Interface pressure measurement device

• US 5,838,244 A
• Filed: 10/08/1996
• Issued: 11/17/1998
• Est. Priority Date: 10/08/1996
• Status: Expired due to Fees

• Current Assignee: Cleveland Medical Devices Inc.
• Original Assignee: Cleveland Medical Devices Inc.
• Inventors: Schmidt, Robert N., Hendrix, Steven P.
• Primary Examiner(s): Lefkowitz, Edward
• Application Number:
  US08/727,240
• Time in Patent Office: 770 Days
• Field of Search: 340/635, 340/626, 128/774, 128/782, 73/172
• US Class Current: 340/635
• CPC Class Codes: A61B 5/1036 Measuring load distribution, e.g. podologic studies
• CPC Class Codes: G01L 1/02 by hydraulic or pneumatic means

Abstract

An interface pressure measurement device, comprising a sensor comprising two sensor sheets formed from thin flexible plastic material, each sensor sheet has a sensor area having flexible conductive ink printed thereon comprising a conductive surface with an electrical lead such that when the sensor sheets touch, an electrical contact is present forming a sensor switch, and the sensor also has sensor tubing. A digital device is connected to the sensor by the sensor tubing. The digital device comprises an enclosure, a push button, pressure transducer, signal conditioning, microcontroller with processor, analog-to-digital converter, memory, clock, display, buzzer and battery/power supply wherein the processor interrupts the battery/power supply current flow to shut off the digital device after a preset time. An inflator bulb having inflator tubing is connected to the digital device by the inflator tubing such that the inflator bulb is used to manually pump air through the digital device to the sensor whereby the pressure from the air in the sensor between the sensor sheets is sensed by the pressure transducer. When the microcontroller senses the opening of the sensor switch, the microcontroller through the processor transmits a signal to the display to provide a visual indication corresponding to the pressure in the sensor and transmits a signal to the buzzer to provide an audible tone.

Claims

1. An interface pressure measurement device for measuring the pressure applied upon a body, comprising:

a) A sensor comprising two sensor sheets formed from thin flexible plastic material and said sensor having sensor tubing;

b) A digital device connected to said sensor by said sensor tubing and further comprising an enclosure, a push button, pressure transducer, signal conditioning means, microcontroller with processor means, analog-to-digital converter, memory means, clock, display, and battery/power supply wherein said processor means interrupts said battery/power supply current flow to shut off said digital device after a preset time; and

c) an inflator bulb having inflator tubing and connected to said digital device by said inflator tubing such that said inflator bulb is used to manually pump air through said digital device to said sensor whereby the pressure from the air in said sensor between said sensor sheets is sensed by said pressure transducer and whereby said microcontroller through said processor means transmits a signal to said display to provide a visual indication corresponding to the pressure in said sensor, said pressure transducer located downstream of said sensor such that the effects of the pressure transients from said inflator bulb are minimized.

2. The interface pressure measurement device of claim 1 wherein the shut off preset time of said digital device is 10 seconds or greater.

3. The interface pressure measurement device of claim 1, wherein said sensor sheets each has a sensor area having flexible conductive ink printed thereon comprising a conductive surface with an electrical lead such that when said sensor sheets touch, an electrical contact is present forming a sensor switch.

4. The interface pressure measurement device of claim 3 further comprising two sensor wires connected between said electrical leads and said microcontroller providing an electrical connection from said sensor switch to said microcontroller.

5. The interface pressure measurement device of claim 1 wherein said sensor sheets are formed from vinyl.

6. The interface pressure measurement device of claim 1 wherein said pressure transducer converts the pressure sensed to a millivolt signal and wherein said signal conditioning means converts said millivolt signal to an analog signal of about 0 to 5 volts.

7. The interface pressure measurement device of claim 6 wherein said analog-to-digital converter reads said analog signal from said signal conditioning means and converts it to a digital signal.

8. The interface pressure measurement device of claim 1 wherein said clock keeps time for said microcontroller and causes a pressure reading to be recorded periodically.

9. The interface pressure measurement device of claim 1 wherein said memory means contains calibration constants determined by the calibration of said pressure transducer to relate the digital signal from the analog-to-digital converter to actual pressure.

10. The interface pressure measurement device of claim 1 wherein said display is a light emitting diode.

11. The interface pressure measurement device of claim 1 wherein said display is a liquid crystal display.

12. An interface pressure measurement device for measuring the pressure applied upon a body, comprising:

a) A sensor comprising two sensor sheets formed from thin flexible plastic material wherein said sensor sheets each has a sensor area having flexible conductive ink printed thereon comprising a conductive surface with an electrical lead such that when said sensor sheets touch, an electrical contact is present forming a sensor switch, and said sensor having sensor tubing;

b) A digital device connected to said sensor by said sensor tubing and further comprising an enclosure, a push button, pressure transducer, signal conditioning means, microcontroller with processor means, analog-to-digital converter, memory means, clock, display, and battery/power supply; and

c) An inflator bulb having inflator tubing and connected to said digital device by said inflator tubing such that said inflator bulb is used to manually pump air through said digital device to said sensor whereby the pressure from the air in said sensor between said sensor sheets is sensed by said pressure transducer such that when the microcontroller senses the opening of sensor switch such that said microcontroller through said processor means transmits a signal to said display to provide a visual indication corresponding to the pressure in said sensor, said pressure transducer located downstream of said sensor such that effects of the pressure transients from said inflator bulb are minimized.

13. The interface pressure measurement device of claim 12 wherein said processor means interrupts said battery/power supply current flow to shut off said digital device after a preset time.

14. The interface pressure measurement device of claim 12 wherein said digital device further comprises a buzzer and said processor means transmits a signal to said buzzer to provide an audible tone upon the opening of said sensor switch.

15. The interface pressure measurement device of claim 12 wherein said digital device includes a single push button.