A flexible air puff tonometer

Abstract

The application provides a flexible air blowing device for measuring intraocular pressure, which comprises an ocular surface intraocular pressure measuring optical system and a pulse air flow jetting system; light emitted by a fixation lamp of the ocular surface intraocular pressure measuring optical system sequentially passes through a fixation beam splitter and a first semi-transparent half mirror and reaches an ocular surface; imaging light of the ocular surface sequentially passes through the first semi-transparent half mirror, a second semi-transparent half mirror and an ocular surface imaging lens group and reaches a surface array CCD for ocular surface imaging; the pulse air flow jetting system is arranged on a light path from the first semi-transparent half mirror to the ocular surface and comprises a rigid metal gas storage cavity; a flexible pressure stabilizing cavity is arranged in the rigid metal gas storage cavity; an air inlet end of the flexible pressure stabilizing cavity is connected with a constant pressure air supplement valve; an air outlet end is connected with a rigid jetting nozzle; the rigid jetting nozzle penetrates through the rigid metal gas storage cavity and is aligned with the ocular surface; and an axis of the rigid jetting nozzle is coaxially arranged with the light path from the first semi-transparent half mirror to the ocular surface. The application can optimize output characteristics of pulse air flow, and comprehensively improve the precision of intraocular pressure measurement and the stability of the device.

Description

Technical Field

[0001] This invention relates to the field of optical equipment technology, and in particular to a flexible air-blowing device for measuring intraocular pressure. Background Technology

[0002] Non-contact tonometers rely on air pulses to compress the cornea and cause deformation, combining optical detection and signal processing to obtain intraocular pressure values. Because they are contactless and pose no risk of cross-infection, they are widely used in medical institutions and health check centers at all levels.

[0003] Currently, all non-contact tonometers on the market use rigid metal gas storage chambers for their gas supply units. These metal chambers are mostly cylindrical or cylindrical in shape, with internal corners and steps. Under millisecond-level rapid inflation and deflation conditions, eddies and turbulence easily form within the chamber, causing uneven distribution of the jet airflow. Furthermore, the rigid chamber lacks buffering capacity; instantaneous depressurization can lead to pressure overshoot, oscillation, and tailing issues, resulting in poor consistency of the pressure curve for each jet, directly reducing the accuracy of corneal planarization recognition.

[0004] Furthermore, the metal cavity is susceptible to changes in volume and pressure reference due to ambient temperature and mechanical vibration, leading to significant accuracy drift after long-term use. Uneven airflow can cause irregularities in the corneal pressure area, further affecting the quality of optical signal acquisition. In summary, the traditional rigid air reservoir has become a major bottleneck restricting the improvement of measurement accuracy in non-contact tonometers. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention aims to provide a flexible air blowing device for measuring intraocular pressure, so as to optimize the output characteristics of pulse airflow and comprehensively improve the accuracy of intraocular pressure measurement and the stability of the device.

[0006] To achieve the above objectives, the present invention proposes a flexible air-blowing device for measuring intraocular pressure, comprising an ocular surface intraocular pressure measuring optical system and a pulsed airflow jet system;

[0007] The ocular surface intraocular pressure measurement optical system includes a fixation lamp, a fixation beam splitter, a first semi-transparent and semi-reflective mirror, a second semi-transparent and semi-reflective mirror, and an ocular surface imaging mirror group. The light emitted by the fixation lamp passes through the fixation beam splitter and the first semi-transparent and semi-reflective mirror in sequence before reaching the ocular surface. The imaging light from the ocular surface passes through the first semi-transparent and semi-reflective mirror, the second semi-transparent and semi-reflective mirror, and the ocular surface imaging mirror group in sequence before reaching the ocular surface imaging area array CCD.

[0008] The pulsed airflow jet system is arranged in the optical path from the first semi-transparent mirror to the ocular surface. The pulsed airflow jet system includes a rigid metal gas storage chamber. The end of the rigid metal gas storage chamber near the ocular surface is provided with an anterior ocular window glass that allows light to pass through, and the end away from the ocular surface is provided with a chamber window glass that allows light to pass through. The interior of the rigid metal gas storage chamber is provided with a flexible pressure-stabilizing gas chamber. The flexible pressure-stabilizing gas chamber is an integral smooth bladder-shaped structure. Its air inlet end passes through the rigid metal gas storage chamber through an air tube and is connected to a constant pressure air supply valve. Its air outlet end is connected to a rigid jet nozzle. The rigid jet nozzle passes through the anterior ocular window glass and is aligned with the ocular surface. Its axis is coaxial with the optical path from the first semi-transparent mirror to the ocular surface. The flexible pressure-stabilizing gas chamber can adaptively expand and contract elastically with inflation and jet pulses. During the ocular pressure detection jet process, the gas pressure inside the chamber is uniformly and stably output.

