Biological Signal Amplifier Patents (Class 128/902)
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Patent number: 10945653Abstract: The present invention relates to determining a neural respiratory drive (NRD) in patients with chronic obstructive pulmonary disease (COPD) based on surface electromyography measurements taken from the intercostal muscles on the chest of a subject (100).Type: GrantFiled: May 31, 2016Date of Patent: March 16, 2021Assignee: Koninklijke Philips N.V.Inventors: Alan James Davie, Sandrine Magali Laure Devot, Rene Martinus Maria Derkx, Jakob Van De Laar
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Patent number: 10682076Abstract: A system for monitoring medical conditions including pressure ulcers, pressure-induced ischemia and related medical conditions comprises at least one sensor adapted to detect one or more patient characteristic including at least position, orientation, temperature, acceleration, moisture, resistance, stress, heart rate, respiration rate, and blood oxygenation, a host for processing the data received from the sensors together with historical patient data to develop an assessment of patient condition and suggested course of treatment. In some embodiments, the system can further include a support surface having one or more sensors incorporated therein either in addition to sensors affixed to the patient or as an alternative thereof. The support surface is, in some embodiments, capable of responding to commands from the host for assisting in implementing a course of action for patient treatment.Type: GrantFiled: June 3, 2016Date of Patent: June 16, 2020Assignee: LEAF HEALTHCARE, INC.Inventors: Barrett J. Larson, Daniel Z. Shen
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Patent number: 10298334Abstract: Embodiments include a technique for a signal strength boosting in a human-body near-field communication systems, the technique includes receiving a configuration of a set of devices disposed on a body of a user for transmitting a signal across the body of the user, the devices being configured to amplify the signal, and receiving an indication of a signal strength of the signal transmitted through the devices of the set of devices. The technique also includes identifying a location of signal loss based on the signal strength, and providing a recommendation to modify the configuration of the set of devices based on the identified location of signal loss, wherein the recommendation provides a location for placement of one or more additional devices to increase the signal strength. The technique includes updating the configuration based on the one or more additional devices.Type: GrantFiled: February 21, 2017Date of Patent: May 21, 2019Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: James E. Bostick, John M. Ganci, Jr., Martin G. Keen, Sarbajit K. Rakshit
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Patent number: 10251712Abstract: Apparatus for generating an organ timing signal relating to an inspected organ within the body of a patient, including a medical positioning system, and a processor coupled with the medical positioning system, the medical positioning system including at least one reference electromagnetic transducer placed at a reference location, at least one inner electromagnetic transducer attached to a surgical tool inserted in a blood vessel in the vicinity of the inspected organ, and a medical positioning system processor coupled with the reference electromagnetic transducer and the inner electromagnetic transducer, the medical positioning system processor determining the three-dimensional position of the inner electromagnetic transducer, by processing transmitted electromagnetic signals transmitted from one of the reference electromagnetic transducer and the inner electromagnetic transducer with detected electromagnetic signals detected by the other of the reference electromagnetic transducer and the inner electromagneType: GrantFiled: November 29, 2017Date of Patent: April 9, 2019Assignee: MediGuide Ltd.Inventors: Itzhak Shmarak, Gera Strommer, Uzi Eichler
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Patent number: 10194827Abstract: An active protective circuit for a measuring amplifier of an electrical impedance tomograph includes a circuit component arrangement including an electrode input and an output and a control input for a control voltage. The output is configured for connection to a measuring amplifier for an electrical impedance tomograph. The circuit component arrangement creates a conductive connection between the electrode input of the circuit component arrangement and the output of the circuit component arrangement when the applied control voltage is within a first voltage range and does not create a conductive connection when the applied control voltage is within a second voltage range. The voltage being applied to the control input is within the second voltage range when a voltage, which is within a cut-off range, is applied to the electrode input. An electrode belt for impedance tomography has the active protective circuits associated with the electrodes.Type: GrantFiled: December 8, 2016Date of Patent: February 5, 2019Assignee: Drägerk AG & Co. KGaAInventors: Jianhua Li, Frank Sattler, Karsten Hiltawsky
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Patent number: 9980669Abstract: Methods and devices for providing application specific integrated circuit architecture for a two electrode analyte sensor or a three electrode analyte sensor are provided. Systems and kits employing the same are also provided.Type: GrantFiled: November 7, 2012Date of Patent: May 29, 2018Assignee: ABBOTT DIABETES CARE INC.Inventors: Jean-Pierre Cole, Martin J. Fennell
