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PubMed2002

Quantifying power output during cycling through measuring strain energy in a bicycle frame.

Quantifying power output is becoming more popular in training and competition for cycling. This popularity comes from the fact that power is a direct means of measuring intensity, which is considered by many to be the most important variable in a successful training program. Although other methods are available for measuring power output, there is no frame that is available that uses strain to quantify power output. Using a frame may prove superior to currently available products. Additionally, strain may prove useful for cycling technique analysis, another critical factor for success. In this study, a cyclocross bicycle frame was instrumented with six strain gages to determine if strain energy in the frame correlates with power output. For pilot data, an 85 kg subject rode the bike on rollers with a fork stand at 250 watts and a cadence of 90 rpm. Although more data needs to be collected and analyzed to find a correlation with power output, initial pilot data shows that the strain in the frame is cyclic in nature when pedaling and has a corresponding frequency with the pedaling cadence. It is hypothesized that the strain in the frame will have a high correlation with power output. While this application is specific to cycling, correlating strain to power output may prove useful in other applications.

Bicycling↗

PubMed2002

Jump evaluation of elite volleyball players using two methods: jump power equations and force platform.

BACKGROUND: The aim of the present study was to determine the best jump power equation in the evaluation of elite volleyball players using both the force platform and peak power equations. METHODS: Nine elite volleyball players and nine sedentary subjects performed counter-movement jump tests on a force platform. RESULTS: Peak power and height were greater in the volleyball players than in the sedentary subjects, whatever the method used. The results demonstrated that the peak power values obtained on the force platform and those scored from the equations of Lewis, Harman and Sayers et al. were correlated when the whole sample was taken into account. However, a significant equation x level interaction (p<10(-4)) indicated different behaviour as a function of performance level. In sedentary subjects, peak power was significantly underestimated using the Lewis equation (943+/-162 W; p<10(-4)) and did not differ using both the Harman (3004+/-563 W) and Sayers (3400+/-604 W) equations when compared to the peak power noted with the force platform (3372+/-532 W). In contrast, in volleyball players, peak power was underestimated using the three equations (1246+/-78 W, p<10(-4); 4314+/-216 W, p<0.001; 4607+/-251, p<0.005; for the Lewis, Harman and Sayers equations, respectively, versus 5355+/-522 W for the force platform). CONCLUSIONS: The results of the present study demonstrate the difficulty in choosing the most relevant equation in the jump power calculation.

Adult↗

PubMed2002

The clinical effectiveness of a novel power toothbrush and its impact on oral health.

This review details the invention and clinical testing of a new power toothbrush designed to provide a low cost, effective toothbrush, which has a combination of a round oscillating head in conjunction with fixed bristles. The data demonstrate this power toothbrush (Crest SpinBrush) is an effective cleaning toothbrush with respect to plaque removal. Four independent 4-period crossover studies, where subjects used each brush twice, have demonstrated that brushing with this power toothbrush results in 10-40% greater plaque removal relative to a series of control manual toothbrushes. Separate research has confirmed that adults and children tend to brush longer, 35.8% and 38.3% respectively, when using this power toothbrush relative to manual toothbrushes. In addition, it has been shown to be superior to a battery-powered toothbrush (Colgate ActiBrush) in two independent studies and has demonstrated comparable efficacy to a leading powered toothbrush (Oral-B Ultra Plaque Remover). In parallel, this power toothbrush has also been shown to be safe relative to manual and power toothbrushes.

Adult↗

PubMed2003

Evaluation of powered mobility use in home and community environments.

The purpose of this study was to evaluate the use of powered mobility by young individuals with physical disabilities. The four study objectives were to: (a) describe the characteristics of children and adolescents who received powered wheelchairs at eighteen years of age or younger, (b) evaluate the longitudinal use or disuse of powered mobility by these participants, (c) describe the extent and locations of powered mobility use, and (d) explore environmental (i.e., physical, social and attitudinal) barriers and facilitators to successful powered mobility use with the participants and their families. Sixty-six families shared information during a structured telephone interview. The results of this study confirm that younger children are now receiving powered wheelchairs. The results also suggest that powered mobility is reserved for children with the most severe disabilities. Physical and occupational therapists can work collaboratively with more families to explore powered mobility as one of an array of early movement options.

Adolescent↗

PubMed2003

A comparison of a waterpik dual-motor powered toothbrush and a manual toothbrush in affecting interproximal bleeding reduction and dental biofilm accumulation.

