Go to previous article
Return to the 1994 VR Table of Contents
Return to the Table of Proceedings
By: T.Yamaguchi, N.Furuta, K.Shindo, T.Hayasaka,
Department of Bio-Medical Engineering
School of High-Technology for Human Welfare
Japan Advanced Institute of Science and Technology
Department of Life Science
Himeji Institute of Technology
Department of Information Technology
Kyoto Institute of Technology
T. Yamaguchi MD, Ph.D
Dept. Bio-Medical Engineering
School of High-Technology for Human Welfare,
317 Nishino, Numazu, Shizuoka 410-03 Japan
Telephone +81-559-68-1211(ext. 4527)
In the modern hospital, the medical therapeutic procedure is regarded as paramount and psychological or spiritual care is quite frequently put aside. The goal of the "Hyper Hospital" is to correct this. The Hyper Hospital is constructed in the computer based electronic network using an alternate reality system, such as the virtual reality system, as the human-machine-human interface. The nodes of the Hyper Hospital belong to a patient and also to a variety of medical care facilities; for example, the out patient office, the nursing care center, the medical examination unit, the operating theater, etc. Most of the physical contact, such as the visit to the out patient office by the patient, is actualized by the electronic connection of the patient private space and the public space of the hospital system. Prescription drugs, special care, and even the admission to the ward will beintegrated into the distributed electronic network. To realize such a system, we need to solve many problems, such as the research on the network oriented architecture of the alternate reality, the development of human-machine interface particularly fitted to various disabilities. As the first step, we studied the physiological and psychological responses of healthy subjects induced by the usage of the VR in terms of fatigue. Twenty healthy young male subjects were exposed to the virtual reality system and they performed some psychological tasks with a virtual nurse for 30 minutes. None of the physiological or psychological parameters such as urinary catecholamine release, ECG, etc showed significant fatigue induced by our VR system. However some kinds of subjective fatigue were noted and they werethought to be indicating a direction of improvement for our VR system.
In modern medicine, it is frequently pointed out that the total patient care tends to be neglected and conversely curing diseases apart from the patients is apt to be looked upon as the final target. How far the medicine goes, as has long believed in Buddhism is that life, senescence, disease, and death are the things we can never run away from. The human being is born as a whole entity and dies the same. Medical care should be conducted bearing this in mind and the final goal must not be just to cure the disease. Unfortunately, in modern society, the scientific advancement of medicine paradoxically results in the tragedy that human beings or patients are treated as a collection of organs, and not as a whole organism.
Another pitfall of modern medicine is the negligence of theauto-healing ability of patients. Ambroise Par, one of the most important antecedents of modern surgery, left a famous aphorism, "Je le pansay, et Dieu le guarit" (I dressed him, and God healed him). This was said in slightly different circumstances, nevertheless the point he wanted to stress is quite the same as what we are facing in modern medicine. He clearly indicated, whatever the conditions were, that the medical treatment is just an assistance to the patients' auto-healing ability. The most important aspect of the cure of diseases is, therefore, how to reinforce such an ability and to draw on the patients own healing power.
As a matter of fact, most of doctors and other medical professionals would admit that virtually nothing essential can be done to sustain the life of seriously ill patients. The terminal stage of cancer would be a good example. Although many so-called therapeutic means were developed against cancer, we have to admit that treatment is very limited, for example, morphine is only effective for the patients at the terminal stage of cancer after all. Almost the same can be said in other diseases. In such a condition, psychological or rather a spiritual support can be the only meaningful remedy.
Hospital as a cohabitation organizationFrom this point of view, an ideal hospital should be designed primarily as a space which has a function of interfacing human communications between patients and medical care takers. The hospital as the facility where the physical and/or chemical treatments are provided may not be the primary goal in the whole medical system. Communication between patients and medical personnel should facilitate an effective exchange of medical and psychological information and should also lead to the process of enhancement of the patient's auto-healing capability. Humane care based on the long-term mutual communication between the patients and the medical care staff is sometimes much more necessary to overcome the disease than the physical or chemical treatment. This is currently most serious in modern health care issues, particularly under the pressure of the increased aged population in industrialized societies. Indeed, the historical hospital used to be, when it was originally founded as "Hospital Dieu," a cohabitation organization where human met human with a deep sympathy and pursuit of the benefit of the total existence of the human being.
PROPOSAL OF THE HYPER HOSPITAL
The Hyper Hospital we propose is a medical system constructed virtually) in the computer based electronic network. The Hyper Hospital realizes several aspects of medical activities: patients' visit to a hospital, their consultation to the medical and the social personnel, and some levels of oral and physical examination. Not only diagnostic and consulting activities are included, but even simple therapeutic measures such as insulin self-injection and drug administration can be included. These functions will be implemented in the Hyper Hospital system through an alternate reality system, such as the virtual reality. This implementation can be possible because most of these functions are mainly related with human-to-human communication, and they can be replaced by an alternate reality system which is the human-machine-human interface. In order not to hurt the reality of the medical care process by introducing such a machine mediated system, the alternate reality system must be able to provide realistic experiences. In this sense, an employment of the virtual reality is crucial.