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Patent number: 9956049Abstract: Apparatus for generating an organ timing signal relating to an inspected organ within the body of a patient, including a medical positioning system, and a processor coupled with the medical positioning system, the medical positioning system including at least one reference electromagnetic transducer placed at a reference location, at least one inner electromagnetic transducer attached to a surgical tool inserted in a blood vessel in the vicinity of the inspected organ, and a medical positioning system processor coupled with the reference electromagnetic transducer and the inner electromagnetic transducer, the medical positioning system processor determining the three-dimensional position of the inner electromagnetic transducer, by processing transmitted electromagnetic signals transmitted from one of the reference electromagnetic transducer and the inner electromagnetic transducer with detected electromagnetic signals detected by the other of the reference electromagnetic transducer and the inner electromagneType: GrantFiled: February 9, 2017Date of Patent: May 1, 2018Assignee: MediGuide Ltd.Inventors: Itzhak Shmarak, Gera Strommer, Uzi Eichler
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Patent number: 9872629Abstract: A differential voltage measuring system is described. The differential voltage measuring system has a signal measuring circuit for measuring bioelectric signals, and an interference-signal measuring circuit coupled to the potential of the differential voltage measuring system and electrically connected to a fixed reference potential. In this case, the interference-signal measuring circuit is designed for measuring a current flowing from the potential of the differential voltage measuring system to the fixed reference potential. A differential voltage measuring system with an additional path is also described. Furthermore, a differential voltage measuring system with an averaging potential measuring method is described.Type: GrantFiled: February 3, 2016Date of Patent: January 23, 2018Assignee: Siemens AktiengesellschaftInventors: Ulrich Batzer, Peter Greif, Harald Karl
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Patent number: 9853611Abstract: An instrumentation amplifier that includes input capacitance cancellation is provided. The architecture includes programmable capacitors between the input stage and a current feedback loop of the instrumentation amplifier to cancel input capacitances from electrode cables and a printed circuit board at the front end. An on-chip calibration unit can be employed to calibrate the programmable capacitors and improve the input impedance.Type: GrantFiled: March 2, 2015Date of Patent: December 26, 2017Assignee: Northeastern UniversityInventors: Chun-hsiang Chang, Marvin Onabajo
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Patent number: 9808170Abstract: An electrode includes separate first and second electrical contacts to contact the skin of a subject. A charge-holding structure is electrically connected between the first and second contacts. An indicator is operatively coupled to the charge-holding structure so that the indicator changes visibly in response to a change in the charge stored in the charge-holding structure. The electrode can include a rectifier across the contacts. A container for electrodes includes an electrical supply and a plurality of receptacles for electrodes so that a voltage difference is maintained across conductors of each receptacle (and contacts of an electrode therein) for at least one week. A method of making electrodes includes arranging the contacts over a support, connecting the charge-holding structure between them, arranging the indicator over the support, and charging the charge-holding structure so that the indicator has a first visual appearance.Type: GrantFiled: March 15, 2013Date of Patent: November 7, 2017Assignee: Welch Allyn, Inc.Inventors: John A. Lane, Benjamin Freer, David E. Quinn, Frederik W. Kroon
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Patent number: 9757071Abstract: Systems and methods for suppressing electrical noise in an electrocardiogram (ECG) signal obtained by at least one electrode and displayed on an ECG monitor are disclosed. The system includes a conductive material distinct from the at least one electrode and configured to contact a surface of a patient, and filtering circuitry connected in series between the conductive material and ground. The filtering circuitry may be configured to filter to ground the electrical noise present within the patient before it is received by the at least one electrode and is prevented from distorting the ECG signal that is displayed on the ECG monitor.Type: GrantFiled: April 29, 2016Date of Patent: September 12, 2017Assignee: BAYER HEALTHCARE LLCInventors: Bruno Fazi, Jr., Jason Palmer
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Patent number: 8961412Abstract: Virtual dipole signal amplification for in-body devices, such as implantable and ingestible devices, is provided. Aspects of the in-body deployable antennas of the invention include antennas configured to go from a first configuration to a second configuration following placement in a living body, e.g., via ingestion or implantation. Embodiments of the in-body devices are configured to emit a detectable signal upon contact with a target physiological site. Also provided are methods of making and using the devices of the invention.Type: GrantFiled: September 25, 2008Date of Patent: February 24, 2015Assignee: Proteus Digital Health, Inc.Inventors: Hooman Hafezi, Benedict James Costello, Timothy L. Robertson, Maria Casillas Holen
