July 31, 1998

Does a Ventilator Management Protocol Improve With Virtual Reality?

By Antonio Ortiz, RCP


This is a hypothetical paper for the study of a comprehensive ventilator management protocol that enables the respiratory therapist to adjust ventilator settings along with virtual reality settings, in order to determine if there is an improvement to patient outcome. I propose a retrospective review of ventilated patients from the preprotocol periods and postprotocol periods. Variables will include: the ability to rest patients totally; number of tachypneic events; the monitoring of vital signs; the time to respond to abnormal arterial blood gas values or oxygen saturations by pulse oximetry; the subsequent change in ventilator and virtual reality settings; and the duration of mechanical ventilation and weaning time. These will be evaluated before and after the introduction of the protocol. The use of positive feedback along with both subjective and objective data collection should be analyzed in order to evaluate the ventilator management protocol.

The ventilator virtual reality protocol would use biosensor interfaces, and Virtual Reality (VR), along with mechanical ventilation to create a new therapeutic modality that will reduce the time needed for mechanical ventilation and the weaning process. The application of immersive virtual reality will enable the research team to assess the efficacy of the interface treatment. In immersive virtual reality, the user feels totally enclosed in the simulated environment with the head-mounted display or goggles. This protocol will not use non-immersive virtual reality, which is when you are still looking at an image on a flat television screen in front of you. In non-immersive virtual reality the display may be three dimensional, but it does not surround the user by 360 degrees. The patient will be placed on a special biosensor bed interface, which will have ,surface electrodes that will permit electrical signals acquired via electromyogram (EMG) sensors, electrocardiogram (ECG) sensors, pulse oximetry sensors, stereophonic video goggles or a helmet head set and the mechanical ventilator equipment incorporated into one unit. In addition, in order to make interaction with virtual objects the patient will use a glove or joystick for input, which will have sensors on it that allows the computer to tell the position of the hand. With stable patients, they may sometimes wear a full body suit lined with sensors, so that the entire body can be used for interaction. The use of 3D or stereo sound earphones can also be used to make the patient feel immersed in a three dimensional sound environment, as the computer images makes the visual environment immersive. Other sensors such as for heat and cold can be used along with taste and smell devices. The sensors will be used to quantify the measurements and to diagnose preprotocol and postprotocol applications.

Professor Wheeler from my neonatal class at N.Y.U. calms that "Mechanical ventilation does not cure anything, it only buys us time so that the array of medications are effective in treating the underlying cause of the exacerbation." Mechanical ventilation can be life saving, but its use may cause adverse effects. High levels of oxygen, high pressures and high inspiration volumes may all damage the lungs (barotrauma), thereby prolonging the ventilation period. In addition, mechanical ventilation if used improperly can cause the arterial partial pressures of carbon dioxide and oxygen, to cause changes in the normal acid-base balance of pH. Other problems of mechanical ventilation include balancing the pulmonary blood flow and gas distribution. Furthermore, when spontaneous ventilation is suppressed, respiratory muscles may atrophy and also weaken. The causes of ventilatory problems are also associated with air trapping, gastric distention, respiratory tract infections, pulmonary edema, slower healing of damaged tissue, imbalances of hormonal activity, mucosal ischemia, liver malfunction, decreased urinary flow and renal function, decreasing cardiac output, increases in intracranial pressures, and ventilation perfusion mismatching. We must remember that mechanical ventilation in an invasive technique, and that the normal homeostatic balance can be interrupted by its use. However, the benefits of mechanical ventilation outweigh the complications since failure to support ventilation may result in death. Conversely, when mechanical ventilation fails to unload the overworked respiratory muscles, fatigue may ensue which only prolongs the weaning process.

