JP5584997B2 - Probe for measuring biological information - Google Patents

Description

  The present invention relates to a probe attached to a finger and used for measuring biological information such as blood oxygen saturation and pulse.

  By measuring biological information such as the pulse and blood oxygen saturation, it is possible to objectively observe the state of the subject's body. In the measurement of this biological information, photoelectric pulse wave measuring devices such as a photoelectric pulse wave meter and a pulse oximeter equipped with a probe attached to a human finger are used. For example, the pulse oximeter first projects light of two different wavelengths (red light and infrared light) from the probe attached to the finger of the subject, and the amount of light passing through the living body (finger). Detect changes. Then, the blood oxygen saturation (SpO2) is obtained based on the two-wavelength pulse waveform obtained from the detected light quantity change.

  Since the photoelectric pulse wave measuring device does not require blood collection when measuring blood oxygen saturation and / or pulse rate, the invasion of the subject's body is very little and continued for a long time ( (Continuous) measurement is possible. In addition to short-term measurements such as diagnosing the condition of patients with chronic respiratory disease and routine monitoring of the patient's respiratory status, this also monitors sudden changes in the respiratory status of critically ill patients, It is also used for long-term measurements such as monitoring of respiration and blood oxygen saturation. Recently, the device has been miniaturized, and even when worn for a long time such as in daily life or exercise, it is difficult to get in the way, so measurement of blood oxygen saturation in a patient with sleep apnea syndrome (SAS) (approximately 8 It is also used for measurement of blood oxygen saturation during sports training.

  As a probe to be mounted on a conventional finger, for example, there are probes described in JP-A-11-188019 and JP-A-7-236625. The probe described in Japanese Patent Application Laid-Open No. 11-188019 includes a pair of housings arranged to face each other, a pair of knob portions, and a spring that urges the pair of knob portions in a direction to separate the pair of knob portions, The pair of housings are separated when the pair of knobs are close to each other, and conversely, the pair of housings are close when the pair of knobs are separated from each other. By using the probe with this configuration, the optical axes of the light emitting element provided in one of the pair of housings and the light receiving element provided in the other are constant regardless of the thickness of the finger.

  Moreover, the probe described in Japanese Patent Application Laid-Open No. 7-236625 includes a pair of arms and a resilient bending member that connects the pair of arms. The pair of arms includes a soft member in contact with the part to be measured and a hard member provided on the outside thereof. According to this structure, the said soft member contacts with a subject's finger | toe, and the contact pressure to the said finger is adjusted because the said soft member deform | transforms.

Japanese Patent Laid-Open No. 11-188019 JP 7-236625 A

  In the probe described in Japanese Patent Laid-Open No. 11-188019, the displacement of the spring varies greatly depending on the thickness of the finger of the subject. In this case, if the spring is adjusted so that there is no discomfort and pain when worn on a thin finger, the tightening force when attached to a thick finger is increased, causing discomfort and pain to the subject. End up. On the other hand, if the spring is adjusted so that it has an appropriate tightening force when attached to a thick finger, the tightening force when attached to a thin finger becomes insufficient, the probe becomes unstable, and accurate measurement cannot be performed. .

  In the probe described in Japanese Patent Laid-Open No. 7-236625, the probe becomes large and heavy due to the attachment of the soft member, and the burden on the subject increases accordingly. For example, if there is a large difference in the size of fingers, such as adults and children, the ability to adjust the contact pressure with the soft member alone will be insufficient, and the fingers will be tightened more than necessary, causing discomfort and pain to the subject. May cause inconveniences such as inadequate installation, unstable mounting, and inaccurate measurement.

  Therefore, the present invention can accurately measure biological information over a long period of time regardless of the thickness of the finger to be worn, and reduce discomfort and pain to the finger on which the subject is worn. It is an object to provide a probe that can

  In order to achieve the above object, the present invention is a probe for measuring biological information, comprising a pair of housings and a connecting portion for connecting the pair of housings so that the tip portions of the pair of housings approach and separate from each other. Thus, there is provided an opening amount adjusting mechanism that suppresses separation of a portion of the pair of housings that holds fingers of the pair during operation and does not restrict movement of the pair of housings during non-operation.