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Patent number: 8545402Abstract: Ingestible event markers having high reliability are provided. Aspects of the ingestible event markers include a support, a control circuit, a first electrochemical material, a second electrochemical material and a membrane. In addition, the ingestible event markers may include one or more components that impart high reliability to the ingestible event marker. Further, the ingestible event markers may include an active agent. In some aspects, the active agent, such as a pharmaceutically active agent or a diagnostic agent may be associated with the membrane.Type: GrantFiled: April 27, 2010Date of Patent: October 1, 2013Assignee: Proteus Digital Health, Inc.Inventors: Hooman Hafezi, Kityee Au-Yeung, Robert Duck, Maria Holen, Timothy Robertson, Benedict Costello
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Patent number: 8430860Abstract: A system and method of introducing interface elements for interfacing with laryngeal structures of a subject such as for diagnosis or treatment of a laryngeal impairment is presented. Illustrative embodiments include generating a tunnel in geographical relation to the lateral wing of the cricoid cartilage of the subject and introducing at least one interface element via the tunnel for interfacing with at least one laryngeal structure of the subject.Type: GrantFiled: August 30, 2007Date of Patent: April 30, 2013Assignee: MED-EL Elektromedizinische Geraete GmbHInventors: Werner Lindenthaler, Andreas Müller
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Patent number: 7734333Abstract: A method of detecting a cardiac event in a medical device that includes sensing a cardiac signal from a plurality of electrodes, determining amplitudes of the sensed cardiac signal during a predetermined sensing window, determining a noise to signal ratio corresponding to the determined amplitudes, and determining the sensed cardiac signal during the predetermined sensing window is corrupted by noise in response to the determined noise to signal ratio being greater than a noise to signal ratio threshold.Type: GrantFiled: April 28, 2006Date of Patent: June 8, 2010Assignee: Medtronic, Inc.Inventors: Raja N. Ghanem, Robert W. Stadler, Xusheng Zhang
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Patent number: 7587239Abstract: An implantable cardiac lead comprises a lead body having a proximal end and a distal end, the proximal end of the lead body carrying a connector assembly connectable to an implantable medical device, and the distal end of the lead body carrying a distal electrode, a proximal electrode and an intermediate electrode positioned between the distal and proximal electrodes. The distal and proximal electrodes are connected together at a node point located within the distal end of the lead body, the node point being electrically connected to a first terminal contact on the connector assembly and the intermediate electrode being electrically connected to a second terminal contact on the connector assembly. Preferably, the intermediate electrode is positioned approximately midway between the distal and proximal electrodes.Type: GrantFiled: June 26, 2006Date of Patent: September 8, 2009Assignee: Pacesetter, Inc.Inventors: Mark W. Kroll, John W. Poore
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Patent number: 7299083Abstract: A chadd disposed on a patient's skin generates heat at a substantially constant temperature for an extended period of time (e.g., hours and days) when exposed to air. The chadd becomes porous when heated and produces a porosity in the patient's skin as a result of the heat generation to pass ions through the pores in patient's skin to a layer disposed on the chadd. The layer (e.g., silver or silver chloride) has properties of converting the ions to electrons. The electrons pass to an electrical lead disposed on the layer. The electrical lead passes an electrical signal (produced from the electrons) to a terminal. An amplifier connected to the terminal amplifies the signal without changing the characteristics of the signal and without producing noise.Type: GrantFiled: December 9, 2004Date of Patent: November 20, 2007Assignee: Signalife, Inc.Inventor: Budimir Drakulic
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Patent number: 7235050Abstract: An implantable device comprising a sensing unit, wherein the sensing unit is adapted to rectify biological/neurological signals in the form of sensed electrical signals from body tissue adjacent to the location of the implantable device. The sensing unit of the implantable device comprises at least one amplifier, wherein the supply current to the at least one amplifier is responsive to the magnitude of the sensed electrical signals provided to the at least one amplifier. The implantable device is further capable of integrating the rectified sensed electrical signals and generating output signals, wherein the output signals contain indicia of biopotential parameters of the body tissue.Type: GrantFiled: August 18, 2004Date of Patent: June 26, 2007Assignee: Alfred E. Mann Foundation for Scientific ResearchInventors: Joseph H. Schulman, Christian Perron
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Patent number: 7171269Abstract: A method of analysis of medical signals which uses wavelet transform analysis to decompose cardiac signals. Apparatus for carrying out the method, and cardiac apparatus adapted to employ the method are also described.Type: GrantFiled: May 2, 2000Date of Patent: January 30, 2007Assignee: Cardiodigital LimitedInventors: Paul Stanley Addison, James Nicholas Watson
