Biological Signal Amplifier Patents (Class 128/902)
  • Patent number: 10945653
    Abstract: 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: Grant
    Filed: May 31, 2016
    Date of Patent: March 16, 2021
    Assignee: Koninklijke Philips N.V.
    Inventors: Alan James Davie, Sandrine Magali Laure Devot, Rene Martinus Maria Derkx, Jakob Van De Laar
  • Patent number: 10682076
    Abstract: 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: Grant
    Filed: June 3, 2016
    Date of Patent: June 16, 2020
    Assignee: LEAF HEALTHCARE, INC.
    Inventors: Barrett J. Larson, Daniel Z. Shen
  • Patent number: 10298334
    Abstract: 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: Grant
    Filed: February 21, 2017
    Date of Patent: May 21, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: James E. Bostick, John M. Ganci, Jr., Martin G. Keen, Sarbajit K. Rakshit
  • Patent number: 10251712
    Abstract: 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 electromagne
    Type: Grant
    Filed: November 29, 2017
    Date of Patent: April 9, 2019
    Assignee: MediGuide Ltd.
    Inventors: Itzhak Shmarak, Gera Strommer, Uzi Eichler
  • Patent number: 10194827
    Abstract: 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: Grant
    Filed: December 8, 2016
    Date of Patent: February 5, 2019
    Assignee: Drägerk AG & Co. KGaA
    Inventors: Jianhua Li, Frank Sattler, Karsten Hiltawsky
  • Patent number: 9980669
    Abstract: 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: Grant
    Filed: November 7, 2012
    Date of Patent: May 29, 2018
    Assignee: ABBOTT DIABETES CARE INC.
    Inventors: Jean-Pierre Cole, Martin J. Fennell
  • Patent number: 9956049
    Abstract: 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 electromagne
    Type: Grant
    Filed: February 9, 2017
    Date of Patent: May 1, 2018
    Assignee: MediGuide Ltd.
    Inventors: Itzhak Shmarak, Gera Strommer, Uzi Eichler
  • Patent number: 9872629
    Abstract: 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: Grant
    Filed: February 3, 2016
    Date of Patent: January 23, 2018
    Assignee: Siemens Aktiengesellschaft
    Inventors: Ulrich Batzer, Peter Greif, Harald Karl
  • Patent number: 9853611
    Abstract: 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: Grant
    Filed: March 2, 2015
    Date of Patent: December 26, 2017
    Assignee: Northeastern University
    Inventors: Chun-hsiang Chang, Marvin Onabajo
  • Patent number: 9808170
    Abstract: 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: Grant
    Filed: March 15, 2013
    Date of Patent: November 7, 2017
    Assignee: Welch Allyn, Inc.
    Inventors: John A. Lane, Benjamin Freer, David E. Quinn, Frederik W. Kroon
  • Patent number: 9757071
    Abstract: 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: Grant
    Filed: April 29, 2016
    Date of Patent: September 12, 2017
    Assignee: BAYER HEALTHCARE LLC
    Inventors: Bruno Fazi, Jr., Jason Palmer
  • Patent number: 8961412
    Abstract: 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: Grant
    Filed: September 25, 2008
    Date of Patent: February 24, 2015
    Assignee: Proteus Digital Health, Inc.
    Inventors: Hooman Hafezi, Benedict James Costello, Timothy L. Robertson, Maria Casillas Holen
  • Patent number: 8545402
    Abstract: 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: Grant
    Filed: April 27, 2010
    Date of Patent: October 1, 2013
    Assignee: Proteus Digital Health, Inc.
    Inventors: Hooman Hafezi, Kityee Au-Yeung, Robert Duck, Maria Holen, Timothy Robertson, Benedict Costello
  • Patent number: 8430860
    Abstract: 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: Grant
    Filed: August 30, 2007
    Date of Patent: April 30, 2013
    Assignee: MED-EL Elektromedizinische Geraete GmbH
    Inventors: Werner Lindenthaler, Andreas Müller
  • Patent number: 7734333
    Abstract: 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: Grant
    Filed: April 28, 2006
    Date of Patent: June 8, 2010
    Assignee: Medtronic, Inc.