  According to this configuration, since the opening amount adjusting mechanism is provided, it is possible to adjust the contact pressure when the fingers are clamped at the time of wearing, and even if the thickness of the fingers changes, the thickness of the fingers can be adjusted. At the same time, it can be attached to the finger with a constant contact pressure.

  As a result, it is possible to provide a biological information measuring probe capable of measuring biological information while reducing discomfort and pain felt by the subject accurately and continuously for a long period of time regardless of the thickness of the fingers. is there.

  In the above configuration, the pair of housings may be rotatable about the connecting portion, respectively, and the opening adjustment mechanism may regulate a rotation direction of the pair of housings.

  In the above configuration, the opening amount adjusting mechanism has a convex curved surface having the center of curvature as the center of rotation of the pair of housings, and one housing having ratchet teeth arranged circumferentially on the outer peripheral portion of the curved surface. Examples include a fixed ratchet and a check piece that is rotatably supported by the other housing and leans against the ratchet teeth to suppress reverse rotation of the ratchet ring.

  In the above configuration, the opening amount adjusting mechanism has a concave curved surface with the center of curvature as the center of rotation of the pair of housings, and one housing having ratchet teeth arranged circumferentially on the outer peripheral portion of the curved surface. A fixed ratchet, a non-return piece supported by the other housing so as to be pivotable, leaning against the ratchet teeth and suppressing reverse rotation of the ratchet ring, and a support frame for slidably supporting the non-return piece; The thing provided with the spring which urges | biases the part engaged with the said ratchet teeth of the said check piece toward the said ratchet can be mentioned.

  In the above-described configuration, the opening amount adjusting mechanism has a rotating shaft disposed in one housing, a shaft fixed to the rotating shaft, a cylindrical shape fixed to the other housing and loosely fitted to the outside of the shaft. An outer ring, a roller formed on an inner circumferential surface of the outer ring, and disposed on a cam whose distance from the shaft decreases in the circumferential direction; and a spring that biases the roller, and the rotating shaft May be provided with a rotation preventing mechanism capable of selecting a fixed state and a rotatable state with respect to the one housing.

  The said structure WHEREIN: You may provide the spring which urges | biases force to a pair of said housing so that the front-end | tip part of a pair of said housing may open.

  According to the present invention, it is possible to accurately measure biological information over a long period of time regardless of the thickness of a finger to be worn, and to reduce discomfort and pain on the finger on which the subject is worn. It is possible to provide a probe that can

It is a perspective view in the state where the probe concerning the present invention was attached to a finger. It is sectional drawing of the probe shown in FIG. It is sectional drawing of the probe before mounting | wearing with a finger. It is sectional drawing of the probe in the middle of closing. It is sectional drawing of the probe with which the finger was mounted | worn. It is sectional drawing of the other example of the probe concerning this invention. It is the expanded sectional view which expanded the circumference of the opening amount adjustment mechanism of other examples of the probe concerning the present invention.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a probe according to the present invention mounted on a finger, and FIG. 2 is a cross-sectional view of the probe shown in FIG. The probe A according to the present invention is a probe for a pulse oximeter that is connected to a measuring device by a cable Ca and is attached to a finger of a subject and measures blood oxygen saturation (SpO2) and a pulse.

  As shown in FIG. 1, the probe A connects the upper housing 1 disposed on the back side of the finger, the lower housing 2 disposed on the palm side of the finger, and the upper housing 1 and the lower housing 2. A connecting portion 3, a spring 4 having one end supported by the upper housing 1 and the other end supported by the lower housing 2, and an opening adjustment mechanism 5 for adjusting the opening of the probe A are provided. .

  The upper housing 1 includes an upper holding portion 11 that comes into contact with the back side of the finger. The lower housing 2 includes a lower holding portion 21 that comes into contact with the palm side of the finger. The upper hold unit 11 and the lower hold unit 21 are members that press a finger. The upper hold portion 11 or the lower hold portion 21 is preferably in close contact with the fingers, and a material having flexibility that can be deformed according to the shape of the fingers, such as urethane foam resin or gel-like resin, may be employed. it can.