I propose that virtual reality be used in this scenario to enhance healing, pain management, limiting and reducing the amount of mechanical ventilation time, the relief of stress and end the boredom that all ventilator patients must endure, in order to see if better patient outcomes will result. Larry Zalin states in his html (June 17, 1998), "Virtual reality may also play a role in helping burn patients alleviate their pain. Some dentists already use virtual reality with their patients, and children viewing cartoons through TV "glasses" have been reported to experience less pain and fear." By using virtual reality in this way, the patient can be placed in an artificially immersive reality where the therapist can control the environment. The use of VR with mechanical ventilation technology will provide an augmented therapy, providing relief of the psychological patient effect associated with intensive care. Critically ill patients who are confused, lethargic, and unresponsive, with prolonged stays in ICU may be suffering from sleep deprivation, due to the constant around the clock interventions. Their mobility, privacy, speech and control of bodily functions are also lost. Preoccupation with physical complaints is a common feature in patients with chronic disease and can become exaggerated. Preoccupation is a predominant feature of depression (Kerr, 1998). Anxious patients with many physical complaints and poor overall quality of life require and overuse emergency care services. Caregivers continually ask these patients about their symptoms, creating a symptom-focused mind set for the patient. The patients coordination is changed by this unconscious response, which only adds to the overall problem. These patients are under psychological and physical stress. Often, the patient is unaware of the purpose of mechanical ventilation, monitoring devices and lines, endotracheal tubes, blood sampling, or mentioned how long they will be used or why they are present. The patient eventually becomes concerned over the reliability of the personnel and equipment.

Many patients experience feelings of despair, helplessness, loneliness, and depression, isolation from family members and familiar surroundings, and weakness. They become disorientated as to time and place since there is often and absence of the normal environmental information systems such as clocks, newspapers, calendars, radios and television. Family and personnel often remain emotionally distant from the patient, giving vague and automatic responses to searching questions. For the hospital personnel, their own depersonalization saves them from the grief and guilt brought on by their treatment of the patient, which often causes the patient pain. For the family, it is a way to maintain an emotional distance so that they do not have to deal with the problems associated with critical care, such as illness and death. These problems complicate the patients healing process and are usually not considered or implemented, when planing a health care program.

The goal of mechanical ventilation is to provide total rest, until the respiratory system is capable of resuming control. Mechanical ventilation weaning protocols are developed to ensure that ventilatory support can be safely withdrawn. However, the variable lung mechanics during severe to resolving illness necessitate frequent ventilator adjustments. In addition, the patient�s psychological and physical problems complicate the mechanical ventilation management strategy. The weaning protocol relies on frequent assessment of patient response to ventilator setting changes. Patient management and stabilization requires the regular evaluating, gathering and storing of information and data. Parameters such as: time, mode of ventilation, minute volume, alveolar ventilation, rate, tidal volume, peak and plateau pressures, static and dynamic lung compliance, sigh volume, sigh frequency, inspired temperatures, sigh rate, inspiratory-expiratory ratio, continuous positive airway pressure, or positive end-expiratory pressure, fractional concentration of oxygen in inspired gas (FIO2), arterial blood gases the physiologic dead space-tidal volume ratio, the alveolar-arterial oxygen tension difference, the ratio of partial pressure of arterial oxygen to alveolar oxygen, shunt, vital capacity, vital signs, maximum inspiratory pressure, and alarm settings must be carefully monitored.

Volumes, pressures, temperature, vital signs, and FIO2 are measured every few hours. Alarms are activated to ensure that the patient is being ventilated. Arterial blood gases, shunt, dead space-tidal volume ratios, alveolar-arterial oxygen tension difference, are determined when there is a major change in the patient�s condition or in the ventilator settings. The respiratory therapist must adjust the ventilator settings according to a standardized physical assessment, to continuous oxygen saturations measurements by pulse oximetry, and when needed, to arterial blood gas results.

In order to prevent the occurrence of mishaps and complications, no alarm system replaces the presence of vigilant personnel at the patient�s bedside. Most of the harm to a patient occurs most often when the patient is unattended. In addition, some patients must be restrained, otherwise they may pull out the various life support lines and tubes, that are required. Patients may also "fight the ventilator", which happens when the ventilator is trying to do it one way while they breathe another way. The recognition of patient distress must be recognized by the clinician, in order to identify and prevent it. Since the patient can�t explain the problem, the onset of distress must be visually recognized.

The physical signs of distress include tachypnea, diaphoresis, retractions of the suprasternal, supraclavicular or intercostal spaces, nasal flaring, paradoxical or abnormal chest or abdomen movement, abnormal findings on auscultation, tachycardia, hypotension and possibility of arrhythmias. Other signs of sudden respiratory distress in patients receiving mechanical ventilation include: improper inspiratory flow settings, inadequate ventilator settings, system leaks, artificial airway problems, brochospasm, dynamic hyperinflation, abnormal respiratory drive, circuit malfunctions or disconnection, inadequate trigger sensitivity, inadequate FIO2, drug-induced problems, alteration in body posture, pnemothorax, secretions, abdominal distention, pulmonary edema, and anxiety. These problems can occur anytime from the onset of intubation until extubation, and sometimes immediately after extubation when laryngeal edema occurs.

