Patents by Inventor Daniel K. Freeman
Daniel K. Freeman has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11774520Abstract: Ferrimagnetic oscillator magnetometers do not use lasers to stimulate fluorescence emission from defect centers in solid-state hosts (e.g., nitrogen vacancies in diamonds). Instead, in a ferrimagnetic oscillator magnetometer, the applied magnetic field shifts the resonance of entangled electronic spins in a ferrimagnetic crystal. These spins are entangled and can have an ensemble resonance linewidth of approximately 370 kHz to 10 MHz. The resonance shift produces microwave sidebands with amplitudes proportional to the magnetic field strength at frequencies proportional to the magnetic field oscillation frequency. These sidebands can be coherently averaged, digitized, and coherently processed, yielding magnetic field measurements with sensitivities possibly approaching the spin projection limit of 1 attotesla/?{square root over (Hz)}. The encoding of magnetic signals in frequency rather than amplitude relaxes or removes otherwise stringent requires on the digitizer.Type: GrantFiled: May 12, 2021Date of Patent: October 3, 2023Assignee: Massachusetts Institute of TechnologyInventors: John F. Barry, Reed Anderson Irion, Jessica Kedziora, Matthew Steinecker, Daniel K. Freeman, Danielle A. Braje
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Patent number: 11327102Abstract: Aspects are generally directed to a compact and low-noise electric field detector, methods of operation, and methods of production thereof. In one example, an electric field detector includes a proof mass, a source of concentrated charge coupled to the proof mass, and a substrate having a substrate offset space defined therein, the proof mass being suspended above the substrate offset space. The electric field detector further includes a sense electrode disposed on the substrate within the substrate offset space and proximate the proof mass, the sense electrode being configured to measure a change in capacitance relative to the proof mass from movement of the proof mass in response to a received electric field at the source of concentrated charge. The electric field detector includes a control circuit coupled to the sense electrode and configured to determine a characteristic of the electric field based on the measured change in capacitance.Type: GrantFiled: August 25, 2020Date of Patent: May 10, 2022Assignee: THE CHARLES STARK DRAPER LABORATORY, INC.Inventors: James A. Bickford, Stephanie Lynne Golmon, Paul A. Ward, William D. Sawyer, Marc Steven Weinberg, John J. Le Blanc, Louis Kratchman, James S. Pringle, Jr., Daniel K. Freeman, Amy Duwel, Max Lindsay Turnquist, Ronald Steven McNabb, Jr., William A. Lenk
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Patent number: 11261465Abstract: A method and system of delivering a charged cargo, such as a biomolecule, to a target structure, such as cells, exosomes, other vesicles or micelles, using an electroactive porous membrane. This method comprises contacting an electroactive porous membrane with a fluid flow toward the membrane. The fluid contains charged biomolecules and the membrane and biomolecules are oppositely charged so that the biomolecules in the fluid are trapped on the membrane as the fluid flows through the pores of the membrane. Acceptor cells of interest are pinned to the membrane by the flow of the fluid, thereby aggregating the cells onto the membrane in close proximity to the trapped biomolecules. Finally, the acceptor cells are permeabilized.Type: GrantFiled: July 3, 2018Date of Patent: March 1, 2022Assignee: The Charles Stark Draper Laboratory, Inc.Inventors: Vishal Tandon, Daniel K. Freeman, Jonathan R. Coppeta, Jeffrey T. Borenstein, Jenna L. Balestrini
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Publication number: 20220011383Abstract: Ferrimagnetic oscillator magnetometers do not use lasers to stimulate fluorescence emission from defect centers in solid-state hosts (e.g., nitrogen vacancies in diamonds). Instead, in a ferrimagnetic oscillator magnetometer, the applied magnetic field shifts the resonance of entangled electronic spins in a ferrimagnetic crystal. These spins are entangled and can have an ensemble resonance linewidth of approximately 370 kHz to 10 MHz. The resonance shift produces microwave sidebands with amplitudes proportional to the magnetic field strength at frequencies proportional to the magnetic field oscillation frequency. These sidebands can be coherently averaged, digitized, and coherently processed, yielding magnetic field measurements with sensitivities possibly approaching the spin projection limit of 1 attotesla/?{square root over (Hz)}. The encoding of magnetic signals in frequency rather than amplitude relaxes or removes otherwise stringent requires on the digitizer.Type: ApplicationFiled: May 12, 2021Publication date: January 13, 2022Applicant: Massachusetts Institute of TechnologyInventors: John F. Barry, Reed Anderson Irion, Jessica Kedziora, Matthew Steinecker, Daniel K. Freeman, Danielle A. Braje
