JP5401618B1 - Pulse oximeter probe - Google Patents

Abstract

In a pulse oximeter probe attached to a finger, relative movement between the probe and the finger is prevented, and blood flow is not stopped due to finger pressure, and stable measurement is performed.
An integrated pulse oximeter composed of a light emitting unit side housing 1 and a light receiving unit side housing 2 has a lower recess 2R for accommodating a subject's finger on the upper surface of the light receiving unit side housing 2. The rib 5 extending in the longitudinal direction of the concave portion is provided. The ribs 5 are provided at symmetrical positions on both sides of the light receiving part PD placed at the center of the recess 2R. At the time of measurement, the light-emitting portion side housing 1 pressed by the spring presses the finger against the surface of the recess 2R, and the rib 5 slightly enters the finger skin and is held in the recess 2R. And the contact pressure is weakened at the part of the finger facing the light receiving part PD, and blood flow is not stopped.
[Selection] Figure 1

Description

  The present invention relates to a probe attached to a fingertip of a subject for measurement in a pulse oximeter that optically measures oxygen saturation of arterial blood.

  A pulse oximeter is equipped with a measurement probe equipped with a light emitting part and a light receiving part on the subject's fingertip, etc., and utilizes the light transmission characteristics that change according to the ratio of oxyhemoglobin in the blood, This is a device for measuring oxygen saturation. Arterial blood oxygen saturation is a fundamental factor that evaluates the respiratory function of how much oxygen has been taken into the body, and this is detected not only by patients with respiratory disease but also by the diagnosis of the health level of healthy individuals. It also has important implications for the management of exercise status. The pulse oximeter is a so-called non-invasive device that does not need to insert a measurement part such as a probe into the human body when measuring the oxygen saturation of arterial blood, and it is simple and safe for a long time. It has the great advantage of being measurable.

  The reliability of pulse oximeters has increased dramatically in recent years due to the development of arterial blood flow analysis technology based on heartbeat and the use of LED, which is a powerful light source. Rapid spread has been promoted. At present, it is used in a wide range of applications from use as a monitor for patients and the like in specialized medical settings to use as a diagnostic instrument in home nursing. At the same time, pulse oximeters of various structures have emerged, including an integrated pulse oximeter that has a body consisting of a battery for power supply, a display for displaying measurement results, etc., which is integrated into the probe and attached to the finger. There is a meter. There is also a small pulse oximeter in which the main body is wound around the wrist like a wristwatch and the probe and the probe are connected by a communication cable.

FIG. 5 shows an example of an integrated pulse oximeter described in US Patent Application Publication No. 2009/43180.
The integrated pulse oximeter includes an upper housing (light emitting unit side housing) 1 and a lower housing (light receiving unit side housing) 2. In order to facilitate understanding, both housings are shown in a separated state in this figure. However, in actuality, both housings arranged opposite to each other are connected by a linear spring 3 so as to be like a clothespin. A spring force is applied in a direction in which the tip portion (left side in the drawing) comes close to and comes into contact. On the upper part of the upper housing 1, a display unit 4 for displaying a numerical value of the measured oxygen saturation or the like (usually displaying a heart rate detected accompanying the oxygen saturation) is installed. Stores a power supply battery (not shown).

In the upper part of the lower housing 2, a lower recess 2 </ b> R that mainly accommodates the lower side (abdomen) of the subject's finger is formed. Although not clearly shown in FIG. 5, Is formed with an upper recess that mainly accommodates the upper side (back part) of the finger. The lower recess 2R is a recess having an arc-shaped cross section extending in the longitudinal direction of the pulse oximeter, and has a light receiving element such as a photodiode at the center of the arc-shaped cross section on the relatively back side of the lower recess 2R. A light receiving unit PD is installed, and a light emitting unit having a light emitting element such as an LED is installed in an upper concave portion of the upper housing 1 located immediately above the light receiving unit PD. The light emitting element emits two types of light beams having different wavelengths of red light and infrared light (light beams having different light absorption characteristics).
When measuring oxygen saturation, pinch the right ends of the figures of both housings to open the tip against the linear spring 3, insert the subject's finger, and place the finger on the light receiving portion PD. Position the tip. When the right end portion is released, the finger is held between the upper concave portion and the lower concave portion 2R by the spring force of the linear spring 3, and optical measurement of oxygen saturation is performed. Such a measuring method is the same in a pulse oximeter including a probe separated from a main body, and an upper concave portion and a lower concave portion are also formed in the probe.