OBJECTIVE: This single-blind, 21-day clinical study was designed to compare the effectiveness of a dual-motor powered toothbrush (SynchroSonic) and a manual toothbrush in affecting interproximal bleeding reduction and dental biofilm accumulation in a cohort of 70 subjects. METHODOLOGY: After baseline evaluations of soft tissue trauma, dental biofilm and interproximal bleeding, subjects were randomly assigned to one of the two experimental groups, given toothbrushing instructions and had their teeth cleaned. At 21 days, the clinical parameters were again evaluated. RESULTS: In the powered toothbrush group, there were 37 subjects at baseline and 36 subjects at follow-up. In the manual toothbrush group, there were 34 subjects at baseline and 33 subjects at follow-up. In the powered toothbrush group, the mean biofilm index fell from 3.46 to 3.12; a 9.7% reduction. In the manual toothbrush group, the mean biofilm index fell from 3.51 to 3.30; a 5.4% reduction. The powered toothbrush group showed significantly greater biofilm reduction (9.7% vs. 5.4%, p = 0.043). In the powered toothbrush group, the mean gingival bleeding index fell from 0.66 to 0.44; a 32% reduction. In the manual toothbrush group, the mean gingival bleeding index fell from 0.66 to 0.53; a 20% reduction. The powered toothbrush group showed significantly greater gingival bleeding reduction (32% vs. 20%, p = 0.02). CONCLUSION: The results demonstrated that both the manual toothbrush and the SynchroSonic powered toothbrush were safe, with no evidence of clinically significant hard or soft tissue abrasion observed. Additionally, the powered toothbrush was more effective in reducing biofilm and gingival bleeding than the manual toothbrush.

Adult↗

PubMed2004

Comparison of intraocular lens power calculation methods in eyes that have undergone laser-assisted in-situ keratomileusis.

PURPOSE: To compare methods of calculating intraocular lens (IOL) power for cataract surgery in eyes that have undergone myopic laser-assisted in-situ keratomileusis (LASIK). METHODS: Eleven eyes of eight patients who had previously undergone myopic LASIK (amount of LASIK correction, -5.50 +/- 2.61 D (SD); range, -8.78 to -2.38 D) and subsequently phacoemulsification with implantation of the SA60AT IOLs were included (refractive error after cataract surgery, -0.61 +/- 0.79 D; range, -2.0 to 1.0 D). We evaluated the accuracy of various combinations of (1) single-K versus double-K (in which pre-LASIK keratometry is used to estimate effective lens position) versions of the IOL formulas; the Feiz-Mannis method was also evaluated; (2) four methods for calculating corneal refractive power (clinical history, contact lens overrefraction, adjusted EffRP (EffRP(adj)), and Maloney methods); and (3) four IOL formulas (SRK/T, Hoffer Q, Holladay 1, and Holladay 2). The IOL prediction error was obtained by subtracting the IOL power calculated using various methods from the power of the implanted IOL, and the F test for variances was performed to assess the consistency of the prediction performance by different methods. RESULTS: Compared to double-K formulas, single-K formulas predicted lower IOL powers than the power implanted and would have left patients hyperopic in the majority of the cases; the Feiz-Mannis method had the largest variance. For the Hoffer Q and Holladay 1 formulas, the variances for EffRP(adj) were significantly smaller than those for the clinical history method (0.43 D2 vs 1.74 D2, P = .018 for Hoffer Q; 0.75 D2 vs 2.35 D2, P = .043 for Holladay 1). The Maloney method consistently underestimated the IOL power but had significantly smaller variances (0.19 to 0.55 D2) than those for the clinical history method (1.09 to 2.35 D2) (P < .015). There were no significant differences among the variances for the four formulas when using each corneal power calculation method. CONCLUSIONS: The most accurate method was the combination of a double-K formula and corneal values derived from EffRP(adj). The variances in IOL prediction error were smaller with the Maloney and EffRP(adj) methods, and we propose a modified Maloney method and second method using Humphrey data for further evaluation.

Adult↗

PubMed2005

Intranuclear cytoplasmic inclusions and nuclear grooves in fine needle aspiration smears of papillary thyroid carcinoma and its variants: advantage of the count under an oil-immersion objective over a high-power objective.