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Publication number: 20210369206Abstract: Circuits are provided for detecting an electrosurgical unit signal. An example circuit includes: a filter configured to process a floating ground signal associated with measuring a bio-potential signal of a patient, and a detector configured to output a sensing signal based at least in part on the floating grounding and the Earth ground for detecting an electrosurgical unit signal.Type: ApplicationFiled: August 12, 2021Publication date: December 2, 2021Inventors: Daniel K. Freeman, Ronald Gatzke
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Patent number: 11167134Abstract: A system for providing biphasic stimulation is disclosed. The system includes an electrode, an antenna coupled to a transmitter, a capacitor, a power supply, a backscatter load selectively coupled to the antenna via a switching device, a plurality of switches, and a controller configured to control the switching device to output, by the antenna, an acknowledgement signal to the transmitter responsive to receiving the power. The controller is further configured to control the plurality of switches to electrically couple a first plate of the capacitor to the electrode to provide a first nerve stimulation signal having a first polarity, and electrically couple a second plate of the capacitor to the electrode to provide a second nerve stimulation signal having a second polarity opposite the first polarity. The system further includes a housing encapsulating the antenna, the capacitor, the power supply, the backscatter load, the switches, and the controller.Type: GrantFiled: December 3, 2018Date of Patent: November 9, 2021Assignee: THE CHARLES STARK DRAPER LABORATORY, INC.Inventors: Daniel J. Guyon, Daniel K. Freeman, Jesse J. Wheeler
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Patent number: 11103190Abstract: Circuits are provided for detecting an electrosurgical unit signal. An example circuit includes: a filter configured to process a floating ground signal associated with measuring a bio potential signal of a patient, and a detector configured to output a sensing signal based at least in part on the floating grounding and the Earth ground for detecting an electrosurgical unit signal.Type: GrantFiled: December 17, 2015Date of Patent: August 31, 2021Assignee: Drägerwerk AG & Co. KGaAInventors: Daniel K. Freeman, Ronald Gatzke
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Publication number: 20200386803Abstract: Aspects are generally directed to a compact and low-noise electric field detector, methods of operation, and methods of production thereof. In one example, an electric field detector includes a proof mass, a source of concentrated charge coupled to the proof mass, and a substrate having a substrate offset space defined therein, the proof mass being suspended above the substrate offset space. The electric field detector further includes a sense electrode disposed on the substrate within the substrate offset space and proximate the proof mass, the sense electrode being configured to measure a change in capacitance relative to the proof mass from movement of the proof mass in response to a received electric field at the source of concentrated charge. The electric field detector includes a control circuit coupled to the sense electrode and configured to determine a characteristic of the electric field based on the measured change in capacitance.Type: ApplicationFiled: August 25, 2020Publication date: December 10, 2020Inventors: James A. Bickford, Stephanie Lynne Golmon, Paul A. Ward, William D. Sawyer, Marc Steven Weinberg, John J. Le Blanc, Louis Kratchman, James S. Pringle, JR., Daniel K. Freeman, Amy Duwel, Max Lindsay Turnquist, Ronald Steven McNabb, JR., William A. Lenk
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Patent number: 10390727Abstract: A system and method for imaging in connection with electrical currents includes nanoparticles introduced into a region in which the electrical currents are present. A low-field magnetic resonance imaging (MRI) scanner detects an effect of a magnetic field generated by interaction of the nanoparticles with the electrical currents in the region. The MRI scanner operates at a magnetic field intensity below a level at which the nanoparticles would be magnetically saturated.Type: GrantFiled: April 21, 2017Date of Patent: August 27, 2019Assignees: THE CHARLES STARK DRAPER LABORATORY, INC., THE GENERAL HOSPITAL CORPORATIONInventors: Daniel K. Freeman, Matthew Rosen