    Inventors: Raja N. Ghanem, Robert W. Stadler, Xusheng Zhang
  • Patent number: 7587239
    Abstract: 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: Grant
    Filed: June 26, 2006
    Date of Patent: September 8, 2009
    Assignee: Pacesetter, Inc.
    Inventors: Mark W. Kroll, John W. Poore
  • Patent number: 7299083
    Abstract: 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: Grant
    Filed: December 9, 2004
    Date of Patent: November 20, 2007
    Assignee: Signalife, Inc.
    Inventor: Budimir Drakulic
  • Patent number: 7235050
    Abstract: 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: Grant
    Filed: August 18, 2004
    Date of Patent: June 26, 2007
    Assignee: Alfred E. Mann Foundation for Scientific Research
    Inventors: Joseph H. Schulman, Christian Perron
  • Patent number: 7171269
    Abstract: 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: Grant
    Filed: May 2, 2000
    Date of Patent: January 30, 2007
    Assignee: Cardiodigital Limited
    Inventors: Paul Stanley Addison, James Nicholas Watson
  • Patent number: 7092762
    Abstract: 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: Grant
    Filed: May 23, 2003
    Date of Patent: August 15, 2006
    Assignee: Advanced Bionics Corporation
    Inventors: Scott M Loftin, Kelly H McClure
  • Patent number: 7079901
    Abstract: 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: Grant
    Filed: May 23, 2003
    Date of Patent: July 18, 2006
    Assignee: Advanced Bionics Corporation
    Inventors: Scott M Loftin, Kelly H McClure
  • Patent number: 6865409
    Abstract: 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: Grant
    Filed: November 7, 2002
    Date of Patent: March 8, 2005
    Assignee: Kinesense, Inc.
    Inventors: Robert M. Getsla, Victor F. Simonyi
  • Patent number: 6834205
    Abstract: 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: Grant
    Filed: January 20, 2004
    Date of Patent: December 21, 2004
    Assignee: Cardiac Pacemakers, Inc.
    Inventors: Jason W. Eberle, LeAnne Marie Mackey
  • Patent number: 6807438
    Abstract: 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: Grant
    Filed: September 30, 2002
    Date of Patent: October 19, 2004
    Inventors: Riccardo Brun Del Re, Izmail Batkin, Wayne Young
  • Patent number: 6778855
    Abstract: 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: Grant
    Filed: July 9, 2001
    Date of Patent: August 17, 2004
    Assignee: Cardiac Pacemakers, Inc.
    Inventors: Jason W. Eberle, LeAnne Marie Mackey
  • Patent number: 6728564
    Abstract: 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: Grant
    Filed: July 3, 2001
    Date of Patent: April 27, 2004
    Assignee: Instrumentarium Corp.
    Inventor: Markku Lähteenmäki
  • Patent number: 6718191
    Abstract: 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: Grant
    Filed: June 11, 2001
    Date of Patent: April 6, 2004
    Assignee: Medikro Oy
    Inventors: Mikko Eloranta, Olli Pohjolainen
  • Patent number: 6334068
    Abstract: 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: Grant
    Filed: September 14, 1999
    Date of Patent: December 25, 2001
    Assignee: Medtronic Xomed, Inc.
    Inventor: David C. Hacker
  • Patent number: 6317625
    Abstract: 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: Grant
    Filed: November 15, 2000
    Date of Patent: November 13, 2001
    Assignee: Medtronic Inc.
    Inventors: Dana J. Olson, David W. Van Ess, Robert W. Stadler, Steven N. Lu, Jeffrey D. Wilkinson, Tara N. Ptak
  • Patent number: 6302686
    Abstract: 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: Grant
    Filed: December 2, 2000
    Date of Patent: October 16, 2001
    Assignee: Keller Laboratories Inc.
    Inventors: Bradley J. Chott, Michael R. Mohrhard
  • Patent number: 6208888
    Abstract: 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: Grant
    Filed: February 3, 1999
    Date of Patent: March 27, 2001
    Assignee: Cardiac Pacemakers, Inc.
    Inventor: David J. Yonce
  • Patent number: 6016446
    Abstract: 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: Grant
    Filed: February 27, 1998
    Date of Patent: January 18, 2000
    Assignee: Cardiac Pacemakers, Inc.
