METHOD OF PUNCTURING A MEDICAL INSTRUMENT UNDER GUIDANCE OF ULTRASOUND

• US 3,556,079 A
• Filed: 04/03/1968
• Issued: 01/19/1971
• Est. Priority Date: 05/16/1967
• Status: Expired due to Term

• Current Assignee: Omizo Haruo
• Original Assignee: Omizo Haruo
• Inventors: OMIZO HARUO
• Application Number:
  US04/718,474
• Time in Patent Office: 1,021 Days
• US Class Current: 600/461
• CPC Class Codes: A61B 17/3403 Needle locating or guiding means guides for suture needles A61B17/0482; guiding or tracking by nuclear magnetic resonance G01R33/285
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures
• CPC Class Codes: A61B 8/0841 for locating instruments
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61M 5/46 having means for controlling depth of insertion

Abstract

A method of inserting a medical instrument under guidance of ultrasound, which is characterized by transmitting an ultrasonic beam toward the internal parts of the human body, receiving backscattered waves which have changed their frequency in accordance with the Doppler effect caused by the movement of a part of the internal parts, and utilizing the backscattered waves as a guide to insert a medical instrument such as a puncture needle so that the instrument can approach or reach or puncture the part easily.

Claims

1. A method of inserting a medical instrument into a body under the guidance of ultrasound, comprising the steps of actuating a transmitting transducer means to transmit a beam of ultrasonic sound waves into the human body toward a moving part, picking up backscattered waves on a receiving transducer means the frequency of which have been changed due to the Doppler effect by the movement of the part toward which the beam is directed, at least one of said transducer means being mounted on said instrument, converting the received backscattered waves into an electrical signal having an audiofrequency amplifying the audiofrequency signal and reproducing it as an audible signal, and inserting the medical instrument into the body and guiding it toward the moving part by adjusting the position or the direction of insertion so as to obtain the maximum detected sound.

2. A method as claimed in claim 1 in which the transducer means for tramsmitting and receiving ultrasonic waves are both mounted on a part of the medical instrument and directed in substantially the same direction as the instrument extends during insertion.

3. A method as claimed in claim 1 in which the ultrasonic tram transmitting transducer means is on said medical instrument and said ultrasonic receiving transducer means is applied to the body into which the instrument is being inserted.

4. A method as claimed in claim 1 in which the ultrasonic receiving transducer means is on said medical instrument and said ultrasonic transmitting transducer means is applied to the body into which the instrument is being inserted.

5. A method as claimed in claim 1 in which the instrument is inserted toward a vessel or artery and said receiving transducer means has a pass band for the amplified signal which has a frequency almost the same as the frequency distribution of the backscattered waves, being slightly less when the angle between the direction of insertion of the instrument and the flow of blood in the vessel or the artery is obtuse and being slightly more when the angle between the direction of insertion of the instrument and the flow of blood in the vessel or the artery is acute, whereby the gain in amplification in the frequency range corresponding to that of the backscattereD signal is greater than the gain in amplification corresponding to the transmitting signal.