Echographic suction cannula and electronics therefor

• US 5,379,773 A
• Filed: 09/17/1993
• Issued: 01/10/1995
• Est. Priority Date: 09/17/1993
• Status: Expired due to Fees

• Current Assignee: James J. Hornsby
• Original Assignee: James J. Hornsby
• Inventors: Hornsby, James J.
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US08/124,403
• Time in Patent Office: 480 Days
• Field of Search: 128/662.03, 128/662.05, 128/662.06, 128/753, 128/734, 128/660.06, 128/749, 604/27, 604/28, 607/97
• US Class Current: 600/466
• 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 2202/0014 removed from the body
• CPC Class Codes: A61M 2202/08 Lipoids

Abstract

The Echographic Suction Cannula and Electronics Therefor provides a display of adipose tissue thickness for the Doctor to observe as he moves the cannula within the patient. The cannula includes a piezoelectric transducer which is pulsed by the electronics as a send pulse, to cause ultrasound to penetrate the adipose tissue and provide a reflected receive pulse. A known value fixed frequency source continuously emits cycles, and the electronics counts the cycles emitted between the send and receive pulses. This number is fed to a computer which generates bars equal in height to the thickness and moving across the CRT as the Doctor moves the cannula so he can determine regions where further Liposuction is necessary to even out the patient'"'"'s appearance.

Claims

1. Apparatus for displaying the thickness of adipose tissue between a transducer in a cannula and the patient'"'"'s dermis, comprising in combination:

a cannula;

a transducer in said cannula;

means for applying periodic spaced-apart bursts of a fixed frequency output to said cannula as send pulses to produce reflected receive pulses by said transducer;

means for producing a further fixed frequency output;

means responsive to said pulses for selecting the number of further fixed frequency cycles occurring during the time interval between said transducer send and said transducer receive pulses to develop a count of said cycles which is an absolute measurement of adipose thickness;

output display means; and

,

means for applying said count to the display means to produce a display of bars corresponding in height to the absolute measured thickness of adipose tissue between the cannula transducer and the patient'"'"'s dermis.

2. Apparatus for displaying the thickness of adipose tissue between a transducer in a cannula and the patient'"'"'s dermis, comprising in combination:

a cannula;

a transducer in said cannula;

means for applying periodic spaced-apart bursts of a fixed frequency output to said cannula as send pulses to produce reflected receive pulses by said transducer;

means for producing a further fixed frequency output;

means responsive to said pulses for selecting the number of further fixed frequency cycles occurring during the time interval between said transducer send and said transducer receive pulses to develop a count of said cycles which is an absolute measurement of adipose thickness;

output display means;

means for applying said count to the display means to produce a display of bars corresponding in height to the absolute measured thickness of adipose tissue between the cannula transducer and the patient'"'"'s dermis; and

,

said further fixed frequency cycles are selected to provide a one-to-one correspondence between counts and adipose tissue depth is millimeters.

3. The apparatus of claim 2, wherein:

said means responsive to said pulses is a flip-flop clocked by each of said pulses to initiate said count and discontinue said count.

4. The apparatus of claim 3, wherein:

said means responsive to said pulses further comprises a video filter connected between said cannula and said flip-flop to discern and amplify the receive pulses.

5. The apparatus of claim 4, wherein:

said flip-flop provides a data valid signal to said means for applying said count for the display means if the receive pulse is received before a stop count pulse.

6. The apparatus of claim 5, wherein:

said further fixed frequency cycles are 0.73728 MHz to establish one count per millimeter in adipose tissue.

7. Apparatus for displaying the incremental thickness of adipose tissue between a transducer in a cannula and the patient'"'"'s dermis, comprising in combination:

a cannula;

a transducer in said cannula;

means for producing a fixed frequency output;

means for deriving a start count pulse from the fixed frequency output;

means using the start count to delineate a burst of fixed frequency output;

means applying said burst as a send pulse to the cannula transducer to produce a reflected receive pulse by said transducer;

means for producing a further fixed frequency output;

means responsive to said pulses for selecting the number of further fixed frequency cycles occurring during the time interval between said send and said receive pulses to develop a count of said cycles which is an absolute measure of adipose thickness;

output display means; and

,

means for applying said count to the display means to produce a display proportional to the absolute measured thickness of adipose tissue between the cannula transducer and the patient'"'"'s dermis.

