Patents by Inventor Donald L. Lappe

Donald L. Lappe 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).

  • Patent number: 4109647
    Abstract: An apparatus for measuring the flow parameter of blood flowing in an organ includes a laser and associated optics which effect the illumination of tissues. The laser light, scattered by the tissues, emerges with a spectrum broadened by Doppler effect due to motion of red blood cells in the micro-circulation vessels. The light from the tissues is fed to a photomultiplier tube or photodiode via a pinhole mask and interference filter. The photomultiplier tube or photodiode, as a result of beating of various components of the light it receives, produces as its output signals a homodyne or heterodyne spectrum or both. These output signals are fed, via a low pass filter, to a differentiator, which differentiates the output signals from the multiplier tube or photodiode, which are passed by the filter, with respect to time. The output of the differentiator is fed to a root-mean-square (RMS) detector. The low pass filter passes, for example, signals having a frequency up to about 20 KHz.
    Type: Grant
    Filed: March 16, 1977
    Date of Patent: August 29, 1978
    Assignee: The United States of America as represented by the Secretary of the Department of Health, Education and Welfare
    Inventors: Michael D. Stern, Donald L. Lappe