A provisional model to predict blood pressure response to biofeedback-assisted relaxation

Blood pressure (BP) response to biofeedback-assisted relaxation is not uniform among hypertensive individuals. The purpose of this exploratory study was to determine if selected psychophysiological variables could be used to identify individuals able to lower blood pressure using biofeedback-assisted relaxation. Responders were defined using a preset criterion of 5 mm Hg or greater decrease in mean arterial pressure. A logistic regression model derived from five variables (heart rate, finger temperature, forehead muscle tension, plasma renin response to furosemide, and mean arterial pressure response to furosemide) provided significant predictive power for BP response, exhibiting a sensitivity of 84.6% and a specificity of 80.0%. With future validation, the proposed model may provide useful information to identify patients likely to benefit from biofeedback-assisted relaxation.     

EMG stability as a biofeedback control

Factors that may confound comparisons between electromyographic (EMG) biofeedback training and its control conditions include feedback quality and experience of success. We investigated the usefulness of a control procedure designed to overcome these potential sources of confounding. The procedure consisted of training muscle tension stability. We used it as a control for frontal EMG relaxation training in children with asthma. To equate the groups for feedback quality and experience of success, we gave each child in the control condition audio feedback decreasing in pitch when muscle tension was at or near baseline levels, and feedback increasing in pitch when muscle tension was either substantially above or below baseline levels. Children in both groups were instructed to decrease the pitch of the tone. In comparison to children in the relaxation condition, the children in the control condition exhibited stable levels of muscle tension throughout eight training sessions. We concluded that feedback for stable muscle tension may be a useful control procedure for EMG biofeedback training whenever experimental and control procedures differ in either feedback quality of degree to which they permit subjects to experience success.This research was supported by NIH-Grant HL 27402. We are grateful to Paul Schnitter who constructed the EMG stability feedback device.     

Biofeedback in treatment of urinary incontinence in stroke patients

Urinary incontinence can occur poststroke owing to weakness or incoordination of sphincter muscles, impaired bladder sensation, or hyperreflexic, neurogenic bladder. Four male subjects who had urinary incontinence associated with a stroke that had occurred 8 months to 10 years earlier, and who averaged 1.6 to 7.5 accidental voidings per week, participated in an outpatient study with a 4-week scheduled-voiding baseline, 2 to 5 sessions of biofeedback-assisted bladder retraining, and 6- to 12-month follow-up. Training sessions included stepwise filling of the bladder and manometric feedback display of bladder pressure, abdominal pressure, and external anal sphincter pressure. Training procedures were designed to teach subjects to attend to bladder sensations, inhibit bladder contractions, and improve voluntary sphincter muscle control. All four subjects achieved and maintained continence regardless of substantial differences in subject characteristics, including laterality of stroke, degree of sensory impairment, and independence in daily activities.     

Clinical observations on behavioral treatment of a patient with insulin-dependent diabetes mellitus

This report uses a single case format to describe clinical observations on the use of biofeedback-assisted relaxation in Type I insulin-dependent diabetes mellitus. It is suggested that treatment based on relaxation training may be utilized in diabetics provided that certain conditions are met and that the relaxation procedure is modified to conform to the special requirements of persons taking insulin. Since both client characteristics and type of training protocol can markedly affect outcome, it may be especially important to tailor the training protocol for each insulin-dependent diabetic patient, based on careful and continuous monitoring of treatment effects.     

Subjective experiences associated with thermal biofeedback treatment of hypertension

Reports of subjective experiences of 73 hypertensive patients who were treated with thermal biofeedback for hand warming were obtained over 16 treatment sessions. Most of the differential responding in subjective report occurred in the first 5 sessions. Differences in reports of throbbing were associated with medication status during treatment (presence of sympatholytic antihypertensive agent). From 4 to 9% of patients report negative subjective experiences at any one session. When short-term clinical successes (either elimination of medication or reduction of BP) were compared with short-term failures, it was found that successes reported more warmth, more likelihood of falling asleep, and more dreamlike experiences. The latter were more likely to occur suddenly for the successes. Correlational analyses revealed consistent positive associations between reports of warmth and relaxation with highest temperature achieved in the session and consistent negative associations between experiencing physical sensations and degree of temperature change within the session.This research was supported in part by grants from NHLBI, HL-27622 and HL-31189.     

Yawning: A possible confounding variable in EMG biofeedback studies

An elderly hemiplegic patient participating in an EMG biofeedback training program was observed to produce a synergistic flexion movement of the plegic (determined by functional evaluations) upper limb while yawning. In the course of the training sessions the electrical activity of the anterior deltoid (the target muscle) was recorded during yawning. These peak EMG values were greatly facilitated in comparison with the session mean peak values obtained during an attempted maximum voluntary isometric contraction (shoulder flexion) of the same limb (e.g., Trial 1: 85.00 vs. 4.33 µV). The possibility of yawning as a confounding variable in EMG biofeedback studies is presented and discussed.This research was supported in part by Health and Welfare Canada (NHRDP).     