OBJECTIVE: To determine the advantage of examining fine needle aspiration (FNA) smears of papillary thyroid carcinoma (PTC) under a 100 x oil-immersion objective, which is capable of optically sectioning the cells. STUDY DESIGN: Two hundred neoplastic cells were counted under a high-power (40x) objective as well as oil-immersion (100x) objective in 54 PTC cases classified into variants: 14 follicular neoplasms, 8 Hürthle cell neoplasms, 5 medullary thyroid carcinomas and 9 hyperplastic lesions. The counts of cells with 2 important diagnostic features of PTC, intranuclear cytoplasmic inclusions (INCIs) and grooved nuclei, were compared between various groups and between high-power and oil-immersion objectives in each group. RESULTS: Cytomorphologic features, such as INCI and nuclear grooves, were visible usually under 2 or 3 focal planes under the oil-immersion objective as opposed to a single plane under the high-power objective. In PTC cases, the mean cell count, 10.1 (+/- 1.75 SE) with INCIs, under the oil-immersion objective was significantly higher than the count, 6.1 (+/- 1.32 SE), under the high-power objective (p = 0.023). INCIs were not observed under the high-power objectives in 11 (20.4%) PTC cases, but in 5 (45.5%) of these they were visible under the oil-immersion objective. In PTC the mean cell count, 88.0 (+/- 4.96 SE), with grooved nuclei under the oil-immersion objective was also significantly higher than the count, 69.5 (+/- 4.87 SE), under the high-power objective (p = 0.010). Under the high-power objective, < 20.0% of cells with grooved nuclei were observed in 12 (22.2%) cases of PTC. However, examination under the oil-immersion objective revealed > or = 20.0% cells with grooved nuclei in 9 (75%) of these. In PTC the mean cell counts with INCIs as well as grooved nuclei under the oil-immersion objective were significantly higher than those of follicular neoplasms, Hürthle cell neoplasms, medullary carcinoma and hyperplastic lesions. CONCLUSION: In PTC, examination of FNA smears for INCIs and grooved nuclei under an oil-immersion objective was diagnostically more useful as compared to a high-power objective.

Adult↗

PubMed2006

Effect of reduced exposure times on the microhardness of 10 resin composites cured by high-power LED and QTH curing lights.

PURPOSE: To compare the effect of reduced exposure times on the microhardness of resin composites cured with a "second-generation" light-emitting diode (LED) curing light and a quartz-tungsten-halogen (QTH) curing light. METHODS: Ten composites were cured with a LED curing light for 50% of the manufacturers" recommended exposure time or a QTH light at the high power setting for 50% of the recommended time or on the medium power setting for 100% of the recommended time. The composites were packed into Class I preparations in extracted human molar teeth and cured at distances of 2 or 9 mm from the light guide. The moulds were separated, and the Knoop microhardness of the composites was measured down to 3.5 mm from the surface. RESULTS: The LED light delivered the greatest irradiance at 0 and 2 mm, whereas the QTH light on the standard (high power) setting delivered the highest irradiance at 9 mm. According to distribution-free multiple comparisons of the hardness values, at 2 mm from the light guide the LED light (50% exposure time) was ranked better than or equivalent to the QTH light on the high power setting (50% exposure time) or on the medium power setting (100% exposure time). At 9 mm, the LED light was ranked better than or equivalent to the QTH light (both settings) to a depth of 1.5 mm, beyond which composites irradiated by the LED light were softer (p < 0.01). At both distances, the QTH light operated on the high power setting for 50% of the recommended exposure time produced composites that were as hard as when they were exposed on the medium power setting for 100% of the recommended exposure time. CONCLUSIONS: The ability to reduce exposure times with high-power LED or QTH lights may improve clinical time management.

Acrylic Resins↗

PubMed2006

[Changes in autonomic function and EEG power during mental arithmetic task and their mutual relationship].