[0009] The above scheme also includes an XY optical positioning system, which includes a first light source and an XY positioning focusing lens group. The XY optical positioning system and the ocular surface pressure measurement optical system share a fixation beam splitter, a first semi-transparent and semi-reflective mirror, and a second semi-transparent and semi-reflective mirror. The light emitted from the first light source passes through the fixation beam splitter and the first semi-transparent and semi-reflective mirror in sequence before reaching the ocular surface. The imaging light from the ocular surface passes through the first semi-transparent and semi-reflective mirror, the second semi-transparent and semi-reflective mirror, and the XY positioning focusing lens group in sequence before reaching the XY positioning detection area array CCD.

[0010] The above scheme also includes a Z-optical positioning system, which includes a second light source, a positioning cemented lens, and a cylindrical lens. The light emitted by the second light source reaches the ocular surface, and the imaging light from the ocular surface passes through the positioning cemented lens and the cylindrical lens in sequence before connecting to the PSD position sensor.

[0011] In the above scheme: the flexible pressure-stabilizing air chamber is made of transparent silicone or TPU polyurethane, with a chamber wall thickness of 0.8mm–1.2mm and a Shore hardness of 40–60HA. It has the characteristics of being resistant to repeated inflation and deflation deformation, anti-aging, and having a low temperature deformation coefficient. It does not undergo permanent deformation during long-term operation, ensuring consistent air pressure output.

[0012] In the above scheme: the wall thickness of the flexible pressure-stabilizing air chamber is 1.0 mm, and the material has a Shore hardness of 50HA.

[0013] In the above scheme: the ocular surface imaging lens group consists of three lenses, which are, in order from the closest to the ocular surface to the furthest away from the ocular surface, a first positive lens, a first negative lens, and a second positive lens.

[0014] In the above scheme: the operating wavelength of the first light source is 850nm, and a laser collimation optical system is arranged on the optical path from the first light source to the fixed beam splitter.

[0015] In the above scheme: the operating wavelength of the second light source is 760nm, and a laser collimation optical system is arranged on the optical path from the second light source to the surface of the eye.

[0016] The beneficial effects of this invention are:

[0017] 1. The flexible pressure-stabilizing air chamber adopts an integrated, smooth, sac-like structure with no internal corners or steps. It can adaptively expand and contract elastically with inflation and jet pulses. During the millisecond-level pulse jet process in intraocular pressure (IOP) detection, it achieves a turbulent, uniform, and stable pressure output within the chamber, ensuring an axisymmetric laminar flow distribution of the airflow to the cornea. This, combined with the optical detection module, completes corneal flattening detection, improving the accuracy and repeatability of IOP measurement. 2. The rigid jet nozzle is coaxially positioned with the measurement optical path, ensuring the pulsed airflow is directed directly at the center of the cornea. This, combined with the optical system's fixation alignment structure, ensures the airflow force center coincides with the optical detection center, further improving the accuracy of IOP measurement. 3. The flexible pressure-stabilizing air chamber can adaptively absorb minor mechanical vibrations of the equipment and compensate for pressure drift caused by changes in ambient temperature, reducing IOP measurement system errors caused by overall equipment vibration and temperature drift. 4. The flexible pressure-stabilizing air chamber's elastic contraction response time is ≤5ms, matching the ultra-fast pulse detection rhythm of the non-contact IOP meter. It eliminates jet lag and pressure tailing issues, meeting the requirements of high-speed clinical IOP detection. Attached Figure Description

[0018] Figure 1 This is a system optical path diagram of the present invention. Only the front eye window glass 10 and the chamber window glass 11 of the pulse airflow jet system are shown in the diagram.

[0019] Figure 2 This is a schematic diagram of the pulse airflow injection system in this invention. Detailed Implementation

[0020] like Figure 1 As shown in Figure 2, a flexible air-blowing device for measuring intraocular pressure mainly consists of an ocular surface intraocular pressure measurement optical system, a pulsed airflow jet system, an XY optical positioning system, and a Z optical positioning system.

[0021] The ocular surface pressure measurement optical system includes a fixation lamp 1, a fixation beam splitter 2, a first semi-transparent mirror 3, a second semi-transparent mirror 4, and an ocular surface imaging lens group 5. The light emitted from the fixation lamp 1 passes sequentially through the fixation beam splitter 2 and the first semi-transparent mirror 3 before reaching the ocular surface 6. The imaging light from the ocular surface 6 passes sequentially through the first semi-transparent mirror 3, the second semi-transparent mirror 4, and the ocular surface imaging lens group 5 before reaching the ocular surface imaging area array CCD 8.