Variations in digital temperature during frontal EMG biofeedback training in normal subjects

During frontal EMG biofeedback training, the relationship between frontal EMG and digital skin temperature was investigated in two experiments, which varied the number of baseline and feedback sessions. The results of Experiment 1 suggested a general relaxation effect, where digital temperature increased as frontal EMG decreased, especially for subjects with initially low hand temperature. Experiment 2 extended the number of baseline and feedback sessions and qualified the results of Experiment 1. EMG and digital temperature did not simultaneously converge toward general relaxation over the extended baseline or feedback sessions in Experiment 2. Furthermore, when the feedback signal was introduced, digital temperature dropped quickly but recovered to baseline levels within three feedback sessions; this drop in digital temperature was interpreted within the context of attentional demands of the biofeedback task. The results appeared consistent with the view that frontal biofeedback training teaches a discriminative skill of lower frontal EMG, and that this skill does not readily generalize to digital skin temperature.This research was supported by Grant 2 S06RR08038-17 funded by the National Institutes of Mental Health.     

The use of biofeedback in a behavioral program designed to teach an anxious child self-catheterization

This paper presents a case study of a 7-year-old girl with a noncompliant bladder who was trained to self-catheterize using biofeedback and behavior therapy techniques. Initial attempts to train her to self-catheterize were unsuccessful owing to excessive amounts of fear, muscle tension, and refusal. After seven treatment sessions in which she was instructed in proper self-catheterization technique by a urology nurse clinician and coached in biofeedback-assisted relaxation by a clinical psychologist, the child successfully learned to self-catheterize. EMG readings showed a decrease in quadriceps muscle tension levels across sessions. Eight additional sessions were held in order to train the child's parents in proper technique and coaching procedures. Through the use of portable biofeedback equipment during actual training sessions, the biofeedback served as a cue—first to the child and coach, and later to the child and parents—for when the child needed to stop and relax. This case illustrates the usefulness of biofeedback in a comprehensive behavioral program designed to teach self-catheterization to fearful children.     

Frequency characteristics of signals and instrumentation: Implication for EMG biofeedback studies

Signals can be analyzed in either the time or frequency domain. In the time domain, the analysis consists of manipulating and measuring one or more characteristics of the signal that may vary with time. One can, for instance, rectify a signal, filter it, calculate its mean value, display the histogram of its amplitude, and so forth. Frequency analysis is less well understood because it requires a lengthy mathematical treatment most easily done by computer. However, it gives exclusive information on a signal. For instance, when the frequency content of a signal is known, it is easy to specify which characteristics an amplifier must have in order to amplify the signal without distortion, or to set the cutoff frequencies of filters to eliminate noise. Also, in many circumstances, frequency spectra are more easily interpreted than the original raw data. Such is the case with the EMG where the random aspect of the signal makes some form of processing (i.e., rectification, filtering, etc.) necessary, but not always as meaningful as we would like. Thus we present here the principal characteristics of frequency analysis, and discuss its usefulness in analyzing EMG signals and its application to biofeedback, clinical practice, and research.The authors acknowledge the technical assistance of F. Kemp, M. Goyette, and C. Goulet. T. Milner kindly reviewed the final version of the text. The preparation of this paper was supported through funds from Health and Welfare Canada (NHRDP) and the Centre de recherche, Institut de réadaptation de Montréal.     

Evaluation of home-based thermal biofeedback treatment of pediatric migraine headache

Sixteen children and adolescents with migraine headache were treated with thermal biofeedback. Seven were seen individually in the clinic while the other nine participated in a limited-contact, partly home-based regimen. Evaluation of headache diary data from 4-week monitoring periods before and after treatment showed significant (p<.01) reduction in headaches, with no significant difference in efficacy between the two conditions.This research was supported in part by grants from NIMH, MH-41341, and NINCDS, NS-23440.     

Effects of Biofeedback in Phonatory Disorders and Phonatory Performance: A Systematic Literature Review

The purpose of this article was to systematically review the literature on the effects of biofeedback therapy in the domain of phonatory disorders and phonatory performance, using studies in peer-reviewed journals. An extensive definition of biofeedback is given and its place in voice treatment is defined. Eighteen group or case studies or reports considering the effects of electromyographic, laryngoscopic and acoustic biofeedback in dysphonic patients (hyperfunctional voice disorders, hypofunctional voice disorders, psychogenic voice disorder, laryngeal trauma, total laryngectomy, vocal cord dysfunction) and participants with normal voices are included and an analysis of procedure as well as research design and results is presented. The usefulness of biofeedback in phonatory disorders and performance was to be interpreted based on tendencies, since there is a lack of randomized controlled efficacy studies. In only 3 of 18 studies (16.7%) did biofeedback therapy fail to improve voice quality or not result in better results than other forms of therapy. Recommendations for improved methodologies are made, which include the use of acoustic voice quality parameters.     

