Kevin S Librett

49728407, Nov 27, 1990

Jan 11, 1990

7/463527

John LaViola - Orange CT
Kevin S. Librett - Westport CT

Cas Medical Systems, Inc. - Branford CT

A61B 502

128681

A method and apparatus for determining mean blood pressure involves the use of a pre-programmed microprocessor which interprets pressure oscillation values from a pressure cuff affixed to a subject's limb. The pressure cuff is inflated to a value above apparent systolic pressure and then deflated in steps. The steps are all substantially equal mmHg declinations in cuff pressure. At each step cuff ocsillation values are taken and stored. The greatest cuff oscillation and its associated cuff pressure are noted, along with the next greatest cuff oscillations and associated cuff pressures on either side of the greatest oscillation. The actual mean blood pressure is then determined by forming a window adjacent to the greatest oscillation and calculating, on which side of the greatest oscilation, within the window, the mean pressure is disposed.

55706967, Nov 5, 1996

Jan 26, 1994

8/187275

Jeffrey M. Arnold - Wellesley MA
Paul Albrecht - Bedford MA
Kevin S. Librett - Boston MA
Richard J. Cohen - Waban MA

Cambridge Heart, Inc. - Bedford MA

A61B 50452

128707

The temporal pattern of cycle-to-cycle variability in physiologic waveforms, such as alternans, is assessed by applying transducers to a subject, recording physiologic signals, and analyzing the cycle-to-cycle variation in waveform morphology. Preferred embodiments include the application of physiologic stress to the subject in order to adjust heart rate to the desired range, real-time analysis of waveform variability, reduction in the effect of intercycle variability on waveform variability, improved techniques for determining the statistical significance of the amplitude of a temporal pattern of variability, handling of abnormal beats such as atrial and ventricular premature beats, and assessment of the statistical significance of a measured level of a temporal pattern of variability.

49171160, Apr 17, 1990

Sep 22, 1988

7/247634

John La Viola - Orange CT
Kevin S. Librett - Westport CT

CAS Medical Systems, Inc. - Branford CT

A61B 502

128681

A method and apparatus for determining mean blood pressure involves the use of a pre-programmed microprocessor which interprets pressure oscillation values from a pressure cuff affixed to a subject's limb. The pressure cuff is inflated to a value above apparent systolic pressure and then deflated in steps. The steps are all substantially equal mmHg declinations in cuff pressure. At each step cuff oscillation values are taken and stored. The greatest cuff oscillation and its associated cuff pressure are noted, along with the next greatest cuff oscillations and associated cuff pressures on either side of the greatest oscillation. The actual means blood pressure is then determined by forming a window adjacent to the greatest oscillation and calculating, on which side of the greatest oscillation, within the window, the means pressure is disposed.

59083930, Jun 1, 1999

May 4, 1998

9/071834

Paul Albrecht - Bedford MA
Paul G. Grimshaw - Acton MA
Kevin S. Librett - Natick MA
Jeffrey M. Arnold - Wellesley MA

Cambridge Heart, Inc. - Bedford MA

A61B 50402

600509

A method of reducing noise in a biological signal, such as an ECG signal, includes acquiring a biological signal, comparing the biological signal to a representative signal, and generating a predicted signal corresponding to the representative signal when the biological signal sufficiently matches the representative signal. The predicted signal is subtracted from the biological signal to produce a second signal, and a filter is applied to the second signal to produce a filtered signal. The predicted signal and the filtered signal then are combined to produce a noise-reduced signal.

