Patents Assigned to VSM MedTech
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Patent number: 7062391Abstract: The invention provides a method for magnetic imaging of an object. The method comprises monitoring a magnetic field of sources in the object at a plurality of magnetic detectors to obtain a corresponding plurality of sensor outputs, monitoring a position of the object while monitoring the magnetic field of the sources, modeling the magnetic field of the sources in the object as a gradient of a scalar potential, the scalar potential comprising a sum of spherical harmonic functions each multiplied by a corresponding coefficient, and, compensating for the position of the object by applying a transformation to the plurality of sensor outputs, the transformation including, at least in part, a spherical harmonic translation transformation.Type: GrantFiled: March 12, 2004Date of Patent: June 13, 2006Assignee: VSM Medtech Systems Inc.Inventor: Harold Wilson
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Publication number: 20060095220Abstract: The invention provides a method of compensating for crosstalk between electromagnetic sensors in an array, each sensor having a flux transformer with a current therein which does not vary smoothly with an applied magnetic field, each sensor configured to produce an output signal comprising a stepwise varying component and a finely varying component. The method comprises, for each sensor to be compensated, applying a crosstalk compensation function to the output signal of the sensor to be compensated, the crosstalk compensation function based at least in part on at least one of the stepwise and the finely varying components of at least one other of the sensors in the array.Type: ApplicationFiled: November 1, 2004Publication date: May 4, 2006Applicant: VSM MedTech Systems Inc.Inventors: Jiri Vrba, Peter Spear, Jack McCubbin, Richard Willis
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Patent number: 7039547Abstract: A method for locating an object relative to an array of magnetic sensors in an environment in which there is present a noise signal having a fundamental frequency fNOISE, includes generating one or more magnetic signals by means of one or more magnetic emitters mounted at known locations on the object during an integration time T. The one or more magnetic signals have one or more frequencies. The one or more magnetic signals and the noise signal are detected at six or more magnetic detectors. Relative amplitudes of the magnetic signals are determined. The one or more frequencies of the magnetic signals are substantially equal to frequencies at which a power spectrum of the detected noise signal has zeros.Type: GrantFiled: March 12, 2004Date of Patent: May 2, 2006Assignee: VSM Medtech Systems Inc.Inventor: Harold Wilson
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Patent number: 6893401Abstract: A non-invasive apparatus and method for monitoring the blood pressure of a subject detects a pulse signal at both a first and second location on the subject's body The elapsed time between the arrival of corresponding points of the pulse signal at the first and second locations is determined. Blood pressure is related to the elapsed time by relationships such as: P=a+b ln(T), where a and b are constants dependent upon the nature of the subject and the signal detecting devices.Type: GrantFiled: May 15, 2003Date of Patent: May 17, 2005Assignee: VSM Medtech Ltd.Inventors: Yunquan Chen, Luya Li, Cecil Hershler, Ryan Peter Dill
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Publication number: 20050033131Abstract: A sensor assembly for monitoring physiological characteristics interfaces to a subject's ear. The sensor assembly has a projection that projects into the subject's concha. The projection may have a notch to accommodate the subject's anti-tragus. A clip connected to the projection holds a sensor against the subject's lobule. The sensor may comprise a pulse-oximetry-type sensor.Type: ApplicationFiled: July 28, 2004Publication date: February 10, 2005Applicant: VSM MedTechInventors: Yunquan Chen, Luya Li, Rakesh Sethi, Ming Sun, Christopher Denny, Scott Phillips
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Patent number: 6719703Abstract: A method and apparatus for measuring blood pressure by the oscillometric technique. The method incorporates variable PIP's. The method comprises the steps of obtaining a value for the peak amplitude Amax of an oscillometric envelope; determining a cuff pressure, CP, which corresponds in time with Amax, this pressure representing the MAP of the subject; computing a variable value PIPSBP as a function of MAP; performing the calculation Asbp=Amax*PIPSBP to determine a systolic amplitude value Asbp along the oscillometric envelope; and determining the cuff pressure C which corresponds in time to Asbp, this value representing the systolic blood pressure (SBP) of the subject. PIP can be calculated using a piece-wise linear, polynomial, exponential or other function.Type: GrantFiled: June 15, 2001Date of Patent: April 13, 2004Assignee: VSM Medtech Ltd.Inventors: Yunquan Chen, Anton Bogdan Zorn, Kevin Daryl Strange
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Publication number: 20030199770Abstract: A non-invasive apparatus and method for monitoring the blood pressure of a subject detects a pulse signal at both a first and second location on the subject's body The elapsed time between the arrival of corresponding points of the pulse signal at the first and second locations is determined.Type: ApplicationFiled: May 15, 2003Publication date: October 23, 2003Applicant: VSM MEDTECH LTD.Inventors: Yunquan Chen, Luya Li, Cecil Hershler, Ryan Peter Dill
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Patent number: 6599251Abstract: A non-invasive apparatus and method for monitoring the blood pressure of a subject detects a pulse signal at both a first and second location on the subject's body. The elapsed time between the arrival of corresponding points of the pulse signal at the first and second locations is determined. Blood pressure is related to the elapsed time by relationships such as: P=a+b ln(T) where a and b are constants dependent upon the nature of the subject and the signal detecting devices. The system can be calibrated by measuring a single pair of reference blood pressure and corresponding elapsed time.Type: GrantFiled: July 27, 2001Date of Patent: July 29, 2003Assignee: VSM Medtech Ltd.Inventors: Yunquan Chen, Luya Li, Cecil Hershler, Ryan Peter Dill
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Publication number: 20030045801Abstract: A method and apparatus for measuring blood pressure by the oscillometric technique. The method incorporates variable PIP's. The method comprises the steps of obtaining a value for the peak amplitude Amax of an oscillometric envelope; determining a cuff pressure, CP, which corresponds in time with Amax, this pressure representing the MAP of the subject; computing a variable value PIPSBP as a function of MAP; performing the calculation Asbp=Amax*PIPSBP to determine a systolic amplitude value Asbp along the oscillometric envelope; and determining the cuff pressure C which corresponds in time to Asbp, this value representing the systolic blood pressure (SBP) of the subject. PIP can be calculated using a piece-wise linear, polynomial, exponential or other function.Type: ApplicationFiled: June 15, 2001Publication date: March 6, 2003Applicant: VSM Medtech Ltd.Inventors: Yunquan Chen, Anton Bogdan Zorn, Kevin Daryl Strange
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Patent number: 6503206Abstract: Apparatus for monitoring one or more vital signs of a subject has a number of sensors. There is at least one redundant sensor. Each sensor originates a signal. A selection system determines performance criteria for a number of groups of signals. Each group includes one or more signals. The apparatus computes a predicted value for a vital sign by either computing a value from each group of signals and taking a weighted average with weights based upon the performance criterion or by selecting one of the groups of signals for which the performance criterion is best and computing the output value from that group of signals. The output values are relatively insensitive to artifacts and to errors caused by the disconnection or malfunctioning of one sensor.Type: GrantFiled: July 27, 2001Date of Patent: January 7, 2003Assignee: VSM Medtech LTDInventors: Luya Li, Yunquan Chen, Rakesh Kumar Sethi, Ming Sun