ABSTRACT
Objetivo: evaluar la toxicidad y eficacia terapéutica del Sm153 EDTMP en pacientes con cáncer de mama avanzado y dolor producido por metástasis óseas con reacción osteoblástica y su repercusión centellográfica y de laboratorio. Materiales y métodos: 54 pacientes (edad promedio: 62) con metástasis óseas y dolor con Samario en dosis de 0,5; 1 y 1,5 mCi/kg; 5 pacientes fueron retratadas. Se realizó control clínico y laboratorio al inicio, semanalmente durante el primer mes y luego mensualmente. Se correlacionaron centellografías óseas pre y post tratamiento. De las 54 pacientes, 21 (primer grupo) recibieron 0,5 mCi/kg; 29 (segundo grupo) 1 mCi/kg y 4 pacientes (tercer grupo) 1,5 mCi/kg. Resultados: la respuesta positiva al tratamiento se valoró mediante la atenuación o desaparición del dolor y la disminución del uso de analgésicos. El primer grupo tuvo una respuesta positiva del 76 por ciento, el segundo de 83 por ciento y el tercero de 75 por ciento. La duración de la respuesta varió entre 3 y 9 meses. La toxicidad más frecuente fue trombocitopenia y luego leucopenia, ambas fueron reversibles y presentaban relación directa a la dosis administrada. La correlación centellográfica muestra una disminución de la intensidad de fijación en las pacientes retratadas. Conclusiones: el uso de radiofármacos con afinidad ósea como el Sm resulta ser una alternativa, dada su eficacia y accesibilidad de costos. En nuestro grupo de pacientes tratadas con una dosis de 1 mCi/kg se alcanzó una respuesta del 83 por ciento sin mayor aaumento de la toxicidad, la cual fue reversible
Subject(s)
Humans , Female , Middle Aged , Breast Neoplasms , Samarium , Bone Neoplasms , Breast Neoplasms , Pain , Samarium , Treatment OutcomeABSTRACT
Objetivo: evaluar la toxicidad y eficacia terapéutica del Sm153 EDTMP en pacientes con cáncer de mama avanzado y dolor producido por metástasis óseas con reacción osteoblástica y su repercusión centellográfica y de laboratorio. Materiales y métodos: 54 pacientes (edad promedio: 62) con metástasis óseas y dolor con Samario en dosis de 0,5; 1 y 1,5 mCi/kg; 5 pacientes fueron retratadas. Se realizó control clínico y laboratorio al inicio, semanalmente durante el primer mes y luego mensualmente. Se correlacionaron centellografías óseas pre y post tratamiento. De las 54 pacientes, 21 (primer grupo) recibieron 0,5 mCi/kg; 29 (segundo grupo) 1 mCi/kg y 4 pacientes (tercer grupo) 1,5 mCi/kg. Resultados: la respuesta positiva al tratamiento se valoró mediante la atenuación o desaparición del dolor y la disminución del uso de analgésicos. El primer grupo tuvo una respuesta positiva del 76 por ciento, el segundo de 83 por ciento y el tercero de 75 por ciento. La duración de la respuesta varió entre 3 y 9 meses. La toxicidad más frecuente fue trombocitopenia y luego leucopenia, ambas fueron reversibles y presentaban relación directa a la dosis administrada. La correlación centellográfica muestra una disminución de la intensidad de fijación en las pacientes retratadas. Conclusiones: el uso de radiofármacos con afinidad ósea como el Sm resulta ser una alternativa, dada su eficacia y accesibilidad de costos. En nuestro grupo de pacientes tratadas con una dosis de 1 mCi/kg se alcanzó una respuesta del 83 por ciento sin mayor aaumento de la toxicidad, la cual fue reversible (AU)
Subject(s)
Humans , Female , Middle Aged , Aged , Breast Neoplasms/radiotherapy , Samarium/therapeutic use , Breast Neoplasms/pathology , Samarium/adverse effects , Samarium/administration & dosage , Treatment Outcome , Bone Neoplasms/radiotherapy , Pain/radiotherapyABSTRACT
Muscle fibre conduction velocity is an important measurement in electrophysiology, both in the research laboratory and in clinical practice. It is usually measured by placing electrodes spaced at known distances and estimating the transit time of the action potential. The problem, common to all methods, is the estimation of this time delay. Several measurement procedures, in the time and frequency domains, have been proposed. Time-domain strategies usually require two acquisition channels, whereas some frequency-domain methods can be implemented using a single one. The method described operates in the time domain, making use of the autocorrelation function of the difference signal obtained from two needle electrodes and only one acquisition channel. Experimental results were obtained from the electromyogram of two biceps muscles (two adult male subjects, nine records each) under voluntary contraction, yielding an average of 3.58 m s(-1) (SD=0.04 m s(-1)) and 3.37m s(-1) (SD=0.03 m s(-1)), respectively. Several tests showed that the proposed method works properly with electromyogram records as short as 0.3 s.