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Patent number: 7092762Abstract: An external transmitter circuit drives an implantable neural stimulator having an implanted coil from a primary coil driven by a power amplifier. For efficient power consumption, the transmitter output circuit (which includes the primary coil driven by the power amplifier inductively coupled with the implanted coil) operates as a tuned resonant circuit. When operating as a tuned resonant circuit, it is difficult to modulate the carrier signal with data having sharp rise and fall times without using a high power modulation amplifier. Sharp rise and fall times are needed in order to ensure reliable data transmission. To overcome this difficulty, the present invention includes an output switch that selectively inserts a resistor in the transmitter output coil circuit in order to de-tune the resonant circuit only during those times when data modulation is needed. Such de-tuning allows sharp rise and fall times in the data modulation without the need for using a high power modulation amplifier.Type: GrantFiled: May 23, 2003Date of Patent: August 15, 2006Assignee: Advanced Bionics CorporationInventors: Scott M Loftin, Kelly H McClure
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Patent number: 7079901Abstract: An external transmitter circuit drives an implantable neural stimulator having an implanted coil from a primary coil driven by a power amplifier. For efficient power consumption, the transmitter output circuit (which includes the primary coil driven by the power amplifier inductively coupled with the implanted coil) operates as a tuned resonant circuit. When operating as a tuned resonant circuit, it is difficult to modulate the carrier signal with data having sharp rise and fall times without using a high power modulation amplifier. Sharp rise and fall times are needed in order to ensure reliable data transmission. To overcome this difficulty, the present invention includes an output switch that selectively inserts a resistor in the transmitter output coil circuit in order to de-tune the resonant circuit only during those times when data modulation is needed. Such de-tuning allows sharp rise and fall times in the data modulation without the need for using a high power modulation amplifier.Type: GrantFiled: May 23, 2003Date of Patent: July 18, 2006Assignee: Advanced Bionics CorporationInventors: Scott M Loftin, Kelly H McClure
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Patent number: 6865409Abstract: An electrode assembly for use on a surface of biological tissue to measure bio-electric signals including an electrode apparatus having an electrode device adapted to directly contact the surface of the biological tissue. The electrode apparatus receives and transmits bio-electric signals measured across the biological tissue having a first voltage and a minute first current. A signal transmission line is included having a signal transmission conductor electrically coupled at one portion to the electrode device for transmission of the bio-electric signals. The transmission includes a second conductor electrically coupled to the amplifier apparatus and arranged to substantially shield the transmission conductor from ambient electric fields generated from sources external to the transmission line. A high impedance amplifier device is included having a signal input and a signal output.Type: GrantFiled: November 7, 2002Date of Patent: March 8, 2005Assignee: Kinesense, Inc.Inventors: Robert M. Getsla, Victor F. Simonyi
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Patent number: 6834205Abstract: A system and method for automatically adjusting the gain for a shock lead system in an implantable medical device is provided. The system and method operate when, after a pre-selected period of time, the gain has not been programmed. The system and method then automatically produce and set the gain for the shock lead system. The system and method poll and determine a maximum value for the output of the shock lead system amplifier and produce a new gain value to scale the output to facilitate providing useful data that is large enough to separate signal from noise but small enough to avoid clipping.Type: GrantFiled: January 20, 2004Date of Patent: December 21, 2004Assignee: Cardiac Pacemakers, Inc.Inventors: Jason W. Eberle, LeAnne Marie Mackey
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Patent number: 6807438Abstract: An electric field sensor employs a capacitive pick-up electrode in a voltage divider network connected to a body emanating an electric field. The system is relatively insensitive to variations in the separation gap between electrode and body, reducing sensor motion artifacts in the output signal and stabilizing its low frequency response. The pick-up electrode may be positioned at a “stand off” location, spaced from intimate contact with the surface of the body. This is equivalent to providing low level capacitive values for the capacitive coupling between the pick-up electrode and the body whose electric field is to be monitored. Or a series limiting capacitor may be provided in the input stage. Human body-generated electrical signals may be acquired without use of conductive gels and suction-based electrodes, without direct electrical contact to the body, and even through thin layers of clothing.Type: GrantFiled: September 30, 2002Date of Patent: October 19, 2004Inventors: Riccardo Brun Del Re, Izmail Batkin, Wayne Young
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Patent number: 6778855Abstract: A system and method for automatically adjusting the gain for a shock lead system in an implantable medical device is provided. The system and method operate when, after a pre-selected period of time, the gain has not been programmed. The system and method then automatically produce and set the gain for the shock lead system. The system and method poll and determine a maximum value for the output of the shock lead system amplifier and produce a new gain value to scale the output to facilitate providing useful data that is large enough to separate signal from noise but small enough to avoid clipping.Type: GrantFiled: July 9, 2001Date of Patent: August 17, 2004Assignee: Cardiac Pacemakers, Inc.Inventors: Jason W. Eberle, LeAnne Marie Mackey
