Type Of Biofeedback Research Articles

Comparing tomographic EEG neurofeedback and EMG biofeedback in children with attention-deficit/hyperactivity disorder

Two types of biofeedback (BF), tomographic electroencephalogram (EEG) neurofeedback (NF) and electromyographic biofeedback (EMG-BF), both with phasic and tonic protocols, were compared for treatment effects and specificity in attention-deficit/hyperactivity disorder (ADHD). Thirteen children with ADHD trained their brain activity in the anterior cingulate cortex (ACC), and twelve trained activity of arm muscles involved in fine motor skills. In each training session, resting state 24-channel EEG and training performances were recorded. Both groups showed similar behavioral improvements and artifact reduction in selected conditions, with no significant advantages despite medium effect sizes on primary outcomes for NF. Only the EMG-BF group, however, showed clear improvement in training regulation performance, and specific motor coordination effects. The NF group tended to present individual normalization of trained frequency bands in the ACC during rest across training. The results provide evidence for some specific effects in our small sample, albeit only to a small extent.

Abstract 122: AMES Treatment of Severe Hand Impairment Following Stroke

The objective of this study was to determine whether AMES (Assisted Movement with Enhanced Sensation), a novel therapeutic intervention that addresses impairments, rather than function, can reduce impairment and restore lost function in persons with a severely disabled hand. Forty-three participants with stroke (>1 yr post-injury) were provided with thirty 30-min AMES treatments over 10 weeks. Of these participants, 24 had no baseline active extension of any finger of the affected hand. Participants were randomized to 1 of 2 treatment groups differentiated by the kind of biofeedback (active torque or EMG) associated with the AMES intervention. During treatment, a robotic device cyclically opened and closed the hand (5 deg/s, ±15 deg) while the participant assisted this movement using visual biofeedback, and while vibration (60 pulses/s, 2 mm) was applied to the lengthening muscles. Participants were evaluated twice, before and after the treatment period, with the Fugl-Meyer Assessment (FMA-UE), Stroke Impact Scale (SIS), and Box-and-Block Test. In addition, during each treatment session, the AMES robot tested each participant’s strength of thumb-and-finger flexion and extension. Both torque and EMG were recorded during this Strength Test in participants assigned to the EMG-biofeedback group. The results showed overall a significant increase in the FMA-UE score (t-test, p<0.001), SIS score (t-test, p<0.05), and Box-and-Block Test score (Wilcoxon, p<0.005), without any difference between the 2 treatment groups. Four of the 24 initially plegic participants recovered the ability to move one or more blocks; however, all participants showing improvement in the Box-and-Block Test had a baseline FMA score of ≥17. Analysis of EMG during the hand-opening part of the Strength Test showed that AMES treatment of the EMG-biofeedback group significantly increased the amplitude of extensor activity (t-test, p<0.001) and decreased flexor co-contraction (t-test, p<0.05). We conclude that AMES coupled with either type of biofeedback may be effective at reducing impairment and increasing function in the severely impaired hand following stroke.

Biofeedback in rehabilitation

This paper reviews the literature relating to the biofeedback used in physical rehabilitation. The biofeedback methods used in rehabilitation are based on biomechanical measurements and measurements of the physiological systems of the body. The physiological systems of the body which can be measured to provide biofeedback are the neuromuscular system, the respiratory system and the cardiovascular system. Neuromuscular biofeedback methods include electromyography (EMG) biofeedback and real-time ultrasound imaging (RTUS) biofeedback. EMG biofeedback is the most widely investigated method of biofeedback and appears to be effective in the treatment of many musculoskeletal conditions and in post cardiovascular accident (CVA) rehabilitation. RTUS biofeedback has been demonstrated effective in the treatment of low back pain (LBP) and pelvic floor muscle dysfunction. Cardiovascular biofeedback methods have been shown to be effective in the treatment of a number of health conditions such as hypertension, heart failure, asthma, fibromyalgia and even psychological disorders however a systematic review in this field has yet to be conducted. Similarly, the number of large scale studies examining the use of respiratory biofeedback in rehabilitation is limited. Measurements of movement, postural control and force output can be made using a number of different devices and used to deliver biomechanical biofeedback. Inertial based sensing biofeedback is the most widely researched biomechanical biofeedback method, with a number of studies showing it to be effective in improving measures of balance in a number of populations. Other types of biomechanical biofeedback include force plate systems, electrogoniometry, pressure biofeedback and camera based systems however the evidence for these is limited. Biofeedback is generally delivered using visual displays, acoustic or haptic signals, however more recently virtual reality (VR) or exergaming technology have been used as biofeedback signals. VR and exergaming technology have been primarily investigated in post-CVA rehabilitation, however, more recent work has shown this type of biofeedback to be effective in improving exercise technique in musculoskeletal populations. While a number of studies in this area have been conducted, further large scale studies and reviews investigating different biofeedback applications in different clinical populations are required.

