Medical Applications of 8K Technology

Takayuki ItoPhD
Senior Advising Manager, System Engineering Division
NHK Engineering System Inc.

Video technology is an aspect of broadcasting that has
been applied to various industries as a means of visualization.
In particular, various life-saving advances have been made in
the medical field through the prompt application of the latest
video technology. Here, we introduce the efforts made by NHK
Engineering System Inc. (NES)[1][2] to apply 8K technology
developed by NHK to the medical field.

■ Figure 1: A neurosurgical procedure performed under amicroscope (2015)

1. Development of an 8K camera and filmingof surgery

Medical applications of 8K began with the filming of various
surgical procedures in 8K. During each year from 2010 to 2014,
we filmed heart surgery operations using 4K/8K cameras so thatlive video can be transmitted to other venues and presented atlarge-scale conferences attended by many medical professionals(organized by Tokyo Heart Lab).
In 2014, as part of an 8K technology demonstration
experiment by the Ministr y of Interna l A ffairs andCommunications, we obtained 8K video of operations being
performed in the fields of cardiac surgery, esophageal surgery,and liver/gall bladder/pancreas surgery at the University of Tokyo
Hospital. These were presented at conferences related to eachfield within the hospital in order to elicit the opinions of medical
professionals on the usefulness and issues of 8K images.
In 2014, we also obtained 8K video of an off-pump coronary
artery bypass procedure performed by Dr. Atsushi Amano ofJuntendo University Hospital. Dr. Amano is a cardiac surgeon
who performs highly difficult coronary artery bypass surgery
while the heart is beating and without the use of an artificial heart(i.e., off-pump). In the 8K video, it is even possible to see subtle
deformations of the vessel walls while the blood vessels are being
sewn together with fine thread. This highlighted the usefulnessof 8K video in medical applications, with viewers remarking that
it was possible to grasp the amount of force applied to the thread,and that this sort of video is extremely useful for passing on theskills of skilled physicians [2].
In February 2015, an 8K camera was attached to a surgicalmicroscope to film a neurosurgical operation performed by Dr.
Arakawa of Kyoto University School of Medicine (Fig. 1). Here,the lead surgeon and his assistant performed the surgery whilelooking through a microscope, and the same operative site wasfilmed from different optical paths. It may eventually capture
microscope images with an 8K camera so that surgery can be

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performed while viewing a large 8K monitor.
These demonstrations not only confirmed the usefulness of8K in the medical field, but also helped us to accumulate knowhow and clarify the requirements for cameras and other equipment
for such purposes. It was also suggested that 8K could be used
for education by filming and storing video footage of surgeries
performed by prominent surgeons.

2. Experimental demonstration of 8K
telemedicine

For some time, hopes have been pinned on the use oftelemedicine as a way of addressing the uneven regional
distribution of medical experts and regional disparities inadvanced medical care. If the use of 8K technology makes it
possible to perform diagnoses that have been difficult to makewith conventional technology, then it could bring about rapid
progress in telemedicine. In 2016, a telemedicine demonstration
experiment in which video was captured, transmitted anddisplayed using 8K technology was conducted by the Ministry ofInternal Affairs and Communications to verify the applicabilityof 8K to telemedicine and the medical efficacy of this technology.
(1) Remote pathological diagnosis
Pathological diagnosis involves examining thin sections oforgan parts, etc. under a microscope to check for the presence ofcancer cells, bacteria, or lesions. In the case of cancer surgery, rapid
pathological diagnosis is performed while surgery is in progressto confirm whether a tumor has been completely removed, andthat the surfaces left after excision do not contain any cancer cells.
However, since pathologists are not available at every hospital that

performs cancer surgery, there is a need for the implementation ofhigh-precision remote pathological diagnosis.
In this experiment, a microscope equipped with an 8K camera
was installed in a hypothetical hospital with no pathologist, andthe 8K images were transmitted over broadband Ethernet to aspecialist hospital where they could be observed by a pathologist
for diagnosis. The video signals were encoded using the HEVC
(H.265) compression standard. Figure 2 shows an overview of theexperiment.
The results of this experiment showed that 8K remotediagnosis is not inferior to direct diagnosis (103 out of 104
correct answers). The 8K remote diagnosis system is also idealfor displaying large areas of prepared specimens at once on asingle high-definition screen so that the pathologist can approach
the screen to get a close-up view of areas of interest in much thesame way as would be achieved by switching the objective lensof a microscope. This new system is expected to be effective at
improving diagnostic accuracy and reducing the burden on themedical examiner.

