Development and Validation of a Remote Image Transmission System for Prehospital Emergency Care

Takuma SADAMORI1, Shinji KUSUNOKI2, Tadatsugu OTANI1, Tomoko TAMURA1, Kohei OTA1, Yoshiko KIDA1, Yasumasa IWASAKI1, Nobuyuki HIROHASHI1

and Koichi TANIGAWA1

1Department of Emergency and Critical Care Medicine, Hiroshima University Hospital,

Hiroshima, 734-8551, Japan 2Critical Care Medical Center, Hiroshima Prefectural Hospital, Hiroshima, 734-8530, Japan

ABSTACT

Objective: The aim of the study was to validate the effectiveness of a newly-developed video transmission system using a commercially available video-inubation device, a transmission device, and mobile telephone networks for prehospital emergency care. Methods: We designed a three-step approach for the study. As a pilot study, we examined the possibility of remote transmission of airway management images, i.e. tracheal intubation, using a rigid video-laryngoscope and mobile phone networks. Next, we developed a prototype system using a video-laryngoscope, a specially developed transmission device, and mobile telephone networks, which combined multiple images from devices installed in an ambulance and transmitted them to a remote hospital. Finally, we verified the feasibility of the image transmission system in a simulated concurrent

multiple emergency. Image information from 4 ambulances in Hiroshima city was transmitted to a virtual control center in Tokyo. Results: In the pilot study, image transmission of tracheal intubation using the commercial available devices was successfully performed. Our prototype transmission system promptly transmitted the multiple visual data from the scene to our hospital or the remote virtual control center. Conclusions: Our system promptly transmitted multiple visual data from the scenes to the control center in a distance. The incorporated images transmitted from multiple emergency scenes were found to be quite useful for medical control and quality assurance of emergency care. Keywords: Remote image transmission system, Prehospital emergency care, Communication system, Medical control, Ambulance crew.

1. INTRODUCTION

The role of the pre-hospital emergency care has become more important as it has become more sophisticated. In Japan, the emergency medical service personnel are non-physicians, therefore medical control is prerequisite to assure quality of emergency care. We have a one-tiered system and the ambulance is staffed by three crews trained in rescue, stabilization, transportation, and advanced care of traumatic and medical emergencies. Among them, the most advanced level ambulance crews called Emergency Life Saving Technicians (ELSTs) have been expected to play a large role in the initial emergency care. In addition to perform appropriate evaluation of patients, the ELSTs are permitted to perform high-level emergency care, such as tracheal intubation and intravenous administration of emergency medicines. Although their activities are based on pre-set protocol, on-line communication between the pre-hospital scene and the medical director is essential to guarantee the quality of the emergency care. However, limitations have been pointed out regarding conventional verbal-based interfaces, therefore a video-image transmitting system has been sought. The major obstacle to develop video-image transmitting systems includes cost and the quality of video image transmitted using available wireless networks. We have developed a video transmission system using commercially available medical devices, video-image transmitting devices and mobile telephone networks, and are working toward

practical use of this system in the Japanese pre-hospital settings.

2. METHODS

Pilot study: We examined the possibility of remote transmission of airway management image, i.e. tracheal intubation of a rigid video-laryngoscope, the PENTAX-AWS® (HOYA Corp., Tokyo, Japan; AWS) in this pilot study. By using the AWS, the laryngeal images on the screen can be shared by not only the practitioner but also assistants or teaching staff during the procedure [1]. In addition, the AWS has a video outlet through which the image can be transmitted to other monitor screens. This function can be used to transmit the image via a mobile phone to other mobile devices or a remote computer [2]. We experimentally developed an image transmission system using a commercially available remote monitoring system (Portable EYE C, Mitsubishi Electric Corp., Tokyo, Japan) and a 3G mobile telephone network (FOMA, NTT DOCOMO Corp., Tokyo, Japan). Thereafter, we planed remote transmission of tracheal intubation images of the AWS, because practical applications of this system would enable medical directors to verify the procedures performed by ELSTs in a distance. To determine the feasibility of video-transmission using this system, we attempted to transmit video-images during intubation attempts of a manikin model (Heartsim® 4000, Laerdal Medical, Stavanger, Norway) using the AWS to our critical care

center 12 km away from the firefighter academy.