  The upper hold member 11 has a light emitting unit 12 that can emit light having a wavelength necessary for measurement (in the case of a pulse oximeter, about 660 nm: red light and about 880 nm: two different wavelengths of infrared light) to the finger. Is provided. Although the LED is used as the light emitting unit 12, the light emitting unit 12 is not limited thereto, and a light source (for example, a discharge tube, a laser light source, etc.) capable of emitting light of a predetermined wavelength can be widely used. It is. The lower hold unit 21 is provided with a light receiving unit 22 that receives light emitted from the light emitting unit 12 and transmitted through the finger and converts the light amount into an electrical signal. The light receiving unit 22 is a silicon photodiode. However, the present invention is not limited to this, and an element that can convert light emitted from the light emitting unit 12 and transmitted through the finger into an electric signal can be widely used.

  The connecting portion 3 has an upper connecting portion 31 formed at the intermediate portion of the upper housing 1 and a lower connecting portion 32 formed at the intermediate portion of the lower housing 2. The upper connecting portion 31 and the lower connecting portion 32 are arranged so as to overlap with each other, and are slidably supported by the lower housing 2 and the upper housing 1, respectively. The upper housing 1 and the lower housing 2 rotate freely within the movable range around the connecting portion 3, so that the upper hold portion 11 and the lower hold portion 21 approach or separate from each other. In addition, the axis | shaft may be penetrated so that the upper connection part 31 or the lower connection part 32 may not shift | deviate a rotation center. Further, the upper housing 1 and the lower housing 2 are made to approach / separate an end portion on the opposite side to the upper holding portion 11 and the lower holding portion 21 with the connecting portion 3 interposed therebetween, so that the upper holding portion 11 and the lower holding part 21 can be separated / approached.

  The spring 4 is a torsion coil spring that exerts a repulsive force when twisted. The spring 4 includes a coil portion 41 and a support portion 42 protruding in a tangential direction from both ends of the coil. The spring 4 is disposed in the connecting portion 3 and is disposed so that the center of the coil portion 41 overlaps the rotation center when the upper housing 1 and the lower housing 2 rotate. One support portion 42 is attached to the upper housing 1, and the other support portion 42 is attached to the lower housing 2.

  The spring 4 is attached to the probe A in a state of being twisted so that a repulsive force is generated in advance, and the upper housing 1 and the lower housing 2 are attached to the upper hold portion 11 and the lower side by attaching the spring 4. The hold unit 21 is biased in the direction of leaving. In the state where the probe A is not attached to the finger (initial state), the probe A is in the most open state (the state in which the upper hold unit 11 and the lower hold unit 21 are farthest apart).

  The opening adjustment mechanism 5 adjusts the amount of rotation about the connecting portion 3 between the upper housing 1 and the lower housing 2 and adjusts the distance between the upper hold portion 11 and the lower hold portion 21. The opening amount adjusting mechanism 5 includes a ratchet ring 51 fixed to the lower housing 2 such that a central axis thereof overlaps with a rotation center of the lower housing 2, and a check piece 52 rotatably supported by the upper housing 1. And. When the upper housing 1 and the lower housing 2 rotate, the ratchet ring 51 and the locking piece 52 are arranged to rotate in opposite directions.

  On the outer periphery of the ratchet ring 51, serrated ratchet teeth 511 having one loose inclination are arranged at equal intervals in the circumferential direction. The check piece 52 is rotatably supported by the upper housing 1, and is arranged so that the tip end portion leans against the ratchet teeth 511. In the opening amount adjusting mechanism 5, the rotation in the direction in which the check piece 52 gets over the ratchet teeth 511 is forward rotation (arrow a1 in the figure). When the opening amount adjusting mechanism 5 tries to reversely rotate (arrow b1 in the figure), the check piece 52 is engaged with the ratchet teeth 511 and the reverse rotation is prevented (the reverse rotation preventing function of the opening amount adjusting mechanism 5 is activated). Although not shown in the probe A shown in FIG. 2, the actual check piece 52 is provided with a biasing member (for example, a spring) that biases the tip so as to contact the ratchet ring 51. ing. A plurality of check pieces 52 may be provided.

  In the probe A, when the probe A is closed, the opening amount adjusting mechanism 5 is arranged to rotate forward. When the probe A is closed, the opening amount adjusting mechanism 5 is rotated forward, the check piece 52 gets over the ratchet teeth 511, and the upper housing 1 and the lower housing 2 are smoothly rotated in the direction in which the probe A is closed.