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Publication number: 20190167989Abstract: A system for providing biphasic stimulation is disclosed. The system includes an electrode, an antenna coupled to a transmitter, a capacitor, a power supply, a backscatter load selectively coupled to the antenna via a switching device, a plurality of switches, and a controller configured to control the switching device to output, by the antenna, an acknowledgement signal to the transmitter responsive to receiving the power. The controller is further configured to control the plurality of switches to electrically couple a first plate of the capacitor to the electrode to provide a first nerve stimulation signal having a first polarity, and electrically couple a second plate of the capacitor to the electrode to provide a second nerve stimulation signal having a second polarity opposite the first polarity. The system further includes a housing encapsulating the antenna, the capacitor, the power supply, the backscatter load, the switches, and the controller.Type: ApplicationFiled: December 3, 2018Publication date: June 6, 2019Inventors: Daniel J. Guyon, Daniel K. Freeman, Jesse J. Wheeler
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Publication number: 20190083048Abstract: A system is described for multi-frequency ultrasonically-encoded tomography of a target object. One or more probe inputs generate probe input signals to the target object. An ultrasound transducer array is placed on the outer surface of the target object and has multiple ultrasound transducers each generating a different time-dependent waveform to form a plurality of ultrasound input signals to a target probe volume within the target object. One or more sensors sense tomography output signals from the target probe volume, wherein the tomography output signals contain an interaction component generated by interaction of the probe input signals with the ultrasound input signals. A tomography analysis of the tomography output signals is performed to create a three-dimensional object map representing structural and/or functional characteristics of the target object.Type: ApplicationFiled: September 18, 2018Publication date: March 21, 2019Inventors: Steven J. Byrnes, Joseph Hollmann, Daniel K. Freeman
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Publication number: 20190010516Abstract: A method and system of delivering a charged cargo, such as a biomolecule, to a target structure, such as cells, exosomes, other vesicles or micelles, using an electroactive porous membrane. This method comprises contacting an electroactive porous membrane with a fluid flow toward the membrane. The fluid contains charged biomolecules and the membrane and biomolecules are oppositely charged so that the biomolecules in the fluid are trapped on the membrane as the fluid flows through the pores of the membrane. Acceptor cells of interest are pinned to the membrane by the flow of the fluid, thereby aggregating the cells onto the membrane in close proximity to the trapped biomolecules. Finally, the acceptor cells are permeabilized.Type: ApplicationFiled: July 3, 2018Publication date: January 10, 2019Inventors: Vishal Tandon, Daniel K. Freeman, Jonathan R. Coppeta, Jeffrey T. Borenstein, Jenna L. Balestrini
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Publication number: 20190000393Abstract: Circuits are provided for detecting an electrosurgical unit signal. An example circuit includes: a filter configured to process a floating ground signal associated with measuring a bio potential signal of a patient, and a detector configured to output a sensing signal based at least in part on the floating grounding and the Earth ground for detecting an electrosurgical unit signal.Type: ApplicationFiled: December 17, 2015Publication date: January 3, 2019Applicant: Drägerwerk AG & Co. KGaAInventors: Daniel K. Freeman, Ronald Gatzke
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Publication number: 20180303373Abstract: A system and method for imaging in connection with electrical currents includes nanoparticles introduced into a region in which the electrical currents are present. A low-field magnetic resonance imaging (MRI) scanner detects an effect of a magnetic field generated by interaction of the nanoparticles with the electrical currents in the region. The MRI scanner operates at a magnetic field intensity below a level at which the nanoparticles would be magnetically saturated.Type: ApplicationFiled: April 21, 2017Publication date: October 25, 2018Applicants: The Charles Stark Draper Laboratory, Inc., The Massachusetts General HospitalInventors: Daniel K. Freeman, Matthew Rosen