Comparative study on the efficacy of electromyography and galvanic skin resistance biofeedback in tension type headache: a single blinded randomized controlled trial

AbstractTension type headache is the most widespread and most common primary headache disorder accounting for nearly 90% of all headaches. Efficacy of electromyography biofeedback in patients with tension type headache has been proven but efficacy of galvanic skin resistance biofeedback has not been studied adequately. The aim of the present study was to compare the efficacy of electromyography biofeedback and galvanic skin resistance biofeedback in patients with tension type headache.We performed a randomized single blinded controlled study. Out of 116 recruited subjects, 91 (59 females and 32 males) were randomly assigned to three groups receiving electromyography biofeedback (n=30), galvanic skin resistance biofeedback (n=30), and a control group (n=31). Each subject (except the control group) received 15 biofeedback sessions for 30 min each in an isolated room. The control group received only medication prescribed by their physician. Each patient was blinded to the type of biofeedback being given. Pain variables, SF-36 quality of life scores, and analgesic usage were recorded at baseline, 1 month, 6 months, and 1 year after therapy.There was a significant difference in frequency and duration of headache in electromyography and galvanic skin resistance groups (p<0.01), whereas the control group showed significant differences in intensity (p=0.05) and duration (p<0.001). Significant improvement was seen only in total SF-36 scores after 1 year in the electromyography and control groups (p=0.03 and p=0.00, respectively). A significant drop in analgesic usage was seen in all groups at 1 year (p<0.001).Electromyography and galvanic skin resistance biofeedback are effective in the treatment of tension type headache, with electromyography biofeedback being more effective than galvanic skin resistance biofeedback.

Using a false biofeedback methodology to explore relationships between learners’ affect, metacognition, and performance

We used a false-biofeedback methodology to manipulate physiological arousal in order to induce affective states that would influence learners’ metacognitive judgments and learning performance. False-biofeedback is a method used to induce physiological arousal (and resultant affective states) by presenting learners with audio stimuli of false heart beats. Learners were presented with accelerated, baseline, or no heart beat (control) while they completed a challenging learning task. We tested four hypotheses about the effect of false-biofeedback. The alarm vs. alert hypothesis predicted that false biofeedback would be appraised as either a signal of distress and would impair learning (alarm), or as a signal of engagement and would facilitate learning (alert). The differential biofeedback hypothesis predicted that the alarm and alert effects would be dependent on the type of biofeedback (accelerated vs. baseline). The question depth hypothesis predicted that these effects would be more pronounced for challenging inference questions. Lastly, the self vs. recording hypothesis predicted that effects would only occur if participants believed that false biofeedback was indicative of their own physiological arousal. In general, learners experienced more positive/activating affective states, made more confident metacognitive judgments, and achieved higher learning when they received accelerated or baseline biofeedback while answering a challenging inference question, irrespective of the perceived source of the biofeedback. Thus, our findings supported the alert and question depth hypotheses, but not the differential biofeedback or self vs. recording hypotheses. Implications of the findings for the integration of affective processes into models of cognitive and metacognitive processes during learning are discussed.

Interface computacional 3D para biofeedback multimodal em tempo real

Este artigo descreve o projeto de um sistema computacional em tempo real para biofeedback multimodal. As informacoes biologicas ou psico-fisiologicas do paciente sao detectadas por sensores especificos e processadas para prover feedback visual, por meio de ambientes virtuais tridimensionais e feedback auditivo. O dispositivo foi projetado para coleta e tratamento de seis sinais distintos: EMG, EEG, GSR, temperatura, frequencia cardiaca e frequencia respiratoria. O aplicativo de software foi projetado em linguagem Visual C++ e utiliza tecnicas de programacao concorrente para permitir o tratamento adequado de todas as acoes em tempo real. Os ambientes virtuais foram criados no software 3D Studio Max® e renderizados utilizando os recursos da biblioteca grafica DirectX® da Microsoft Corp. O sistema desenvolvido resultou, conforme relatos dos voluntarios, em sessoes agradaveis e interessantes, que permitiam a escolha de diferentes tipos de ambientes virtuais capazes de se adequar as necessidades individuais. Todos os dados coletados durante as sessoes de biofeedback sao armazenados em um banco de dados especifico, possibilitando a geracao de relatorios para o terapeuta e permitindo o acompanhamento da evolucao dos pacientes ao longo do tratamento. O sistema possui potencialidade para utilizacao como apoio ao tratamento de diversas patologias e disfuncoes, como demonstrado pelos experimentos realizados nas diferentes modalidades de biofeedback. Com este trabalho, os autores esperam ainda contribuir para o desenvolvimento de know-how nacional na area, a medida que disponibilizam tecnicas avancadas para producao de hardware e software aplicaveis a tratamentos em biofeedback multimodal.