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Patent number: 6728564Abstract: A configurable system for obtaining a measurement of activity producing biopotentials in a subject, for example EEG or EMG biopotentials. The system includes a three electrode array positionable on the head of the patient to detect signals generated in the head of the subject. The array is connected to a monitor that includes a switch arrangement that is selectively configurable to direct the incoming signals received by the electrode array to specified inputs of a differential amplifier that creates signals that are displayed on the monitor. The switch arrangement is configurable to measure the activity of the subject in a conventional 1-channel measurement mode. The switch arrangement can also be configured to simulate a 2-channel measurement mode by alternating the configuration of the switch arrangement in a pre-determined manner.Type: GrantFiled: July 3, 2001Date of Patent: April 27, 2004Assignee: Instrumentarium Corp.Inventor: Markku Lähteenmäki
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Patent number: 6718191Abstract: A skin potential measuring sensor includes a measuring electrode to be placed on the skin and a signal transfer element attached thereto. The elements which measure, handle and digitize the signal in order to convert it into a digital signal are placed close to the measuring electrode.Type: GrantFiled: June 11, 2001Date of Patent: April 6, 2004Assignee: Medikro OyInventors: Mikko Eloranta, Olli Pohjolainen
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Patent number: 6334068Abstract: An economically manufactured, highly sensitive, noise and interference resistant, AC powered, two, four or eight channel intraoperative neuroelectrophysiological monitor includes a mainframe having a touch panel display and a low noise interface cable providing connection via a patient interface box for one or more stimulator probes and one or more EMG signal sensing electrodes.Type: GrantFiled: September 14, 1999Date of Patent: December 25, 2001Assignee: Medtronic Xomed, Inc.Inventor: David C. Hacker
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Patent number: 6317625Abstract: A signal measuring system for use with an Implantable Medical Device (IMD) is provided for measuring physiologic signals having a relatively large effective dynamic range. In one embodiment, the system includes a High-Pass Filter (HPF), an Analog-to-Digital Converter (ADC), a Decimation Filter (DF), and a Compensation Filter (CF). The HPF receives an input signal that includes both the baseline wander imposed on a physiological signal. According to one aspect of the invention, the HPF attenuates low frequency components of the input signal, including a portion of the frequency band within the desired output signal bandwidth. The ADC then oversamples the output signal of the HPF. The DF receives the output samples from the ADC and generates output samples at rate that is at least twice the maximum frequency of the desired output signal. The CF then amplifies the low frequency end of the DF output samples.Type: GrantFiled: November 15, 2000Date of Patent: November 13, 2001Assignee: Medtronic Inc.Inventors: Dana J. Olson, David W. Van Ess, Robert W. Stadler, Steven N. Lu, Jeffrey D. Wilkinson, Tara N. Ptak
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Patent number: 6302686Abstract: An interocclusal dental appliance has a liner and an outer shell of a material harder than the liner. The shell extends around the liner through the occlusal surface, the buccal and lingual surfaces, and around an undercut edge of the liner mechanically to secure the harder shell and the liner, but to permit the teeth of the user to engage the liner. The method of producing the appliance includes making a mold of the teeth of a patient forming a liner with cavities complementary to the teeth and occlusal surface, and forming, over the occlusal surface of the liner, over the buccal and lingual surfaces of the liner and around a parimetric edge of the liner a shell of material harder than the liner.Type: GrantFiled: December 2, 2000Date of Patent: October 16, 2001Assignee: Keller Laboratories Inc.Inventors: Bradley J. Chott, Michael R. Mohrhard
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Patent number: 6208888Abstract: A voltage sensing system includes input impedance balancing for electrocardiogram (ECG) sensing or other applications, providing immunity to common-mode noise signals while capable of use with two electrodes. Signals are received at first and second electrodes having associated impedances. An impedance circuit includes a feedback controller that adjusts an effective impedance associated with the second electrode based on a difference signal, a common mode signal, a phase-shifted (e.g., quadrature common mode) signal, and an impedance associated with the first electrode. As a result, signals associated with each electrode undergo a similar degree of gain/attenuation and/or phase-shift. This reduces common mode noise and enhances the signal-to-noise characteristics of a desired ECG or other output signal, without requiring the use of more than two electrodes.Type: GrantFiled: February 3, 1999Date of Patent: March 27, 2001Assignee: Cardiac Pacemakers, Inc.Inventor: David J. Yonce