  By the way, the measurement of arterial blood oxygen saturation with a pulse oximeter is performed by measuring light transmitted through a finger sandwiched between probes, so that a light emitting element and a light receiving element fixed to the probe and a subject's finger are measured. When a relative movement occurs between the two, the noise is mixed due to the disturbance of the transmitted light and an error occurs in the measurement result. In order to cope with this, Japanese Patent Laid-Open No. 6-319727 discloses that a light emitting element and a light receiving element are fixed to a plate-like elastic body, and these plate-like elastic bodies are deformed and attached so as to be in close contact with a finger. Thus, a technique for preventing relative movement between the light emitting element and the finger is disclosed.

  Further, in order to measure the oxygen saturation of arterial blood, it is necessary to detect pulsed arterial blood flow accompanying heartbeat. For example, in the case of a subject whose blood flow is considerably small, the finger is a probe. There is a risk that the blood flow of the capillaries at the fingertips stops and the oxygen saturation cannot be measured. In the utility model registration No. 2574628, a wave-like uneven portion formed by an elastic member is provided on the surface of the probe that comes into contact with the finger, and the protrusion and the finger are contacted in a dotted manner so as not to inhibit blood flow. Have been disclosed.

US Patent Application Publication No. 2009/43180 JP-A-6-319727 Utility Model Registration No. 2574628

In the pulse oximeter, if the relative position of the finger and the light receiving portion of the probe changes with the movement of the subject's body (body movement), noise is mixed into the received signal and the measurement error increases. . In particular, in an integrated pulse oximeter in which the main body including the battery for power supply and display unit and the probe are integrated, the mass of the entire device to be worn on the finger increases, so the inertial force generated in the entire device due to acceleration during body movement And the relative movement between the finger and the probe tends to occur.
As disclosed in Patent Document 2, a light-emitting element or light-receiving element fixed to a plate-like elastic body to prevent the influence of body movement cannot be applied to a commonly used probe that sandwiches a finger. Furthermore, it is practically difficult to fix the light emitting element and the light receiving element without their optical axes being shifted by a plate-like elastic body that does not adversely affect the human body.

And in the pinching type probe generally used, the surface of the probe is smooth, so that the finger is pressed on the surface during measurement, and depending on the subject, blood flow in the capillary blood vessels Stop. This fear becomes stronger when the spring force for closing the probe is set large in order to prevent relative movement between the finger and the probe.
In the probe of Patent Document 3, a wave-like uneven portion made of an elastic member is provided on the surface, and the blood flow is not inhibited by bringing the protrusion into contact with a finger in a dot shape. However, attaching an elastic member that does not adversely affect the human body to the surface of the probe and providing an uneven portion therewith is difficult in terms of technical or cost, such as material selection and processing problems, When the surface of the probe is wiped with alcohol or the like, dirt is likely to remain between the uneven portions. Further, when the point-like convex portion is pressed against the finger, the subject is painful.
An object of the present invention is to provide a pulse oximeter probe that has a simple structure, prevents relative movement between the fingers without causing pain to the subject, and stops blood flow due to finger compression. It is to prevent and solve the above-mentioned problems.

In view of the above-described problems, the present invention provides a rib that extends in the longitudinal direction on both sides of the light receiving portion on the surface of the concave portion in which the light receiving portion is provided in the sandwich type probe of the pulse oximeter. The relative movement is suppressed. That is, the present invention is “a light emitting part side housing having a light emitting part and a light receiving part side housing having a light receiving part are arranged to face each other, and the front ends of both housings are biased by a spring so as to be close to each other. A pulse oximeter probe,
The light receiving unit side housing is formed with a concave part having an arcuate cross section extending from the tip part in the longitudinal direction of the light receiving unit side housing for accommodating a subject's finger, and the light receiving unit is formed in the circular shape. It is installed in the center of the cross-section of the recess of the arc-shaped cross section,
Ribs extending in the longitudinal direction of the concave portions are provided on the surface of the concave portion of the arc-shaped cross section at symmetrical positions on both sides of the light receiving portion, respectively. ''
The probe is characterized by this.

