No / The aim of the present study was to investigate an opioid receptor involvement in the adaptation response to motion sickness in Suncus murinus. Different groups of animals were treated intraperitoneally with either saline, morphine (0.1 and 1.0 mg/kg), naloxone (1.0, 10.0 and 5.0 mg/kg) or a combination of naloxone plus morphine in the absence or 30 min prior to a horizontal motion stimulus of I Hz and 40 mm amplitude. For the study of adaptation, different groups received saline on the first trial, and in subsequent trials (every 2 days) they received either saline, naloxone (1.0 and 10.0 mg/kg, ip) or morphine (0.1 mg/kg, ip) 30 min prior to the motion stimulus. Pretreatment with morphine caused a dose-related reduction in emesis induced by a single challenge to a motion stimulus. Pretreatment with naloxone alone did not induce emesis in its own right nor did it modify emesis induced by a single challenge to a motion stimulus. However, pretreatment with naloxone (5.0 mg/kg, ip) revealed an emetic response to morphine (P<.001) (1.0 mg/kg, ip) and antagonised the reduction of motion sickness induced by morphine. In animals that received saline or naloxone (1.0 mg/kg), a motion stimulus inducing emesis decreased the responsiveness of animals to a second and subsequent motion stimulus challenge when applied every 2 days for 11 trials. However, the animals receiving naloxone 10.0 mg/kg prior to the second and subsequent challenges showed no significant reduction in the intensity of emesis compared to the first trial. The data are revealing of an emetic potential of morphine when administered in the presence of a naloxone pretreatment. The administration of naloxone is also revealing of an additional inhibitory opioid system whose activation by endogenous opioid(s) may play a role in the adaptation to motion sickness on repeated challenge in S. murinus.

Carbody tilting is today a mature and inexpensive technology allowing higher speeds in curves and thus reduced travel time. The technology is accepted by most train operators, but a limited set of issues still holding back the full potential of tilting trains. The present study identifies and report on these issues in the first of two parts in this thesis. The second part is dedicated to analysis of some of the identified issues. The first part contains Chapters 2 to 5 and the second Chapters 6 to 12 where also the conclusions of the present study are given. Chapters 2 and 3 are related to the tilting train and the interaction between track and vehicle. Cross-wind stability is identified as critical for high-speed tilting trains. Limitation of the permissible speed in curves at high speed may be needed, reducing the benefit of tilting trains at very high speed. Track shift forces can also be safety critical for tilting vehicles at high speed. An improved track standard must be considered for high speed curving. Chapters 4 and 5 cover motion sickness knowledge, which may be important for the competitiveness of tilting trains. However, reduced risk of motion sickness may be contradictory to comfort in a traditional sense, one aspect can not be considered without also considering the other. One pure motion is not the likely cause to the motion sickness experienced in motion trains. A combination of motions is much more provocative and much more likely the cause. It is also likely that head rotations contribute as these may be performed at much higher motion amplitudes than performed by the train. Chapter 6 deals with services suitable for tilting trains. An analysis shows relations between cant deficiency, top speed, tractive performance and running times for a tilting train. About 9% running time may be gained on the Swedish line Stockholm – Gothenburg (457 km) if cant deficiency, top speed and tractive performance are improved compared with existing tilting trains. One interesting conclusion is that a non-tilting very high-speed train (280 km/h) will have longer running times than a tilting train with today’s maximum speed and tractive power. This statement is independent of top speed and tractive power of the non-tilting vehicle. Chapters 7 to 9 describe motion sickness tests made on-track within the EU-funded research project Fast And Comfortable Trains (FACT). An analysis is made showing correlation between vertical acceleration and motion sickness. However, vertical acceleration could not be pointed out as the cause to motion sickness as the correlation between vertical acceleration and several other motions are strong. Chapter 10 reports on design of track geometry. Guidelines for design of track cant are given optimising the counteracting requirements on comfort in non-tilting trains and risk of motion sickness in tilting trains. The guidelines are finally compared with the applied track cant on the Swedish line Stockholm – Gothenburg. Also transition curves and vertical track geometry are shortly discussed. Chapters 11 and 12 discusses the analysis, draws conclusions on the findings and gives proposals of further research within the present area. / QC 20101119