Utility of the Balloon-Evacuation Test for Identifying Patients With Dyssynergic Defecation

Background/Aims: Dyssynergic defecation (DD) accounts for 30-40% of patients with chronic constipation and is particularly prevalent in referral practices. Standard treatments (ST) including exercise, avoidance of constipating drugs, and increasing fluid & fiber intake often fail to improve symptoms. Laxatives provide inconsistent relief of constipation related symptoms, particularly in DD patients. Recent studies suggest that biofeedback (BF) therapy provides an effective treatment for DD patients. Aims: To conduct a systematic review and meta-analysis of randomized-controlled trials (RCTs) comparing BF therapy to standard treatments in DD patients. Methods: A search of MEDLINE, EMBASE, Google Scholar, Cochrane Central Register of Controlled Trials, ACP Journal Club, DARE, CMR, HTA, and abstracts from major GI meetings was performed. RCTs comparing the efficacy of BF vs. ST for weekly bowel movement (BM) frequency or global satisfaction in patients with DD were selected. Meta-analysis was performed using metan command in Strata 10.1. A funnel plot was created to assess for publication bias. The heterogeneity of the pooled estimate was tested with the inconsistency index (I2) statistic. Subgroup analyses (type of BF, duration of follow-up, study location, primary & secondary study outcomes, concurrent laxative use) were performed to account for any observed heterogeneity. Results: Systematic review identified >1000 citations. Upon detailed review, 7 treatment trials were identified of which 4 studies which randomized 241 patients with DD fulfilled our inclusion criteria and were included in the meta-analysis. Patients treated with BF reported an increase of 1.30 BM/ week, compared to 0.87 BM/week for patients treated with ST (WMD: 01.11, 95% CI: -0.99-3.20). Significant heterogeneity amongst studies was noted. Three studies reported data on patient satisfaction. The number of patients reporting satisfaction with therapy was higher in the BF group compared to the ST group (75.0% vs. 36.7%, RR: 2.15, 95% CI: 1.64-2.81, I2=81%). No other constipation-related outcomes were consistently reported amongst the included trials. Conclusions: These results suggest that BF therapy offers benefits for global satisfaction in patients with DD. Our analysis identified the need for further large, well designed clinical trials and the development of a common set of outcome measures which can be applied to randomized trials evaluating the efficacy of BF training for DD. Though stool frequency is commonly employed as the primary outcome measure in constipation trials, our results raise questions about whether this endpoint is the most appropriate primary outcome for trials evaluating BF for DD.

Salient and placebo vibrotactile feedback are equally effective in reducing sway in bilateral vestibular loss patients

This study explores the effect of vibrotactile biofeedback on body sway in stance in patients with severe bilateral vestibular losses in a placebo-controlled study. A tilt sensor mounted on the head or trunk is used to detect head or body tilt and activates via a microprocessor 12 small vibrators that are placed around the waist with a mutual distance of 30°. Two positions of the tilt sensor (head and trunk) and three types of biofeedback (normal, full and random) were evaluated, besides no biofeedback. Body sway during stance was assessed in 10 patients with bilateral vestibular areflexia and performance was scored in the seven different conditions. Inter-individual and test–retest variability without biofeedback was assessed in 10 additional patients with bilateral vestibular areflexia. In six patients no significant change in body swaypath was observed using biofeedback. In four patients body swaypath decreased significantly using biofeedback and sensor on the head in all three activation modes, whereas with sensor on the trunk only one patient showed a significant improvement in swaypath in all three activation modes. The patients rated the functionality of the AVBF system and its effect on balance on average 6.5 on a scale from 0 to 10. Thus, body sway improved in 4 out of 10 patients using biofeedback, but the improvement with true biofeedback was only observed in those subjects where an improvement was present in placebo mode as well. The improvement was, at least partially, caused by other effects than biofeedback, like training, increased self-confidence or alertness.

