Transformer miniaturization for transcutaneous current/voltage pulse applications

A general procedure for the design of a miniaturized step up transformer to be used in the context of surface electrode based current/voltage pulse generation is presented. It has been shown that the optimum secondary current pulse width is 4.5 tau, where tau is the time constant associated with the pulse forming network associated with the transformer/electrode interaction. This criteria has been shown to produce the highest peak to average current ratio for the secondary current pulse. The design procedure allows for the calculation of the optimum turns ratio, primary turns, and secondary turns for a given electrode load/tissue and magnetic core parameters. Two design examples for transformer optimization are presented.

Visceral chest pain in unstable angina pectoris and effects of transcutaneous electrical nerve stimulation. (TENS). A review

A substantial proportion of patients with chest pain referred to hospital, show signs of coronary artery disease. Anginal pain could be conceptualized as a warning signal for coronary artery disease and impending death. But, for many reasons this theory is partly disputed. Firstly, not all ischemic episodes are accompanied by anginal pain (silent ischemia). Secondly, chest pain indistinguishable from true angina pectoris may be the result of other abnormalities of thoracic viscera. Nevertheless acute severe cardiac ischemia often gives rise to anginal chest pain. Unstable angina pectoris is carrying a higher risk for future events in spite of intensive medical treatment. A special problem are patients awaiting coronary intervention because of severe ischemia and maximum medical treatment, who experience ischemic pain. New treatment regimens are needed for these patients. This review discusses the symptom of visceral pain from the heart, angina pectoris, its relation to ischemia and unstable angina pectoris. It also addresses the role of afferent nerve stimulation (transcutaneous electrical nerve stimulation, TENS) in the treatment of severe angina pectoris as well as recent findings of TENS applicability in unstable angina.

Transcutaneous electrical nerve stimulation: nonparallel antinociceptive effects on chronic clinical pain and acute experimental pain

OBJECTIVE

To investigate to what extent a single 60-minute session of transcutaneous electrical nerve stimulation (TENS) would modify chronic clinical pain, acute experimental pain, and the flexion reflex evoked in chronic low back pain patients.

STUDY DESIGN

Thirty young subjects with chronic low back pain were randomly allocated to two groups, receiving either TENS or placebo stimulation to the lumbosacral region for 60 minutes. The flexion reflex was elicited by an electrical stimulation applied to the subject's right sole and recorded electromyographically from the biceps femoris and the tibialis anterior muscles.

MAIN OUTCOME MEASURES

Subjective sensation of low back pain and the electrically induced pain were measured by two separate visual analog scales, termed VAS(LBP) and VAS(FR), respectively. Data obtained before, during, and 60 minutes after TENS and placebo stimulations were analyzed using repeated measures ANOVA.

RESULTS

The VAS(LBP) score was significantly reduced to 63.1% of the prestimulation value after TENS (p<.001), but the reduction was negligible after placebo stimulation (to 96.7%, p = .786). In contrast, no significant change was found in the VASFR score (p = .666) and the flexion reflex area (p = .062) during and after stimulation within each group and between the two groups (p = .133 for VASFR and p = .215 for flexion reflex area).

CONCLUSIONS

The same TENS protocol had different degrees of antinociceptive influence on chronic and acute pain in chronic low back pain patients.

Mind machines: a controlled study on the effects of electromagnetic and optic-acoustic stimulation on general well-being, electrodermal activity, and exceptional psychological experiences

Mind machines are said to induce relaxation and an altered state of consciousness. The influence of optical-acoustic (OAS) and electrical stimulation (ES) mind machines on general well-being, electrodermal activity, and altered states of consciousness was investigated and compared with pure rest and a placebo. Thirty participants underwent 4 conditions in random sequence: rest, placebo stimulation, OAS, and ES. Statistical evaluations before and after the experimental stimulations showed differences in general well-being and electrodermal activity measures but no between-conditions effect. ES and OAS produced significantly more visionary experiences and fear of ego dissolution than rest and placebo. Differences in mystical experiences were found between ES and OAS. Mind machines do not have a specific effect on general well-being and physiological relaxation, although they may produce unusual psychological experiences; people with psychiatric illnesses should not use such devices.

Percutaneous electrical nerve stimulation (PENS): a complementary therapy for the management of pain secondary to bony metastasis

OBJECTIVE

To evaluate the use of a novel nonpharmacologic analgesic therapy known as percutaneous electrical nerve stimulation (PENS) in the management of opioid-resistant cancer pain.

