an analog TV or VHS recorder. In order to obtain an appropriate image, the camera must be zoomed to about ⫻6. This may vary depending on camera model, but in general the image obtained without zooming will be a fairly small image. It is best to use the optical zoom over the digital zoom because the digital zoom is not a true zoom; rather a zooming of a digital pixel and not the true image from the lens. This is critical for MPEG video. If the camera does not allow for zooming during MPEG recording, the video will be very small. The Epson Photo PC 3000Z (Epson USA, Long Beach, CA) allows for zooming during MPEG video recording. If the intent is to record video with the camera, ensure it allows for zooming during video recording. Limitations in zooming are not an issue when using as an analog output to a TV/VCR (inset, Fig 1). On the other hand, an otolaryngologist may desire the numerous benefits of full, uncompressed, digital video. Various endoscopy vendors have different solutions for providing digital video that often costs thousands of dollars. These “systems” usually contain a laptop or work station and a patient database manage-
Otolaryngology– Head and Neck Surgery Volume 132 Number 5
MELDER 805
.
.
Fig 1. Simplified video endoscopy: Canon PowerShot G3 (Canon USA, Lake Success, NY) is used to perform flexible video nasopharyngoscopy. Image of endoscopy is seen on a standard TV routed through a VHS recorder. Inset: Audio/visual cables supplied with camera to route image into the audio/video input on the TV/VCR
Fig 2. Simplified digital endoscopy: Canon ZR45MC (Cannon USA, Lake Success, NY) is used to perform digital video recording. S-video cable is used in the s-video output on the Karl Storz Camera Control Unit (20242120U) (Karl Storz Endoscopy, Culver City, CA). Image seen through the Karl Storz Tricam camera head (20221030U) is routed to the analog video tower components and the hand-held digital camera. This view is from the rear of the tower system
ment system with video input: very similar to commonly available video stroboscopy setups. Other vendors provide recordable compact disk (or digital video disk) systems for archiving digital video. A simplified and inexpensive approach is to use an appropriate digital video camcorder with an S-video input (Fig 2). This system requires a standard video tower system to include: (1) monitor; (2) camera source (with s-video or out-put); (3) light source; and (4) video camera. Many tower systems sold by vendors have available VHS recorders. Taping to a VHS recorder limits easy editing and incorporation into other digital formats. Digital video can also be easily compressed and archived. Unlike its more expensive tower counterpart, a hand-held digital camera can be easily transported from the OR to the office thereby eliminating the cost of a redundant system.
Inexpensive and simplified video systems are available, usable, and fun. In this era of cost savings, it is refreshing to know that ingenious applications of seemingly unrelated products can provide such meaningful results. An off-the-shelf digital camera can provide excellent digital endoscopic photographs, compressed digital video, and full analog output to a standard TV and/or VCR. In addition, affordable hand-held digital video recorders offer an inexpensive and versatile means of capturing full uncompressed digital video that can then be easily edited on a laptop with commonly available software. REFERENCES 1. Melder PM, Mair EA. Endoscopic photography: digital or 35mm? Arch Otolaryngol Head Neck Surg 2003;129(5):570-5.
MD,
Washington, DC
T
he addition of video to the practice of otolaryngology enhances patient care and serves as an educational tool; taping an examination or procedure further enhances these results and provides a means of dynamic medicolegal documentation. However, the equipment for accomplishing such a task can be quite expensive. In addition, commonly available VHS recorders are analog devices that limit editing and incorporation into other digital formats without additional equipment.1 New digital cameras and digital video recorders afford the otolaryngologist a varied means to perform video documentation (digital or analog). There are a variety of scaled applications for a digital camera in the clinical setting for capturing digital images. First, a digital still camera can be used as a single chip camera source for output to a standard TV or VHS recorder. The required equipment is: (1) a digital camera with audio/visual (AV) output capability and associated cables; (2) an endoscopic coupler; (3) a light source; (4) a TV and/or VHS recorder, depending on need; and (5) a flexible nasopharyngoscope or rigid nasal endoscope. The necessary equipment for digital endoscopy has previously been reported.1 Assuming any busy practice would already have appropriate scopes and light sources, the cost of this would range from $1000 to $1200. In this setup the digital camera acts as a direct video feed from the camera to the AV input for a VHS recorder/TV. This is accomplished by use of the AV output on the camera (inset, Fig 1). Necessary cables are usually provided with the camera and do not require additional cost. The intended purpose of these cables is to provide an output directly to a TV for review of photos on a large screen for a slide show. When the camera is configured for input rather than review, this provides a live camera feed to an input From the Department of Otolaryngology–Head and Neck Surgery, Walter Reed Army Medical Center. EBM rating: D. Reprint requests: Patrick C. Melder, MD, Department of Otolaryngology–Head and Neck Surgery, Walter Reed Army Medical Center, 6900 Georgia Ave. NW, Bldg 2 6BENT, Washington, DC 20012-0017; e-mail, [email protected]. Otolaryngol Head Neck Surg 2005;132:804-5. 0194-5998/$30.00 Copyright © 2005 by the American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. doi:10.1016/j.otohns.2004.03.047