  Conversely, when force is applied to the upper housing 1 and the lower housing 2 to open the probe A, the opening adjustment mechanism 5 attempts to reverse. When the opening amount adjusting mechanism 5 tries to reversely rotate, the check piece 52 engages with the ratchet teeth 511 and the reverse rotation is prevented. Thereby, the probe A does not move in the opening direction.

  In the opening amount adjusting mechanism 5, the check piece 52 includes an operation unit 521 for rotating the tip in a direction away from the ratchet ring 51. When the tip of the check piece 52 is separated from the ratchet teeth 511 of the ratchet ring 51, the ratchet ring 51 and the check piece 52 are in a free state. As a result, the opening amount adjusting mechanism 5 can perform not only forward rotation but also reverse rotation (the reverse rotation preventing function of the opening amount adjusting mechanism 5 is released).

  When the operation portion 521 of the check piece 52 is operated and the opening amount adjusting mechanism 5 is free to rotate, the upper housing 1 and the lower housing 2 are connected to the upper hold portion 11 and the lower hold portion 21 by the amount of force of the spring 4. Can be rotated in the opening direction.

  From the above, when the reverse rotation prevention function of the opening amount adjusting mechanism 5 is operating, the probe A can only be closed, and when the reverse rotation prevention function is released, the probe A can be opened and closed. It is.

  The operation of the probe A will be described with reference to the drawings. 3 is a cross-sectional view of the probe before being attached to a finger, FIG. 4 is a cross-sectional view of the probe in the middle of closing, and FIG. 5 is a cross-sectional view of the probe attached to the finger. As shown in FIG. 3, the force of the spring 4 acts on the upper housing 1 and the lower housing 2 so that the probe A is separated from the upper hold portion 11 and the lower hold portion 21 with the connecting portion 3 as a fulcrum. . That is, the probe A is in an open state. The tip of the check piece 52 is urged toward the ratchet ring 51. Thereby, the reverse rotation prevention function of the opening amount adjusting mechanism 5 is activated, and the probe A can only be closed.

  First, a finger is placed on the lower holding portion 21 of the probe A in an open state. At this time, the finger is placed on the probe A so that the palm side is in contact with the lower hold unit 21 and the upper side is opposed to the upper hold unit 11. Then, the upper housing 1 is rotated with the connecting portion 3 as a fulcrum so that the upper hold portion 11 is brought into contact with the back side of the finger.

  In the probe A, when the probe A is closed, the opening amount adjusting mechanism 5 rotates forward, and the check piece 52 and the ratchet ring 51 rotate smoothly in the opposite directions relatively. Thereby, the upper housing 1 rotates and the upper hold part 11 approaches the back side of the fingers (see FIG. 4).

  By further rotating the upper housing 1, the upper hold portion 11 comes into contact with the back side of the finger. After the contact, by pressing the upper housing 1, the upper hold portion 11 is pressed against the finger with an appropriate pressing force. The upper hold unit 11 and the lower hold unit 21 are deformed, and a predetermined contact pressure acts on the fingers. At this time, the force due to the repulsive force of the upper hold portion 11 and the lower hold portion 21 is acting on the upper housing 1 and the lower housing 2, but the reverse rotation prevention function of the opening amount adjusting mechanism 5 is in operation. The probe A is not opened and is maintained in a state where the fingers are pinched (see FIG. 5).

  A frictional force is generated between the upper hold unit 11 and the lower hold unit 21 and the finger due to the contact pressure on the finger. By making this frictional force larger than a predetermined frictional force, it is possible to suppress the probe A from being displaced from the finger. In addition, when a contact pressure greater than a certain contact pressure is applied to the finger on which the probe A is attached, the finger becomes congested or the muscles become stiff and feels uncomfortable and painful.

  The contact pressure acting on the fingers from the upper hold unit 11 and the lower hold unit 21 is higher than the contact pressure that prevents the probe A from shifting, and the contact pressure that causes discomfort and pain. Therefore, the contact pressure acting on the fingers at the upper hold unit 11 and the lower hold unit 21 is adjusted to be between the contact pressure at which the probe A can be prevented from shifting and the contact pressure at which discomfort and pain are felt. . By adjusting and attaching the contact pressure in this way, the probe A is less likely to be displaced and accurate measurement can be performed regardless of long-time measurement. In addition, it is difficult for the subject to feel discomfort and pain in the fingers even after long-time wearing.