Meditation is a specific consciousness state in which deep relaxation and increased internalized attention coexist. Autonomic nervous activity during meditation was reported to be characterized by decreased sympathetic activity and increased parasympathetic activity. And concerning EEG power, slow alpha power and fast theta power increased during meditation. On the other hand, mental arithmetic (MA) tasks have been reported to induce an increase in blood pressure and heart rate with enhanced sympathetic activity. However, changes in autonomic nervous activity and EEG power during MA tasks and their mutual relationship have not been adequately studied. In the present study, we quantitatively analyzed the changes in autonomic nervous activity using heart rate variability (HRV) and EEG power during MA task in 30 healthy volunteers. MA task induced significant increases in normalized LF, LF/HF ratio (as a sympathetic index), and a decrease in normalized HF (as a parasympathetic index). On the other hand, significant decrease in EEG power (slow theta: 4-6 Hz and fast alpha: 10-13 Hz in the posterior region and fast theta: 6-8 Hz and slow alpha: 8-10 Hz in all the regions) were induced by MA task. Further evaluation of these changes showed a negative correlation between the change rates (with the control resting condition as the baseline) in fast alpha power and that in LF/HF. These results suggest that specific correlated relationships exist between the change in autonomic nervous activity and EEG power depending on the difference in mental task (i.e., meditation or MA).

Adult↗

PubMed1990

Direct, vec and other squares, and sample variance-covariance of dioptric power.

Matrices can be multiplied in several ways. As a result one can define a number of distinct squares of the dioptric power matrix. Additional squares can be defined for matrices vectorized by means of the vec and vech operators. These various squares can form the basis for the definition of variance and covariance of samples of dioptric powers. The complete form of the variance of dioptric powers is a 4 x 4-matrix (a variance-covariance matrix) with 10 distinct elements; four of them represent the variances of the four elements of the dioptric power matrix and the other six are the covariances between those four elements. For thin systems there are only six distinct elements of the variance-covariance matrix, three of which are variances and three covariances. Examples are included that show the calculation of the different types of squares and the variance-covariance matrix for a sample of equivalent powers of thick bitoric lenses and for a sample of powers of thin systems, including conventional refractive errors. Variances calculated in the past, including those of nearest equivalent spheres and Gartner's and Churm's variances turn out to be components (or combinations of components) of the generalized variance defined here. They are valid as far as they go but they do not completely represent the dispersion of a sample of dioptric powers. The complete variance-covariance matrix does represent the dispersion fully and thus opens the way for the formal statistical analysis of measurements of dioptric power.

Analysis of Variance↗

PubMed1989

A comparison of EEG determinants of near-awakening from isoflurane and fentanyl anesthesia. Spectral edge, median power frequency, and delta ratio.

To evaluate the efficacy of the computer-processed electro-encephalogram (EEG) for determining near-awakening from anesthesia, 14 patients were monitored during emergence from either isoflurane or fentanyl anesthesia at the termination of major surgical procedures. The raw EEG was obtained using bilateral frontomastoid electrodes. The compressed spectral array was digitized and recorded on disk in 4-s epochs using a Tractor Northern "Nomad" processor. The EEG information was displayed in four formats: 1) the frequency-power spectrum from 1-20 Hz, 2) the 95% power frequency, 3) the 50% power frequency, and 4) the ratio of power in the 8-20 Hz frequency range to the power in the 1-4 Hz frequency range (delta ratio). During emergence from isoflurane, there were obvious changes in the EEG frequency-power spectrum that occurred several minutes before patients opened their eyes in response to verbal stimuli. Although no one descriptor of EEG activity could be shown to be superior in anticipating when patients would respond by opening their eyes, awakening was always presaged by an abrupt decrease in power in the 1-4 Hz frequency range; this resulted in a marked increase in the delta ratio value. During emergence from fentanyl anesthesia, however, there was no obvious change in the overall EEG frequency-power spectrum. However, the same numeric EEG descriptors that were predictive of awakening from isoflurane also occurred during emergence from fentanyl, even though they usually occurred within 1 min of awakening. It is concluded that EEG criteria for identifying when patients will awaken from anesthesia are more reliable with isoflurane than with fentanyl.

Anesthesia Recovery Period↗

PubMed1989

[Correlation intervals between the power values of artificial lenses deduced from theoretical formulae and regression formulae].

We give a precise theoretical formula used to calculate the power of implants. A spatial representation is shown. It exhibits Dc (power of the cornea) and l (axial length) values which induce a good fit between the power of artificial lens deduced from theoretical and statistical (S.R.K.) formulae. These values are situated on a look like parabolic curve (C) centered on a 26.13 mm or 27.2 mm l value according to anterior or posterior implants. We show the existence of area of (Dc, l) points giving a fit between theory and statistic within a given uncertainty delta DI. This fit is depicted on a chart (Dc, l, delta DI) on which the different curves which correspond to various delta DI, are deduced from the curve of equal power (C) by single translations. We indicate that an uncertainty near 1 dioptre on the power of the cornea induces a deviation near 0.21 dioptre on the powers of the anterior implant when calculated using the two methods. Moreover, we establish that the power SRK is always higher than the theoretical power for axial lengths situated in the 24 to 28.5 mm range.