The management of sudden respiratory distress requires removing the patient from the ventilator, initiating manual ventilation using a self-inflating resuscitation bag containing 100% oxygen, while performing a rapid physical examination and assessing the monitored indications. In addition, checking the patency of the airway and passing a suction catheter through the airway is also advisable. If death is imminent, then consider treating the most likely causes. Once the patient is stabilized, then perform a more detailed assessment and management. Because respiratory therapist assess the patient frequently for physical signs known to predict either fatigue or an excessive respiratory load, the use of mechanical ventilation weaning protocols allows the team to initiate the weaning process soon after intubation. Weaning protocols are used even before the underlying disease has completely resolved.

The study I propose is to use virtual reality in combination with mechanical ventilation weaning protocols, in an effort to improve the time required for weaning. The protocol will introduce a virtual reality ventilatory management modality, that will improve the ability to rest patients totally following acute respiratory failure, to decrease tachypnea during weaning, to shorten the time required to abnormal arterial blood gas results, and to decrease the duration of mechanical ventilation and drug administration. The merger of both processes will provide a new modality, which will reduce the patient�s ventilator dependency time. For example, by immersing the patient into a virtual reality scenario, the stress associated with mechanical ventilation can be eliminated or reduced. Patients that are "fighting the ventilator", can be placed in a calming, summer scenario with the wind blowing, the sea gulls flying in the air, and the waves crashing gently on the sea shore. This will help produce a calming effect, and will help reduce the amount of mechanical ventilation time and the need for paralytic drugs. The application of this technology will provide therapeutic capabilities that can help many patients relieve pain. Subhas C. Grupta, MD, et al claims, "Virtual Interface Therapy (VIT) has the potential to have the profound impact on the rehabilitation of thousands of patients. It provides physicians and therapists with an additional therapeutic modality and evaluative tool, while ensuring patients the most rapid and painless recovery possible." (June 18, 1998).

The respiratory therapist will have to evaluate the patient carefully, in order to determine the best settings that suit the patients needs. Physical signs that will indicate patient comfort would include: no use of abdominal muscles during expiration; no paradoxical breathing; no use of accessory muscles of inspiration; stable blood pressure, respiratory rate and heart rate; no intercostal or supraclavicular retractions; and stable lung compliance. Therefore, Patent ventilator synchrony; will be easier to control with virtual reality. In a html by Nathaniel Bletter (Spring 1993 p.1), he claims: "Virtual reality can be considered a socially acceptable electronic LSD." By controlling the virtual images, respiratory therapist will be able to produce a sense of reality, where the patient feels at ease; thereby avoiding the need for mood enhancing medications. Patients that are confused, lethargic and unresponsive can be placed in a familiar setting, where they can visualize a peaceful afternoon at the park. Therapist will be able to transport patients to any place they desire, or to a place where the patient feels comfortable. Since it is well known that patients in comatose states remember certain events, once they come out of their comas. These patients can be placed in a virtual reality environment, where they can be stimulated with a pleasant scene.

Another application of the protocol will be to prevent the disorientation associated with time and place, since a virtual clock, newspaper, calendar and television can all be simulated. Patients will also become less concerned with the reliability of the personnel and equipment, when they are being mentally and physically stimulated. The patient�s feelings of despair, loneliness and depression will all be minimized. In another article (Advance, May 1998), Lesperance also states that "Modern medicine has ignored an important tenet. Our short-sighted goal of helping to heal and prolong life has largely ignored the individual patient." Patients are suffering enough without additional help; therefore, why are they continuously being ignored? It can be easy to overlook the patient, especially when the laboratory data values are very important. When patients are ignored, they can become depressed. Depression is a growing concern, as it can deter the effects of the ventilation weaning protocol. Health care providers generally do not treat depression in their hospital ventilator population. According to Tom Kerr (Advance, March 1998), he claims that studies show Health Maintenance Organizations (HMO) do not monitor the treatment of patients diagnosed with depression. Most of the time these patients are given tranquilizers, instead of the new antidepressants. In addition, sedatives also cause additional complications such as respiratory depression, cardiac problems and mental confusion. All of which increases the anxiety and stress already apparent in these patients, and also prolongs the weaning process. The use of virtual reality can help alleviate many of these problems, and decrease the anxiety, stress and depression associated with mechanically ventilated patients.