Symptoms after surgery and anaesthesia influence the patient´s ability to resume daily activities. If postoperative symptoms are controlled rehabilitation may be accelerated. The aims of this dissertation were to identify disturbing symptoms reported by patients after gynaecological surgery, to investigate what effect prohylactic treatment with antiemetics has on these symptoms and whether or not sensory simulation of the P6-acupressure has an effect on postoperative nausea and vomiting (PONV) and motion sickness. Methods: Total 1138 women participated in three clinical trials (Studies I, II, III) and one experimental study (Study IV). A questionnaire investigating postoperative symptoms was constructed and validated. The questionnaire was used in a prospective, consecutive, doubleblind, randomised, multicentre, and controlled study to identify incidence, and intensity of postoperative symptoms and the effect of common antiemetics (droperidol and granisetron) (Study III). The patients were followed for 24 h. In two studies (I, II) P6-acupressure was compared (prospective, double-blind, ransomised, controlled) with placebo acupressure and a reference group where the effect on PONV was followed over 24 h. The effect of P6-acupressure and placebo acupressure on motion sickness induced by a nauseogenic motion challenge was studied (Study III). Results: A high incidence and severity of postoperative symptoms were found after gynaecological surgery in a group with a high risk (&gt;30%) for PONV. Sixty-four per cent (107/165) of the patients experienced disturbing symptoms after surgery and 46 % (76/165) scored their symptoms as moderate to very severe. Fourty-eight per cent (79/165) had two or more symptoms. A higher incidence of symptoms were reported in the groups with prophylactic treatment, granisetron 74% (123/165) and droperidol 80% (133/165) compared to the control group 41% (69/165) (P &lt;0.05). The relative risk reduction for PONV with granisetron or droperidol prophylaxis is 27% respective 22%. The relative risk increase for headache is 63% after granisetron, and 44% for difficulty with accommodation after droperidol. Less PONV was seen after P6-acupressure, 33% (44/135) compared to reference group 46% (63/136) (p = 0.019), number needed to treat (NNT) was 7 [95% confidence interval (CI) 4- 6]. When comparing laparoscopic and vaginal surgery (subgroup analysis) the main effect was in the vaginal group (day-case surgery), 36% (27/75) in the reference group to 27% (23/86) in the placebo group and to 20% (17/84) in the P6-acupressure group, (P = 0.017), NNT for the vaginal group was 6 [95% CI 3-18]. P6-acupressure increased time to nausea after a laboratory motion challenge and reduced the total number of symptoms reported (p &lt;0.009). Conclusions: There is no clinical efficacy in the form of reduced postoperative symptoms after prophylactic antiemetics (droperidol and granisetron) in females with a high risk (&gt;30%) for PONV undergoing gynaecological surgery. P6-acupressure reduces the incidence of PONV after gynaecological surgery in females with a high (&gt;30%) risk for PONV. The effect seems to be most prominent after vaginal surgery. P6-acupressure increased tolerance to experimental nausogenic stimuli and reduced the total number of symptoms reported in females with a history of motion sickness. / On the day of the public defence the status of article IV was: Submitted.

Diss. (sammanfattning) Linköping : Univ., 2004. / Härtill 4 uppsatser.

Virtuell verklighet (VR) har under de senaste åren fått en uppsving i popularitet. Rörelsesjuka i VR har länge varit ett problem och är idag fortfarande ett stort hinder för kommersiell succé. Detta arbete ämnar till att implementera stöd för Oculus Rift i programmet Configura, och utvärdera navigering med handkontroll i en VR-miljö. Fokuset ligger på att hitta lämpliga gång- och rotationshastigheter för effektiv navigering med handkontroll, och effekten hastigheterna har på rö- relsesjuka. En användarstudie genomfördes där personer testade olika gång- och rotationshastigheter i olika tester med ökande svårighetsgrad i navigering. Resultaten från användarstudien visar på att i alla hastigheter upplevde testpersonerna allvarliga symptom av rörelsesjuka. Det fanns även indikationer att användare med lägre hastigheter presterar bättre. / Virtual Reality (VR) have risen in popularity during the last years. Motion sickness however have been a big problem and still is an obstacle for commercial success. This thesis work aims to implement VR-support in the space planning program Configura, and evaluate navigation with a controller in a VR-environment. The focus of this study is to find suitable walking and rotational speeds for effective navigation with a controller, and the effects different speeds have on motion sickness. A user study was preformed where users tested different speeds in tests with an increasingly difficulty in navigation. The results from the study shows that people had severe symptoms of motion sickness in all speeds. There were also indications that lower speeds made people perform better.

People call the year of 2016 as the year of virtual reality. As the world leading tech giants are releasing their own Virtual Reality (VR) products, the technology of VR has been more available than ever for the mass market now. However, the fact that the technology becomes cheaper and by that reaches a mass-market, does not in itself imply that long-standing usability issues with VR have been addressed. Problems regarding motion sickness (MS) and motion control (MC) has been two of the most important obstacles for VR technology in the past. The main research question of this study is: “Are there persistent universal access issues with VR related to motion control and motion sickness?” In this study a mixed method approach has been utilized for finding more answers related to these two important aspects. A literature review in the area of VR, MS and MC was followed by a quantitative controlled study and a qualitative evaluation. 32 participants were carefully selected for this study, they were divided into different groups and the quantitative data collected from them were processed and analyzed by using statistical test. An interview was also carried out with all of the participants of this study in order to gather more details about the usability of the motion controllers used in this study. The results of this study has validated several existing frameworks for VR. And in conclusion, this study has also shown that both previous motion sickness experiences and gender factors weren’t significant in terms of general accessibility issues on PCVR platforms. There are hints showing that the VR technology on PC platform could be universal accessible, since both of the quantitative and qualitative results has provided some evidences supporting this finding. However, more similar studies need to be carried out in order to identify more possible factors that would give an impact on user experiences in VR. The results of this study has also given implications of that today’s VR technology is developing on the right track and it could slowly become adopted by the mainstream and mass-market in the future.

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