Interacting with virtual objects via embodied avatar hands reduces pain intensity and diverts attention

The current study introduces a new paradigm for exploring cognitive factors in pain. Interacting with virtual objects via embodied avatar hands increased the illusion of “being there” in the virtual world, increased VR analgesia for acute pain, and reduced accuracy on an attention demanding task. Twenty-four healthy volunteer college students participated in this within-subject randomized crossover design study. During Phase 1, each participant received brief thermal pain stimuli during interactive embodied avatar VR vs. passive VR (no avatar and no interactivity), VR treatment order randomized. After each pain stimulus, participants provided subjective 0–10 ratings of pain. Compared to the passive VR condition, during the interactive avatar VR, participants reported significant reductions in (1) worst pain, (2) pain unpleasantness, (3) time thinking about pain and (4). they had significantly more fun during the pain stimulus (p = .000 for each). During Phase 2, participants performed a divided attention task in each of the two VR conditions. Participants made significantly more errors on the divided attention task during the interactive avatar VR condition, compared to passive VR, implicating an attention mechanism for how virtual reality reduces pain and helping understand how VR influences pain perception.Trial registration: NCT04245475. Date of registration: 29/01/2020.

Infusión continua de fentanil, dexmedetomidina o maropitant en perros sometidos a ovariohisterectomía

The aim of this study was to compare the analgesic effects of continuous infusion of fentanyl, dexmedetomidine, or maropitant. The animals received pre-anesthetic medication and anesthetic induction. Subsequently, continuous infusion of drugs was instituted, distributed in the following groups: fentanyl, dexmedetomidine, and maropitant. During the surgical procedure, the analgesic effects were evaluated by recording the cardiorespiratory parameters at the moments of greatest pain stimulus. When evaluating analgesic effects, the maropitant group showed greater stability in cardiorespiratory parameters compared to the fentanyl and dexmedetomidine group. From this study, it is suggested that continuous infusion of maropitant has analgesic effects similar to fentanyl and greater than dexmedetomidine.

Interacting With Virtual Objects via Embodied Avatar Hands Increases the Illusion of Presence, Increases Distraction, and Modulates VR Analgesia Effectiveness: A Randomized Crossover Trial.

The current study introduces a new experimental environment and apparatus for exploring cognitive factors in pain. Interacting with virtual objects via embodied avatar hands increased the illusion of “being there” in the virtual world, increased VR analgesia for acute pain, and reduced accuracy on an attention demanding task. Twenty-four healthy volunteer college students participated in this within-subject randomized crossover design study. During Phase 1, each participant received brief thermal pain stimuli during interactive embodied avatar VR vs. passive VR (no avatar and no interactivity), VR treatment order randomized. After each pain stimulus, participants provided subjective 0-10 ratings of pain. Compared to the passive VR condition, during the interactive avatar VR, participants reported significant reductions in 1). worst pain, 2). pain unpleasantness, 3). time thinking about pain and 4). they had significantly more fun during the pain stimulus (p = .000 for each). During Phase 2, participants performed a divided attention task in each VR condition. Participants made significantly more errors on the divided attention task during the interactive avatar VR condition, compared to passive VR, implicating an attention mechanism for how virtual reality reduces pain and helping understand how VR influences pain perception.

Effects of a Painful Stimulus on Stress Regulation in Male Patients With Borderline Personality Disorder: A Pilot Study

Pain processing in relation to stress has so far not been investigated in male patients with borderline personality disorder (BPD). This experimental pilot study examined 17 male BPD patients and 20 male healthy controls (HCs) to assess the effects of a pain stimulus on arousal, aggression, pain (ratings), and heart rate. At baseline, BPD patients showed significantly higher arousal and aggression; however, there was no significant difference in heart rate compared to the HC group. Following stress induction, a noninvasive mechanical pain stimulus was applied. No significant differences in pain ratings or heart rates were found between the groups. For arousal, a significantly stronger decrease was revealed in the BPD group compared to the HC group (t = 2.16, p = .038). Concerning aggression, the BPD group showed a significantly greater decrease after the pain stimulus than the HC group (t = 3.25, p = .002). This data showed that nonsuicidal self-injury can reduce arousal and aggression in male BPD.

A Systematic Review of Devices and Techniques that Objectively Measure Patients’ Pain

Background: Assessment of pain is important in daily clinical practice and as an endpoint in clinical studies. Because pain perception is highly subjective, pain measurement is complex. Selfrating pain scales are currently of great importance but have limitations. They depend on many more factors than pain, which could lead to an incorrect assessment of therapies or clinical studies. Therefore, there is need for valid, reliable, safe, and low-cost methods to determine and quantify patients’ pain more objectively. Objective: To provide an overview of devices and techniques that can be used to administer a pain stimulus with similar intensity as the endogenous pain experienced by the patient, in order to quantify and subsequently follow patients’ pain more objectively. Study Design: In this systematic review, articles from PubMed, EMBASE, Cochrane library and Scopus were reviewed for eligibility. Methods: Studies that described a device or technique that could be used to induce a variable, controlled, and measurable pain stimulus were included. Studies that made correlations with established pain scales or those who compared outcomes in multiple tests were selected to assess validity and reliability. Results: A total of 1,308 manuscripts were initially retrieved. After independent screening by a team of 4 reviewers, 19 studies were eventually included describing 15 different devices or techniques. These devices could be divided into groups based on stimulus administration: electrical, external pressure (probe) and miscellaneous pain stimulators. Electrical stimulators were found to be tested extensively and proven to be both valid and reliable. Limitations: To correlate new techniques with older methods such as the Numeric Rating Scale (NRS) and Visual Analogue Scale (VAS) for which an improvement is desired, is debatable. To (partially) address this problem, the reliability is added as an additional primary outcome to assess which device works best. Further limitations include the heterogeneity of studies found in both the types of pain measured as in outcome measures presented. In addition, it is important to note that part of the devices described cannot directly be used for clinical practice due to products that have cease to exist or the description of solely techniques rather than testing ready-to-use devices. Conclusion: Several devices and techniques compared pain intensity experienced by patients with an external pain stimulus that potentially could be used as a new objective pain measurement tool. Given the results of our review, electrical stimulators that have been tested extensively with high validity, reliability, and feasibility would be recommended for use for clinical and research purposes. Moreover, normalization of pain intensity scores for current perception is important. Pain intensity normalization leads to higher correlations with established pain scales and possibly to increased inter-patient reliability. Registration number: Registered in the PROSPERO database (PROSPERO 2016:CRD42016041974) Key words: Systematic review, objective pain measurement, pain scales; devices, techniques, validity, reliability, safety, feasibility

“MigraineMonitor” – Towards a System for the Prediction of Migraine Attacks using Electrostimulation

Migraine attacks can be accompanied by many different symptoms, some of them appearing within 24 hours before the onset of the headache. In previous work, reduced habituation to an electrical pain stimulus at the head was observed in the pre-ictal phase within 24 hours before the headache attack. Based on these results, this work presents an application to track influence factors on migraine attacks and an Arduino-based control unit which replaces the traditional approach of manual electrical stimulation. The usability of both components of the project was evaluated in separate user studies. Results of the usability study show a good acceptance of the systems with a mean SUS score of 92.4. Additionally, they indicate that the developed control unit may substitute the current manual electrical stimulation. Overall, the designed system allows standardized repeatable measurements and is a first step towards the home-use of a device for establishing a new method for migraine prediction.