The on-line alternate reality system of Hyper Hospital is thought to keep several strategic merits both for patients and medical provider. From the patient side, first, the Hyper Hospital can make it possible for patients to have remote access to preferable medical care from anywhere and at anytime. Second, electronic access in a virtual environment can allow patients to play an equal roll in the medical care situation and even allow them to act as a different person from his own when he or she is with his own doctor and other medical staff. Long time and long term conversation is also possible. Third, the non-verbal interface can be provided. Fourth, patients can exclusively possess and use their own medical records cumulated in the electronic files in order to receive consistent medical care. Finally, the individually customized medical environment can be actualized.
From the medical care staff side, first, a case can be cooperatively and speedily consulted, inspected, diagnosed and treated by several experts including an artificial expert system in different fields at electronic conferences through the Hyper Hospital network. Second, medical and pharmacological data and news of all over the world can be utilized everyday at work. Third, establishments of rapport with a patient and the follow up to evaluate the effect of the treatment become very easy.
The Hyper Hospital will be built as a multi-layered distributed system on a network (Fig. 1). A node of the network represents a variety of medical care facilities; for example, the out patient office, the nursing care center, the medical examination unit, the operating theater, etc. The Hyper Hospital space consists of numerous independent and freely interconnected virtual spaces, for example, the virtual reality space owned and exclusively controlled by the patient himself or herself. Most of the physical contact, such as the visit to the out patient office by the patient, is actualized by the electronic connection of the patient private space and the public space of the hospital system. Prescription drugs, special care, and even the admission to the ward will be integrated into the distributed electronic network. A re-entry from the virtual reality spaces to the "real" reality space, that can be called virtual home visit, for example, will be also facilitated by introducing a flexible tele-existence technology.
Medical Care System
Specific Design of Parts of the Hyper Hospital and Their Prototyping
1. Out Patient Office
When a patient receives medical treatment, medical care takers visit the patient's consulting room which is constructed in an on-line virtual space for the patients own sake (Fig. 2). The consulting room is a private space that the patient can exclusively arrange an outlook. Environmental conditions, such as a wall color, furniture setting, lighting conditions and the number of medical equipments, can be set to his or her preference. We developed a prototype of the virtual consulting room using a distributed computer graphics system. The system is composed of several objects (object-oriented design) and these objects are independent of each other and are placed in distributed manner on several different computing nodes. The integrity of the system is maintained by the communication among the objects by using UNIX and XWindow utilities on the Ethernet network. Synchronization mechanisms, control mechanism, and rendering mechanisms composed the fundamental parts of the system objects designed to construct the entire system. In order to make it possible for patients or users to be able to dynamically modify the environment, the main part of the entire system, which corresponds to the conventional main loop of the system, was written using the TCL language. A dynamically modifiable list structure that determines the structure and the behavior of the virtual environment is kept by the TCL system, so that no re-compilation of the system is necessary when the users want to change the environment.
2. Electronic Medical Personnel
Medical consultation at a private virtual space is conducted by a synthesized intelligent agent using computer graphics, called an electronic doctor or an electronic nurse. The electronic staff consists of medical and psychological parts. A patient can modify the electronic staff by replacing these parts as he or she likes. We also implemented such a facility in our prototype system. In this implementation the face of an electronic nurse can be chosen from several templates. We conducted a human ethological study to examine the responses of the users using different faces of the electronic nurse, for example, a real photographic image of human nurse, and a cartoon. The results of this study were reported elsewhere. In the development of the Hyper Hospital, the behavior of the electronic staff such as this electronic nurse will be designed to allow control by a team of medical personnel who are remotely connected in the Hyper Hospital network. Thus the electronic personnel, although it looks like a person from the patients' view, may not be necessarily representing a single person but may represent a medical team, and even the electronic staff can be controlled by an artificial expert system.
3. Non-Verbal and Cybernetic Interface
To support handicapped and aged persons, the Hyper Hospital provides the non-verbal interface such as sign languages, bodily movements, eye blinks and vocalizations, and the cybernetic interface such as electroencephalogram and a unit pulse of nerve fibers. We are developing a system in which the P300 component of the event related potentials (ERPs) of the electroencephalogram schematically shown in Fig. 3. As a preliminary result obtained from our prototype system, an internal (ie. only in the mind) decision could be detected using the P300 components of ERPs. The detected decision can be fed back to the user or to patients using the virtual reality system, and can be used as navigating commands in the virtual environment. This kind of technology is not particularly suitable to healthy people, but the benefits expected could be significant for severely handicapped persons, such as patients in a locked-in state.