DESIGN

PENS therapy was administered to three cancer patients on three or more occasion using acupuncturelike needle probes that were stimulated for 30 minutes at frequencies of 4-100 Hz.

RESULTS

Two of the three patients achieved good to excellent pain relief that lasted 24-72 hours after each treatment session.

CONCLUSION

PENS therapy is a useful supplement to opioid analgesics for the management of pain secondary to bony metastasis in terminal cancer patients.

Inappropriate shocks delivered by an ICD as a result of sensed potentials from a transcutaneous electronic nerve stimulation unit

Although the potential for transcutaneous electronic nerve stimulation (TENS) units to interfere with appropriate function of cardiac pacemakers is well documented, an adverse interaction between a TENS unit and an ICD has never been reported. We describe a patient in whom a TENS unit created an electrical artifact that was interpreted by a transvenous ICD as ventricular fibrillation, leading to the delivery of inappropriate therapy. TENS units should be used with caution in patients with ICDs.

Electromagnetic interference and ICD discharge related to chiropractic treatment

Electromagnetic interference is well known to cause false sensing in ICDs. Sources may include instrumentation involved with acupuncture, arc welding, electrocautery, diathermy, electrolysis, and transcutaneous electric nerve stimulator units as well as power lines. Patients with ICDs are cautioned to avoid exposure to these sources.

Rebox effect on exercise-induced acute inflammation in human muscle

OBJECTIVE

To evaluate the effect of Rebox stimulation on an experimental model of soft tissue inflammation.

DESIGN

Randomized trial, partially blinded, comparing a control group with active and placebo Rebox.

SUBJECTS

Thirty healthy volunteers, 15 women.

METHODS

Delayed onset muscle soreness was induced in biceps brachii muscle by weighted eccentric exercise. Rebox stimulation was applied daily for 3 days using a negatively charged probe electrode, at pulse duration of 100 microsec, amplitude of 160 microamp, and frequency of 3000 Hz.

OUTCOME MEASURES

DAILY ratings of pain by visual analogue scale (VAS), and tenderness by pressure-pain threshold (PPT) and pressure-pain tolerance (PT).

RESULTS

Significant increases in VAS and decreases in PPT and PT were found at 24 and 48 hours. There were no differences between groups.

CONCLUSION

Rebox had no effect on this experimental model of soft tissue injury.

Current trends in assistive technology education in entry-level occupational therapy curricula

OBJECTIVE

This replication study investigated what changes, if any, occurred in the education of entry-level occupational therapy students relative to assistive technology between 1989 and 1994-1995.

METHOD

A questionnaire was mailed to all entry-level occupational therapy programs in the United States (N = 79). The response rate was 88.6% (n = 70). Results were compared with those of a similar survey that examined the same issues in 1989.

RESULTS

Assistive technology education had increased from 1989 to 1994-1995 in 11 identified areas. The highest increases were found in environmental access and robotics, sensory aids, augmentative communication, and prosthetics and orthotics. Only 10% of the respondent programs had less than 20 hours of assistive technology education compared with 50% in the earlier study. Thirty (43%) programs included one or more technology courses in the curriculum compared with 17 (29%) in 1989, and 62 (89%) programs included assistive technology content in lectures or units throughout the curriculum compared with 32 (54%) in 1989.

CONCLUSION

Occupational therapy educators are placing more emphasis on assistive technology education than they did in 1989 and are learning the skills to teach this content. If this trend continues, we will see assistive technology content taught in all occupational therapy programs in the next millennium.

[Value of electrotherapy within the scope of conservative treatment of anorectal incontinence]

The following study reports on transanal electric stimulation as a conservative method of treatment in anal incontinence. In the centre of interest are clinical examinations on 45 patients that underwent a combined treatment with the IT-system 100 from Reha-Medi and pelvic floor training. A collective of 29 patients only treated with pelvic floor training was used as a control group. The results were based on a thorough medical history ascertainment and the corresponding clinical examinations at the beginning and end of the treatment. Our findings were classified according to the modified score of incontinence of Holschneider [16]. After therapy 42.2% of patients with electric stimulation therapy and 27.6% of the control group showed continence. 40 respectively 62.1% were non responder without relevant benefit. In the electric stimulation group the median score before and after therapy amounted to 6.57 versus 9.24 points. The control group achieved 6.72 respectively 8.58 points. The differences are statistically significant (p < 0.05, Student t-test). Concerning the results in relation to the cause of the incontinence, no significant differences between idiopathic and traumatic origin of the insufficiency of the sphincter mechanism are found in both groups. Therefore all variations of anorectal incontinence are seen as indication for treatment. The international literature as well as our own results confirm that electric stimulation is effective and may be in special cases a major factor in the conservative treatment of anorectal incontinence.