EMG biofeedback treatment of dysphonias and related voice disorders.

Abstract This article reviews the development of EMG biofeedback as a tool for operant learning, including the development of surface EMG biofeedback and support for the use of such biofeedback for treating dysphonias and related voice disorders. A few, well controlled empirical investigations suggest that EMG biofeedback helps some individuals with dysphonias to gain volitional control over specific laryngeal muscles, reduce tension around the vocal cords and (sometimes) improve vocal quality. EMG biofeedback has also been found effective for treating rare cases of ventricular fold dysphonia and paradoxical vocal cord motion. Further research is needed with clearer specification of electrode placement. However, EMG biofeedback represents a promising application of behavioral technology in the treatment of various functional dysphonias and voice disorders. Key Words: EMG, biofeedback, dysphonia, voice disorders, vocal tension, vocal quality Defining Biofeedback In biofeedback, internal autonomic events such as heart rate, blood pressure, or muscle tension are electronically amplified, providing an individual with body (i.e., bio) information (i.e., feedback) that is commonly unavailable. By using electronic instruments to accurately measure, process, and feed back information about the body, an individual is able to learn to develop control over these internal physiological events (Shapiro & Surwit, 1979). That is, internal responses thought to be involuntary have been found to be affected by consequences (i.e., operant learning) and subject to voluntary control as well. Indeed, empirical research has repeatedly demonstrated that through operant learning, humans can gain volitional control over numerous different internal physiological functions and the principle means of developing this control has been with consequences delivered via biofeedback (Schwartz & Olsen, 1995). The importance of biofeedback in learning to control internal physiology should not be surprising. Skinner predicted as much when he suggested that, there is no reason why covert behavior could not be amplified so that the individual himself could make use of the additional information... (pg 282) (Skinner, 1953). Indeed, much of the research on biofeedback has been made possible precisely because of significant advancements in instrumentation for measuring covert physiological behavior (Peek, 1995). Biomedical engineers have developed noninvasive and sophisticated technology for using surface recordings to measure what goes on inside the body. Thus, we can now accurately and reliably monitor, amplify, and transform physiological behavior into audio and or visual signals that are easily understandable. An individual can sit casually in front of a computer, have sensors taped to their skin, and watch a computer monitor to receive information about what is going on within the skin. The biofeedback allows individuals to experience immediate, frequent and potent consequences for even small changes in covert behavior; all features known to enhance the reinforcing effects of consequences during operant learning trials (Miltenberger, 2001). Defining Surface EMG (sEMG) Biofeedback One type of biofeedback involves electromyography. An electromyogram is a record of electrical activity from a muscle or group of muscles. The electrical activity is typically reported in microvolts ([micro]V). When that record is obtained from electrodes applied to the skin and the information is used to control muscle activity, it is called surface electromyographic (sEMG) biofeedback. The specificity of the biofeedback from surface muscles depends in part, upon the specificity of the signal, which is influenced by the arrangement of the electrodes. Electrodes placed close together and parallel to the muscle fibers will provide more specificity with respect to the targeted muscles, while electrodes placed farther apart and/or perpendicular to the muscle fibers will provide a more global measure of tension in the targeted area (Fogel, 1995; Sherman, 2003). …

Effects of Linear versus Sigmoid Coding of Visual or Audio Biofeedback for the Control of Upright Stance

Although both visual and audio biofeedback (BF) systems for postural control can reduce sway during stance, a direct comparison between the two systems has never been done. Further, comparing different coding designs of audio and visual BF may help in elucidating how BF information is integrated in the control of posture, and may improve knowledge for the design of innovative BF systems for postural control. The purpose of this paper is to compare the effects of linear versus sigmoid coding of trunk acceleration for audio and visual BF on postural sway in a group of eight, healthy subjects while standing on a foam surface. Results showed that sigmoid-coded audio BF reduced sway acceleration more than did a linear-coded audio BF, whereas a linear-coded visual BF reduced sway acceleration more than a sigmoid-coded visual BF. In addition, audio BF had larger effects on reducing center of pressure (COP) displacement whereas visual BF had larger effects on reducing trunk sway. These results suggest that audio and visual BF for postural control benefit from different types of sensory coding and each type of BF may encourage a different type of postural sway strategy.

