Use of Smartphone-Based Head-Mounted Display Devices to View a Three-Dimensional Dissection Model in a Virtual Reality Environment: Pilot Questionnaire Study.

BACKGROUND: Virtual reality (VR) technology has started to gain attention as a form of surgical support in medical settings. Likewise, the widespread use of smartphones has resulted in the development of various medical applications; for example, Google Cardboard, which can be used to build simple head-mounted displays (HMDs). However, because of the absence of observed and reported outcomes of the use of three-dimensional (3D) organ models in relevant environments, we have yet to determine the effects of or issues with the use of such VR technology. OBJECTIVE: The aim of this paper was to study the issues that arise while observing a 3D model of an organ that is created based on an actual surgical case through the use of a smartphone-based simple HMD. Upon completion, we evaluated and gathered feedback on the performance and usability of the simple observation environment we had created. METHODS: We downloaded our data to a smartphone (Galaxy S6; Samsung, Seoul, Korea) and created a simple HMD system using Google Cardboard (Google). A total of 17 medical students performed 2 experiments: an observation conducted by a single observer and another one carried out by multiple observers using a simple HMD. Afterward, they assessed the results by responding to a questionnaire survey. RESULTS: We received a largely favorable response in the evaluation of the dissection model, but also a low score because of visually induced motion sickness and eye fatigue. In an introspective report on simultaneous observations made by multiple observers, positive opinions indicated clear image quality and shared understanding, but displeasure caused by visually induced motion sickness, eye fatigue, and hardware problems was also expressed. CONCLUSIONS: We established a simple system that enables multiple persons to observe a 3D model. Although the observation conducted by multiple observers was successful, problems likely arose because of poor smartphone performance. Therefore, smartphone performance improvement may be a key factor in establishing a low-cost and user-friendly 3D observation environment.

Throughput and latency programmable optical transceiver by using DSP and FEC control.

We propose and experimentally demonstrate a proof-of-concept of a programmable optical transceiver that enables simultaneous optimization of multiple programmable parameters (modulation format, symbol rate, power allocation, and FEC) for satisfying throughput, signal quality, and latency requirements. The proposed optical transceiver also accommodates multiple sub-channels that can transport different optical signals with different requirements. Multi-degree-of-freedom of the parameters often leads to difficulty in finding the optimum combination among the parameters due to an explosion of the number of combinations. The proposed optical transceiver reduces the number of combinations and finds feasible sets of programmable parameters by using constraints of the parameters combined with a precise analytical model. For precise BER prediction with the specified set of parameters, we model the sub-channel BER as a function of OSNR, modulation formats, symbol rates, and power difference between sub-channels. Next, we formulate simple constraints of the parameters and combine the constraints with the analytical model to seek feasible sets of programmable parameters. Finally, we experimentally demonstrate the end-to-end operation of the proposed optical transceiver with offline manner including low-density parity-check (LDPC) FEC encoding and decoding under a specific use case with latency-sensitive application and 40-km transmission.

Lanceocrepidiasides A-F, glucosides of guaiane-type sesquiterpene from Crepidiastrum lanceolatum.

From the aerial parts of Crepidiastrum lanceolatum, six guaiane-type sesquiterpene glucosides, lanceocripidiasides A-F were isolated together with five known sesquiterpene glucosides, ixerin Y, crepidialanceosides A and B, and youngiasides A and D, two known megastigmane glucosides, icariside B1 and corchoionoside A, and benzyl 6'-O-beta-D-apiofuranosyl-beta-D-glucopyranoside. Structures were elucidated by spectroscopic analyses.

Terpenic and phenolic glycosides from leaves of Breynia officinalis HEMSL.

From the leaves of Breynia officinalis, collected on Okinawa Island, six terpenic glucosides and six phenolic glycosides were isolated. Two of the terpenic glucosides were found to be known, and they were identified as turpinionoside B and betulalbuside A. The structures of the remaining terpenic glucosides were elucidated to be megastigmane glucosides, named breyniaionosides A-D, using spectroscopic analyses. The absolute structure of breyniaionoside D was determined using the modifed Mosher's method. The absolute structure of the known compound betulalbuside A was determined for the first time in this study. Six phenolic glycosides were found to be arbutin and its derivatives. Two known compounds were found to be robustaside A and eximine. New compounds were named isorobustaside A, and breyniosides A and B, and their structures were elucidated from spectroscopic evidence.