Microprobe for monitoring biophysical phenomena associated with cardiac and ...

[76] Inventors: Trygve Aaby, 312 S. Hayford St., Lansing, Mich. 48910; Barnett Rosenberg, 2687 Ramparte Path, Holt, Mich. 48824 [21] Appl. No.: 136,317 [22] Filed: Apr. 1, 1980 [51] Int. C1.3 .............................................. .. A61B 5/04 [52] U.S. Cl. ................................ .. 128/653; 324/58 B; 324/58.5 B; 343/772 [58] Field of Search ............. .. 128/653, 718, 715, 748, 128/804; 179/1 ST; 324/58 B, 58.5 B; 343/772; 329/161, 193 [56] References Cited U.S. PATENT DOCUMENTS 2,407,690 9/1946 Southworth ...................... .. 128/804 3,102,232 8/1963 Leonard et al. 324/58.5 B 3,115,131 12/1963 Holliday ..... .. 128/653 3,483,860 12/1969 Namerow 128/653 3,561,430 2/1971 Filler et al. 128/661 3,796,208 3/1974 Bloice ........ .. 128/653 3,951,134 4/1976 Malech 128/653 4,085,740 4/1978 Allen, Jr. . 128/653 4,138,998 2/1979 Nowogrodzki 128/736 4,162,500 7/1979 Jacobi et al. ...................... .. 128/653 OTHER PUBLICATIONS

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Primary Examiner-Kyle L. Howell

Assistant Examiner—Francis J . J aworski

Attorney, Agent, or Firm—Kerkam, Stowell, Kondracki & Clarke

[57] ABSTRAC1‘

A portable microprobe uses 10 gigahertz CW microwave radiation at a power level of less than 10 milliwatts for recording of a number of biophysical phenomena associated with the cardiac and neural activity of the life system. The microprobe consists of a Gunn diode feeding power into a short, insulated dielectric waveguide, the free end of which houses a point contact semiconductor diode isolated by a metal shield from the incident beam. The wave guide concentrates and delivers a pencil shaped beam into the tissue of interest and the back-scattered radiation is modulated and detected by the diode. The detected signal is filtered, amplified and recorded to reflect on-going biological activity. The receiver electronics is housed in a small self-contained package and has its output connected through a flexible attachment to two ear tubes which enable continuous monitoring of the audio response through an electrical and-audio converter indicative of the ongoing biological activity. By scanning step wise across the chest, the microprobe allows localization of many details of cardiac activity. The microprobe can also be used to monitor activities of the brain and the spinal cord.