United States Patent  [ii] Patent Number: 5,031,618
Mullett  Date of Patent: Jul. 16, 1991
 POSITION-RESPONSIVE NEURO STIMULATOR
 Inventor: Keith R. Mullett, Minneapolis, Minn.
 Assignee: Medtronic, Inc., Minneapolis, Minn.
 Appl. No.: 490,065
 Filed: Mar. 7,1990
 Int. CI.' A61N 1/05
 U.S. CI 128/421; 128/784
 Field of Search 128/419 R, 421, 422,
128/423, 783, 784
 References Cited
U.S. PATENT DOCUMENTS
4,044,774 8/1977 Corbin et al 128/419 R
4,141,365 2/1979 Fischell et al .. 128/419 R
4,538,624 9/1985 Tarjan 128/419 R
4,846,195 7/1989 Alt 128/782
Electrical Stimulation of the Spinal Cord, The Phenomenon of Changing Paresthesias, by G. H. Spincemaille and C. H. A. Wittens.
Primary Examiner—Lee S. Cohen
Assistant Examiner—Scott M. Getzow
Attorney, Agent, or Firm—John L. Rooney
An apparatus and technique for electrical stimulation of the central or peripheral nervous system based upon changes in position of the patient. A position sensor may be chronically implanted in the patient. One preferred mode uses a mercury switch position sensor which indicates whether a patient is erect or supine. This position information is used by a chronically implanted pulse generator to vary the stimulation intensity. The intensity may be controlled by changes in pulse amplitude, pulse width, number of pulses per second, burst frequency, number of pulses per burst, electrode polarity, or any other convenient parameter which accomplishes the particular medical purpose within an application. The Output of the chronically implanted pulse generator is applied to the spinal cord, peripheral nerves, and/or targets in the brain with leads and electrodes, in a manner consistent with the given medical need. Such stimulation is useful in the treatment of chronic intractable pain, hemodynamic insufficiency resulting in angina, peripheral vascular disease, cerebral vascular disease, various movement disorders, and bowel and bladder control.
5 Claims, 5 Drawing Sheets