Capsule endoscopy is a medical imaging technology that lets doctors see parts of the digestive tract without using a long flexible tube. A patient swallows a pill-sized camera that takes thousands of pictures as it moves naturally through the body. This is especially useful for viewing the small intestine, which is difficult to reach with standard endoscopy.
The technology helps identify bleeding, inflammation, ulcers, tumors, and signs of diseases such as Crohn's disease.
Key Facts
- A capsule endoscope is typically about 11 mm in diameter and 26 mm long.
- Image count = frame rate x recording time, such as 2 frames/s x 8 h x 3600 s/h = 57,600 images.
- The capsule moves by peristalsis, which is the wave-like contraction of digestive tract muscles.
- Main components include a lens, image sensor, LEDs, battery, transmitter, antenna, and protective shell.
- Wireless transmission sends image data from the capsule to sensors or a recorder worn by the patient.
- Capsule endoscopy is diagnostic only, so it cannot take biopsies, remove tissue, or directly treat bleeding.
Vocabulary
- Capsule endoscope
- A swallowable medical device with a tiny camera that captures images inside the digestive tract.
- Peristalsis
- The rhythmic muscle contractions that push food, fluids, and the capsule through the digestive system.
- Image sensor
- An electronic component that converts light from the digestive tract into digital image data.
- Wireless transmitter
- A component that sends image information from the capsule to an external recording device.
- Small intestine
- The long section of the digestive tract between the stomach and large intestine where most nutrient absorption occurs.
Common Mistakes to Avoid
- Thinking the capsule is remotely steered, which is wrong because it usually moves passively by peristalsis and gravity.
- Assuming capsule endoscopy replaces all other endoscopy, which is wrong because standard endoscopy can take biopsies and perform treatments while the capsule cannot.
- Forgetting battery life limits the exam, which is wrong because recording time and frame rate determine how many images can be captured.
- Ignoring the risk of capsule retention, which is wrong because a narrowed or blocked intestine can trap the capsule and may require medical treatment.
Practice Questions
- 1 A capsule records at 2 frames per second for 8 hours. How many images does it capture?
- 2 A capsule travels 6 meters through the small intestine in 4 hours. What is its average speed in meters per hour?
- 3 Explain why capsule endoscopy is useful for imaging the small intestine but is not used to remove a polyp or stop active bleeding.