4. Medical and Physical Examination
Medical and physical examination and surgical therapy can be carried out by means of tele-existence. Various kinds of micro monitoring robots can be used to sense the patients' physical condition and micro surgical robots can be used to inspect and give medical treatments; these may be equipped in the patients' consulting and examination rooms. We have already proposed the idea of such facility, namely "virtual stand-in" (Fig. 4). This is a machine which can represent a person, in other word, "possessed" by a person and can perform a series of tasks in the real world controlled through the virtual space. This can be used to care and monitor the distributed manner of living patients without interfering with their privacy. By using this, patients who are unable to operate computer facilities will also be included into the Hyper Hospital network and will be taken care of remotely.
SAFETY FEATURES OF THE VR TECHNOLOGY
To realize the Hyper Hospital, it is mandatory to develop human-machine interfaces utilizing the VR technology which will accommodate various types and severity levels of physical and mental disabilities. This must be based on the ethological study of the behavior of normal and diseased people. After these fundamental studies the virtual reality technology can be applied to the humans in the medical care environment. This is the reason why we examined the safety features of our own virtual reality system from the physiological, neurological and psychological view points.
An overview of our VR system used for the study
To build a virtual reality system, there are some prerequisites, such as a high-speed graphics computer, certain types of custom hardware such as a head mounted stereoscopic display, and software that allows us to create the virtual world from which the view is displayed. The graphics workstation used for the creation of the virtual world was the Silicon Graphics IRIS 4D-310VGX with the GL graphics system. The custom hardware of our virtual reality system (Head Mounted Display:HMD) used in the present experiment was developed in our laboratory, which is composed of the ultrasound view point detector and two liquid crystal graphic image displays (LCD) with an optical system to magnify the graphic images. The software which is used to create our virtual space was also developed from scratch in our laboratory, which was discussed above. The graphics image generated to view the created virtual world was displayed in the stereoscopic display in the HMD.
Experimental setup for the VR workload
To measure the stress exerted by the use of virtual reality, we conducted an experiment using healthy subjects. Twenty young male volunteers were subjected to an interview in the virtual reality space from an electronic nurse displayed in the HMD. This is a part of a series of human ethological studies in which human responses to virtual reality stimuli were quantitatively measured and analyzed. To determine whether the responses were different according to the graphical outlook of the interviewer, we randomly chose one of two nurses faces, either a cartoon image or a photographic image.
In the former half of the session, the volunteers were subjected to low stress questions, such as questions about their daily life style, for 15 minutes. In the later half of the session, they were subjected to high stress questions, such as those on their private sexual behavior, for 15 minutes. The responses of the subjects were recorded on a video recorder and the results of an analysis will be reported elsewhere.
Measurements of influence of the VR usage
We conducted various measurements to assess the influence of the usage of our virtual reality system. They can be classified into several categories, though most of them are related to each other. First, we measured circulatory and respiratory physiological condition continuously throughout a mental work load session. These were an electrocardiogram (ECG), a digital pulse wave pattern, the thermography of the hand, and the respiratory chest movement. The blood pressure was measured by an automatic sphygmomanometer at a 5 minutes interval throughout the session. Second, some biochemical measurements were carried out to examine the physiological fatigue. Autonomic nerve activity was measured by the urinary release of three kinds of catecholamines, namely dopamine, epinephrine and nor-epinephrine. The time course of the PH of saliva was also monitored for the detection of fatigue. Third, we tested some of neurological parameters of the subjects. To examine the visual fatigue, the critical flicker fusion
frequency (CFF) was measured. A light emission diode was set in the HMD for this purpose. The subjects were asked to turn a knob of an oscillator to adjust the frequency of flickering. In addition, the auditory response time was measured to detect the over all neurological fatigue. Fourth, some psychological examinations were conducted before and after the work load. Objective psychological fatigue was measured by the Uchida-Kraepelin test, which is known to measure a capability dealing with information. The results of this test were analyzed with respect to the individual character categorized by using the Yatabe-Guilford test. Finally, subjective fatigue was rated by using a standard questionnaire and the general impressions of the usage of the VR system were obtained by another questionnaire.
a. Physiological and neurological measurements
An ECG, a digital pulse wave measured by the photometric method, and the respiratory chest movements were digitally recorded throughout the session including 15-15 minute interviews by an electronic nurse. The blood pressure was measured at an interval of five minutes throughout the session. The CFF value and the auditory response time were measured three times, initially, before the former interview with the low stress questions, at an interval of time between the former half and the later half of the session, and finally after the later interview with the high stress questions.
b. Biochemical measurements
The subjects were kept in a fasting state for three hours before, during, and one hour after the session. One hour before the session, they were asked to urinate completely and then to drink 500 ml of water. The urine samples were taken just before, just after, and one hour after the end of the session. The total amount of urine was also measured at the time of urine sampling. We immediately froze the urinary samples, and measured the concentration of three catecholamine fractions in these urine samples by using a high performance liquid chromatography (HPLC) method. The pH of the saliva was also measured three times at the same time that the urine samples were taken.
c. Psychological and subjective fatigue measurements
We used a simple version of the Uchida-Kraepelin test, and the subjects underwent the test before and after the sessions. The questionnaires on the subjective fatigue and the impressions of the usage of the VR were shown and answered after the session.