[0022] The ocular surface imaging lens group 5 consists of three lenses, which are, from the closest to the ocular surface 6 to the furthest from the ocular surface 6, the first positive lens, the first negative lens, and the second positive lens.

[0023] The pulsed airflow jet system is arranged in the optical path from the first semi-transparent mirror 3 to the ocular surface 6. The pulsed airflow jet system includes a rigid metal gas storage chamber 9. The rigid metal gas storage chamber 9 has a front eye window glass 10 that allows light to pass through at one end near the ocular surface 6 and a chamber window glass 11 that allows light to pass through at the other end away from the ocular surface 6. A flexible pressure-stabilizing gas chamber 12 is arranged inside the rigid metal gas storage chamber 9.

[0024] The flexible pressure-stabilizing air chamber 12 is an integral smooth bladder-shaped structure. Its air inlet end passes through the rigid metal air storage chamber 9 through the air pipe and is connected to the constant pressure air replenishment valve. Its air outlet end is connected to a rigid jet nozzle 18. The rigid jet nozzle 18 passes through the front eye window glass 10 and is aligned with the eye surface 6. Its axis is coaxial with the optical path from the first semi-transparent semi-reflective mirror 3 to the eye surface 6.

[0025] The flexible pressure-stabilizing air chamber 12 can adaptively expand and contract elastically with inflation and jet pulses. During the jet process of intraocular pressure detection, it achieves uniform and stable air pressure output within the chamber. During the millisecond-level pulse jet process of intraocular pressure detection, it achieves uniform and stable air pressure output without turbulence within the chamber, making the airflow sprayed onto the cornea present an axisymmetric laminar flow distribution. This, combined with the optical detection module, completes corneal flattening detection, improving the accuracy and repeatability of intraocular pressure measurement.

[0026] The XY optical positioning system includes a first light source 13 and an XY positioning focusing lens group 14. The XY optical positioning system shares a fixation beam splitter 2, a first semi-transparent mirror 3, and a second semi-transparent mirror 4 with the ocular surface pressure measurement optical system. Light emitted from the first light source 13 passes sequentially through the fixation beam splitter 2 and the first semi-transparent mirror 3 before reaching the ocular surface 6. The imaging light from the ocular surface 6 then passes sequentially through the first semi-transparent mirror 3, the second semi-transparent mirror 4, and the XY positioning focusing lens group 14 before reaching the XY positioning detection area array CCD 15. The first light source 13 operates at a wavelength of 850 nm. A laser collimation optical system is arranged along the optical path from the first light source 13 to the fixation beam splitter 2.

[0027] The Z-optical positioning system includes a second light source 16, a positioning cemented lens 17, and a cylindrical lens 7. The light emitted from the second light source 16 reaches the ocular surface 6, and the imaging light from the ocular surface 6 passes sequentially through the positioning cemented lens 17 and the cylindrical lens 7 before connecting to the PSD position sensor. The operating wavelength of the second light source 16 is 760nm, and a laser collimating optical system is arranged along the optical path from the second light source 16 to the ocular surface 6.

[0028] The flexible pressure-stabilizing air chamber 12 is made of transparent silicone or TPU polyurethane with a wall thickness of 0.8mm–1.2mm and a Shore hardness of 40–60HA. It has the characteristics of being resistant to repeated inflation and deflation deformation, anti-aging, and having a low temperature deformation coefficient. It does not undergo permanent deformation during long-term operation, ensuring consistent air pressure output.

[0029] Specifically, the flexible pressure-stabilizing air chamber 12 has a wall thickness of 1.0 mm and a material Shore hardness of 50HA.

[0030] The working principle of this invention is as follows: In standby mode, the constant pressure air supply valve continuously supplies a small amount of air, keeping the flexible pressure-stabilizing air chamber 12 in a slightly pre-expanded state. After the detection is started, the solenoid valve on the rigid jet nozzle 18 opens rapidly, and the spherical cavity releases the air pulse by uniformly retracting due to its own elasticity. The flexible pressure-stabilizing air chamber 12 has a continuous curvature, and the airflow maintains an axisymmetric laminar flow state throughout, without the generation of eddies. The damping effect of the flexible pressure-stabilizing air chamber 12 suppresses pressure peaks and oscillations, resulting in a linear and stable pressure curve, and uniform pressure on the cornea with a regular flattened shape. The optical module emits parallel light to irradiate the cornea, and the reflected light is collected by the receiving module. The main control module accurately determines the corneal flattening moment based on the signal and calculates the intraocular pressure data.