  Each time the check piece 52 gets over the ratchet teeth 511 of the ratchet ring 51, the distance between the upper hold portion 11 and the lower hold portion 21 decreases. Therefore, as the ratchet teeth 511 of the ratchet ring 51 are finer and the number is larger, the distance between the upper hold portion 11 and the lower hold portion 21 can be finely adjusted.

  In the probe A, the contact pressure is applied to the finger after the upper hold portion 11 contacts the finger. Therefore, the spring 4 is not involved in the contact pressure acting on the finger and is determined by the pressure contact between the upper hold portion 11 and the lower hold portion 21 and the finger. As a result, the probe A can hold the finger with the same contact pressure regardless of the thickness of the finger (opening amount of the probe A).

  In the embodiment described above, the spring 4 that biases the force with respect to the upper housing 1 and the lower housing 2 so that the distance between the upper hold portion 11 and the lower hold portion 21 is increased with the connecting portion 3 as the center. Although provided, the spring 4 does not have to be provided if it is opened manually when the reverse rotation prevention function of the opening adjustment mechanism 5 is released. In the opening adjustment mechanism 5, the ratchet ring 51 is fixed to the lower housing 2 and the check piece 52 is supported by the upper housing 1. However, the present invention is not limited to this, and the ratchet ring 51 is reverse to the ratchet ring 51. The stop piece 52 may be attached to each of the upper housing 1 and the lower housing 2 separately.

  Another example of the probe according to the present invention will be described with reference to the drawings. FIG. 6 is a cross-sectional view of another example of the probe according to the present invention. The probe B shown in FIG. 6 has the same configuration as the probe A shown in FIGS. 1 to 5 except that the configuration of the opening adjustment mechanism is different, and substantially the same parts are denoted by the same reference numerals. Detailed descriptions of substantially the same parts are omitted. For convenience, the illustration of a spring that biases the probe in the opening direction is omitted.

  The probe B includes an opening amount adjusting mechanism 6. The opening amount adjusting mechanism 6 includes a ratchet ring 61 formed on the lower housing 2, a support frame 62 formed on the upper housing 1, a slidably supported by the support frame 62, and a reverse engagement with the ratchet ring 61. A stop piece 63 and a spring 64 that urges the check piece 63 toward the ratchet ring 61 are provided.

  As shown in FIG. 6, the lower housing 2 includes a wall portion 20 having an arc-shaped cross section centering on a central axis when rotating with the connecting portion 3 as a fulcrum, and the ratchet ring 61 is a concave side of the wall portion 20. Is formed. On the ratchet ring 61, ratchet teeth 611 having a triangular cross section are arranged in the circumferential direction. One inclined surface of the ratchet teeth 611 is a loose inclination that the check piece 63 can easily get over, and the opposite inclined surface is a tight inclination that the check piece 63 cannot get over.

  The support frame 62 is formed at the rotation center of the upper housing 1. The support frame 62 slidably supports the check piece 63, and an opening is formed so that the check piece 63 can protrude from a portion facing the ratchet ring 61. The check piece 63 includes an edge portion 631 formed obliquely so that the tip end portion can get over the loose inclined surface of the ratchet teeth 611. Further, the opposite side of the edge portion 631 is provided with a spring engaging portion 632 with which the spring 64 is engaged, and the spring engaging portion 633 that presses the spring 64 is provided at the end portion on the edge portion 631 side of the spring engaging portion 632. Is formed.

  The spring 64 is a coil spring. The spring 64 is externally fitted to the spring engaging portion 632 of the check piece 63 and is in contact with the spring fastening portion 633. The end portion of the spring 64 opposite to the spring retaining portion 633 is in contact with the wall surface opposite to the opening of the support frame 62. The check piece 63 is biased so as to protrude outward from the opening by the amount of force of the spring 64, and the edge portion 631 is pressed against the ratchet teeth 611 of the ratchet ring 61.