The time course of the heart rate was measured by averaging the R-R interval of the ECG at each minute. The pulse wave propagation velocity was calculated from the R wave of the ECG and the onset of the measured digital pulse wave. Although the heart rate measured from the ECG seemed to slightly increase during the interviews, it was not statistically significant (Fig. 5). All the other circulatory and respiratory physiological parameters, such as the blood pressure, etc., did not show any statistically significant differences either during the experimental session or as compared between the averages taken before and after the session.
The CFF value did not show any significant change by the usage of our V.R. system. The auditory response time showed no significant change either. Of three fractions of urinary catecholamines, the total release of epinephrine showed a slight yet not statistically significant increase as compared between those before and just after the interview session. The other catecholamine fractions (norepinephrine and dopamine) did not show any significant changes as illustrated in Fig. 6. The pH of saliva did not significantly change before, during, and after the VR interview session.
In an analysis of the answers given in the standard questionnaire for the subjective fatigue, the most frequent complaints were those related to sleepiness and easy fatigability. The second most frequent complaints were about the difficulty of attention and concentration, complaints about the feeling of physical fatigue were the least. This can be interpreted to mean that the psychological fatigue represented by the complaints related to the sleepiness and easy fatiguability was more significant than other types of fatigue.
CONCLUSION AND REMARKS OF THE FUTURE STUDIES
In the present study, it was pointed out that it is now the time to discuss what the hospital system should be when it is facing the rapid advancement of medical and information technology. A functional reorganization of the medical care system should also be examined. The Hyper Hospital we proposed can influence the original role of medical treatment. To actualize such system, we need to solve many conceptual as well as real problems. The former conceptual problem could be medico-legal, sociological, and ethical problems, for example. The latter, real problems should be classified into several classes, such as the research on the network oriented architecture of the alternate reality, the development of human-machine interfaces particularly fitted to various natures of disability, and the study of the behavior of normal and diseased people, etc. Based on these fundamental studies, the concept of the "Hyper Hospital" can be a new paradigm of the next generation of medical care in cyberspace ages.
The authors thank to the following grants and foundations for their support.
Figure 1. The Hyper Hospital network. It consists of many medical facilities constructed in the computer information network. Different functional units are united by electronic connection using the virtual reality as a human interface. These are, for example, a hopital ward, a dispensary, an inspection center, and the personal VR system owned by a patient. The personal VR system will consist of a VR interface to the network, a personal treatment instrument, and a personal database for his or her history of diseases and medications.
Figure 2. Scheme of the patient-medical caretakers' relationship in the Hyper Hospital. Patients meet the medical staff in an on-line virtual space using their own virtual environment. The medical personnel uses their own VR interface. The patients also use proper interfaces fitted to their particular disabilities. Nursing care and social welfare support will also help the medical care performed in the Hyper Hospital network cooperatively.
Figure 3 Block diagram of the control scheme of the virtual reality using the event related potential (ERP) of the electroencephalogram (EEG). EEG signal was measured from the subject in an electromagnetic shield. The VR image was shown to the subject via a HMD (head mounted display). The EEG signal was digitized and transferred from a dedicated PC to an engineering workstation where the numerical analysis was carried out. The results were transferred to a graphic workstation where the VR image was build incorporating the switching signal obtained from the EEG analysis. All these machines were connected using an Ethernet inhouse network.
Figure 4. A Virtual Stand In (VSI) which ensures re-entry from a virtual space to the real space operated through a virtual space. The VSI takes any forms according to its facility. In the figure, it takes a form of robot whose face is a computer display. The face of the user will be displayed to convey feeling of personality.
Figure 5. Change of the heart rate during the psychological loading. The heart rate measured just before the experiment was used as a control and subsequent measured heart rates are displayed as a ratio to the control value. Although it was not statistically significant, there was a slight tendency of decreasing of the heart rate during the experiment.
Figure 6. Time course of the catecholamine release. Measured concentrations of three fractions of the catecholamine were multiplied by the urinary volume to calculate the total release. All the values of total release are shown relatively to the control value measured before the experiments started. Only the epinephrine release showed a slight tendency to increase, but it was not statistically significant.
Go to previous article
Return to the 1994 VR Table of Contents
Return to the Table of Proceedings