Dual tonometer pressure measurement device

• US 20020169390A1
• Filed: 05/11/2001
• Published: 11/14/2002
• Est. Priority Date: 05/11/2001
• Status: Active Grant

• Current Assignee: Jordaan Technologies LLC (Intellectual Ventures LLC)
• Original Assignee: Jordaan Technologies LLC (Intellectual Ventures LLC)
• Inventors: Fresco, Bernard B.
• Granted Patent: US 6,706,001 B2
• Time in Patent Office: Days
• US Class Current: 600/558
• CPC Class Codes: A61B 3/16 for measuring intraocular pressure, e.g. tonometers

Abstract

An applanation tonometry system, for measuring pressure within an eye, the tonometry system comprising: an applanation tonometer device for providing specific applanation pressure to a plurality of locations on an eye; an electrical process controller for measuring pressure within the eye; and a tonometer hands free holder adapted to secure the tonometer device over the eye whilst measuring the pressure within the eye.

Claims

1. An applanation tonometry system for measuring pressure within an eye, the system comprising:

(a) a tonometer securing device for securing the tonometer device in a substantial constant position relative to the eye; and

(b) a plurality of tonometer devices mounted to the tonometer securing device for measuring pressure at a plurality of locations on an eye.

2. An applanation tonometry system as claimed in claim 1, wherein each of the tonometer devices includes an applanation disk for measuring pressure within an eye by applanation tonometry through one of contact directly with an eye and contact with an eyelid.

3. An applanation tonometry system as claimed in claim 2, wherein the tonometer securing device includes:

(a) a main body having a first end portion and a second end portion;

(b) a plurality of plunger members slidably mounted in the main body, each of the plurality of plunger members having a first end and a second end, the second end including said applanation disk and protruding from the first end portion of the main body, and a second end mounted within the main body; and

(c) a plurality of transducer devices mounted within the main body, each transducer device being mounted between one plunger member and the main body, for converting an applanation pressure into an electrical signal.

4. An applanation tonometry system as claimed in claim 3, wherein the plurality of transducer devices each comprises:

(a) a sensing device having an sensor input and output, the input adapted to detect the magnitude of specific applanation pressure from each contact member, and the output adapted to generate an electrical pressure signal; and

(b) an analog-to-digital convertor device comprising an analog input and a digital output, the analog input adapted to receive the electrical pressure signal, and the digital output adapted to generate a digitized pressure signal.

5. The applanation tonometry system as claimed in claim 4, wherein the electrical process controller comprises:

(a) a plurality of digital pressure inputs for receiving a plurality digitized pressure signals from each of the plurality of transducer devices respectively;

(b) a digital reading output for generating a digitized pressure reading corresponding to intraocular pressure within the eye; and

(c) a plurality of digital control outputs for generating a plurality of digital control signals corresponding to each of the plurality of digital pressure inputs.

6. The applanation tonometry system as claimed in claim 5, wherein the plurality of transducer devices each further comprise a digital-to-analog convertor having a digital input and an analog output, whereby the digital input receives one of the plurality of digital control outputs and generates a corresponding analog control signal at the analog output.

7. The applanation tonometry system as claimed in claim 6, wherein each of the plurality of transducer devices further comprises:

an actuator device for providing linear slidable movement of a plunger member, wherein the plunger member is one of the plurality of plunger members.

8. The applanation tonometry system as claimed in claim 7, wherein the actuator device includes:

(a) a motor device, and means for mounting the motor device within the main body, the motor device having a rotatable shaft member;

(b) a coupling interface device for coupling the rotatable shaft member to the plunger member; and

(b) a motor controller device having a control input and a control output, the control input adapted to receive the analog control signal from the analog output of the digital-to-analog convertor, and the control output adapted to generate rotation movement of the rotatable shaft member.

9. The applanation tonometry system as claimed in claim 7, wherein the actuator device includes:

(a) a motor device, and means for mounting the motor device within the main body, the motor device having a rotatable shaft member;

(b) a coupling interface device for coupling the rotatable shaft member to the plunger member; and

(b) a motor controller device having a control input and a control output, the control input adapted to receive one of the plurality of digital control outputs from the electrical process controller, and the control output adapted to generate rotation movement of the rotatable shaft member.

10. The applanation tonometry system as claimed in claim 8 or 9, wherein the coupling interface device includes a coupling input and a coupling output, the coupling input detecting the rotation movement of the rotatable shaft member and the coupling output providing a linear slidable movement for the plunger member.

11. The applanation tonometry system as claimed in claim 10, which includes a plurality of elongate frame members, each of the plurality of elongate frame members longitudinally extending between one of the plurality of plunger members and the second end portion of the main body, the elongate frame members each having a first and second end, the first end attaching to one of the plurality of plunger members, and the second end located in close proximity to a screw member, wherein the screw thread is threaded into the second end portion of the main body.