Humans↗

PubMed1977

Metabolic responses to interval training programs of high and low power output.

The metabolic responses of 30 college-aged males were compared following high power (30-sec runs with 19 repetitions-Group HP) and low power (120-sec runs with 7 repetitions-Group LP) interval training programs (8-wk, 3 days/wk). Measurements included: maximal aerobic power (Vo2max, open circuit spirometry); maximal lactacid capacity (net-LAmax, blood LA accumulation following exhaustive exercise); net energy production (net Vo2 and netLA) following a 2-min run that was exhaustive before but not following training; and maximal muscular power (stair-climbing procedure). The results indicated: 1) significant but equal increases in Vo2 max in both groups; 2) no change in either group in netLAmax; 3) net Vo2 during the 2-min run was unchanged, however, netLA was significantly greater in Group LP; 4) no changes in either group in muscular power. It was concluded that low power and high power output interval training programs elicit similar changes in maximal aerobic and anaerobic metabolism, and that the physiological and or biochemical changes responsible for lowered lactic acid production during heavy, but submaximal exercise following training are produced to a greater extent by the low power program.

Adolescent↗

PubMed1975

Clinical application study of externally powered upper-limb prosthetics systems: the VA elbow, the VA hand, and the VA/NU myoelectric hand systems.

The results have been presented of a 2-year survey designed to determine whether external power systems offer a significant contribution to the needs of the upper-limb amputee or whether they represent novelties duplicating the functions of conventional mechanical components. The following conclusions have been drawn: 1. External power does offer advantages to the arm amputee. Myoelectric control, especially combined with a self-suspending socket, offers an otherwise normal partial forearm amputee better function without the necessity of a harness. External power, especially for the short partial or total arm amputee and others with limited excursion, brings increased function with less effort. For these patients the advantages of such components as the electric elbow outweigh the recent disadvantages. 2. The components evaluated in this Study are not without limitations. Maintenance requirements of the VA Elbow were excessive. The VA Elbow should not be prescribed for patients who do heavy work with their prostheses because the flexspline may break. Regarding such concerns as lack of sensory feedback, noise, weight, and flexion/extension speed, the advantages of each unit must be weighed against the disadvantages with preference to the individual amputee. 3. The endoskeletal forearm with soft cover is an advantage because of its lightness and cosmesis. 4. Because of the many malfunctions attributed to prosthetist errors, the need is evident for thorough specialized education in the field of external power. A few centralized fabrication facilities may be desirable as opposed to fabrication by many facilities with limited experience. Modular components that are interchangeable and field repairable would be desirable. The systems should be fitted, installed and repaired only by trained prosthetists who have successfully completed a course in externally powered upper-limb prostheses. All members of the Clinic Team should be thoroughly educated in external power as it is related to prosthetics. 5. Many malfunctions were due to patient misuse. Patients, too, after careful selection must be given thorough training in the care and use of externally powered components, including the limitations and capabilities of these devices. 6. Finally, and most important, the Clinic Team must be recognized as the focal point for the selection of patients and prescription of devices. Each patient must be carefully screened for information such as occupation, motivation, prosthesis use (as opposed to wear), ability to learn and follow through with instructions (charging batteries, etc.), and most importantly, the benefits that external power can offer.

Adolescent↗

PubMed1995

[Restoration filtering based on projection power spectrum for single-photon emission computed tomography].

To improve the quality of single-photon emission computed tomographic (SPECT) images, a restoration filter has been developed. This filter was designed according to practical "least squares filter" theory. It is necessary to know the object power spectrum and the noise power spectrum. The power spectrum is estimated from the power spectrum of a projection, when the high-frequency power spectrum of a projection is adequately approximated as a polynomial exponential expression. A study of the restoration with the filter based on a projection power spectrum was conducted, and compared with that of the "Butterworth" filtering method (cut-off frequency of 0.15 cycles/pixel), and "Wiener" filtering (signal-to-noise power spectrum ratio was a constant). Normalized mean-squared errors (NMSE) of the phantom, two line sources located in a 99mTc filled cylinder, were used. NMSE of the "Butterworth" filter, "Wiener" filter, and filtering based on a power spectrum were 0.77, 0.83, and 0.76 respectively. Clinically, brain SPECT images utilizing this new restoration filter improved the contrast. Thus, this filter may be useful in diagnosis of SPECT images.