Clinical test: We designed a system which combines multiple images from devices installed in an ambulance and transmits it to a remote hospital. Informed consent was obtained from all of the patients and their families for participating in this study. The ambulance used in this study was equipped with a video camera (CX560V, Sony Corp., Tokyo, Japan), a bio-monitor (WEC-5003, Nihon-Koden, Tokyo, Japan), the AWS and a specially designed transmission device (RVT-SD100, SONY Corp., Tokyo, Japan), which transmits high-resolution images via a conventional telephone network. We combined visual and digital information from these equipments and incorporated them into the tetrameric screen display, then transmitted the information to our critical care center. With collaboration with SONY Corp, we developed the RVT-SD100 that uses a 3G mobile phone networks and the Internet to transmit high quality video images (Figure). This device uses the H.264/MPEG-4 AVC Main Profile codec and supports video resolution up to 352 x 240. Also, the system enables to send images from up to 12 transmitters to one receiver at the same time. Two to 10 seconds delay for transmission would be expected for coding process.

System development: Finally, we

developed the aforementioned high-resolution image transmission system and used it in a simulated multiple emergency. Four ambulances were equipped with a video image transmission system, a bio-monitor and the AWS, and then

deployed at 4 different points in Hiroshima city. We set up a virtual information control center in Tokyo approximately 900 km away from Hiroshima city to monitor all images transmitted from multipoint emergency scenes using a receiving device (RVT-MR212, Sony Corp., Tokyo, Japan), which could simultaneously incorporate information from up to 12 transmission devices. Each ELST in 4 ambulances in Hiroshima city simultaneously performed evaluation procedures and emergency care for simulated patients, such as advanced life support, assessment of a trauma victim with open fracture of lower leg and an acute abdominal condition. Image information from each ambulance was incorporated and transmitted to the virtual control center in Tokyo.

3. RESULTS

Pilot study: Ninety percent of the video-image transmissions during intubation attempts were successfully performed and the laryngeal anatomy during the procedure was clearly recognized at the medical center. Four percent failed because of poor connection of mobile telephone networks.

Clinical test: Three emergency patients,

i.e., a multiple trauma, an acute abdominal condition and a panic syndrome, were enrolled. The video images of the patients, vital monitoring data were transmitted to the center. No transmission failure was encountered, and all the combined images transmitted from the

ambulance were clear enough to examine and evaluate appearances or conditions of the patients and medical care provided by ELSTs through transmitted images at our critical care center. Especially in a trauma patient, the transmitted image was found to be quite useful for recognition of the severity of the injuries.

System development: The images

simultaneously transmitted from 4 ambulances in Hiroshima city were clearly recognized on the PC screen at the virtual information control center in Tokyo. The medical director at the control center was able to examine and evaluate conditions of the simulated patients appropriately, and tracheal intubation procedures performed by ELSTs were clearly confirmed via transmitted video images. The advising medical director participated in the initial assessment in multiple emergency scenes in parallel, and individually gave instructions to ambulance crews as required.

4. DISCUSSION

The system developed in this study promptly transmitted the high-resolution visual data from the scene to the medical director in the hospital or the remote information control center via mobile phone networks. Furthermore, the incorporated images transmitted from multiple emergency scenes were found to be quite useful for medical control and quality assurance of emergency care.

In this study, we used a commercially available medical device, i.e. a

video-laryngoscope, with combination of a monitoring and a transmission device. The transmission device transmits large volume of data such as video images via mobile phone networks by using an encoding-decoding program. The time delay required for this process ranges from 2 to 5 seconds depending on the availability of mobile phone lines. The total cost to develop this system was approximately $ 40,000 per unit, and appears to be quite reasonable considering the functions it provides.

Limitations in this system include the time delay in transmission by coding process, operability of the transmission device, and information security. We are now in the process for solution of these problems and refining this system for practical use in the pre-hospital setting.

5. CONCLUSIONS

Our system promptly transmitted multiple visual data from the scenes to the control center in a distance. The incorporated images transmitted from multiple emergency scenes were found to be quite useful for medical control and quality assurance of emergency care.

6. REFERENCES

[1] T. Sadamori, S. Kusunoki, T. Otani, M. Ishida, R. Masuda, T. Tamura, T. Takeda, R. Tsumura, T. Shokawa, T. Kondo, H. Sakai, Y. Iwasaki, T. Yamanoue, N. Hirohashi,

K. Tanigawa, “Airway scope for emergency intubations: usefulness of a new video-laryngoscope” Hiroshima Journal of Medical Sciences, Vol. 57, No. 3-4, 2008, pp. 99-104. [2] T. Sadamori, S. Kusunoki, M. Ishida, T. Otani, K. Tanigawa, “Video laryngoscopy for emergency tracheal intubation during chest compression” Resuscitation, Vol. 77, No. 2, 2008, pp. 155-156.