8. Apparatus for displaying the incremental thickness of adipose tissue between a transducer in a cannula and the patient'"'"'s dermis, comprising in combination:

a cannula;

a transducer in said cannula;

means for producing a fixed frequency output;

means deriving a start count pulse from the fixed frequency output;

means using the start count to delineate a burst of fixed frequency output;

means applying said burst as a send pulse to the cannula transducer to produce a reflected receive pulse by said transducer;

means for producing a further fixed frequency output;

means responsive to said pulses for selecting the number of further fixed frequency cycles occurring during the time interval between said send and said receive pulses to develop a count of said cycles which is an absolute measure of adipose thickness;

output display means;

means for applying said count to the display means to produce a display proportional to the absolute measured thickness of adipose tissue between the cannula transducer and the patient'"'"'s dermis; and

,

said means responsive to said pulses is a logical element clocked by each said send and receive pulse, and said start count influences a data input for said element to switch LO and HI outputs, thereby determining the count of said cycles.

9. The apparatus of claim 8, wherein:

said further fixed frequency is selected so that its velocity through the adipose tissue yields a count period of 1.3563 microseconds, which represents 1 millimeter of travel through the tissue.

10. A method of displaying the incremental thickness of adipose tissue between a moving transducer-equipped cannula and the patient'"'"'s dermis, comprising the steps of:

developing a start count from a fixed frequency clock output pulse;

using the start count to delineate a burst of fixed frequency clock output pulses;

applying said burst to the cannula as a send pulse to develop a reflected receive pulse by the transducer;

using said send and receive pulses to select a number of fixed frequency clock output pulses occurring during the time interval between the send and receive pulses to develop a count which is an absolute measure of adipose tissue thickness; and

,

applying said count to a computer to produce a moving display of bars corresponding in height to the absolute measured thickness of adipose tissue between the moving cannula and the patient'"'"'s dermis.

11. A method of energizing a transducer-equipped cannula to develop a display showing height proportional to the thickness of adipose tissue between the cannula and the patient'"'"'s dermis, comprising the steps of:

applying periodic spaced-apart bursts of a fixed frequency output to said cannula as send pulses to produce reflected receive pulses by said transducer;

providing further fixed frequency output pulses;

counting the number of further fixed frequency output pulses occurring during the time interval between the send and said receive pulses which is an absolute measure of adipose tissue thickness; and

,

applying the count so obtained to a display means.

12. A method of energizing a transducer-equipped cannula to develop a display showing height proportional to the thickness of adipose tissue between the cannula and the patient'"'"'s dermis comprising the steps of:

applying periodic spaced-apart burst of a fixed frequency output to said cannula as send pulses to produce reflected receive pulses by said transducer;

providing further fixed frequency output pulses;

counting the number of further fixed frequency output pulses occurring during the time interval between said send and said receive pulses which is an absolute measure of adipose tissue thickness;

applying the count so obtained to a display means; and

,

extracting a timing start count from said fixed frequency output pulses; and

,

using said start count to extract said bursts from said fixed frequency output pulses.

13. The method of claim 12, comprising the further step of:

selecting the frequency of said further fixed frequency output pulses so that its velocity through the adipose tissue yields a count period having a one-to-one relationship with travel distance through the tissue in millimeters.