  In the opening amount adjusting mechanism 6, the forward rotation state is when the edge portion 631 of the check piece 63 rotates so as to get over the ratchet teeth 611. When the opening amount adjusting mechanism 6 tries to reversely rotate, the check piece 63 engages with the ratchet teeth 611 and the reverse rotation preventing function is activated to prevent reverse rotation. Further, the edge 631 of the check piece 63 is separated from the ratchet teeth 611 by sliding the check piece 63 against the force of the spring 64. Accordingly, the movement of the ratchet ring 61 is not restricted by the check piece 63, and the reverse rotation prevention function of the opening amount adjusting mechanism 6 is released. When the reverse rotation prevention function of the opening amount adjusting mechanism 6 is released, the opening amount adjusting mechanism 6 can be rotated in either forward rotation or reverse rotation.

  Similarly to the probe A, the probe B can only be closed while the reverse rotation prevention function of the opening adjustment mechanism 6 is in operation, and can be opened and closed when the reverse rotation prevention function is released. When the probe B is attached to the finger, the probe B is attached to the finger in a state in which the reverse rotation prevention function of the opening adjustment mechanism 6 is activated. Accordingly, the probe B moves only in the closing direction, and the force of the spring 4 does not act in the closing direction, so that the finger is pressed with a constant contact pressure regardless of the thickness of the finger (the opening amount of the probe B). Can do. Also, when removing the probe B from the finger, the probe B can be opened and closed by moving the check piece 63 and releasing the reverse rotation prevention function of the opening adjustment mechanism 6, and the upper hold unit 11 and the lower hold unit 21 are Remove from fingers.

  When the check piece 63 is slid against the spring 64, a fixing member may be provided to fix the check piece 63 in a slid state, and the reverse rotation is prevented only during the operation by the operator without being fixed. The function may be canceled.

  Still another example of the probe according to the present invention will be described with reference to the drawings. FIG. 7 is an enlarged cross-sectional view enlarging the periphery of an opening adjustment mechanism of still another example of the probe according to the present invention. The probe C shown in FIG. 7 has the same configuration as the probe A except that the opening adjustment mechanism 7 is different, and substantially the same parts are denoted by the same reference numerals. Detailed descriptions of substantially the same parts are omitted.

  The opening adjustment mechanism 7 used in the probe C shown in FIG. 7 has the same structure as the one-way rotation clutch. That is, a rotating shaft 70 provided in the lower housing 2, a shaft 71 fixed to the rotating shaft 70, an outer ring 72 fitted on the shaft 71, and a roller disposed between the shaft 71 and the outer ring 72. 73 and a spring 74 that pushes the roller 73 in the circumferential direction of the shaft 71.

  The rotating shaft 70 is attached to a cylindrical hole formed in the lower housing 2 and includes a rotation restricting mechanism that restricts rotation. The rotation restricting mechanism includes a key 701 formed at the end of the rotating shaft 70 and protruding in the radial direction of the rotating shaft 70, and a key groove (not shown) in which the key 701 is inserted into a hole formed in the lower housing 2. Is formed. When the key 701 of the rotating shaft 70 is fitted in the key groove, the rotation of the rotating shaft 70 is hindered by the fitting of the key and the key groove, and is fixed to the lower housing 2. When the rotary shaft 70 is slid in the axial direction and the key is displaced from the keyway, the rotary shaft 70 becomes rotatable.

  The shaft 71 is a cylindrical member having a rotation shaft 70 passing through the center thereof. The shaft 71 and the rotating shaft 70 are completely fixed. The outer ring 72 is loosely fitted to the outside of the shaft 71 so as to be rotatable. The outer ring 72 is provided with a plurality of cams 721 whose distance from the shaft 71 is reduced along the circumferential direction. The cam 721 is inclined in a curved shape so as to approach the inside from one side to the other, and the widest portion has a receiving surface orthogonal to the tangent. A roller 73 is disposed inside the cam 721 so as to be in contact with the outer peripheral surface of the shaft 71, and a spring 74 is provided between the receiving surface and the roller 73. The roller 73 is pressed by the spring 74 in a direction in which the distance between the cam 721 and the shaft 71 becomes narrower.

  In FIG. 7, when the upper housing 1 is rotated so that the upper hold portion 11 approaches the lower hold portion 21, the outer ring 72 rotates in the direction of the arrow C <b> 1 with respect to the shaft 71. At this time, the roller 73 rolls and moves in the wide direction of the cam 721. The roller 73 rotates in a free state with respect to the shaft 71 and the outer ring 72, and the upper housing 1 moves so that the upper hold portion 11 approaches the lower hold portion 21.