Physchosocial considerations in patient care must also be evaluated in the weaning protocol. Patients on mechanical ventilation with chronic disease struggle daily to cope with the frustrating effects of their illness. Medical practitioners must help patients face the challenges of coping and adapting to their disease. The patient�s behavioral responses, coping patterns and psychosocial problems must be understood in order to recognize and manage anxiety and depression. The coexisting problems in patients with chronic diseases must be addressed, in order to help resolve the impaired functional capacity and quality of life. The psychosocial manifestations of chronic disease can affect the patient in a variety of ways. Some patients can adapt while others can�t or will not try.

While some patients can recover from most of the problems associated with mechanical ventilation and chronic disease, others do not respond well to medical intervention. Worsening disease severity can lead to multiple problems, which the patient must deal with. Mechanical ventilation and chronic disease can alter the physical appearance of the patient, which can change the body image and threatens the loss of self-esteem. Psychosocial problems can also lead to overdependance of the patient on their health care provider. As the disease becomes more severe, patients require more attention. The loss of healthy independent behavior causes a freedom from responsibility for the patient. This behavior pattern can lead to the patient becoming more childlike, demanding and difficult to please. The patient may actually experience childlike tantrums, fits and an increasing loss of functional capacity. The added stress associated with providing health care to this patient causes an undue hardship on the provider.

Anger is another problem that has to be dealt with, in this scenario. Some patients repress their emotions in an effort to avoid uncomfortable symptoms (called emotional straitjacket effect)(Dudley, 1980). However, this can be counterproductive because anger and frustration mount and feelings are expressed at inappropriate times.

Many of these psychosocial problems can be avoided, simply by making the patient feel at ease. Although a good healthy positive attitude helps, the use of virtual reality can help remove the psychosocial difficulties associated with mechanical ventilation, and help speed up and improve the weaning process.

Family members and hospital personnel can also enter the virtual reality setting, to see how the patient is progressing. In addition, since seeing a patient in an ICU is a sight many family members would rather avoid. They can also put on a virtual reality headset to see their loved one, in a more pleasant scenario. The patients family members will also maintain an emotional link, since it will be easier to deal with the problems associated with critical care. I can visualize a scenario like in the popular television show "Star Trek", where the holographic Doctor interacts with the crew when a medical emergency is occurring. With VR this scene can also be portrayed, since we can also create a Virtual Doctor to interactively assess the patients progress.

This protocol will also reduce and prevent the depersonalization that is apparent, when grief and guilt brought on by the invasive treatment of the patient is required. Therefore, the physical and psychological stress levels will be reduced and or eliminated, with the use of a virtual reality mechanical ventilation protocol. The weaning process will also benefit, from the implementation of this protocol. The frequent assessment of patient response to ventilator setting changes can also be assessed with the changes in the virtual reality environment. We will then be able to use this information to help provide the best techniques and treatment plans, in order to enhance and help the weaning process.

The feasibility for this study will be a costly one, since virtual reality equipment and technology is currently expensive. It is a problem that the researchers interested in this type of a study will have to consider. There are low-cost solutions; however, they are usually of poor quality and resolution. The speed of the low-cost systems is also impractical for use in this protocol. There are also expensive systems, however, only the military can afford their high cost. Neural Human-System Interface (NHSI) technology has been used to link human operators with computer systems (Makeig 1995). This technology makes interaction with real time events possible.

Another problem that my proposed virtual reality protocol has to conquer, is the amount of devices that must be attached to the patient. The headset, earphones, gloves or joysticks all require cables and attachment points. There will be a lot of equipment on the patient�s bed, not to mention all the other medical monitoring equipment that needs to be also attached to the patient. Nathaniel Bletter also states in his paper: "To alleviate this problem, eventually the computer will plug right into the user�s sensory system; there will be a direct neural connection." (Spring 1993 p.3). The user interface devices will eventually become better, with the development of newer technology and further study. In addition, computers are becoming more powerful each day.

VR produces a disorientating effect we must also consider, and it is called Cybersickness. Cybersickness occurs like motion sickness, and has adverse effects on the visual, systemic, neural and psychological state of the individual. According to Gupta, et al (June 18, 1998), "Currently, our society is witnessing an exponential growth of VR applications in multiple fields of interest. Despite this rapid growing of these applications, there remains no safety regulations or guidelines for developers to follow in producing new equipment. In the never ending race to be the first manufacturer to get new equipment to the consumer, the consumer�s safety and general well-being should not be overlooked." Eventually the cost and problems associated with virtual reality system will improve and become more practical. In addition, regulations concerning VR applications will be legislated, and Cyberpathology will then become less common.