Brain↗

PubMed1994

Holding power of orthopedic screws in the large metacarpal and metatarsal bones of calves.

Holding power was determined for various orthopedic screws in bones of calves. Holding power was defined as maximal tensile force required to remove a screw divided by thickness of bone engaged by the screw (kN/mm). Comparative pull-out tests were performed, using pairs of large metacarpal or metatarsal bones from calves aged 3 to 14 days. Comparisons were made of the holding power of 6.5-mm fully threaded cancellous screws and 5.5-mm cortical screws in the proximal and distal metaphyses, and of 4.5-mm and 5.5-mm cortical screws in the diaphysis. Sixteen repetitions of each comparative trial were performed. There was no statistically significant difference in the holding power of 4.5- and 5.5-mm cortical screws in the diaphysis. There was no significant difference in the holding power of 5.5-mm cortical and 6.5-mm fully threaded cancellous screws in the proximal metaphysis. In the distal metaphysis, 6.5-mm fully threaded cancellous screws had significantly (P < 0.001) greater holding power than did 5.5-mm cortical screws. There was no significant difference between the mean holding power of 5.5-mm cortical screws in the proximal metaphysis and 5.5-mm cortical screws in the distal metaphysis. There was significantly (P < 0.01) greater mean holding power of 6.5-mm cortical, fully threaded cancellous screws in the distal metaphysis, compared with the proximal metaphysis.

Animals↗

PubMed1993

Left ventricular peak power during exercise: a noninvasive approach for assessment of contractile reserve.

Cardiac peak power, a contractility index based upon instantaneous changes in intracavitary pressure and systolic peak flow, was measured at rest and during supine exercise in 26 patients with coronary artery disease and 8 healthy subjects. The pathophysiological significance of this index was compared with left ventricular ejection fraction (LVEF) during exercise. Cardiac peak power, ejection fraction, end-diastolic volume, stroke volume, cardiac output and systemic vascular resistance were measured at rest, during three stages of supine bicycle ergometry and two stages of recovery. Cardiac peak power increased continuously in healthy subjects, from 5.4 +/- 0.8 W/ml at rest to 11.4 +/- 3.1 W/ml at peak exercise, p < 0.001. In patients, peak power increased initially, reached a plateau in stage 2, and subsequently remained unchanged in stage 3 (5.6 +/- 2 versus 5.6 +/- 1.6 W/ml, p = ns). Ejection fraction demonstrated a flat response during exercise in patients, contrasting with a 42% increase in cardiac peak power. The lack of increase in ejection fraction was attributed to its dependence on afterload. Peak power showed no correlation with systemic vascular resistance (r = 0.01, p = ns). In a subgroup of patients with low resting LVEF (LVEF = 26% +/- 7%), peak power increased 70% during exercise, from 2.0 +/- 0.7 to 3.5 +/- 1.7 W/ml, p < 0.05, in contrast to a flat ejection fraction response. Thus, cardiac peak power, a relatively afterload-independent index of left ventricular performance and contractility can be obtained noninvasively during exercise.

Blood Pressure↗

PubMed1997

Useful applications and limits of battery powered implants in functional electrical stimulations.

Battery powered stimulation implants have been well-known for a long time as heart pacemakers. In the last few years, fully implantable stimulators have been used in the field of functional electrical stimulation (FES) for applications like dynamic cardiomyoplasty and electro-stimulated graciloplasty for fecal incontinence. The error rate of battery powered implants is significantly smaller than that for conventional stimulator systems, and the quality of life for the patients is increased because the need for an external power and control unit is eliminated. The use of battery powered implants is limited by the complexity of the stimulation control strategies and the battery capacity. Therefore, applications like the stimulation of lower extremities for walking, cochlea stimulation, or direct muscle stimulation cannot be supported. The improvement of implantable batteries, microcontrollers, and ultralow power products is ongoing. In the future, battery powered implants will also meet the requirements of complex applications. Systems for restoration of hand and breathing functions after spinal cord injury can be the next field of use for battery powered implants. For these purposes, we developed a battery powered multichannel implant with a sufficient life span for phrenic pacing. The problems during development and the limits of this system are described in this paper.

Cardiomyoplasty↗