Implantable passive bio-sensor

US005704352A

[ii] Patent Number: 5,704,352 [45] Date of Patent: Jan. 6, 1998

5,423,334 6/1995 Jordan .

5,445,150 8/1995 Dumoulin et al 128/899

OTHER PUBLICATIONS

IEEE Transactions on Biomedical Engineering, vol. 42, No. 5, May, 1995, Title: Data Transmission from an Implantable Biotelemeter by Load-Shift Keying Using Circuit Configuration Modulator, by Zhengnian Tang, Brian Smith, John H. Schild, and P. Hunter Peckham. pp. 524-528. Neurosurgery, vol. 34, No. 5, May, 1994, Concepts and Innovations, Title: A New Ventricular Catheter for the Prevention and Treatment of Proximal Obstruction in Cerebrospinal Fluid Shunts, by Enrique C.G. Ventureyra. M.D., F.R.C.S.(C)., F.A.C.S., Michael J. Higgins, M.D., pp. 924-926.

Neurosurgery, vol. 34. No. 6, Jun. 1994, Rapid Communication, Title: The Use of the Codman-Medos Programmable HaMm Valve in the Management of Patients with Hydrocephalus: Illustrative Cases, by Peter McL. Black. M.D., Ph.D., Rodolfo Hakim. M.D., Nancy Olsen Bailey, R.N., B.S.N., M.B.A., pp. 1110-1113.

(List continued on next page.)

Primary Examiner—Jennifer Bahr

Assistant Examiner—Stephen Huang

Attorney, Agent, or Firm—Hovey, Williams, Timmons &

Collins

[57] ABSTRACT

An implantable, passive bio-sensor (10) for monitoring internal physiological conditions of a patient is disclosed. The bio-sensor (10) includes at least one sensor or transducer (12) for monitoring a physiological condition of the patient and a passive transponder (14) that receives sensor signals from the sensor or sensors (12), digitizes the sensor signals, and transmits the digitized signals out of the patient's body when subjected to an externally generated interrogation signal. In one embodiment, the bio-sensor (100) is incorporated into the sidewall of a shunt (102) used for treating hydrocephalus for non-invasively monitoring the operation of the shunt (102).

24 Claims, 2 Drawing Sheets

OTHER PUBLICATIONS

Neurosurgery Clinics of North America vol. 4, No. 4, Oct., 1993. Hydrocephalus, Title: The Treatment of Hydrocephalus by Paul M. Kanev, MD, and T.S. Park. MD. Neurosurgery Clinics of North America, vol. 4, No. 4, Oct, 1993, Hydrocephalus, Title: Complications in Ventricular Cerebrospinal Fluid Shunting by Jeffrey P. Blount, MD, John A. Campbell. MD, and Stephen J. Haines, MD, pp. 633-636.

Neurosurgery Update II Vascular, Spinal, Pediatric, and Functional Neurosurgery, Published by McGraw-Hill, Inc., Editors Robert H. MWlkins, M.D., and Setti S. Rengachary. M.D., Title Shunt Systems by Elisabeth M. Post pp. 300-319.

Pediatric Neurosurgery 2nd Edition, Surgery of the Developing Nervous System. Published by W.B. Saunders Company Harcourt Brace Jovanovich, Inc., Title: Treatment of Hydrocephalus by Harold L. Rekate, M.D.. pp. 200-229.