Neuromuscular fatigue differs with biofeedback type when performing a submaximal contraction

The aim of the study was to examine alterations in contractile and neural processes in response to an isometric fatiguing contraction performed with EMG feedback (constant-EMG task) when exerting 40% of maximal voluntary contraction (MVC) torque with the knee extensor muscles. A task with a torque feedback (constant-torque task) set at a similar intensity served as a reference task. Thirteen men (26 ± 5 yr) attended two experimental sessions that were randomized across days. Endurance time was greater for the constant-EMG task compared with the constant-torque task (230 ± 156 s vs. 101 ± 32 s, P < 0.01). Average EMG activity for the knee extensor muscles increased from 33.5 ± 4.5% to 54.7 ± 21.7% MVC EMG during the constant-torque task ( P < 0.001), whereas the torque exerted during the constant-EMG task decreased from 42.8 ± 3.0% to 17.9 ± 5.6% MVC torque ( P < 0.001). Comparable reductions in knee extensors MVC (−15.7 ± 8.7% for the constant-torque task vs. −17.5 ± 9.8% for the constant-EMG task, P > 0.05) and voluntary activation level were observed at exhaustion. In contrast, excitation–contraction coupling process, assessed with an electrically evoked twitch and doublet, was altered significantly more at the end of the constant-EMG task despite the absence of M-wave changes for both tasks. Present results suggest that prolonged contractions using EMG biofeedback should be used cautiously in rehabilitation programs.

BIOFEEDBACK METHODOLOGY: DOES IT MATTER HOW WE TEACH CHILDREN HOW TO RELAX THE PELVIC FLOOR DURING VOIDING?

Biofeedback is a noninvasive treatment that has been documented to be helpful for children with daytime wetting and/or urinary tract infection secondary to voiding dysfunction. We wish to determine the effectiveness of biofeedback in a large population of children presenting with voiding dysfunction, and evaluate differences between 2 different methods with regard to resolution of symptoms, improvement of objective measurements and patient satisfaction. The charts of 102 consecutive patients treated with biofeedback were reviewed. Of the patients 21 were asked to void 4 to 8 times in 6 hours seated in front of a uroflow device while receiving coaching by a staff member (method 1), 56 were taught pelvic floor relaxation techniques in front of a computer monitor that displayed electromyogram readings for 45 to 90 minutes (method 2), and both methods were used in 25. Outcome variables were obtained through chart review and telephone contact, and included resolution of symptoms, elimination of urinary tract infection, character of voiding curve, post-void residual, decrease in relaxation score and parental satisfaction. Females comprised 79% of the population and median age at first treatment was 7.7 years (range 4.3 to 15.4 y). Daytime wetting was seen in 84% and recurrent urinary tract infection in 66% of patients. Among children with daytime wetting there was 100% success or improvement with method 1, 91% with method 2 and 80% with both methods (p not significant). Among those with urinary tract infection, 25% had subsequent infection with method 1, 25% with method 2 and 31% with both methods (p not significant). Normalization of the flow curve was seen in 94% with method 1, 67% with method 2 and 30% with both methods. Patients using both methods had a significantly greater post-void residual compared to patients using method 1 (0 versus 33%, p = 0.003). Relaxation scores decreased a median of 6.5% in with method 2 and 20% with both methods. After a median followup of 1.8 years 98% of parents expressed satisfaction with biofeedback with more than 80% indicating a high degree of satisfaction. Reduction of daytime wetting and urinary tract infection can be achieved regardless of the type of biofeedback used. Although symptoms improved, patients using a shorter but more intensive approach aimed at teaching control of the pelvic floor musculature were more likely to demonstrate persistent post-void residuals and abnormal flow curves. A considerable degree of enthusiasm was reported using both of these non-invasive forms of treatment.

Biofeedback treatment of fecal incontinence: a critical review.

The aims of this review are 1) to critically evaluate the literature on the efficacy of biofeedback treatment for fecal incontinence, 2) to compare different types of biofeedback, and 3) to identify patient characteristics which predict a successful outcome. The MEDLINE database was searched for articles published between 1973 and 1999 which included the terms "biofeedback" and "fecal incontinence." Pediatric and adult articles in any language were screened. Inclusion for review required that the study be prospective, have five or more subjects, and have a description of the treatment protocol. Thirty-five studies were reviewed. Only six studies used a parallel treatment design and just three of those randomized subjects to treatment groups. A meta-analysis (weighted by subjects) was performed to compare the results of two treatment protocols that dominate the literature. The mean success rate of studies using Coordination training (i.e., coordinating pelvic floor muscle contraction with the sensation of rectal filling) was 67 percent, while the mean success rate for studies using Strength training (i.e., pelvic floor muscle contraction) was 70 percent. Furthermore, the mean success rate for those Strength training studies using electromyographic biofeedback was 74 percent, while the mean success rate for studies using anal canal pressure biofeedback Strength training was 64 percent. However, these conclusions are limited by the absence of clearly identified criteria for determining success. There are also inconsistencies in the literature regarding the patient selection criteria, severity and cause of symptoms, amount of treatment, as well as the type of biofeedback protocols and instrumentation used. Finally, no patient characteristics were identified that would assist in predicting successful outcome. Although most studies report positive results using biofeedback to treat fecal incontinence, quality research is lacking. Recommendations are made for future investigations to 1) improve experimental design, 2) include long term follow-up data, and 3) to use an adequate sample size that allows for meaningful analysis.

