| 摘要 |
657,138. Electro-therapeutic apparatus. NEMEC, H. Nov. 13, 1948, No. 29533. Convention date, Dec. 8, 1947. [Class 81(ii)] An electro-medical apparatus for producing a deeply placed stimulation without affecting the surface tissues employs two separate sources of current 3, 6 the outputs of which differ slightly in frequency and are applied to the patient by separate pairs of electrodes 8, 9 and 10, 11. The individual frequencies are too high (e.g. 3 Kc/s) to produce any effect on the patient but by suitable placing of the electrodes a resultant field may be produced at a point within the tissue comprising a beat frequency of comparatively low periodicity which produces the required stimulation. In the arrangement shown, a mains transformer 1 supplies the oscillator 3, 6 through power units 2, 5 and these feed the electrodes through output units 4, 7. The frequency of oscillator 6 is made variable by a condenser 14. Specification 651,951, is referred to.
|