Transcutaneous electrical stimulation of thigh muscles in the treatment of detrusor overactivity

OBJECTIVE

To investigate the clinical effects on detrusor overactivity of a new method of transcutaneous reciprocal electrical stimulation of the thigh muscles.

PATIENTS AND METHODS

Nineteen patients with detrusor overactivity, comprising 14 with detrusor hyperreflexia (DH) and five with idiopathic detrusor instability (IDI), were studied. Electrical stimulation was applied alternately to the quadriceps and hamstring muscles of one or both legs through surface electrodes for 20 min. The treatment was given once a day for 14 days and then the patients were evaluated urodynamically.

RESULTS

All 19 patients tolerated the therapy well and none reported any adverse effects. The mean maximum cystometric capacity increased significantly (P < 0.05) after treatment. In 11 of the 19 patients, the maximum cystometric capacity was increased by > 50% of the pretreatment value; this occurred in eight of 14 of those with DH and in three of five of those with IDI. In six of the 11 who responded in this way, there was a clinical improvement in their urinary incontinence and frequency for several weeks to 3 months after the period of therapy. A second 14-day treatment was also effective in all four patients who underwent a repeat trial.

CONCLUSION

This method of transcutaneous electrical stimulation can inhibit DH as well as IDI with no adverse effects. The suppressive effect on detrusor overactivity may persist for several months and repeat trials appear to be effective. Thus, we believe that this new stimulation technique should be tried as an alternative to other types of electrical stimulation and augmentation cystoplasty.

[Value of functional electrostimulation in patients with paraplegia]

This 1-year follow-up study included 17 patients with spinal cord injuries who participated in a functional electrical stimulation (FES) program for restoration of the ability to stand and walk. Four tetraplegic patients reached a mean FES-assisted standing duration of 6.8 min after 6 weeks. After 1 year three patients had stopped FES-assisted standing due to orthostatic problems and only used the system for cyclic stimulation of quadriceps muscles while lying down. Ten paraplegic patients had a mean standing duration of 22.6 min. The gait velocity (gait distance) of seven patients ranged from 2.9 to 24.2 m/min (from 4 to 335 m) in seven patients. Due to flexor spasm in two and unrealistic expectations in seven cases, four patients stopped the program and five only practiced FES-assisted standing. One patient continued FES walking after 1 year. Three patients with an incomplete cervical lesion who had been able to walk a short distance before treatment achieved constant improvement their gait ability. Their gait velocity/walking distance without FES improved for a mean of +33.3%/+163.8%, after 6 weeks. Assuming that FES is used according to the level of impairment, the results favor broader application of the method in the rehabilitation of patients with spinal cord injuries.

Clinical evaluation of a new model of a transcutaneous electrical nerve stimulation device for the management of primary dysmenorrhea

Transcutaneous electrical nerve stimulation (TENS) has been proven effective in pain relief of primary dysmenorrhea (PD). We evaluated the efficacy of a new TENS device (Freelady, Life Care, Tiberias, Israel), designed to correct disadvantages of older models used in previous studies, in 102 nulliparous women with PD, who were treated with various types of pain relief medications. Marked pain relief was reported by 58 patients (56.9%) and moderate relief by 31 (30.4%). These subjective findings were supported by the fact that the same number of patients (58 and 31) either stopped analgesic use altogether during the trial or reduced the quantity of analgesics, respectively. The device examined proved to be efficient and safe in controlling the pain and disability caused by PD.

A portable system for closed loop control of the paralysed hand using functional electrical stimulation

A portable and closed-loop system is described for the paralysed hand using transcutaneous electrical stimulation. It is implemented using a modest microprocessor which receives data from force sensors mounted in a glove on the users hand. A display shows parameter values and a menu for the user to sequentially select controller states. For the grip state, the control loop is basically proportional plus a two stage integral response (gain adaptation). Eight channels can be accommodated in the stimulator. The system was evaluated with the help of a tetraplegic who managed to hold everyday objects in a stable grip.