telemedicine support. 8K images of the affected areas of patientswere transmitted to the dermatologist, who was able to view
them while interviewing the patients and giving instructions
to the doctor on the remote island to enable to acquisition of
information necessary for diagnosis. An outline of the experimentis shown in Fig. 3. By comparing the results of diagnoses made bydermatologists in person with those made by remote diagnosis,
we found that the rate of agreement between these results wasmuch higher than achieved using conventional video systems suchas HD. The dermatologists who participated in the experimentcommented that the ability to observe minute lesions made it
possible to recognize signs of malignancy and refer patients formore thorough examinations at an earlier stage. On the otherhand, it became clear that there is a need for imaging equipmentthat is smaller, more sensitive, and as easy to use as consumeroriented cameras.
■ Figure 3: 8K telemedicine support demonstration (2016)■ Figure 2: 8K remote pathological diagnosis
demonstration experiment (2016)

3. Research and development of an 8K rigid
endoscopic (laparoscopic) surgical system(2) Telemedicine Support
To demonstrate the use of 8K technology in supporting
telemedicine, we chose the field of dermatology, where visual
information is considered to be of particular importance. Using asatellite link, we connected a remote island hospital in Nagasaki
Prefecture, which has no full-time dermatologist, to a university
hospital where a dermatologist was able to provide experimental

A rigid endoscope is a non-flexible endoscope that basicallyconsists of lenses built into a metal pipe, unlike a soft endoscope(which is called a gastric camera). A camera is usually attached tothe eyepiece so that surgery can be performed while viewing theimages displayed on a monitor. A laparoscope is a rigid endoscopethat is used to observe the interior of the abdominal cavity. Most
rigid endoscopes use 2K cameras, but 4K endoscopes are alsocommercially available. To develop an 8K rigid endoscope system,
it is necessary to develop a compact and high-performance 8K
camera and high-performance rigid endoscope lenses that match

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9the high-resolution performance of 8K.
In December 2015, in collaboration with the National Cancer
Center Hospital and Olympus Corporation, NHK Engineering
System Inc. (NES) successfully filmed the intra-abdominal
cavities of animals by using an 8K camera in combination with a4K rigid endoscope. Despite only using 4K apparatus, on seeing
the 8K images for the first time, the medical professionals weresurprised to find that the images were clear enough to demonstrate
the benefits that can be expected from 8K technology.
In addition to clearer images, the medical professionals also
expressed their hopes for the following benefits:(1) With existing laparoscopes, it is often necessary to bring the tipof the laparoscope very close to internal organs for a closer lookat the affected area, and as a result, the laparoscope is liable toget in the way of the surgical implements. With 8K resolution,
it would be possible to obtain a detailed view of the affectedarea by observing the operation area from an overhead position■ Figure 4: 8K endoscopic camera system
Top: Model #1 (2017), Bottom: Model #2 (2020)and using electronic zoom when a close-up view is needed,
thereby resulting in fewer blind spots and less interference
between the surgical instruments and the laparoscope.
(2) With an 8K system, it is relatively easy to identify nerves
that are difficult to see with conventional laparoscopy. Thisis expected to be effective for preserving autonomic nervous
system functions in operations such as colorectal cancer
surgery.
A research group that includes the National Cancer
Center, Olympus and NES was entrusted by the Japan Agency
for Medical Research and Development (AMED) to conduct
research and development related to 8K laparoscopic surgery
systems over the two periods of FY2016–8 and FY2019–21.
In the first period, we worked on the development of acompact, high sensitivity 8K camera and an electronic zoom
device, and we performed animal experiments to verify theperformance of the 8K system combined with a prototype 8K
laparoscope made by Olympus. This 8K laparoscopic camera
is shown in the upper part of Fig. 4. The camera is a modified
broadcast camera using a 1.7-inch imaging device[4], and thecamera head connected to the laparoscope weighs 720 g. In
addition to this camera, we also implemented functions including
an electronic zoom function (magnification 1.0–4.0×) that scales
up a section of the 8K image. From March 2018 to March 2019,
we conducted clinical trials of this system in 25 cases to verify theeffectiveness of the 8K endoscopy system (see Fig. 5). The results
showed that the amount of blood loss during operations wasreduced to about half that of conventional laparoscopic surgery,while the camera, although smaller, was still large and made itdifficult to change the operation area during surgery [5].

4. Development and validation of an 8K rigid
endoscopic surgery system for remotesurgery assistance [6]■ Figure 5: Clinical trial of the 8K endoscopy system

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These clinical trials showed that although the 8K endoscopic
surgery system is effective, further downsizing of the camera isalso required. Based on these findings, we were commissionedby AMED to research and develop a remote surgery-assisted
endoscopic surgery system for three years from FY2019 toFY2021. Recently, endoscopic surgery has become increasingly
commonplace due to its low patient burden, but because it requires
advanced skills, there are sometimes insufficient specialist
surgeons in certain areas. We have developed an endoscopic
surgery system for remote surgery assistance as a candidate
technology for alleviating regional disparities in the availabilityof endoscopic surgeons. This system transmits endoscopic video
images obtained during surgery to a remote specialist, who isable to monitor the progress of the surgery and offer advice to thesurgeon in the operating theater while observing the endoscopic
surgery in progress. This makes it possible to provide support toinexperienced surgeons and assistants. The purpose of the 8K
endoscope is to make it possible for specialists to provide accurate

