Self contained hand held ultrasonic instrument for ophthalmic use

• US 5,165,415 A
• Filed: 03/30/1992
• Issued: 11/24/1992
• Est. Priority Date: 09/27/1985
• Status: Expired due to Term

• Current Assignee: Medtronic Xomed Surgical Products Inc (Medtronic Plc)
• Original Assignee: Bio-Rad Laboratories Incorporated
• Inventors: Wallace, David A., Feldon, Steven E.
• Primary Examiner(s): Smith, Ruth S.
• Application Number:
  US07/861,334
• Time in Patent Office: 239 Days
• Field of Search: 128/661.06, 128/662.03, 128/645-647, 128/652, 128/745, D24/10, D24/17, D24/18, D24/23
• US Class Current: 600/452
• CPC Class Codes: A61B 3/1005 for measuring distances inside the eye, e.g. thickness of the cornea A61B3/11 takes precedence
• CPC Class Codes: A61B 8/0858 involving measuring tissue layers, e.g. skin, interfaces
• CPC Class Codes: A61B 8/10 Eye inspection
• CPC Class Codes: A61B 8/4455 Features of the external shape of the probe, e.g. ergonomic aspects
• CPC Class Codes: A61B 8/462 characterised by constructional features of the display
• CPC Class Codes: A61F 9/013 Instruments for compensation of ocular refraction A61F9/008 takes precedence; Instruments for use in cornea removal, for reshaping or performing incisions in the cornea

Abstract

Disclosed is a completely portable, hand-held digital ultrasonic instrument about the size and shape of an ordinary pen. The housing is contoured such that it can be easily grasped in the manner of a writing pen. An activation button is located on the interior dorsal surface in close approximation to the index fingertip of the user. A liquid crystal display provides a digital readout of a thickness measurement on the barrel of the instrument housing. The instrument incorporates a 10 MHz or 20 MHz solid phase piezoelectric transducer, a microprocessor, a gate array, a hybrid analog circuit, a liquid crystal display, batteries and a removable battery cover. The 20 MHz transducer is used to measure corneal thickness and is attached to a swan neck connector which is attached to the instrument housing. The 10 MHz transducer is used for measuring axial length and it is attached to a truncated conical connector which is also attached to the instrument housing. In addition, a pinjack connector is available to link the unit to other electronic media such as a microcomputer, personal computer, or printer.

Claims

1. A self contained hand-held ultrasonic instrument for measuring ophthalmic thicknesses comprising

a housing with an elongated body with a shape to enable said housing being grasped in the manner of a writing pen, said body having a central axis, a distal end, a top surface and said body having depressions toward the distal end to facilitate grasping said instrument in the manner of a writing pen;

a swan neck connector having a conically tapering neck that is angled downward to a first area connected to a transducer, a second area of said connector being connected to the distal end of said housing and the central axis of said transducer being disposed at such an angle off the central axis of said elongated body that said instrument can be comfortably held in a position in which said elongated body does not contact a patient'"'"'s eyebrow and in which a user can rest said user'"'"'s hand on said patient'"'"'s forehead and in which said transducer is aligned with the visual axis of one of said patient'"'"'s eyes, the size and disposition of said transducer arranged to permit said user to partially view an optical zone of said one of patient'"'"'s eyes, and

a digital display located on the top surface of said body and said body housing an interconnected power supply, a gate array connected to a microprocessor and transmitter/receiver, and said microprocessor is connected to said digital display and said transmitter/receiver.

2. The instrument of claim 1,

wherein said transducer comprises a piezoelectric ultrasonic transducer centered at the posterior edge of a clear cone shaped contact head.

3. A self contained hand-held ultrasonic instrument for measuring axial length of an eye comprising:

a writing pen shaped housing having a central axis, a distal end, a top surface and depressions toward the distal end to facilitate grasping in the manner of a writing pen;

a truncated conical section connected to the distal end of said housing, narrowing distally along the central axis and said section containing a transducer; and

said housing further containing interconnected circuitry including a digital display located on the top surface of said housing, a power supply, a gate array, a transmitter/receiver, and a microprocessor.