[Epidural spinal cord stimulation in the treatment of refractory angina pectoris. Mechanisms of action, clinical results and current indications]

The spinal cord stimulation (SCS) is an antalgic technique which has been used since 1967 for the treatment of several painful syndromes. More recently it was employed in cardiology to treat refractory angina, not suitable for revascularization. Despite the fact that published results on this subject have reported small, non-homogeneous series, and that the mechanisms of action are not completely understood, we can affirm according to the analysis of the literature and our own experience that SCS causes improvement in quality of life, reduction in frequency of angina attacks and reduced consumption of rapid-action nitrates. There is also evidence that electrical stimulation has a definite anti-ischemic effect, as revealed by increased work capacity, improved lactate metabolism and reduced downward slope of ST segment at comparable maximum work load. In expert hands SCS implantation is associated with relatively low frequency of complications, whose incidence is greatly reduced if the main contraindications are respected, particularly in patients receiving anticoagulants or with an infection.

Microprocessor based spatial TENS (transcutaneous electric nerve stimulator) designed with waveform optimality for clinical evaluation in a pain study

A microprocessor based TENS device is developed which utilizes a spatial procedure in the administration of electrical fields to actively interfere with pain signals reaching the brain. This unusual design also has the advantage of requiring the frequency characteristics of the electrical waveform produced to be optimally tuned to the mechanical impedance properties of the skin/tissue. Hence a much more efficient procedure for the transfer of electrical energy from the TENS device to the human tissue is provided. Data are presented involving patients from the Dayton VA Medical Center in Ohio, USA being tested with this new microprocessor system compared to the treatment obtained via a traditional stimulator.

Suppression and prevention of the gag reflex with a TENS device during dental procedures

Individuals who are prone to gagging and apprehension during dental treatments present a problem for the clinician and themselves. Patients may delay prescribed therapy or interfere with the fabrication of accurate oral impressions and diagnostic radiographs, because of this fear. The common wisdom has been to try one of the following procedures: (1) distraction of the patient, (2) forced respiration, (3) induced lagophthalmus, or (4) hypnosis. A preventive approach suggests that the sensory stimulation of the cranial nerves of the superior laryngeal nerve branch, (Cr N, IX, pharyngeal branch of X, Cr. N. V, and Cr N. X.) would block the physiologic response of gagging and retching.

Spectral electromyographic changes during a muscular strengthening training based on electrical stimulation

The aim of this study is to describe the effects of neuromuscular electrical stimulation on electromyographic power spectrum evolution through a program of muscle strengthening. Ten healthy subjects received electrical stimulation of the quadriceps femoris muscle. Surface EMG was obtained from rectus femoris during maximum voluntary isometric contractions of quadriceps. Directly from EMG the Zero Crossing Rate and Root Mean Square (RMS) were calculated. Afterwards, the Mean Power Frequency and Median Frequency from EMG power spectrum were obtained using the Maximum Entropy method to estimate the spectrum. An analysis of variance for repeated measures revealed a statistical significance for RMS through the sessions and for spectral shifts towards higher frequencies between, before and after electrical stimulation. The evolution of power spectrum through sessions showed a curvilinear evolution, first decreasing towards lower frequencies and then increasing. These results suggest that electrical stimulation produces immediate changes on the motor unit: increasing the recruitment number and action potential velocity and a selective recruitment of type II fibres. During the strengthening program sessions two main phases were detected: the appearance and recovery from fatigue.

Bioelectrical impedance changes in regional extracellular fluid alterations

The purpose of this study was to determine whether changes in bioelectrical impedance (BI) can reveal regional extracellular fluid (ECF) alterations. ECF changes were induced by holding various arm positions for ten minutes, and they were evaluated through the measurement of BI in eight normal adult subjects. A low frequency current (100 Hz, 0.50 mA) was applied using an electromyography machine through two current electrodes, and the voltage signals were recorded by two amplitude electrodes. The corresponding BI was calculated by Ohm's law, resistance = voltage/current (R = V/I). There was no significant difference between BI and time interval, but between BI and arm position (two-way ANOVA with replicate, p = 0.954, p < 0.001). BI has a negative correlation with wrist circumference. These results show that this experimental method can be used as reflection of ECF changes and that both position and wrist circumference are major factors for BI in the upper extremity.

