INSTANTANEOUS ULTRASONIC ECHO MEASUREMENT OF BLADDER VOLUME WITH A LIMITED NUMBER OF ULTRASOUND BEAMS

• US 20100198075A1
• Filed: 04/14/2010
• Published: 08/05/2010
• Est. Priority Date: 08/09/2002
• Status: Active Grant

• Current Assignee: Verathon Incorporated (Roper Technologies, Inc.)
• Original Assignee: Verathon Incorporated (Roper Technologies, Inc.)
• Inventors: Bom, Nicolaas, Lancee, Charles Theodoor, Baartmans, Henri, McMorrow, Gerald
• Granted Patent: US 9,993,225 B2
• Time in Patent Office: Days
• US Class Current: 600/449
• CPC Class Codes: A61B 5/204 Determining bladder volume
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/0858 involving measuring tissue layers, e.g. skin, interfaces
• CPC Class Codes: A61B 8/4472 Wireless probes
• CPC Class Codes: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: G01S 15/102 using transmission of pulses having some particular characteristics
• CPC Class Codes: G01S 15/8909 using a static transducer configuration
• CPC Class Codes: G01S 7/52036 using analysis of echo signal for target characterisation
• CPC Class Codes: G06T 2207/10132 Ultrasound image
• CPC Class Codes: G06T 2207/30004 Biomedical image processing
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G06T 7/62 of area, perimeter, diameter or volume

Abstract

An apparatus and methods to quantify the volume of urine in a human bladder with a limited number of acoustic beams is disclosed. In a first version a plurality of narrow ultrasound beams is transmitted in different directions towards the bladder. Returning echoes are converted to digital form and stored in memory. A volume display on the apparatus allows to define the optimal apposition of the transducer assembly. Signal processing software automatically determines the bladder Depth D and Height H and computes the volume of urine. In a second version, a single wide angle ultrasound beam transducer transmits ultrasounds signals at a fundamental frequency to quantify the urine volume. Return signals originating from a depth beyond the usual position of the posterior wall depth of a filled bladder are analyzed for presence of higher harmonic signals, which in turn are related to the presence or absence of urine.

Claims

1. An apparatus for measuring the volume of fluid in a human or animal body cavity using a non-invasive, ultrasound echo technique, comprising:

a transducer assembly including a plurality of ultrasound transducers mounted thereon for transmitting and receiving a plurality of ultrasound signals into the body cavity at plural angles of incidence and/or from plural spatial locations;

means for activating the transducers to produce transmitted ultrasound signals;

means for detecting body cavity wall echoes from received ultrasound signals;

means for determining, from said received signals, a body cavity height H and depth D;

means for determining a specific measurement configuration corresponding to the body cavity filling degree from the ultrasound signals that intercept the fluid filled body cavity to thereby select an appropriate predetermined correction factor K corresponding to that specific measurement configuration, for optimal calculation of the volume; and

means for calculating the fluid volume according to the formula H×

D×

K.

2. The apparatus of claim 1, wherein the body cavity is a bladder and the volume of fluid measured is a volume of urine.

3. The apparatus of claim 1, wherein the means for activating includes means for transmitting said plurality of ultrasound signals in a selected order.

4. The apparatus of claim 1, wherein the means for detecting uses echo travel time and other beam information from the plurality of ultrasound signals.

5. The apparatus of claim 1, wherein the means for determining selects specific ultrasound signals from the plurality of ultrasound signals corresponding to ultrasound beams that have intercepted the fluid filled body cavity.

6. The apparatus of claim 1, further including a display means for instantaneous display of the calculated fluid volume to allow optimization of transducer positioning by the user.

7. The apparatus of claim 1, wherein the means for deriving includes a memory storing a plurality of empirically predetermined correction factors K.