14. The method of limiting data point excursion to a maximum change from the last data of plus or minus 3 millimeters for display in a liposuction system wherein a piezoelectric transducer-equipped cannula receives a burst of energy as a send pulse which causes a reflected pulse from the dermis of the patient to pass through several millimeters of adipose tissue such that the send and receive pulses can define a number of cycles of fixed frequency in the time interval there between to serve as data proportional in height to the thickness of the adipose tissue, comprising the steps of:

determining if the data point under consideration is less than or equal to three counts from the previous data point;

directly outputting the data point if it is less than or equal to three counts difference;

when the data point is not less than or equal to three counts difference, determining if the data point is more than three counts negative from the previous data point;

when the data point is more than three counts negative from the previous data point;

output the previous data point less three millimeters instead of the data point under consideration, which is discarded;

permitting a new data point for consideration each time the previous data under consideration is output;

when the data point is not more than three counts negative from the previous data point and not within plus or minus three counts of the previous data point, output the previous data point plus three millimeters and discard the data point under consideration; and

,

permitting a new data point for consideration each time the data under consideration is discarded.

15. Apparatus for displaying the thickness of adipose tissue in a patient, comprising in combination:

a cannula having a piezoelectric transducer for insertion into a patient'"'"'s body with the cannula disposed between the muscle fascia and the dermis, and the transducer being open to reflected ultrasound waves from the dermis;

means applying periodic spaced-apart bursts of a fixed frequency output to said transducer as send pulses to produce said reflected receive pulses from the transducer;

means for producing a further fixed frequency output;

means responsive to said pulses for selecting the number of fixed frequency cycles occurring during the time interval between said send and said receive pulses to develop a count of said cycles which is an absolute measure of adipose tissue thickness;

computer means with output display; and

,

terminals whereat said computer means with output display may be connected to receive the counts as input information and show height proportional to adipose tissue absolute thickness between the transducer and said dermis.

16. Apparatus for displaying the incremental thickness of adipose tissue in a patient, comprising in combination:

a cannula having a piezoelectric transducer for insertion into a patient'"'"'s body with the cannula disposed between the muscle fascia and the dermis, and the transducer being open to reflected ultrasound waves from the dermis;

means for producing a fixed frequency output;

means for deriving a start count pulse from the fixed frequency output;

means for using the start count to delineate a burst of fixed frequency output;

means for applying said burst as a send pulse to the cannula to produce a reflected receive pulse by said transducer;

means for producing a further fixed frequency output;

means responsive to said pulses for selecting the number of further fixed frequency cycles occurring during the time interval between said send and said receive pulses to develop a count of said cycles which is an absolute measure of adipose tissue thickness;

terminals whereat a computer means with output display may be connected to receive said count; and

,

means for applying said count to said computer means with output display to produce a display outline corresponding in height to the absolute thickness of adipose tissue between the cannula and the patient'"'"'s dermis.

17. Apparatus for developing burst pulses to energize a piezoelectric transducer of a cannula adapted to be placed within the patient'"'"'s body, against a muscle fascia, to direct ultrasonic energy across the adipose tissue between the cannula and the dermis of the patient pursuant to the burst pulses and receive reflected receive pulses from the dermis, comprising in combination:

a clock of fixed frequency cycles so that the velocity of the fixed frequency cycles through the adipose tissue yields a count period having a one-to-one relationship with travel distance through the tissue in millimeters;

timing means for extracting a start count from said clock; and

,

means using said start count to extract said burst from said fixed frequency.

18. Apparatus for developing burst pulses to energize a piezoelectric transducer of a cannula adapted to be placed within the patient'"'"'s body, against a muscle fascia, to direct ultrasonic energy across the adipose tissue between the cannula and the dermis of the patient pursuant to the burst pulses and receive reflected receive pulses from the dermis, comprising in combination:

a clock of fixed frequency cycles so that the velocity of the fixed frequency cycles through the adipose tissue yields a count period having a one-to-one relationship with travel distance through the tissue in millimeters;

timing means for extracting a start count from said clock;

means using said start count to extract said bursts from said fixed frequency;

said clock frequency is 4 megahertz and said start count is derived from the 4 megahertz by the timing means dividing by 8 to produce a 2 microsecond start count; and

,

said means using the start count comprises an AND circuit with one input being the start count and the other input being the clock frequency, whereby said bursts of 4 megacycles are 2 microsecond bursts.