Simultaneous multiple-modality therapy for tension headaches and neck pain

Eighty-one patients suffering from neck pain and tension-type headaches were treated by the application of a unique physical therapy device combining transcutaneous electrical nerve stimulation (TENS), traction, massage, vibration, and acupressure applied to the forehead, posterior cervical spine, and scapula. The device employed eight silver silicone electrodes for modality application. Its safety and effectiveness were assessed by evaluating patients before and after treatment. No complication ensued. Statistical analysis of visual analog scales for neck pain and headache yielded p values < 0.0001. Analysis of fibromyalgia neck and shoulder trigger points with three controls gave nonsignificant results. Conclusions were that 1) the device is safe and effective as judged by subjective patient input and 2) fibromyalgia trigger points are unaffected by the treatments. More objective measures are needed to provide evidence of efficacy.

Dentist and patient evaluation of an electronic dental analgesia system for controlling discomfort of injections

A number of dedicated electronic dental analgesia (EDA) systems have become available in recent years. In this study the attitudes of operators and patients were investigated by means of a post-treatment questionnaire, to the use of a new system for providing surface anaesthesia before administration of local anaesthesia. Levels of effectiveness were rated as similar to those of surface anaesthesia by the dental evaluators, who found the EDA system more time consuming. They felt that the EDA system reduced the discomfort of injections in only 26% of cases. Sixty per cent of the respondent patients who had previously experienced surface anaesthesia thought the EDA system controlled injection discomfort, and 64% stated that they would request the system in future.

[Transcranial electrostimulation: a new approach (experimental and clinical bases and equipment)]

The paper deals with one type of electrostimulation-transcranial electrostimulation (TES). It outlines the physiological mechanisms underlying TES, the clinical features of its application, the equipment performing TES, defines its optimum analgesic mode.

A slowly penetrating interfascicular nerve electrode for selective activation of peripheral nerves

To meet the future needs of functional electrical stimulation (FES) applications, peripheral nerve electrodes must be able to safely, selectively, and independently stimulate small subpopulations of the axons within a common nerve trunk. A new electrode has been designed to place contacts outside of the perineurium, but within the epineurium of the nerve. This slowly penetrating interfascicular nerve electrode (SPINE) combines the safety and simplicity of extraneural cuff electrodes with the intimate interface of intrafascicular wire and probe electrodes. We briefly discuss a mathematical method of quantifying performance of nerve electrodes based on the functional output of the intact neuromuscular system. The quantification involves three variables: 1) the functional recruitment trajectory (FRT), 2) functional overlap (O), and 3) overall functional selectivity (lambda). Second, we present results from six acute SPINE implants on the feline sciatic nerve. Quantification of stimulation results demonstrate interfascicular stimulation is functionally different than extraneural stimulation in 32 of 38 trials. In 19 of 28 trials, interfascicular stimulation is functionally selective based on depth of penetration and 52 of 58 trials demonstrate selectivity based on the side of the penetrating element. Third, tissue sections show that the SPINE electrode penetrates into the nerve within 24 h without evidence of edema or damage to the perineurium.

Muscle selection and walking performance of multichannel FES systems for ambulation in paraplegia

A minimal set of muscles (8 to 16) were identified as candidates for implantation in a clinical system to provide walking function to individuals with complete paraplegia using functional electrical stimulation (FES). Three subjects with complete motor and sensory paraplegia had percutaneous intramuscular electrodes implanted in all major muscles controlling the trunk, hips, knees, and ankles. Stimulation patterns for walking with FES were generated for different sets of eight and 16 muscles. The quality and repeatability of the resulting gait produced by walking patterns consisting of various combinations of muscles were determined. Most eight-channel stimulation patterns resulted in scissoring or insufficient hip flexion, preventing forward progression. One eight-channel system allowed a maximum speed of 0.1 m/s with a cadence of 22 steps/min and a stride length less than 0.3 m. Improved walking performance was observed with 16 channels of stimulation. This ranged from slow step- to gait at 0.1 m/s to smooth reciprocal gait at 0.5 m/s. In all three subjects, the favored combination of 16 channels included erector spinae for trunk extension; gluteus maximus, posterior portion of adductor magnus and hamstrings for hip extension; tensor fasciae latae and either sartorius or iliopsoas for hip flexion; vastus lateralis/intermedius for knee extension; and tibialis anterior/peroneous longus for ankle dorsiflexion. In one subject the 16-channel FES system provided repeatable day-to-day gait averaging 0.4 m/s, 58 steps/min and a stride length at 0.8 m. A maximum repeatable walking distance with 16 channels was 34 m. Multiple 34-m trials were possible with minimal rests between walks. Fatigue of both the hip extensors and upper body was a limiting factor. The selection of target muscles for implantation is critical to the performance of FES systems. This study provides guidelines to muscle selection for walking with FES based on objective measures of gait performance. The findings indicate that a 16-channel FES system for total implantation is feasible for repeatable short distance, independent, walker-support walking in paraplegia.