Subject(s)
Electromyography/methods , Muscle Fibers, Skeletal/physiology , Neural Conduction , Action Potentials , Adult , Humans , Male , Signal Processing, Computer-AssistedABSTRACT
A biopotential amplifier for single supply operation is presented. It uses a Driven Right Leg Circuit (DRL) to drive the patient's body to a DC common mode voltage, centering biopotential signals with respect to the amplifier's input voltage range. This scheme ensures proper range operation when a single power supply is used. The circuit described is especially suited for low consumption, battery-powered applications, requiring a single battery and avoiding switching voltage inverters to achieve dual supplies. The generic circuit is described and, as an example, a biopotential amplifier with a gain of 60 dB and a DC input range of +/-200 mV was implemented using low power operational amplifiers. A Common Mode Rejection Ratio (CMRR) of 126 dB at 50 Hz was achieved without trimming.
Subject(s)
Amplifiers, Electronic , Signal Processing, Computer-Assisted/instrumentation , Electric Impedance , Electric Power Supplies , Electrocardiography , Equipment DesignABSTRACT
A three op-amps instrumentation amplifier (I.A) with active dc suppression is presented. dc suppression is achieved by means of a controlled floating source at the input stage, to compensate electrode and op-amps offset voltages. This isolated floating source is built around an optical-isolated device using a general-purpose optocoupler, working as a photovoltaic generator. The proposed circuit has many interesting characteristics regarding simplicity and cost, while preserving common mode rejection ratio (CMRR) and high input impedance characteristics of the classic three op-amps I.A. As an example, a biopotential amplifier with a gain of 80 dB, a lower cutoff frequency of 0.1 Hz, and a dc input range of +/- 8 mV was built and tested. Using general-purpose op-amps, a CMRR of 105 was achieved without trimmings.
Subject(s)
Amplifiers, Electronic , Bioelectric Energy Sources , Electric Impedance , Electric Wiring/instrumentation , Optics and Photonics , Signal Processing, Computer-Assisted , Action Potentials , ArtifactsABSTRACT
Biopotential measurements are very sensitive to electromagnetic interference (EMI). EMI gets into the acquisition system by many ways, both as differential and common mode signals, driven-right-leg circuits (DRL) are widely used to reduce common mode interference. This paper reports an improvement on the classic DRL. The proposed circuit uses a transconductance amplifier to drive the patient's body. This configuration has some interesting properties, which provide an extended bandwidth for high-frequency EMI rejection (such as fluorescent lights interference). The improvement is around 20 dB for frequencies of few kilohertz and the circuit is easy to compensate for stability. A comparative analysis against a typical DRL is presented, the results obtained have been experimentally tested.
Subject(s)
Electricity , Radiation , Electric Conductivity , Electrophysiology , Humans , Models, TheoreticalABSTRACT
Grid connected wind energy conversion systems (WECS) present interesting control demands, due to the intrinsic nonlinear characteristics of windmills and electric generators. In this paper a direct adaptive control strategy for WECS control is proposed. It is based on the combination of two control actions: a radial basis zfunction network-based adaptive controller, which drives the tracking error to zero with user specified dynamics, and a supervisory controller, based on crude bounds of the system's nonlinearities. The supervisory controller fires when the finite neural-network approximation properties cannot be guaranteed. The form of the supervisor control and the adaptation law for the neural controller are derived from a Lyapunov analysis of stability. The results are applied to a typical turbine/generator pair, showing the feasibility of the proposed solution.
