Ultrasonic monitor for measuring blood flow and pulse rates

• US 20060106310A1
• Filed: 11/17/2004
• Published: 05/18/2006
• Est. Priority Date: 11/17/2004
• Status: Active Grant

• Current Assignee: Salutron, Inc.
• Original Assignee: Salutron, Inc.
• Inventors: Lo, Thomas Ying-Ching, Chang, Rong Jong
• Granted Patent: US 7,798,970 B2
• Time in Patent Office: Days
• US Class Current: 600/459
• CPC Class Codes: A61B 5/411 Detecting or monitoring allergy or intolerance reactions to an allergenic agent or substance
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 8/02 Measuring pulse or heart rate
• 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 8/4227 characterised by straps, belts, cuffs or braces
• CPC Class Codes: A61B 8/4281 characterised by sound-transmitting media or devices for coupling the transducer to the tissue
• CPC Class Codes: A61B 8/4472 Wireless probes
• CPC Class Codes: A61B 8/4483 characterised by features of the ultrasound transducer
• CPC Class Codes: G10K 11/004 Mounting transducers, e.g. provided with mechanical moving or orienting device mountings specially adapted to a particular sound-producing device, see the preceding groups G10K1/00 - G10K9/00, e.g. G10K1/26, G10K1/28, G10K9/22; arrangements of sonic watch equipment on submarines B63G8/39; buoys B63B22/00

Abstract

An ultrasonic monitor implemented on a PCB includes a gel pad comprised of a gel layer and a membrane layer. Ultrasonic signals are transmitted between the ultrasonic monitor and a living subject through the gel pad. An air gap is formed in the PCB underneath transducer elements to provide for more efficient signal transmission. These features provide for a low power, low cost, more efficient ultrasonic monitor. The entire ultrasonic monitor may be encapsulated in plastic, a gel, or both to provide water resistant properties.

Claims

1. An ultrasonic monitor comprising:

a circuit board; and

one or more ultrasonic transducers mounted to the circuit board with one or more air gaps between the circuit board and the one or more transducers.

2. The ultrasonic monitor of claim 1, wherein the one or more air gaps includes a first air gap positioned underneath a transmitting transducer and a second air gap positioned underneath a receiving transducer.

3. The ultrasonic monitor of claim 2, wherein the first air gap has an area about the same as the area of the transmitting transducer element and the second air gap has an area about the same size as the area of the receiving transducer element.

4. The ultrasonic monitor of claim 1, wherein the one or more air gaps are formed by removing a portion of the circuit board.

5. The ultrasonic monitor of claim 1, wherein the one or more air gaps is an undivided air gap underneath a transmitting transducer and a receiving transducer.

6. The ultrasonic monitor of claim 1, wherein the air gap portion includes a support member underneath each of said transmitting transducer element and said receiving transducer element.

7. The ultrasonic monitor of claim 1, wherein the one or more air gaps includes two air gaps separated by a support member, at least one transducer mounted over the support member.

8. An ultrasonic monitor comprising:

a circuit board having an outer layer;

a transmitting transducer mounted to said circuit board;

a receiving transducer mounted to said circuit board, the outer layer including one or more air gaps located underneath the transmitting transducer element and the receiving transducer element; and

a circuit configured to process the received ultrasonic signal.

9. The ultrasonic monitor of claim 8, wherein the one or more air gaps includes a first air gap positioned underneath the transmitting transducer and a second air gap positioned underneath the receiving transducer.

10. The ultrasonic monitor of claim 9, wherein the first air gap has an area about the same as the area of the transmitting transducer and the second air gap has an area about the same size as the area of the receiving transducer.

11. The ultrasonic monitor of claim 8, wherein the one or more air gaps are formed by removing a portion of the outer layer.

12. The ultrasonic monitor of claim 8, wherein the transmitting transducer and the receiving transducer have a slightly longer length than the air gap portion.

13. The ultrasonic monitor of claim 8, wherein the one or more air gaps is an undivided portion underneath the transmitting transducer and the receiving transducer.

14. The ultrasonic monitor of claim 8, wherein the one or more air gaps includes a support member underneath each of said transmitting transducer and said receiving transducer.

15. The ultrasonic monitor of claim 14, wherein the support member is comprised of a strip of an outer layer of the circuit board.

16. The ultrasonic monitor of claim 14, wherein the support member is comprised of an isolated region of an outer layer of the circuit board.

17. The ultrasonic monitor of claim 8, further comprising:

a housing member containing the transmitting transducer, the receiving transducer, and the circuit.

18. The ultrasonic monitor of claim 17, further comprising:

a strap member connected to the housing member.

19. A method for constructing an ultrasonic monitor comprising:

accessing a circuit board;

removing at least a portion of a layer of the circuit board to form one or more air gaps; and

mounting one or more transducers to the circuit board so that the one or more air gaps are between the one or more transducers and the circuit board.

20. The method of claim 19 wherein said removing at least a portion of the outer layer is performed by chemical etching.

21. The method of claim 19 wherein said removing at least a portion of the outer layer includes generating an aperture in the circuit board.

22. The method of claim 19 wherein removing a portion of the circuit board includes:

removing a first portion of the circuit board to form a first air gap; and

removing a second portion of the circuit board to form a second air gap, the first air gap and the second air gap isolated from each other by a portion of the circuit board, the circuit board configured to receive the transmitting transducer over the first air gap and the receiving transducer over the second air gap.

23. The method of claim 22 wherein the first air gap has an area about the same as the transmitting transducer and the second air gap has an area about the same as the receiving transducer.

24. The method of claim 22 wherein removing the first portion includes:

removing an area of the outer layer about the same size as the transmitting transducer except for a supporting member, the supporting member positioned to support a portion of the transducer.

25. The method of claim 24 wherein the supporting member is a strip of the outer layer of the circuit board.

26. The method of claim 24 wherein the supporting layer is isolated from the remainder of the outer layer.

27. The method of claim 24 further including:

mounting a transmitting transducer, a receiving transducer and circuitry to the circuit board, the transmitting transducer and receiving transducer mounted directly to the circuit board over the air gap portion.

28. A method for monitoring a heart rate, comprising:

transmitting an ultrasonic signal from a transmitting transducer mounted on a circuit board, the ultrasonic signal transmitted in a first direction towards a target located away from the circuit board and in a second direction towards the circuit board;

reflecting the signal transmitted towards the circuit board towards the target by an air gap, the air gap positioned underneath the transmitting transducer; and

receiving a reflected ultrasound signal by a receiving transducer.

29. The method of claim 28 wherein the air gap is formed by removing a portion of the circuit board located underneath one of the transducers.

30. The method of claim 28 wherein the air gap portion is positioned underneath both the transmitting transducer and the receiving transducer.

31. The method of claim 28 wherein the air gap is an aperture through the circuit board.

32. The method of claim 28 wherein reflecting includes:

reflecting the signal with a first air gap and a second air gap, the first air gap and the second air gap isolated from each other by a portion of the circuit board.

33. The method of claim 28 wherein the first air gap portion includes a support member, the support member comprised of a portion of an outer layer of the circuit board and positioned underneath the transmitting transducer.