Medical technology has advanced rapidly, and the use of computers enhances the diagnostic process. Within the next century virtual reality will be combined in different medical fields, in an effort to solve many of the problems associated with the imaging sciences. Hiroshi Oyama from Medical Virtual Reality Development Lab National Cancer Center Hospital in Tokyo, Japan says: "We think that VR is an important technology that can be used to overcome various problems in the medical field. Unfortunately, there are currently no established methods for evaluating medical VR systems. Moreover, in the future it will be important to be able to recognize problems with VR technology in terms of the subject�s VR experience."

The combination of mechanical ventilation with virtual reality will produce results that will improve the weaning process, relieve the patients distress and all the associated problems I have attempted to describe. The controversial aspects of my proposed technology will undoubtedly produce unforeseen applications, especially in the medical sciences. According to Suzanne Weghorst (June 23, 1998), "Virtual reality technology offers new visualization capabilities for biomedical researchers, educators, and practitioners. Some of its uses are being fruitfully pursued right now, while others await technological advances in numerous fields. Timely development of this approach requires broad-based collaboration, as well as reinterpretation and adaptation of technologies developed for other purposes."

Patients on mechanical ventilation will have a new therapeutic capability that can help them in the various ways I have described. Applications of immersive mechanical ventilation virtual reality will provide various environments, where patients with different types of anomalies can interact therapeutically. The super computer that would be capable of running an application like this, would be powerful enough to use in diagnostic situations. This virtual reality system would be able to store an retrieve data for future studies. Educators will have an unparalleled ability to use this technology in every area of respiratory education. Teachers will have the capability to explain theories to students about the use of mechanical ventilation easily. The students will comprehend difficult theories and concepts regarding mechanical ventilation, that will make learning and applying them simpler.

With further research into virtual reality and mechanical ventilation, the systems that will be developed will improve our understanding of this science. We may eventually discover solutions to mechanical ventilation problems that are presently difficult if not impossible to solve. The elimination of many respiratory disorders may someday be achieved, with the use of this technology. We may discover ways to manipulate the ventilator to decrease the number of tachypneic events. Characteristics including diagnosis on admission, age, gender would all be recorded to help analyze and interpret results. With the data collected by positive feedback along with objective and subjective information, we may be able to analyze it to produce new modes of mechanical ventilation and weaning procedures. Statistical analysis will be necessary to validate the pre-protocol and post-protocol results.

To conclude, I believe that a ventilatory virtual reality weaning protocol will provide benefits to patient outcomes. The ability to rest patients totally, decrease the tachypneic events, and decreasing the ventilation period will help patients benefit from this application. The relief of the psychological and physiological complications of mechanical ventilation will also improve the weaning process, with the implementation of this protocol. Critically ill patients need all of the help that can be provided, and virtual reality can answer many of the problems they must endure during mechanical ventilation. There will be many questions regarding the use of virtual reality with mechanical ventilation. However, I believe that as respiratory care practitioners we must try new and revolutionary treatment plans, that can help provide the best care our patients can get. The bottom line is in the level of care our patients receive, and the implementation of this protocol will produce positive end results. The VR environment is a great place to create ideas, and its use in treating mechanically ventilated patients may one day become a reality.





Barnhart, AS, RRT, Sherry L.; Czervinske, BSRT, RRT, Michael P. (1995). Perinatal and

Pediatric Respiratory Care.

Philadelphia, PA: W.B. Saunders Co.


Behavioral Medicine Associates, Inc. Quantitative EEG and Neurotherapy Fact Sheet.

URL: <http://www.webcom.com/bmainc/qeefact.html>

(acquired on June 18, 1998).


Bletter, Nathaniel. VR Virtues and Vices.

URL: <http://www.os.sri.com/papers/vrvirtues.html>

(acquired on June 18, 1998).


Canon, Bill. Faking Soup � Biomedical Inquiry_Fall 1996.

URL: <http://www.neosof.com/~tic/pressrel.htm#HYPER>

(acquired on June 18, 1998).


Carrigan, Catherine. To improve Your Game, Try Working Out at the Brain Gym.

URL: <http://www.fitnesslink.com/mind/stress.htm>

(acquired on May 27, 1998).


Des Jardins, Terry.; Burton, Geroge C. (1995). Clinical Manifestations & Assessment of

Respiratory Diseases.

St. Louis, MO: Mosby-Year Book, Inc.