Recruitment characteristics of nerve fascicles stimulated by a multigroove electrode

The recruitment characteristics of fascicle-selective nerve stimulation by a multigroove electrode have been investigated both theoretically and in acute experiments. A three-dimensional (3-D) volume conductor model of fascicles in a multigroove device and a model of myelinated nerve fiber stimulation were used to calculate threshold stimuli of nerve fibers in these fascicles. After their exposition, fascicles from rat sciatic nerve were positioned in different grooves of appropriate sizes and stimulated separately. The device appeared to be suitable for fascicle-selective stimulation, because both computer simulations and acute animal experiments showed that crosstalk between neighboring fascicles is not a problem, even when monopolar stimulation was used. The threshold stimulus was lower for a small fascicle than for a large one. When the amount of (conducting) medium between contact and perineurium or its conductivity was reduced, threshold stimuli were lower. Moreover, simulations predict that the slopes of recruitment curves are smaller and inverse recruitment order is less pronounced. Simulations also showed that a small contact is preferable to a large on, because a small contact gives a slightly smaller slope of the recruitment curve. Both experimentally and theoretically a significantly smaller slope of recruitment curves was obtained by stimulation with a cathode and an anode at opposite sides of the fascicle, driven by two current sources giving simultaneous pulses with different, but linearly dependent amplitudes.

Improved motor function in tetraplegics following neuromuscular stimulation-assisted arm ergometry

The effectiveness of neuromuscular stimulation (NMS)-assisted arm ergometry for strengthening triceps brachii was evaluated in 34 cervical spinal cord injured persons. Group I (n = 12) received eight weeks of NMS-assisted ergometry. Group II (n = 11) received four weeks of NMS-assisted ergometry followed by four weeks of arm ergometry alone. Group III (N = 11) received only arm ergometry (control group). Seventeen of 24 muscles in Group I subjects had improved manual muscle test scores after eight weeks, compared with 10 of 22 Group II muscles and five of 22 Group III muscles. Including only muscles with initial scores < or = 3, Group I demonstrated significant improvements versus Group III after four weeks (p < .003) and after eight weeks (p < .0005) of exercise. A difference was also found between Groups II and III (p < .03) after eight weeks. These results suggest that NMS-assisted ergometry is effective for strengthening voluntary triceps muscle contractions in tetraplegics.

Dental electro-anaesthesia in children: a pilot study

Sixty-six children aged 10-17 years, with previous experience of local anaesthesia, had one or more restorations placed while using the Cedeta Mark 2 electronic dental anaesthesia system. A control group of 121 children were treated routinely using injected local anaesthetic. Following all treatment the patients used a 10 cm visual analogue scale to subjectively report the severity of any pain they had experienced. Eighteen (27%) of the study group required injection of local anaesthetic to complete the episode of treatment. The study group had significantly higher pain scores than the control group. It was concluded that further research is warranted to assess the application of this technique to special groups, but that it is not at present a substitute for local anaesthesia by injection in routine paediatric dental practice.

Clinical study to evaluate the use of electronic anesthesia during dental hygiene procedures

PURPOSE

The purpose of this study was to determine if the 3M Dental Electronic Anesthesia System 8670 would decrease patients' pain/discomfort levels during scaling and root planing procedures.

METHODS

Forty-nine patients possessing hypersensitive teeth and/or 4-6 mm periodontal pockets requiring scaling and root planing were selected as subjects. Patients received treatment using an inactive and then an active stimulator in paired quadrants. The patients scored their pain/discomfort levels after each procedure. They were contacted by telephone 1-2 days following treatment to determine if they experienced any symptoms or discomfort following electronic dental anesthesia.

RESULTS

The overall results for the assessment of pain/discomfort indicated that treatment using the active stimulator resulted in significantly lower pain scores for the total patient population.

CONCLUSIONS

This study found the 3M Dental Electronic Anesthesia System 8670 to be effective for controlling pain during the dental hygiene procedures specified.

