Transbronchial needle aspiration and cytological brush sampling of the bronchi are the methods of choice for early diagnosis of lung cancer. However, sampling lesions in the more peripheral lung have low probability of diagnostic yield (sensitivity) because the tissue cannot be clearly imaged during the biopsy procedure. The major problem is the lack of an ultrathin and flexible bronchoscope that maintains high-resolution imaging while providing a biopsy channel. A new microfabrication technique has been developed that micromachines a single, commercial optical fiber into a resonant cantilever that produces wide a field-of-view of directed laser illumination for low-cost in vivo imaging. The fiberoptic scanner can be fit within a 2 mm diameter, so that a flexible scope resembling a catheter can be constructed. This catheter-like scope can be used for imaging regions of the human body that have been inaccessible to larger, less flexible, and more expensive scopes based on coherent fiberoptic bundles that do not have room for a biopsy channel. The Pentax Corporation has an option to license this fiber-scanning catheterscope technology from the University of Washington, and a joint partnership has been formed to develop this technology to a prototype the device and also to prototype manufacturing processes that will lead to an in vivo imaging instrument with a disposable distal end. The goals of this project are to (I) construct a 2.0 mm diameter prototype catheterscope with a biopsy channel that can pass a 22-gauge needle, (2) use low-cost components and develop high-volume manufacturing processes so the total cost of the distal end is <$100, (3) test the prototype for image-guided biopsy using an in vitro model and an appropriate animal model, and (4) facilitate technology transfer from the academic inventors to the medical device manufacturer so that the successful diagnosis of cancer in the peripheral lung can be significantly improved while healthcare costs are reduced. In future clinical practice, the catheterscope will be introduced into the peripheral lung through the biopsy channel of a larger bronchoscope, and possibly used without the aid of fluoroscopy, further reducing the cost of lung cancer diagnosis. Due to the directed laser illumination, the fiber-scanning catheterscope can be used in conjunction with laser-based diagnoses and therapies, such as laser-induced intrinsic fluorescence at 405 nm for improved selection of biopsy sites, Applications in the future are the diagnosis of pancreatic, breast, bladder, and other lumenal cancers.