    Inventor: Hugo Andres Belalcazar
  • Patent number: 5954660
    Abstract: 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: Grant
    Filed: January 7, 1998
    Date of Patent: September 21, 1999
    Assignee: ELA Medical, S.A.
    Inventors: Thierry Legay, Pascal Pons, Luc Garcia
  • Patent number: 5724967
    Abstract: 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: Grant
    Filed: November 21, 1995
    Date of Patent: March 10, 1998
    Assignee: Nellcor Puritan Bennett Incorporated
    Inventor: Kalpathi Lakshminarayanan Venkatachalam
  • Patent number: 5713365
    Abstract: 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: Grant
    Filed: July 31, 1996
    Date of Patent: February 3, 1998
    Inventor: Arrigo Castelli
  • Patent number: 5709213
    Abstract: 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: Grant
    Filed: September 17, 1996
    Date of Patent: January 20, 1998
    Assignee: Medtronic, Inc.
    Inventors: John M. Kruse, Dave R. Jurek
  • Patent number: 5678559
    Abstract: 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: Grant
    Filed: January 23, 1995
    Date of Patent: October 21, 1997
    Inventor: Budimir S. Drakulic
  • Patent number: 5427111
    Abstract: 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: Grant
    Filed: December 1, 1993
    Date of Patent: June 27, 1995
    Assignee: Hewlett Packard Company
    Inventors: Stefan Traub, Heinz Sommer
  • Patent number: 5427110
    Abstract: 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: Grant
    Filed: September 3, 1993
    Date of Patent: June 27, 1995
    Assignee: Siemens Aktiengesellschaft
    Inventors: Peter Danielsson, Thomas Ohlsson
  • Patent number: 5414392
    Abstract: 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: Grant
    Filed: August 26, 1993
    Date of Patent: May 9, 1995
    Assignee: MedCom Electronics
    Inventor: Leonard Schupak
  • Patent number: 5392784
    Abstract: 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: Grant
    Filed: August 20, 1993
    Date of Patent: February 28, 1995
    Assignee: Hewlett-Packard Company
    Inventor: Algird M. Gudaitis
  • Patent number: 5368041
    Abstract: 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: Grant
    Filed: October 15, 1992
    Date of Patent: November 29, 1994
    Assignee: Aspect Medical Systems, Inc.
    Inventor: John R. Shambroom
  • Patent number: 5360008
    Abstract: 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: Grant
    Filed: November 18, 1992
    Date of Patent: November 1, 1994
    Inventor: William G. Campbell, Jr.
  • Patent number: 5111814
    Abstract: A laryngeal pacemaker stimulates a paralyzed muscle in mirror image synchronism with a normally functioning muscle.
    Type: Grant
    Filed: July 6, 1990
    Date of Patent: May 12, 1992
    Assignee: Thomas Jefferson University
    Inventor: David Goldfarb
  • Patent number: 5018523
    Abstract: 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: Grant
    Filed: April 23, 1990
    Date of Patent: May 28, 1991
    Assignee: Cardiac Pacemakers, Inc.
    Inventors: Stanley M. Bach, Jr., Douglas J. Lang, David K. Swanson, Roger W. Dahl
  • Patent number: 5002064
    Abstract: 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: Grant
    Filed: August 31, 1989
    Date of Patent: March 26, 1991
    Inventors: Joseph L. Allain, Henry Halperin
  • Patent number: 4899760
    Abstract: 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: Grant
    Filed: June 15, 1987
    Date of Patent: February 13, 1990
    Assignee: Colin Electronics Co., Ltd.
    Inventors: Jonathan P. Jaeb, Merle E. Converse
  • Patent number: 4896120
    Abstract: 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: Grant
    Filed: March 24, 1987
    Date of Patent: January 23, 1990
    Inventor: Zvi Kamil
  • Patent number: 4890630
    Abstract: 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: Grant
    Filed: January 23, 1989
    Date of Patent: January 2, 1990
    Assignee: Cherne Medical, Inc.
    Inventors: Mark W. Kroll, Kenneth M. Olson, Patrick S. Flynn
  • Patent number: 4865039
    Abstract: 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: Grant
    Filed: May 20, 1988
    Date of Patent: September 12, 1989
    Assignee: Spring Creek Institute
    Inventor: W. J. Ross Dunseath, Jr.