The role of bioelectronic instruments in the management of TMD

Temporomandibular disorders (TMD) comprise a group of conditions that can affect the form and function of the temporomandibular joint (TMJ), masticatory muscles and dental apparatus. Proper management of TMD by the dentist requires accurate appraisal of the status of the patient's dentition, TMJ and associated neuromuscular apparatus. Certain predefined standards or parameters of function/dysfunction are accepted by the profession. Electronic instrumentation provides objective measurement of many of these biological phenomena, and thus can be used throughout treatment for critical analyses that monitor and enhance treatment efficacy. A treatment protocol for TMD is presented that uses electronic instrumentation to establish a neuromuscular occlusion.

Analgesic effects induced by TENS and electroacupuncture with different types of stimulating electrodes on deep tissues in human subjects

Effects of conditioning peripheral nerve stimulation with different types of stimulating electrodes on pain thresholds in various deep tissues were measured in human subjects. Cone-shaped metal (phi 13 mm), rubber (phi 13 mm), and large soft surface electrodes (50 x 150 mm) were used for transcutaneous electrical nerve stimulation (TENS), and insulated and non-insulated acupuncture needles (diameter: 240 microns) were used for electroacupuncture (EA). Two pairs of electrodes were placed around the point of deep pain measurement. Symmetrical positive and negative square pulses (0.1 msec at 100 Hz) of just below the pain tolerance intensity were used for both TENS and EA. Deep pain thresholds were measured at the center of the thigh with a pulse algometer and insulated needle electrodes. Pain thresholds of deep tissues were in the order periosteum < fascia < skin (including subcutaneous tissues) < muscle. TENS with surface electrodes significantly increased pain thresholds of skin and fascia but not those of muscle or periosteum. The shape, material and size of the surface electrodes hardly affected the degree of analgesic effect, except in the fascia by large soft electrodes. In contrast, EA with non-insulated needles induced a greater increase in pain threshold in skin, fascia and muscle, although statistically significant results were obtained in only the first two tissues. EA with insulated needle electrodes was the only technique with which we obtained a significant increase in pain threshold in muscle and periosteum. These results suggest that the choice of electrode and stimulus parameters is important for the production of sufficient analgesic effects in different somatic tissues and that insulated needle electrodes are useful for pain relief in deeper tissues such as muscle and periosteum.

[Muscle relaxation by transcutaneous electric nerve stimulation (TENS) in bruxism. An electromyographic study]

In recent years transcutaneous electrical neuromuscular stimulation (TENS) has become increasingly more common in the treatment of functional diseases of the masticatory muscles and currently the practitioner can choose among a variety of stimulators. In an electromyographic study of 17 adults suffering from nocturnal bruxism and of a control group consisting of 18 adults without any functional disturbances of the masticatory muscles, the effect of this kind of neuromuscular stimulation on the temporal and masseter muscle was examined. The myoelectric signals were registered before and after TENS treatment in 3 different positions of the mandible. Each person was treated 3 times with both the Myo-Monitor (Myo-Tronics, Seattle) and the TNS SM2 MF stimulator (schwa-medico, Giessen). The different effects of continuous low frequency and intermittent high frequency muscular stimulation were studied simultaneously. Muscular activity was determined by computer aided integration of the electromyographically measured raw signals. A fourier analysis of the power spectrum yielded information on the frequency behavior of the studied muscles resulting from the TENS treatment. A statistical analysis of the results led to the following significant conclusions: 1. TENS treatment decreased the values of the registered integrated signals on all test persons, however, the treatment increased the median frequency and the mean power frequency (MPF). Since this effect is contrary to muscle fatigue, these electromyographic results can be interpreted as providing objective proof of a relaxation in the treated muscles. 2. The electromyographic changes after TENS treatment were similar when using either the Myo-Monitor or the TNS SM2 MF stimulator. In addition, the 2 different types of stimulation (high or low frequency) showed the same effects. 3. Compared to the persons in the control group, there was no significant increased muscular activity in patients with nocturnal bruxism. Following TENS treatment both groups showed the same alterations in the electromyograms. The results of the study provide further evidence that TENS treatment is an adequate supportive procedure in the treatment of nocturnal bruxism.

Effects of cerebral electrical stimulation on alcoholism: a pilot study

Cerebral electrical stimulation (CES), born from research on electroanesthesia in the seventies, consists of the application of a pulsating current of small intensity (usually less than 1 mA, and below the threshold of perception) through the skull, e.g., in daily 30-min sessions. Claims of biological effectiveness (neurochemical, hormonal and EEG changes, naloxone-reversible analgesia in rats, etc.) and of clinical effectiveness (anxiety, depression, cognitive functions in alcoholics) have often relied on poorly controlled data. A recent controlled study in the treatment of opiate withdrawal has been positive. The present double-blind controlled study compares active CES with sham stimulation in 64 alcohol-dependent males. Over 4 weeks, both treatment groups improved significantly in most aspects. In the active treatment group additional significant improvement was observed in week-end alcohol consumption, and in two psychological measures: depression and stress symptoms index, but not in general drinking behavior.