  When the upper housing 1 is moved so that the upper hold portion 11 is separated from the lower hold portion 21, the outer ring 72 tends to rotate in the direction opposite to the arrow C1 with respect to the shaft 71. At this time, the roller 73 is pushed by the outer ring 72 in the direction in which the cam 721 is narrowed. When the roller 73 is pushed by a narrow portion of the cam 721, the roller 73 bites between the cam 721 and the shaft 71 and prevents the outer ring 72 from rotating. As a result, the upper housing 1 is prevented from moving in a direction away from the lower hold portion 21 by the opening adjustment mechanism 7.

  When the rotary shaft 70 is moved in the axial direction, the key 701 of the rotary shaft 70 is disengaged from the key groove (not shown) of the lower housing 2 and the rotary shaft 70 can be rotated. When the rotary shaft 70 is rotatable, the upper housing 1 and the lower housing 2 move so that the upper hold portion 11 and the lower hold portion 21 approach and separate from each other about the rotary shaft 70.

  In the above description, the case where the lower housing 2 is fixed and the upper housing 1 is moved is described as an example. However, even when the upper housing 1 is fixed and the lower housing 2 is moved, the upper housing 1 and the lower housing 1 are moved. Even when both of the side housings 2 are moved simultaneously, the outer ring 72 moves in the same direction as described above with respect to the shaft 71, so that the same effect can be obtained.

  Further, in the opening amount adjusting mechanism 7, since the roller 73 bites between the shaft 71 and the cam 721 to prevent reverse rotation, the reverse rotation can be prevented regardless of the position of the shaft 71 and the outer ring 72. . And the distance of the upper side hold part 11 and the lower side hold part 21 can be adjusted continuously. Thereby, the distance between the upper side hold part 11 and the lower side hold part 21 can be finely adjusted, and the contact pressure can also be finely adjusted.

  From the above, by using the probe C provided with the opening adjustment mechanism 7, the finger can be held with a constant or substantially constant contact pressure regardless of the size of the finger. Difficult to slip, hard to feel discomfort and pain.

  In the above-described embodiment, as an opening adjustment mechanism, a ratchet mechanism or a one-way clutch mechanism is used as an example. However, the present invention is not limited to this, and the rotation of the housing is one-way when in an operating state. Therefore, it is possible to widely adopt a mechanism that can easily release the restriction on the rotation direction of the housing.

  The description of the above embodiment is for explaining the present invention, and does not limit the invention described in the claims or reduce the scope thereof. It is needless to say that each part configuration of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims.

  The probe according to the present invention can be used as a measurement probe of a photoelectric pulse wave measuring apparatus that is attached to a finger and continuously measures a pulse and blood oxygen saturation for a long time.

A Probe 1 Upper housing 11 Upper hold portion 12 Light emitting portion 2 Lower housing 21 Lower hold portion 22 Light receiving portion 3 Connecting portion 4 Spring 5 Opening adjustment mechanism 51 Ratchet ring 511 Ratchet tooth 52 Check piece

Claims (2)

A pair of housings;
A connecting portion that rotatably connects the pair of housings such that the tip portions of the pair of housings approach and separate from each other;
A probe for measuring biological information, comprising an opening amount adjusting mechanism that suppresses separation of a portion that sandwiches the fingers of the pair of housings during operation and does not restrict movement of the pair of housings during non-operation,
The connecting portion has a shaft disposed in one housing, and a cylindrical outer ring fixed to the other housing and loosely fitted on the outside of the shaft,
The opening amount adjusting mechanism is recessed in the inner peripheral surface of the outer ring and formed so that the distance between the peripheral surface and the shaft becomes narrower toward the front in the rotational direction when the tips of the pair of housings approach each other. Cam, a roller disposed in the cam, a spring for urging the roller forward in the rotational direction, and a state where the shaft is fixed to the one housing and rotatable with the outer ring A biological information measuring probe , comprising: a rotation preventing mechanism capable of selecting a different state .
The biological information measuring probe according to claim 1 , further comprising a spring that urges the pair of housings so that tip portions of the pair of housings open .

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