We read with interest the review of mobile phone technology by Sheraton et al.  and its impact in developing world anaesthesia practice. We would like to share a recent innovation for replacing the video-stack systems with which fibreoptic ’scopes are traditionally used.
Fibreoptic intubation remains an essential anaesthetic skill for securing an airway. Ergonomically, it is better to use an intubating fibrescope in conjunction with a traditional video-stack system, as this provides a bigger image than looking through the small eyepiece, better posture for the operator and a shared view of the airway, which is essential for teaching. However, traditional video-stack systems are expensive and have a large carbon footprint. Their key functions are to allow live video and images to be displayed, captured and exported.
We describe a proof of concept method of reproducing these key features of a traditional video-stack system using an Apple iPad™ (Apple, Cupertino, CA, USA), a Proscope Mobile™ (Bodelin Technologies, Lake Oswego, OR, USA), and their free proprietary AirMicro app (iTunes, App Store).
- The Proscope Mobile camera (£180; €224; $290) is a wireless digital microscope camera designed to work with an iPad, iPod or iPhone. It allows live colour video or stills to be viewed simultaneously on multiple Apple iOS devices. It weighs 130 g, runs on three AA batteries, and operates on WiFi 802.11b with a 10-m transmit range. When turned on, it transmits live video over its self-powered WiFi network that can be received by any Apple iOS device running its AirMicro app. It uses a ¼-inch CMOS 5-megapixel sensor with a maximum resolution of 680 × 480 VGA.
- We used a first generation iPad tablet computer (£279; €347; $449) which features a 9.7-inch screen at 1024 × 768 resolution, a 1-Ghz A4 processor and 802.11n Wi-Fi connectivity. The AirMicro app is needed to display the video feed from the Proscope Camera.
- We connected a standard optical fiberscope (Olympus, Center Valley, PA, USA) to the Proscope Mobile camera using a VC-25 Borescope Adaptor (Bodelin Technologies, Lake Oswego, OR, USA: £246; €306; $395). The adaptor was originally designed to attach the Proscope camera to an industrial borescope for inspecting automotive engines, fuel injectors, compressed air inlets, etc. These industrial borescopes conveniently share the same universal 1.25-inch eyepiece with our medical fibrescopes.
One of the authors (DL) tested the device in a simulated intubation using a 3rd generation SimMan™ (Laerdal, Stavanger, Norway; Fig. 4). After 10 recorded attempts, the average time to reach the carina was 19 s and there were no failed attempts. However, there was a detectable lag between the image and the physical movement of the fiberscope. In addition, the camera resolution was felt to be too low and there was visible pixillation on the iPad screen. Additionally, the borescope adaptor allowed the camera to swivel, thereby changing the orientation of the screen image – this was easily resolved by wrapping an elastic band around the rotating part. The camera did change the handling of the fiberscope by making it rather top-heavy.
Despite all these limitations, we believe that we have successfully described a proof of concept idea at a fraction of the cost of a traditional stack system, yet replicating all its key features. Clearly, both hardware and software need to be further refined before it is suitable for clinical use. For example, a camera with higher resolution, using BlueTooth technology rather than WiFi, would improve image quality and lag time.