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Publication number: 20180249954Abstract: This invention provides a system and method for performing a surgical procedure that effectively locates and allows a user to avoid engagement with hidden nerves in tissue in real-time. The system and method employs an integrated stimulating and sensing array. The array includes a plurality of spaced-apart electrodes, which are selectively stimulated while the electrodes then sense for a neural response. Each of the electrodes is stimulated to map of the sensed tissue region for localization of nerve paths. This localization can be stored and used to control cutting of tissue. The locations can be marked as nerve-free and/or no-go regions so as to avoid nerve-containing regions in subsequent procedures or following a stimulation procedure. This marking can be by any acceptable physical and/or virtual fiducial mechanism. The array can be a single structure with all relevant electrodes or some electrodes can be provided in a separate, remote probe assembly.Type: ApplicationFiled: March 1, 2018Publication date: September 6, 2018Inventors: Daniel K. Freeman, Andrew A. Berlin, Jesse Wheeler
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Publication number: 20120083861Abstract: The present invention provides for a method of selectively activating synaptically mediated responses in ganglion cells without activating passing axons, by contacting a focal region around said cells with an electrode that stimulates using low-frequency sinusoidal electric signal. In particular, the selective low-frequency sinusoidal stimulation has a frequency of ?25 Hz. specific frequencies of sinusoidal stimulation, which can be used to preferentially activate certain neural cell types, including retinal cells: ganglion cells at 100 Hz, photoreceptors are activated at 5 Hz, and bipolar cells at 25 Hz.Type: ApplicationFiled: October 4, 2011Publication date: April 5, 2012Applicant: THE GENERAL HOSPITAL CORPORATIONInventors: Shelley I. Fried, Daniel K. Freeman
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Patent number: 5276765Abstract: Voice activity detector (VAD) for use in an LPC coder in a mobile radio system uses autocorrelation coefficient R.sub.0, R.sub.1 . . . of the input signal, weighted and combined, to provide a measure M which depends on the power within that part of the spectrum containing no noise, which is thresholded against a variable threshold to provide a speech/no speech logic output. The measure is formula (I), where H.sub.i are the autocorrelation coefficients of the impulse response of an Nth order FIR inverse noise filter derived from LPC analysis of previous non-speech signal frames. Threshold adaption and coefficient update are controlled by a second VAD response to rate of spectral change between frames.Type: GrantFiled: September 28, 1992Date of Patent: January 4, 1994Assignee: British Telecommunications public limited companyInventors: Daniel K. Freeman, Ivan Boyd
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Patent number: 4991214Abstract: Speech is analyzed to derive the parameters of a synthesis filter and the parameters of a suitable excitation which is selected from a codebook of excitation frames. The selection of the codebook entry is facilitated by determining a single-pulse excitation (e.g., using conventional multipulse excitation techniques), and using the position of this pulse to narrow the codebook search.Type: GrantFiled: May 9, 1989Date of Patent: February 5, 1991Assignee: British Telecommunications public limited companyInventors: Daniel K. Freeman, Ivan Boyd
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Patent number: RE35057Abstract: Speech is analyzed to derive the parameters of a synthesis filter and the parameters of a suitable excitation which is selected from a codebook of excitation frames. The selection of the codebook entry is facilitated by determining a single-pulse excitation (e.g., using conventional multipulse excitation techniques), and using the position of this pulse to narrow the codebook search.Type: GrantFiled: February 3, 1993Date of Patent: October 10, 1995Assignee: British Telecommunications public limited companyInventors: Daniel K. Freeman, Ivan Boyd