804
source (TV/VCR). The output to a TV/VCR will be an analog video. The image can then be directly recorded onto the VHS tape. Since the image is passing through a single charged couple device, this is the equivalent to a single chip image (Fig 1). Second, the digital camera can be used to capture digital still images.1 Third, the camera can be used to capture short segment MPEG (Moving Picture Experts Group) video with audio. Depending on the camera, video of up to 30 seconds and longer can be captured on a digital media card. Multiple examinations can be captured on the memory card: limited only by the memory on the card. This simplified setup can be used in a mobile practice with a portable light source for mobile digital video documentation. An otolaryngologist in the ER or on the ward can easily perform video endoscopy with the ability to archive the examination. However, as the image is captured on the charge coupled device a moiré effect will be noted on review of the video. Many triple chip cameras offered by large endoscopy companies have embedded technology to “blur” the moiré to lessen the distortion of the image seen on a video. The moiré effect is not seen with straight output to an analog TV or VHS recorder. In order to obtain an appropriate image, the camera must be zoomed to about ⫻6. This may vary depending on camera model, but in general the image obtained without zooming will be a fairly small image. It is best to use the optical zoom over the digital zoom because the digital zoom is not a true zoom; rather a zooming of a digital pixel and not the true image from the lens. This is critical for MPEG video. If the camera does not allow for zooming during MPEG recording, the video will be very small. The Epson Photo PC 3000Z (Epson USA, Long Beach, CA) allows for zooming during MPEG video recording. If the intent is to record video with the camera, ensure it allows for zooming during video recording. Limitations in zooming are not an issue when using as an analog output to a TV/VCR (inset, Fig 1). On the other hand, an otolaryngologist may desire the numerous benefits of full, uncompressed, digital video. Various endoscopy vendors have different solutions for providing digital video that often costs thousands of dollars. These “systems” usually contain a laptop or work station and a patient database manage-
Otolaryngology– Head and Neck Surgery Volume 132 Number 5
MELDER 805
.
.
Fig 1. Simplified video endoscopy: Canon PowerShot G3 (Canon USA, Lake Success, NY) is used to perform flexible video nasopharyngoscopy. Image of endoscopy is seen on a standard TV routed through a VHS recorder. Inset: Audio/visual cables supplied with camera to route image into the audio/video input on the TV/VCR
Fig 2. Simplified digital endoscopy: Canon ZR45MC (Cannon USA, Lake Success, NY) is used to perform digital video recording. S-video cable is used in the s-video output on the Karl Storz Camera Control Unit (20242120U) (Karl Storz Endoscopy, Culver City, CA). Image seen through the Karl Storz Tricam camera head (20221030U) is routed to the analog video tower components and the hand-held digital camera. This view is from the rear of the tower system
ment system with video input: very similar to commonly available video stroboscopy setups. Other vendors provide recordable compact disk (or digital video disk) systems for archiving digital video. A simplified and inexpensive approach is to use an appropriate digital video camcorder with an S-video input (Fig 2). This system requires a standard video tower system to include: (1) monitor; (2) camera source (with s-video or out-put); (3) light source; and (4) video camera. Many tower systems sold by vendors have available VHS recorders. Taping to a VHS recorder limits easy editing and incorporation into other digital formats. Digital video can also be easily compressed and archived. Unlike its more expensive tower counterpart, a hand-held digital camera can be easily transported from the OR to the office thereby eliminating the cost of a redundant system.
Inexpensive and simplified video systems are available, usable, and fun. In this era of cost savings, it is refreshing to know that ingenious applications of seemingly unrelated products can provide such meaningful results. An off-the-shelf digital camera can provide excellent digital endoscopic photographs, compressed digital video, and full analog output to a standard TV and/or VCR. In addition, affordable hand-held digital video recorders offer an inexpensive and versatile means of capturing full uncompressed digital video that can then be easily edited on a laptop with commonly available software. REFERENCES 1. Melder PM, Mair EA. Endoscopic photography: digital or 35mm? Arch Otolaryngol Head Neck Surg 2003;129(5):570-5.