12. The applanation tonometry system as claimed in claim 11, wherein each of the elongate frame members further includes an applanation pressure plate adapted to apply a compression force to the sensing device.

13. The applanation tonometry system as claimed in claim 12, wherein the coupling interface device comprises:

a screw threaded barrel having a first end and a second end, the first end having a bore, the bore adapted to receive the rotatable shaft member, and the second end having a rod member for engaging the applanation pressure plate; and

a screw threaded housing adapted to rotatably receive the screw threaded barrel, whereby rotation of the shaft member causes rotation of the screw threaded barrel, such that linear movement of the screw threaded barrel within the screw threaded housing is provided.

14. The applanation tonometry system as claimed in claim 11, wherein the sensing device comprises:

(a) an elastomer interface member having a first and second surface, the first surface in contact with the applanation pressure plate, whereby the applanation pressure plate applies an applanation force to the first surface, which is coupled to the second surface; and

(b) a pressure sensor device having a sensing surface and a sensor output, the sensing surface is contact with the second surface, and the sensor output generating the electrical pressure signal.

15. The applanation tonometry system as claimed in claim 14, wherein the electrical pressure signal corresponds to the magnitude of the specific applanation pressure.

17. A method as claimed in claim 16, wherein applying the constant known reference pressure to the first location on the eyelid comprises pressing a first applanation disk to the first location on the eyelid;

and applying the second pressure to the second location on the eyelid comprises applying a second applanation disk to the second location on the eyeball.

18. A method as claimed in claim 17, which includes the step of measuring a pressure difference between the second pressure and the first reference pressure, at the instance when the increase in the first reference pressure is detected, whereby the pressure difference is indicative of pressure within the eyeball.

19. A method as claimed in claim 18, which includes the step of converting the pressure difference to an electrical signal.

20. A method as claimed in claim 19, which includes providing a display device, for applying the electrical signal to the display device, for displaying of a reading indicative of pressure within the eyeball.

21. A method as claimed in claim 16, which includes applying more than one second pressure to the eyelid, each said second pressure being applied at a separate second location on the eyelid.

16. A method of obtaining pressure within the eyeball of a subject, the method comprising the steps of:

(a) applying a constant known first reference pressure to a first location on the eyelid of the subject;

(b) applying at least a second pressure to an at least second location on the eyelid of the subject;

(c) increasing a second pressure until a slight increase in the constant known reference pressure is detected; and

(d) terminating the increasing of the second pressure, when the increase in the constant known reference pressure is detected, and noting the second pressure as an indication of the pressure within the eyeball.

22. A method of obtaining pressure within the eyeball of a subject, which includes providing a tonometer device comprising:

a main body;

first and second plunger members slidably mounted in the main body, the first and second plunger members having a first end comprising a first and a second contact member respectively and having a second end mounted within the main body, the second end of the first and second plunger member in contact with a first and second transducer device respectively, whereby the first transducer device detects displacement of the first plunger member and the second transducer device detects displacement of the second plunger member, the method comprising;

(a) adjusting movement of the first plunger and the second plunger, so the first plunger is in light contact with the first location on the eyelid, and the second contact member is in light contact with the second location on the eyelid;

(b) actuating the first plunger member so as to apply a constant known applanation pressure to the first location on the eyelid;

(c) actuating the second plunger member so as to apply an increasing second applanation pressure to the second location on the eyelid; and

(d) terminating the actuating movement of the second plunger member, when the first transducer device detects an increase in the constant known applanation pressure.

23. A method as claimed in claim 22, wherein the first transducer generates a first electrical pressure signal corresponding to the constant known applanation pressure;

and the second transducer generates a second electrical pressure signal corresponding to the increasing second applanation pressure.

24. A method as claimed in claim 23, which includes providing an electrical process controller device comprising a first and second pressure input and a pressure reading output, the method comprising:

(a) receiving the first electrical pressure signal at the first pressure input and generating a reference pressure magnitude;

(b) receiving the second electrical pressure signal at the second pressure input and generating a second pressure magnitude;

(c) generating an electrical differential pressure magnitude by subtracting the second pressure magnitude from the reference pressure magnitude; and

(d) sending the electrical differential pressure magnitude to the pressure reading output, when a magnitude increase in the reference pressure magnitude is detected due to the increasing magnitude of the second pressure magnitude.

25. A method as claimed in claim 22, wherein actuating the first plunger member provides the constant known applanation pressure to a first location on the eyelid, which produces a first applanation pressure at a first location on the eyeball.

26. A method as claimed in claim 22, wherein actuating the second plunger member provides the increasing applanation pressure to a second location on the eyelid, which produces a second applanation pressure at a second location on the eyeball.

27. A method as claimed in claim 22, which includes providing a display device, wherein the display device receives the electrical differential pressure signal from the pressure reading output and displays a reading indicative of pressure within the eyeball.

28. A method as claimed in claim 27, wherein the electrical process controller is a microcontroller device.