HEED-HARP technology may be used in endoscope cameras to significantly improve performance

Pioneer will enter the medical device market, starting with the development of cameras for endoscopes. At the end of October 2012, Pioneer reached a business cooperation agreement with Otsuka Medical Devices, a medical device manufacturer under Otsuka Pharmaceutical, and the two parties will work together to develop endoscopes using Pioneer cameras, with the goal of launching them on the market through Otsuka Medical Devices in 2014.

　　The biggest feature is "high sensitivity"

　　Pioneer intends to differentiate itself from other companies by adopting the "HEED-HARP" technology in its endoscope camera heads (Figure 1). HEED-HARP combines the company's cold cathode planar electron source "HEED" (high efficiency electron emission device) and the ultra-high sensitivity photoelectric conversion film "HARP" (high-gain avalanche rushing amorphous photoconductor) developed under the leadership of the NHK Broadcasting Technology Research Institute.

　　

　　As shown in Figure 1 (b), when light enters from the glass, electron-hole pairs corresponding to the amount of light are generated inside the HARP film, which is mainly composed of a-Se (amorphous selenium). The electron holes are amplified in an avalanche manner inside the HARP film. The electron holes are neutralized by the electrons released by the HEED, and an image can be formed by detecting the current flowing at this time. This technology has been demonstrated at the "NHKNHK Technology Research Exhibition" and other occasions before, and has attracted great attention.
Hiroyuki Kamijo, head of the business planning department of Pioneer Medical and Health Business Development Office, introduced that the biggest feature of the camera using this technology (HEEDHARP camera) is "high sensitivity." For example, in an environment with an illumination of 0.6lx (equivalent to moonlight), a clear image can be obtained without digital compensation processing (Figure 2).

　　

　　

　　In order to take advantage of this feature, some manufacturers have previously explored various applications such as night vision cameras and have produced prototype cameras. However, none of them have been put into formal use so far.

　　Pioneer aimed at a new use for this technology, endoscopes. Pioneer believed that this technology, which could be used to observe the inside of the body in the dark, could give endoscopes new features. Pioneer then told this idea to Otsuka Medical, which was also very interested in the capabilities of the HEED-HARP camera, so the two companies decided to jointly develop endoscopes. Endoscope cameras
using HEED-HARP technology and endoscopes using this camera have not yet been trial-produced, so what specific differences can be made from existing endoscopes by utilizing the "high sensitivity" feature? There are three main possibilities, namely (1) reducing heat generation, (2) making the endoscope part thinner, and (3) making the endoscope wireless (Figure 3).

　　

　　

　　(1) The reason for reducing heat generation is that the same image as the previous camera can be obtained even when the ambient illumination is low. Minoru Hayashi, director of Pioneer Medical and Health Business Development Division, said, "Although this is just a technical estimate, it is possible to reduce heat generation to about 1/100 of the previous endoscope."

　　Endoscopes are used to illuminate the dark interior of the body, so generally very large light source units using halogen or xenon light sources are used. Recently, there has been a move to use LED light sources to reduce heat generation, which is one of the issues that endoscopes must address. If heat generation can be significantly reduced, the effects on internal tissues such as burns can be minimized.

　　(2) The reason why the endoscope can be made thinner is that "due to its high sensitivity, the camera can be held in the hand, which can change the current endoscope method of equipping the probe at the tip of the endoscope with a CCD, etc." (Pioneer's article).

　　The diameter of the endoscope of current endoscopes must be at least the same as the size of the CCD, and the pipe must have wiring to connect to the CCD. If the endoscope is thinner, it can reduce the burden on patients.

　　(3) The reason why endoscopes can be made wireless is that the light source unit may no longer be required. Previously, the light source unit and the endoscope were connected by wires. However, if only an LED or the like is installed at the tip of the endoscope, the light source unit and wires will no longer be required.

　　Developing sensors using optical disc technology

　　Pioneer will use the development of the endoscope camera as an opportunity to develop the medical and health field into a new business field for the company. The company established the Medical and Health Business Development Office in April 2012 to promote the application of the company's technology in the medical and health field. In addition to the endoscope camera this time, Pioneer will also develop a small blood flow sensor using optical disk technology.