Application of a cervical stimulating apparatus for bilateral transcutaneous phrenic nerve stimulation

Transcutaneous bilateral phrenic nerve stimulation (tPNS) is frequently used to assess diaphragmatic function in humans. Commonly, stimulation is performed with hand-held electrodes; however, these are unsuitable for studies requiring repeated PNS and where recruitment of rib cage and neck muscles may shift the probes in relation to the nerves. In this study we describe the design of a cervical neck brace and electrode probes that maintain stimulating electrodes in constant position relative to the phrenic nerves and facilitates studies requiring repeated maximal PNS. The effectiveness of the apparatus was examined by 1) reviewing the reproducibility of the transdiaphragmatic pressure response to 0.1 ms tPNS (PdiT) at relaxed functional residual capacity in four subjects studied on 25 +/- 8 (SD) occasions (> or = 24 h apart) over a 4-yr period, and 2) measuring peak-to-peak amplitude of the left and right diaphragmatic compound muscle action potentials (surface electrodes) during two prolonged studies (38 +/- 9 min) in each subject, when tPNS was performed during repeated submaximal and maximal inspiratory efforts. PdiT was reproducible in each subject when measured repeatedly within a single study [coefficient of variation (CV) of 3.8 +/- 0.8%] and over separate days (CV of 11.5 +/- 3.5%). The peak-to-peak amplitudes of the left and right compound muscle action potentials were also reproducible (CV of 8.4 +/- 4.3 and 8.4 +/- 2.9%, respectively) and independent of the degree of effort. The apparatus appears effective for the maintenance of maximal stimulation under varied conditions for long periods and provides reproducible measurements of PdiT both within and between studies.

A robust transcutaneous electro-muscle stimulator (RTES): a multi-modality tool

This paper introduces a transcutaneous electro-muscle stimulator design that has a wide range of output capabilities. Because of this, the unit is referred to as a robust transcutaneous electro-muscle stimulator (RTES). The RTES is a constant current stimulator that is designed to be capable of generating significant tetanic contractions from large muscle groups, such as the quadriceps. It is capable of generating complex current pulse profiles and has been tested at pulse frequencies greater than 7500 Hz. It is routinely used to generate rectangular, bi-phasic pulses in muscle-modelling studies in ranges of widths from 3 to 1000 microseconds, amplitudes from -50 to +50 mA and frequencies from 10 to 60 Hz. The design extrema on pulse width and amplitude, are 1000 microseconds and +/- 100 mA respectively. Because of the stimulator's robust output characteristics, it is suitable for many types of electro-stimulation studies including pain management, edema reduction and more.

[Treatment of spasticity with a transcutaneous neurostimulator. A pilot study]

In this pilot study the neurostimulator KDC 5000 is used with efficacy on seven out of 11 patients with spastic palsy, and treatment was given without any side-effects. No other treatment has sufficiently helped these patients, and we therefore conclude that such treatment with a neuro-stimulator could be beneficial for selected patients with spastic palsy of extremities.

[The effectiveness of the Comptenz electronic analgesic device in dentistry--a pilot study]

This study was undertaken to determine the effectiveness of the Comptenz electronic analgesic device. Fifty (50) patients were used in the study, of which 48 per cent eventually could be totally successfully anaesthetized by using the device. For 36 per cent, however, the device was found to be ineffective. For the rest (16 per cent) the device was only partially successful.

The use of transcutaneous electrical nerve stimulation (TENS) in the treatment of facial pain

The purpose of this article is to provide guidelines for the use of transcutaneous electrical nerve stimulation (TENS) in the differential diagnosis and treatment of facial pain. Most practitioners familiar with electrical modalities are aware that TENS is a physiologically-specific therapy for treating and resolving facial pain related to various neurological and/or myofascial conditions. This article proposes the added use of TENS as a diagnostic tool. The effect on the patient's pain level from the trials of various combinations of rate and width settings provides the practitioner specific information to aid in a diagnosis. Guidelines to differential diagnosis as well as protocols for office and home use of this non-invasive, non-addictive and effective modality will be presented.