8. The apparatus of claim 1, wherein the array further includes five transducers.

9. The apparatus of claim 8, wherein the five transducers are respectively oriented at angles Ø

_A, Ø

_B, Ø

_C, Ø

_D, and Ø

_E, to an axis orthogonal to the plane of the transducer array, the angles being approximately Ø

_A=−

25°

, Ø

_B=0°

, Ø

_C+25°

, Ø

_D=+25°

, Ø

_E=+40°

.

10. A method for measuring the volume of fluid in a human or animal body cavity using a non-invasive, ultrasound echo technique, comprising the steps of:

transmitting a plurality of ultrasonic beams into the region of the body containing the cavity at plural angles of incidence and/or from plural spatial locations;

receiving a plurality of ultrasonic signals from the body;

determining, from said received signals, a body cavity height H and depth D;

determining, from the received signals, a specific measurement configuration corresponding to the body cavity filling degree from the ultrasound signals that intercept the fluid filled body cavity to thereby select an appropriate predetermined correction factor K corresponding to that specific measurement configuration, for optimal calculation of the volume; and

calculating the fluid volume according to the formula H×

D×

K.

11. The method of claim 10, further including the step of transmitting the plurality of ultrasonic beams into the body from a transducer array in which a plurality of transducers are arranged with a predetermined spatial location and mounting angle.

12. An apparatus for measuring the volume of fluid in a human or animal body cavity using a non-invasive, ultrasound echo technique, comprising:

one or more transducers for transmitting at least one ultrasound beam into the body such that the at least one beam encompasses a substantial portion of the target body cavity, the beam having at least a first frequency;

means for receiving ultrasound echo signals from the body cavity and determining a measure of higher harmonic components of the first frequency in the received signals; and

means for determining a volume of fluid in the body cavity from the measured harmonic components.

13. The apparatus of claim 12, wherein the ultrasound transducer is a curved single active piezo-electric element, shaped to form a sector of a sphere or cone like sound beam.

14. The apparatus of claim 12, wherein the transducer is adapted to transmit at a fundamental ultrasound frequency and is adapted to receive the fundamental and higher harmonic signals of the transmitted frequency.

15. The apparatus of claim 14, further including means for transmitting, at the fundamental frequency, a multiplicity of different pulses to enhance the higher harmonic components in the received signals.

16. The apparatus of claim 15, further including means for determining the scattered power of higher harmonics in the received signal and comparing the scattered power with the backscattered power in the fundamental frequency in an algorithm to calculate the urine volume.

17. The apparatus of claim 14, further including means for using combined pulse sequences at low transmit power and high transmit power to enhance bladder filling measurement and eliminate patient variation due to for instance obesity.

18. A method for measuring the volume of fluid in a human or animal body cavity using a non-invasive, ultrasound echo technique, comprising the steps of:

positioning a transducer assembly including a plurality of ultrasound transducers mounted thereon for transmitting and receiving a plurality of ultrasound signals into the body cavity at plural angles of incidence and/or from plural spatial locations;

activating the transducers to produce transmitted ultrasound signals;

detecting body cavity wall echoes from received ultrasound signals;

determining, from said received signals, a body cavity height H and a depth D;

determining a specific measurement configuration corresponding to the body cavity filling degree from the ultrasound signals that intercept the fluid filled body cavity and thereby selecting an appropriate predetermined correction factor K corresponding to that specific measurement configuration, for optimal calculation of the volume; and

calculating the fluid volume according to the formula H×

D×

K.

19. A method for measuring the volume of fluid in a human or animal body cavity using a non-invasive, ultrasound echo technique, comprising the steps of:

using one or more transducers to transmit at least one ultrasound beam into the body such that the at least one beam encompasses a substantial portion of the target body cavity, the beam having at least a first frequency;

receiving ultrasound echo signals from the body cavity;

determining a measure of higher harmonic components of the first frequency in the received signals; and

determining a volume of fluid in the body cavity from the measured harmonic components.

20. The apparatus of claim 19 in which the at least one beam comprises a plurality of narrow beams such as those conventionally used for ultrasound imaging.