■ Figure 6: S ystem configuration of the remote surgery support experiment using live 8K live video transmission■ Figure 7: E xperimental animal surgery performed with remote surgical support
Left: A specialist doctor provides verbal and written instructions via an 8K monitor (KyotoPrefecture); Right: The surgeon proceeds with the surgery in accordance with the specialist
doctor’s instructions (Chiba Prefecture)

surgical support based on high-definition, highly realistic intraabdominal images sent from remote locations.
NES developed this system after clarifying the above system
requirements, and confirmed its medical effectiveness in animalexperiments.
Prior to the development of the system, evaluation
experiments were conducted with medical professionals todetermine the bandwidth required for compression coding of
8K endoscope images and the acceptable lag time of transmitted

images. As a result, it was found that a transmission bandwidthof at least 70 Mbps or thereabouts is required, with a video
transmission lag time of no more than 1.3 seconds. The videocoding method is H.265.
For the 8K camera that forms the core of the system, wedeveloped an endoscope camera using a compact 8K medical
camera that was jointly developed by NES and Ikegami Tsushinki(Figure 4, bottom). The camera weighs 210 g, which is lessthan a third of the weight of the #1 model. We also developedNew Breeze Winter 2023

11a camera control unit (CCU) with electronic zoom and autofocus functions. This camera is light enough to be used with acommercially available scope holder, making it easily adaptableto surgical applications. We also developed a system including an
8K video encoding and transmission device and a drawing anddisplay device (annotation device) that can be used to write support
information on the 8K screen and send it back to the operating
theater, which is a necessary feature for supporting remote surgicaloperations.

5. Experiment verification of the remote
operation support system[6]References[1]	Ito: “Medical application of 8K video systems,” J. Inst. Image Information and TelevisionEng., Vol. 71, No. 5, pp. 707–711 (2017)[2]	Ito: “Development of an 8K laparoscopic system,” J. Inst. Image Information and TelevisionEng., Vol. 74, No. 6, pp. 921–924 (2020)[3]	Ministry of Internal Affairs and Communications: “Report of the Study Group on Intelligent
Medical Care by Application of 8K Technology,” https://www.soumu.go.jp/main_content/000432810.pdf[4]	Yamazaki et al.: “Development of a new endoscopic surgery system using 8K Super HiVision technology,” ITE Conf. Reports, 33-A1 (2017)[5]	Tsukamoto, S. et al: “Laparoscopic surgery using 8K ultra-high-definition technology:
outcomes of a phase II study,” Asian J. Endosc. Surg. 2022 Jan, 15(1), pp. 7–14 (2021)[6]	Ito et al: “Development of 8K laparoscopic surgery system with real-time tele-advice
facilities and evaluation of animal surgery experiment using live transmission of 8K video
via 5G network.” ITE Tech. Rep. Vol.46, No.11 BCT 2022-22 (Mar. 2022)

To verify the effectiveness of this system, we conducted an
animal experiment in which an inexperienced endoscopic surgeon
and a surgical assistant were provided with guidance by a specialist
physician who was able to view the 8K endoscopic images at aremote location. We compared the time taken to complete thesurgery and the quality of operations performed with and without
remote guidance. Figure 6 shows the system configuration usedin this experiment. The experiment was conducted by connecting
an animal experimentation site in Narita City, Chiba Prefecture,with the Keihanna Open Innovation Center, Kyoto Prefecture, via
a wired network and 5G network so that 8K endoscopic images,
bidirectional audio and on-screen instructions could be conveyed
between the two sites. Figure 7 shows the setup at each end of
this connection. The 8K video was transmitted at a bit rate of80 Mbps, and the transmission lag from the endoscopic camera to
the 8K display device at the remote site was approximately 600 ms.
Our experimental results show that two inexperienced
surgeons were able to perform the same procedure in less timewith remote guidance than without. We also evaluated the qualityof surgery with and without support, based on the endoscopic
images, and found that operations achieved better quality withremote guidance than without.

6. Future prospects

We have introduced activities on medical applications of8K technology conducted by NES. High-definition imaging
technology has always attracted attention in the medical field, andapplications in this field have always been promoted. However,this trend is becoming particularly strong in the 8K era. In
addition, “contactless” and “remote” technologies have become
particularly important in the wake of the coronavirus pandemic
over the last couple of years, and 5G is also expected to become
an important part of the communications infrastructure. The
combination of two cutting-edge technologies, 8K and 5G, islikely to become increasingly important in the medical field.

Cover Art
View of Mount Haruna in
the Snow, from Famous
Views of 60 Provinces

Utagawa Hiroshige (1797-1858)
Source: National Diet Library, NDL
Image Bank(https://rnavi.ndl.go.jp/imagebank/)

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