57133670, Feb 3, 1998

Jan 26, 1995

8/379375

Jeffrey M. Arnold - Wellesley MA
Paul Albrecht - Bedford MA
Kevin S. Librett - Boston MA
Richard J. Cohen - Waban MA

Cambridge Heart, Inc. - Bedford MA

A61B 50452

128704

The alternans pattern of cycle-to-cycle variability in physiologic waveforms is assessed by applying transducers to a subject, recording physiologic signals, and analyzing the alternans pattern of variation in waveform morphology. Preferred embodiments include methods and apparatus for measuring and assessing alternans in the presence of physiologic stress, such as exercise, in order to induce or increase the amplitude of the alternans, improvements in signal processing to improve the sensitivity and specificity of the analysis, improvements to provide real-time analysis and feedback to the operator conducting the recording of physiologic signals, reduction in the effect of intercycle interval variability on waveform variability, reduction in the effects of respiration on the alternans measurement, improved means for determining the statistical significance of the alternans measurement, handling of abnormal beats such as atrial and ventricular premature beats, choosing of data epochs over which to perform the alternans measurement, using multiple electrodes to improve the accuracy of the alternans measurement, and combining measurement of alternans with other cardiovascular diagnostic tests to facilitate and improve the combined diagnostic capability.

56737025, Oct 7, 1997

Jun 10, 1994

8/258511

Paul Albrecht - Bedford MA
Jeffrey M. Arnold - Wellesley MA
Paul E. Grimshaw - Sudbury MA
Kevin S. Librett - Boston MA
Richard J. Cohen - Waban MA

Cambridge Heart, Inc. - Bedford MA

A61B 5044

128712

Method and apparatus for improved electronic display and interpretation of physiologic waveforms. The apparatus generates a two-dimensional grid on the video screen simulating the appearance of electrocardiographic recording paper or other physiologic signal recording paper. At least one physiologic signal is superimposed upon the grid for a display of the combined signal and grid. In a preferred embodiment of the invention the grid includes lines some of which are separated by no more than 2. 6 millimeters. In another embodiment of the invention the grid includes horizontal or vertical lines of at least two types.

20160045693, Feb 18, 2016

Mar 17, 2014

14/776783

Kevin Scott LIBRETT - Watertown MA, US
Karl R. LEINSING - Dover NH, US
- Charlottesville VA, US

HUMAN DESIGN MEDICAL, LLC - Allston MA

A61M 16/00
A61M 16/08
A61M 16/06

The systems, apparatus and methods described herein provide a quiet, light-weight, and portable system and apparatus for providing positive air pressure to a patient. The application discloses a CPAP apparatus () comprising: a housing () defining a first acoustic chamber () with a first inlet port (), and a second acoustic chamber () with a blower unit () and a second inlet port () extending from the first to the second chamber. The CPAP apparatus can be portable. A system can comprise the apparatus comprising an adapter () in communication with the blower unit and extending outward from the apparatus, and a detachable patient interface system (). The apparatus can include alternatively a single acoustic chamber () with an inlet port () most of whose length is within the acoustic chamber, and an outlet port (). The blower unit can be vibrationally isolated. The dimensions of inlet ports and acoustic chambers may be proportionally related, in particular defining an acoustic low-pass filter. The application discloses a method for reducing noise in a portable CPAP device with first and second acoustic chambers, including routing the flow of air through the device, wherein the first inlet is sealed from and passes through the second chamber into the first acoustic chamber, and the flow of air is routed through an outlet port sealed from and passing through the first chamber.

20160015919, Jan 21, 2016

Mar 17, 2014

14/776771

Kevin Scott LIBRETT - Watertown MA, US
Karl R. LEINSING - Dover NH, US
- Charlottesville VA, US

Human Design Medical, LLC - Allston MA

A61M 16/00
A61M 16/08

The application discloses a noise attenuating system () for use with a positive airway pressure system providing a flow of gas, comprising: an expansion chamber () having a volume; an intake GP tube () having an inlet () and outlet port or portion separated by a length, wherein a portion of the inlet port or portion extends outside of the expansion chamber; and either: a noise attenuator () having a bottom and protruding sidewall forming a cavity, wherein the noise attenuator is positioned near the inlet portion of the intake tube such that a portion of the intake tube extends into the cavity of the noise attenuator; or: an acoustic deflector () positioned near the outlet port or portion of the intake tube, wherein noise is deflected away from the outlet port or portion of the intake tube. The application also discloses positive air pressure apparatus () comprising a housing (), first and second acoustic chambers, an intake vent or port () in the first chamber, an inlet port or tube coupling the first and second chambers, a noise attenuator in the first chamber, and a blower unit () in the second chamber.