Long-term effects of biofeedback-induced facial relaxation on measures of asthma severity in children

We studied the effects of electromyographic biofeedback on measures of asthma severity in children. Fifteen children received biofeedback training to reduce facial tension, and 14 children, who served as controls, received biofeedback training to maintain facial tension at a stable level. Assignment to experimental condition was random. As a result of training, electromyographic levels decreased in children trained in facial relaxation and remained fairly constant in children trained in facial tension stability. Biofeedback training was augmented for children in both groups by having them practice their facial exercises at home. Each child's condition was followed for a five-month period subsequent to biofeedback training. Throughout the experiment, the following measures of asthma severity were monitored: lung function, self-rated asthma severity, medication usage, and frequency of asthma attacks. In addition, standardized measures of attitudes toward asthma, self-concept, and chronic anxiety were recorded at regular intervals. As compared to the facial stability subjects, the facial relaxation subjects exhibited higher pulmonary scores, more positive attitudes toward asthma, and lower chronic anxiety during the followup period. Subjects in the two groups, however, did not differ on self-rated asthma severity, medication usage, frequency of asthma attacks, or self-concept. Based on the improvements we observed in pulmonary, attitude, and anxiety measures, we concluded that biofeedback training for facial relaxation contributes to the self-control of asthma and would be a valuable addition to asthma self-management programs.This research was supported by NIH grant No. HL27402. We are grateful to Anita D. Baker, Lisa Barclay, Deborah L. Harm, and Douglas J. Miller for serving as experimenters and to Constance K. Cottrell and Cindy Stout for compiling summaries of the data.     

Behavioral strategies for the reduction of pain and anxiety associated with orthopedic trauma

This study examined the efficacy of behavioral strategies in alleviating pain and anxiety associated with severe orthopedic trauma. Sixty-four patients with multiple fractures were divided into four groups: (1) control, (2) attention only, (3) EMG biofeedback-assisted relaxation, and (4) audiotaped relaxation training. All were measured over at least six sessions, or as long as hospital stay permitted. Significant between group differences were found on the following: systolic blood pressure, pheripheral temperature, subjective units of discomfort, state anxiety, with a trend for use of sleep medications. No differences were found on other vital signs, EMG recordings, or other medications. EMG-biofeedback relaxation and relaxation training were relatively equivalent for all measures, and little or no change was observed for those patients who received attention only or served as controls.     

Scientific and clinical biofeedback in the USSR

This paper describes the history of biofeedback research and application in the USSR. The approach of USSR scientists to the study of basic mechanisms of biofeedback and the status of clinical applications of biofeedback in the Soviet Union are described. Trends in the publication of biofeedback-related papers in Russian are presented, and the present state of the art described. Promising prospects for biofeedback research and application are discussed.     

Biofeedback treatments of essential hypertension

Fifteen years of research in the self-regulatory treatment of hypertension by the author is summarized. A model relating expectations, task performance, home practice, and biochemical variables to the thermal biofeedback treatment of hypertension is presented.Essentially, all of the research reported herein was supported by various grants from NHLBI: HL-14906, HL-18814, HL-27622, and HL-31189.     

Fifteen-month follow-up with asthmatics utilizing EMG/Incentive inspirometer feedback

This study reports on the follow-up data of an integrated group program to reduce asthmatic symptoms. The 16 sessions included a comprehensive multibehavioral/desensitization retraining program and utilized EMG/Incentive inspirometer feedback to encourage slow diaphragmatic breathing in all situations. 17 out of 21 volunteers participated in the 15-month follow-up study. At the follow-up all subjects significantly reduced their EMG tension levels while simultaneously increasing their inhalation volumes. Subjects reported reductions in their asthma symptoms, medication use, emergency room visits, and breathless episodes.We thank Ms. Michelle Roland, Kathy Smith, and Jeanne Charbonneau for their helpful assistance.     

Prediction of early termination from the self-regulatory treatment of chronic headache

The ability of demographic, psychological testing and history information to predict which patients will terminate early from nonpharmacological treatment of headache (relaxation and biofeedback) was tested. Information from each of these areas was initially examined for differences between dropouts and treatment completers using univariate analyses. These analyses were followed by a canonical discriminate function analysis that predicted whether patients would complete treatment or drop out. Information from the three predictor sets combined resulted in 77.4% of the patients being correctly classified.This research was supported by a grant from the NINCDS, NS15235.