4. The instrument of claim 3,

wherein said conical section also contains a focusing element and a light source disposed within the focussing element so that a patient can center the patient'"'"'s eye on said transducer by looking at said light source.

5. The instrument of claim 3,

wherein said microprocessor comprises a memory having stored therein a program to ignore an ultrasonic echo from a signal sent by said transducer unless said echo is detected by said transducer corresponding to an expected window.

6. The instrument of claim 5,

wherein said window is a period of time corresponding to any one of the following approximate distance ranges:

1.5 to 5 mm. behind the corneal surface, corresponding to the anterior lenticular surface;

1.5 to 6.5 mm. behind the anterior lenticular surface, corresponding to the posterior lenticular surface;

18.5 to 29.0 mm. behind the corneal surface, corresponding to the retinal surface; and

0.29 to 2.5 mm. behind the retina, corresponding to the scleral surface.

7. A self contained hand-held ultrasonic pachymeter comprising:

a housing with an elongated body with a shape to enable said housing being grasped in the manner of a writing pen, said body having a central axis, a distal end, a top surface and said body having depressions toward the distal end to facilitate grasping said instrument in the manner of a writing pen;

a swan neck connector having a conically tapering neck that is angled downward to a first area connected to a 20 MHz piezoelectric transducer centered at the posterior edge of a clear cone shaped contact head, a second area of said connector being connected to the distal end of said housing and the central axis of said transducer being disposed at such an angle off the central axis of said elongated body, that said instrument can be comfortably held in a position in which said elongated body does not contact a patient'"'"'s eyebrow and in which a user can rest said user'"'"'s hand on said patient'"'"'s forehead and in which said transducer is aligned with the visual axis of one of said patient'"'"'s eyes, the size and disposition of said transducer arranged to permit said user to partially view an optical zone of said one of patient'"'"'s eyes, and

a digital display located on the top surface of said body and said body housing logic means for assessing echo waveforms and connected to a miniature speaker, to an external pinjack, to an activation button, and to said digital display.

8. A self-contained hand-held ultrasonic biometric ruler comprising:

a housing with an elongated body with a shape to enable said housing being grasped in the manner of a writing pen, said body having a central axis, a distal end, a top surface and said body having depressions toward the distal end to facilitate grasping said instrument in the manner of a writing pen;

a truncated conical section connected to the distal end of said housing, narrowing distally along the central axis of the elongated body, and said section containing a 10 MHz transducer, a focusing element, and a light-emitting diode disposed within the focussing element so that a patient centers his eye on said transducer when the patient looks at said diode, said body housing a power supply interconnected logical means, for assessing echo waveforms, digital display means for displaying a readout representing a measurement of the corneal thickness or axial length of an eye, an external pinjack for optional transmission of biometric information, a miniature speaker, and an activation button.

9. A system for measuring ophthalmic thickness comprising:

a miniaturized housing having an integral, self-contained power supply, an elongated body having calculating and displaying means for calculating and displaying corneal thickness and axial length of an eye, a central axis, a distal end, and depressions toward the distal end to facilitate grasping said housing in the manner of a writing pen;

a first connector, in the shape of a swan neck, said connector having a conically tapered neck that is angled downward to a first area connected to a first piezoelectric transducer which is centered at the posterior edge of a clear cone shaped contact head, a second area of said connector being connectable to the distal end of said housing and the central axis of said transducer being disposed at an angle approximately 63% off the central axis of said elongated body; and

a second connector, in the shape of a truncated cone, said connector narrowing distally along the central axis of said elongated body and comprising a second transducer;

means for attaching the connectors to the housing whereby attachment of the first connector to said housing couples said first transducer to said calculating and displaying means to provide first measurement means for reading corneal thickness of the eye and attachment of the second connector to said housing couples said second transducer to said calculating and displaying means to provide second measurement means for reading the axial length of the eye.