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Patent number: 6016446Abstract: A cardiac rhythm management system provides a nonlinear gain characteristic. The system operates without blanking switches that decouple its inputs from electrodes during delivery of a pacing or recharge pulse. The nonlinear gain characteristic includes piecewise linear and logarithmic gain characteristics. Signals having amplitudes that are smaller than an input threshold voltage are amplified by less than signals having amplitudes that exceed the input threshold voltage. Intrinsic heart activity signals are amplified. Detected pacing pulses are attenuated. The system is capable of detecting an evoked response to determine whether a pacing pulse resulted in a successful heart contraction. Autocapture techniques allow adjustment of the pacing pulse energy based on the evoked response.Type: GrantFiled: February 27, 1998Date of Patent: January 18, 2000Assignee: Cardiac Pacemakers, Inc.Inventor: Hugo Andres Belalcazar
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Patent number: 5954660Abstract: A device for filtering cardiac activity signals which receives input signals coming from collected physiological data, and delivers at an output, for processing data, signals spreading, in the frequency domain, over a widened spectral band. A first high-pass filter is used to reduce the extension of the spectral band of the signal received at the input. A compensation stage having a frequency characteristic (32) that is inverted as compared to that of the first high-pass filter is provided. The cut-off frequency (f1) of the first high-pass filter is greater than the low cut-off frequency (fo) of the spectral analysis band. Optionally, a second high-pass filter is provided, whose characteristic (38) presents a cut-off frequency corresponding to the low frequency (fo) of the spectral band. The high frequency of the spectral band may be similarly modified.Type: GrantFiled: January 7, 1998Date of Patent: September 21, 1999Assignee: ELA Medical, S.A.Inventors: Thierry Legay, Pascal Pons, Luc Garcia
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Patent number: 5724967Abstract: Pairs of signal input leads with a low level signal imposed across them usually have noise induced by stray coupling capacitance which is typically unequal. This results in an unfavorable signal to noise ratio. Adding enough capacitance to the lead having the least capacitance, thereby equalizing the coupling capacitances to the noise services thereof, tends to reduces the noise effect considerably. This is accomplished by changing the relative sizes of the anode and/or cathode of a corresponding sensor device. The noise effect is further reduced by a negative feedback process which comprises extracting the induced noise component from the leads, inverting the noise component, and coupling the inverted noise component back to the input leads.Type: GrantFiled: November 21, 1995Date of Patent: March 10, 1998Assignee: Nellcor Puritan Bennett IncorporatedInventor: Kalpathi Lakshminarayanan Venkatachalam
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Patent number: 5713365Abstract: An instrument for detecting an electric biological signal, and wherein a pocket casing housing an electronic circuit presents a rectangular wall fitted with two flat electrodes and a display. The electronic circuit includes an amplifier stage wherein a first operational amplifier communicates at the input with a first electric line receiving a first electric signal picked up from a first portion of the human body, and a second operational amplifier communicates at the input with a second electric line receiving a second electric signal picked up from a second portion of the human body. An inverting amplifier receives a signal equal to the average of the output signals of the first and second operational amplifiers, and is connected at the output to a signal divider for supplying the signal at the output of the inverting amplifier to the first and second electric lines.Type: GrantFiled: July 31, 1996Date of Patent: February 3, 1998Inventor: Arrigo Castelli
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Patent number: 5709213Abstract: Disclosed are a method of and apparatus for deriving augmented lead electrocardiograph (ECG) signals from electrical signals sensed at three skin surface, limb electrodes attached to a patient's limbs without the use of a high impedance resistor network. First, second and third pairs of the three limb electrodes are combined to provide first, second and third positive and negative limb lead signal pairs. The first, second and third positive and negative limb lead signal pairs are combined and amplified to provide first, second, and third limb lead signals (LI, LII and LIII). The first, second and third amplified lead limb signals LI, LII and LIII are combined into augmented lead signals aVR, aVL, aVF through a low impedance resistor network and operational amplifiers, in accordance with the formulas: aVR=-0.5 (LI+LII), aVL=0.5 (LI-LIII), and aVF=0.5 (LII+LIII).Type: GrantFiled: September 17, 1996Date of Patent: January 20, 1998Assignee: Medtronic, Inc.Inventors: John M. Kruse, Dave R. Jurek
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Patent number: 5678559Abstract: Electrodes, preferably paired on a patient's head, produce signals representing the patient's brain waves at one of the paired electrodes and reference signals at the other paired electrode. Pre-amplifiers juxtaposed to the paired electrodes and having a balanced operation even with impedance differences between the paired electrodes produce signals representing the difference in the signals between such electrodes. After filtering to eliminate DC and band limit the upper frequency, the signals from each pre-amplifier pass to a post-amplifier displaced and electrically isolated from the pre-amplifier. The post-amplifier linearly amplifies the pre-amplifier signals and filters the signals at the lower and upper frequencies within a particular frequency range dependent upon the frequency range in which the investigator is interested. The upper and lower limits of the frequency range are dependent upon the frequencies of controlling clock signals.Type: GrantFiled: January 23, 1995Date of Patent: October 21, 1997Inventor: Budimir S. Drakulic