Behavioral Treatment of Hypertension

Behavioral Treatment of Hypertension

Evoking [r] Using Visual Feedback

An adult who was not able to produce singleton consonantal [r] or any of the r-colored vowels correctly (although he could produce some consonant clusters containing [r]) was enrolled in a treatment program for remediation of these sounds. When, after 17 therapy sessions, he was still unable to produce any of these sounds accurately, a real-time speech spectrograph was introduced to provide visual feedback. Within two sessions, the client was able to produce [] correctly. We were then able to use his production of [] to obtain a correct [r]. The data indicate that this type of biofeedback can be useful for eliciting correct production of [].

Biofeedback: A Survey regarding Current Clinical Use and Content in Occupational Therapy Educational Curricula

Survey data were collected from a questionnaire mailed to 418 physical dysfunction rehabilitation clinics and 176 occupational therapy educational programs throughout the United States. Information collected from the clinics included: 1) current use of biofeedback, 2) types of biofeedback used, 3) frequency of biofeedback use, and 4) type of biofeedback training received. Information collected from the occupational therapy educational programs included: 1) current inclusion of biofeedback in the curriculum, 2) types of biofeedback included in the curriculum, 3) length of time biofeedback has been included in the curriculum, and 4) type of biofeedback training received by the course instructor. Questionnaires were returned from 301 clinics (72% of the sample) and 91 educational programs (67% of the sample). Forty-seven percent of the clinics reported current use of biofeedback while 59% of those not using biofeedback indicated they would like to in the future. Sixty-three percent of the professional level occupational therapy educational programs indicated current inclusion of biofeedback in the physical dysfunction portion of the curriculum while 13% of the technical level programs reported its inclusion. Electromyographic biofeedback is used in 95% of the clinics using biofeedback as a modality and is taught in 84% of the occupational therapy educational curricula that include biofeedback. Seventy-three percent of the clinicians using biofeedback reported their major training as “on-the-job,” while 66% of the educators including biofeedback in their curricula also reported their training primarily as “on-the-job.”

Blood pressure reductions during self-recording of home blood pressure

Blood pressure readings were taken at home twice a day for one month by 60 subjects with essential hypertension. The average change-perday value based on quadratic curves fit to each subject's data (for the entire month or to the day of medication change) was negative and was statistically significant for both systolic and diastolic and for a.m. and p.m. readings. Clinically significant decreases in blood pressure, defined as systolic and/or diastolic decreases ≥ 10 mm. Hg from the first two to the last two days, occurred in 43 per cent of the subjects. The observed blood pressure decreases may have been due to (1) placebo effects and/or increased compliance associated with the change of treatment program, (2) increased attention of health care practitioners, (3) habituation of blood pressure to the conditions of measurement, or (4) biofeedback effects. The most likely explanation for the initial blood pressure decrease in habituation. The smaller but continuing decrease after the first two days was probably due, at least in part, to a biofeedback effect. If further studies support such an hypothesis, then home blood pressure readings should be used on a wider scale for treatment purposes. They are easier to administer than other behavioral treatments and the observed decreases appear to be of the same order of magnitude. Regardless of the treatment potential of this type of biofeedback, the decreases in home blood pressures while patients are taking their own pressures daily at home suggest the importance of a diagnostic waiting period until blood pressure stabilizes and before pharmacological treatment is prescribed. This period may last a month or longer for some patients.

Deconditioning by the use of EMG signals

This paper describes the use of a miniature EMG circuit in deconditioning neuro-muscular tension. The circuit is described and its use illustrated by reference to a patient who suffered with pain in the jaws. This evidence suggests that the treatment was beneficial and the possibility of using this type of biofeedback is briefly discussed.