Claims

1. A flexible air-blowing device for measuring intraocular pressure, characterized in that: Includes an optical system for measuring intraocular pressure on the ocular surface and a pulsed airflow jet system; The ocular surface intraocular pressure measurement optical system includes a fixation lamp (1), a fixation beam splitter (2), a first semi-transparent mirror (3), a second semi-transparent mirror (4), and an ocular surface imaging lens group (5). The light emitted by the fixation lamp (1) passes through the fixation beam splitter (2) and the first semi-transparent mirror (3) in sequence before reaching the ocular surface (6). The imaging light of the ocular surface (6) passes through the first semi-transparent mirror (3), the second semi-transparent mirror (4), and the ocular surface imaging lens group (5) in sequence before reaching the ocular surface imaging area array CCD (8). The pulsed airflow jet system is arranged in the optical path from the first semi-transparent mirror (3) to the ocular surface (6). The pulsed airflow jet system includes a rigid metal gas storage cavity (9). The rigid metal gas storage cavity (9) has a front eye window glass (10) that allows light to pass through at one end near the ocular surface (6) and a chamber window glass (11) that allows light to pass through at the other end away from the ocular surface (6). A flexible pressure-stabilizing gas cavity (12) is arranged inside the rigid metal gas storage cavity (9). The flexible pressure-stabilizing gas cavity (12) is an integrated optical... The bladder-like structure has an air inlet that passes through a trachea through a rigid metal air storage chamber (9) and is connected to a constant pressure air supply valve. Its outlet is connected to a rigid jet nozzle (18). The rigid jet nozzle (18) passes through the front eye window glass (10) and is aligned with the ocular surface (6). Its axis is coaxial with the optical path from the first semi-transparent mirror (3) to the ocular surface (6). The flexible pressure-stabilizing air chamber (12) can adapt to elastic expansion and contraction with inflation and jet pulses. During the intraocular pressure detection jet process, the air pressure inside the chamber is uniformly and steadily output.

2. The flexible air-blowing device for measuring intraocular pressure according to claim 1, characterized in that: It also includes an XY optical positioning system, which includes a first light source (13) and an XY positioning focusing lens group (14). The XY optical positioning system and the ocular surface pressure measurement optical system share a fixation beam splitter (2), a first semi-transparent mirror (3), and a second semi-transparent mirror (4). The light emitted from the first light source (13) passes through the fixation beam splitter (2) and the first semi-transparent mirror (3) in sequence before reaching the ocular surface (6). The imaging light from the ocular surface (6) passes through the first semi-transparent mirror (3), the second semi-transparent mirror (4), and the XY positioning focusing lens group (14) in sequence before reaching the XY positioning detection area array CCD (15).

3. The flexible air-blowing device for measuring intraocular pressure according to claim 1, characterized in that: It also includes a Z optical positioning system, which includes a second light source (16), a positioning cemented lens (17) and a cylindrical lens (7). The light emitted by the second light source (16) reaches the ocular surface (6), and the imaging light of the ocular surface (6) passes through the positioning cemented lens (17) and the cylindrical lens (7) in sequence before connecting to the PSD position sensor.

4. The flexible air-blowing device for measuring intraocular pressure according to claim 1, characterized in that: The flexible pressure-stabilizing air chamber (12) is made of transparent silicone or TPU polyurethane, with a wall thickness of 0.8mm–1.2mm and a Shore hardness of 40–60HA.

5. The flexible air-blowing device for measuring intraocular pressure according to claim 4, characterized in that: The flexible pressure-stabilizing air chamber (12) has a wall thickness of 1.0 mm and a material with a Shore hardness of 50 HA.

6. The flexible air-blowing device for measuring intraocular pressure according to claim 1, characterized in that: The ocular surface imaging lens group (5) consists of three lenses, which are the first positive lens, the first negative lens and the second positive lens, respectively, from the closest to the ocular surface (6) to the furthest from the ocular surface (6).

7. The flexible air-blowing device for measuring intraocular pressure according to claim 2, characterized in that: The first light source (13) has a working wavelength of 850nm, and a laser collimation optical system is arranged on the optical path from the first light source (13) to the fixed beam splitter (2).

8. The flexible air-blowing device for measuring intraocular pressure according to claim 3, characterized in that: The second light source (16) has a working wavelength of 760nm, and a laser collimation optical system is arranged in the optical path from the second light source (16) to the ocular surface (6).

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