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Patent number: 5427111Abstract: A receiver or preamplifier for differential signals, in particular electrocardiogram signals, includes n electrodes to provide at least one signal at an acceptable common mode rejection ratio, even if the subject to which the electrodes are applied has a different ground potential than the assigned monitor. This is achieved by two current sources which are controlled by a sum signal representing a sum of the electrode signals, said current sources injecting a corresponding current into the electrodes.Type: GrantFiled: December 1, 1993Date of Patent: June 27, 1995Assignee: Hewlett Packard CompanyInventors: Stefan Traub, Heinz Sommer
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Patent number: 5427110Abstract: Circuit arrangement for the processing of physiological measurement signals. In a known circuit arrangement, each one of a plurality of electrodes for picking up physiological measurement signals connects with a first input connection of an input amplifier associated with the pertinent electrodes; the input amplifiers connect, at their respective second input connections, with a common reference potential connection. To check the functional capability of the input amplifiers, a calibration pulse generator connects on the output side with one of the electrodes and the reference potential connection. In addition, to check the electrodes (1, 2, 3) and their supply lines, an additional amplifier (24) connects, by its input, with the reference potential connection (7) and, at its output, with an additional electrode (25) on the patient.Type: GrantFiled: September 3, 1993Date of Patent: June 27, 1995Assignee: Siemens AktiengesellschaftInventors: Peter Danielsson, Thomas Ohlsson
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Patent number: 5414392Abstract: An electrical circuit comprising means for receiving an input signal for encoding or modulating and amplification. Multiple amplification stages including at least one transconductance amplifier are provided. There are means for having the input signal modulate the oscillator constituted by the multiple amplification stages to provide a 360.degree. phase-shifted signal at a predetermined frequency. Gain control means are also provided for developing level for permitting oscillation under conditions including at least the conditions of turn on of the circuit and other operating conditions. The gain control means includes a transistor and resistor network for adjusting the gain to sustain the oscillation. The transistor and resistor also regulate amplification of an intermediate stage of the amplifier. The preamplifier directly converts an EKG and/or other signals to linearized control currents which modulate the oscillator.Type: GrantFiled: August 26, 1993Date of Patent: May 9, 1995Assignee: MedCom ElectronicsInventor: Leonard Schupak
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Patent number: 5392784Abstract: An isolated amplifier, typically a biomedical amplifier, includes a main amplifier having inputs for receiving signals, a circuit for sensing a common mode voltage received by the inputs from the electrodes and providing a compensation voltage representative of the common mode voltage, and a capacitance to chassis ground for receiving a voltage representative of the compensation voltage. The circuit and the capacitance cause the amplifier power supply voltages to track the common mode voltage. The capacitance permits the feedback loop gain to be increased, thereby reducing common mode voltage errors.Type: GrantFiled: August 20, 1993Date of Patent: February 28, 1995Assignee: Hewlett-Packard CompanyInventor: Algird M. Gudaitis
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Patent number: 5368041Abstract: A monitor which receives electrical signals from a human body includes a portable data acquisition module and a substantially stationary processing module. The EEG signals are acquired and converted to an oversampled stream of digital signals by a sigma-delta modulator located in the data acquisition module. The signals are then filtered by a decimation filter located in the processing module. Additional means are also provided to monitor the electrode leads to detect when the leads become unplugged. The monitor provides all power to the data acquisition module over a single twisted line which transmits data as well.Type: GrantFiled: October 15, 1992Date of Patent: November 29, 1994Assignee: Aspect Medical Systems, Inc.Inventor: John R. Shambroom
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Patent number: 5360008Abstract: A respiratory monitor (apnea detector) utilizes the discovery that the magnetic permeability of a person's body varies with the respiratory and cardiac cycles. The respiratory and optionally cardiac monitor of the invention includes an oscillator circuit which produces a signal, and a transmitter placed in close proximity of the body of the person (patient) whose respiratory cycle is to be monitored. The transmitter directs and transmits the signal originally generated in the oscillator circuit toward the trunk of the patient. A receiver-transducer is located also in close proximity of the trunk of the patient, and receives the electromagnetic signals which are modulated due to the varying permeability of the body caused by the respiratory and cardiac cycles.Type: GrantFiled: November 18, 1992Date of Patent: November 1, 1994Inventor: William G. Campbell, Jr.