 Dudley, D. et al: Psychosocial concomitants to rehabilitation in chronic obstructive pulmonary


Chest 77:544, 1980.


Dubin, M.D., Dale. (1997). Rapid Interpretation of EKG�s.

Tampa, FL: Cover Publishing Co.


Ebersole, Samuel. A Brief History of Virtual Reality and its Social Applications.

URL: <http://www.uscolo.edu/ebersole/336/vrhist.html>

(acquired on June 18, 1998).


Fischbach, Frances. (1996). A Manual of Laboratory & Diagnostic Tests.

Philadelphia, PA.: Lippincott-Raven.


Gupta, Subhas C.; Wantland, Cyril A.; Klein, Scott A. Cyberpathology: Medical Concerns of VR


URL: <http://www.webmed.com/mi/cyberpath.html>

(acquired on June 18, 1998). Also:

URL: <http:www.webmed.com/mi/vit.html. >

(acquired on June 18, 1998).


Hodgkin, John E.; Connors, Gerilynn L.; Bell. (1993). Pulmonary Rehabilitation: Guidelines to


Philadelphia, PA: J.B. Lippincott Co.


Horgan, John. (1996). The End of Science.

New York: Broadway Books.


Howard, Piersce. (1994). The owner�s Manual for the Brain.

Austin, Texas: Leornin Press.


Kerr, T. (1998, March). Depression and the Elderly.

Advance for the Respiratory Care Practitioner, p.29


McPherson, Steven P. (1995). Respiratory Care Equipment.

St. Louis, MO: Mosby-Year Book, Inc.


Makeig, Scott.; Jung, Tzyy-Ping,; et al. (1995). Neural Human-System Interface (NHSI)


URL: <http://www.cnl.salk.edu/~scott/nhsi.html>

(acquired on June 19, 1998).


May, Cynthia. Human Memory and Attention, Cognitive Aging.

URL: <http://www.w3.arizona.edu/~psych/facsfls/mcynri.htm>

(acquired on May 27, 1998).


Mind Tools LTD. Helping you to think your way in to an excellent life!

URL: <http://www.psysh-web.com/mtsite/smburnt.html>

(acquired on May 27, 1998).


Oyama, Hiroshi. Virtual Reality for the Palliative Care of Cancer.

URL: <http://www.medvr.res.ncc.go.jp/doc/POSS1.html>

(acquired on June 17, 1998).

Ruppel, Gregg L. (1998). Manual of Pulmonary Function Testing.

St. Louis, MO: Mosby-Year Book, Inc.


Rothen, Albert. (1990). Creativity and Madness.

Baltimore: John Hopkins Press.


Scanlan, Craig L.; Spearman, Charles B.; Sheldon. (1995). EGAN"S Fundamentals of

Respiratory Care.

St. Louis, MO: Mosby-Year Book, Inc.


Shapiro, Barry A.; Peruzzi, William T.; Templin. (1994). Clinical Applications of Blood


St. Louis, MO: Mosby-Year Book, Inc.


Tortora, Gerard J.; Funke, Berdell R.; Case. (1998). Microbiology: An Introduction.

Menlo Park, CA: Addison Wesley Longman, Inc.


Troyka, Lynn Q. (1992). Simon & Schuster: Concise Handbook.

Toronto: Prentice-Hall Canada Inc.


Van Wyk, Claudius. Human Potential Actualisation.

URL: <http://www.home.global.coza/~markvw/pni.htm.>

(acquired on June 23, 1998).


Wall, Stephen E. An Overview of Biofeedback.

URL: <http://www.7hz.com/1overview.html>

(acquired on June 23, 1998).


Weghorst, Suzanne. Inclusive Biomedical Visualization.

URL: <http://www.hitl.washington.edu/publications/r~-91-2/>

(acquired on June 17, 1998).


Weinberg, Ian R.; van Wyk.Claudius P.; Mprac. An Intergrative Nerological Model of

Consciousness: The Case of Quantum-Determinism.

URL: <http://www.home.global.co.za/~markvw/conc.htm>

(acquired on June 3, 1998).


Yamauchi, Yasuchi. Internet Resources of Computer Aided Surgery.

URL: <http://www.aist.go.jp/NIBH/~b0673/english/cas_about.html.>

(acquired on June 17, 1998).


Zalin, Larry. The Fires of Pain.

URL: <http://www.washington.edu/alumni/colums/dec96/fires1.html.>

(acquired on June 17, 1998).

Back to Therapy Reference page

Back to Keefer Home Page