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Patent number: 5111814Abstract: A laryngeal pacemaker stimulates a paralyzed muscle in mirror image synchronism with a normally functioning muscle.Type: GrantFiled: July 6, 1990Date of Patent: May 12, 1992Assignee: Thomas Jefferson UniversityInventor: David Goldfarb
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Patent number: 5018523Abstract: An apparatus for stimulating and sensing evoked response to stimulus in the heart. First and second electrodes are in electrical contact with the heart, a third indifferent electrode is also in electrical contact with the heart. A pacemaker provides stimulus signals through the electrodes in the stimulating mode of operation. The first and second electrodes are switched through switching apparatus wherein in the first mode the first and second electrodes are maintained at equal electrical potentials, and in a second, sensing mode, the switch operates between the first and second electrodes so as to allow the first and second electrodes to act as bipolar sensing leads. Evoked response is sensed by a differential amplifier having a first differential input connected to the first electrode and a second differential input connected to the second electrode. The differential amplifier provides a differential signal which is proportional to the evoked cardiac response.Type: GrantFiled: April 23, 1990Date of Patent: May 28, 1991Assignee: Cardiac Pacemakers, Inc.Inventors: Stanley M. Bach, Jr., Douglas J. Lang, David K. Swanson, Roger W. Dahl
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Patent number: 5002064Abstract: An electronic miniaturized, pocket-sized device for monitoring EKG and/or EEG signals and storing such signals. First, second and third electrodes are adapted for connection to a human body and first and second voltage amplifiers are electrically connected to respective ones of the first and second electrodes for producing first and second output signals having low noise content. A third amplifier is connected to both the first and second voltage amplifier for producing two output signals, one being the difference in voltage of the two voltage amplifiers as amplified and the second output being the difference of the bias voltages of the first and second voltage amplifiers. A lead fail detector includes voltage sensing device electrically connected to the second output of the third voltage amplifier and outputting a signal only when the difference of the bias voltages of the electrodes through the respective first and second voltage amplifiers is above a preselected level.Type: GrantFiled: August 31, 1989Date of Patent: March 26, 1991Inventors: Joseph L. Allain, Henry Halperin
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Patent number: 4899760Abstract: An improved biological signal detector which is extremely sensitive, yet resistant to the effects of high frequency noise. A multiplexed signal representation of a plurality biological signals is demultiplexed by a detector circuit comprising a plurality of switches each of which controls an individual storage network. A switch logic control circuit synchronizes the various switches to close during the time intervals corresponding to the pulse amplitudes representing the particular signal of interest. The amplitude of the alternating component of each of the biological signals is stored in one of the respective storage networks over a number of pulse time intervals. In the preferred embodiment, the storage networks of the detector each have a time constant which is purposely chosen to be substantially longer than the time interval of the pulses.Type: GrantFiled: June 15, 1987Date of Patent: February 13, 1990Assignee: Colin Electronics Co., Ltd.Inventors: Jonathan P. Jaeb, Merle E. Converse
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Patent number: 4896120Abstract: A substantially zero average DC output voltage is obtained in an instrumentation amplifier without degrading the gain by detecting the output of the amplifier and operating a non-galvanically coupled device responsive to the detected output to apply feedback to the amplifier for balancing out common mode output voltages.Type: GrantFiled: March 24, 1987Date of Patent: January 23, 1990Inventor: Zvi Kamil
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Patent number: 4890630Abstract: A device and method are provided for bio-electric monitoring apparatus to cancel bio-electric noise on the body of a patient. The device comprises a plurality of monitoring electrodes for reception of bio-electric signals from the body, each monitoring electrode having a conductive lead and a surrounding shield. The device further has a driving electrode for transmission of a correction voltage to the body. The driving electrode has a conductive lead and a surrounding shield. The device has a signal averager with an input and an output. The monitoring electrode leads are connected to the input of the signal averager. An amplifier is connected to the output of the signal averager which has its output connected to the driving electrode lead to provide the correction voltage. The shield around the driving electrode lead is conductively connected to the output of the amplifier.Type: GrantFiled: January 23, 1989Date of Patent: January 2, 1990Assignee: Cherne Medical, Inc.Inventors: Mark W. Kroll, Kenneth M. Olson, Patrick S. Flynn
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Patent number: 4865039Abstract: A dry electrode system for the detection of biopotentials existing on the surface of the skin of a living body, including a dry electrode pad with a resilient conductive pad adhering to at least one adhesive pad or otherwise having opposed adhesive surfaces, one of which is adapted to engage the skin of the living body. The dry electrode pad makes electrical connection to an amplifying circuit which transmits a biopotential derived from the conductive pad to a monitor. The amplifying circuit includes a conductive input contact for making electrical contact to the conductive pad, a lead amplifier having an input coupled to the input contact, and a voltage driven shield coupled to the output of the lead amplifier and surrounding portions of the input contact not in engagement with the dry electrode pad. In a preferred embodiment, conductive adhesive layers are applied to opposed sides of a conductive foam pad to construct the dry electrode pad.Type: GrantFiled: May 20, 1988Date of Patent: September 12, 1989Assignee: Spring Creek InstituteInventor: W. J. Ross Dunseath, Jr.