  According to a second aspect of the present invention, the ribs provided on the surface of the concave portion having the arcuate cross section can be a plurality of parallel ribs. According to a third aspect of the present invention, the rib provided on the surface of the recess can be a rib that is divided into a plurality of portions in the longitudinal direction.

  When the rib provided on the surface of the concave portion having the arc-shaped cross section is a single linear rib extending continuously in the longitudinal direction as described in claim 4, the rib is the surface of the concave portion. The height from the center is set to 0.5 mm to 1.5 mm, the length in the longitudinal direction is set to 10 mm to 15 mm, and the mutual distance between the ribs sandwiching the light receiving part is set to 6 mm to 12 mm. Is preferred.

  As described in claim 5, the rib provided on the surface of the concave portion having the arcuate cross section can be attached to the surface by adhesion.

  7. A light emitting portion side housing provided with the light emitting portion is formed with an opposing concave portion having an arc-shaped cross section at a position facing the concave portion of the light receiving portion side housing, and the light emitting portion is formed into the opposing concave portion. Further, opposing ribs extending in the longitudinal direction of the opposing recess can be provided on the surface of the opposing recess at symmetrical positions on both sides of the light emitting part.

  As described in claim 7, the present invention is suitable for a probe for a pulse oximeter in which a main part of a pulse oximeter including a power source and a display unit is integrated.

The probe for the pulse oximeter of the present invention is arranged so that a light emitting unit side housing provided with a light emitting unit and a light receiving unit side housing provided with a light receiving unit are opposed to each other in the same manner as a general probe for measuring by inserting a finger. In addition, a basic structure is provided in which the front ends of both housings are biased by a spring so as to be close to each other. In the light receiving part side housing, a concave part having an arcuate cross section extending in the longitudinal direction for accommodating the subject's finger is formed, and the light receiving part is installed at the central part of the cross section of the concave part. Further, ribs extending in the longitudinal direction, that is, linear protrusions, are provided on the surface of the concave portion at symmetrical positions on both sides of the light receiving portion.
When the probe of the present invention is attached to the subject's finger, the finger is accommodated in the recess of the light receiving unit side housing, and the lower side (abdomen) of the finger contacts the surface of the recess provided with the rib. This rib protrudes from the surface of the recess at two symmetrical points of the arc-shaped cross section. When the light emitting unit side housing biased by the spring is pressed from above the finger, it is applied to the skin under the elastic finger. The rib is slightly inserted, and the relative movement between the finger and the probe is prevented. In particular, since the rib extends in the longitudinal direction of the recess, the probe of the present invention is effective in suppressing relative rotation between the finger and the probe, and the subject rotates the finger. It is possible to avoid the measurement error of the pulse oximeter due to the body movement (such body movement is likely to occur with the rotational movement of the wrist, elbow, etc.).

When the subject's finger is sandwiched between the probes, the contact pressure acting between the two ribs and the finger is increased, and accordingly, the portion of the finger facing the light receiving portion at the center of the cross section of the recess is increased. As a result, the contact pressure is weakened. For this reason, the probe of the present invention does not strongly press the finger portion for measuring the transmitted light, and even in a subject with low blood flow, the oxygen saturation of the pulse oximeter is stopped by stopping the blood flow in the artery. There is no situation where it is impossible to measure.
Here, since the rib of the present invention provided in the concave portion of the light receiving portion side housing is a linear protrusion extending in the longitudinal direction of the concave portion, for example, the dotted shape of the corrugated uneven portion described in Patent Document 3 is used. The contact pressure at the contact point is much smaller than that in which the convex part of the finger is pressed against the finger, and the subject is hardly painful or uncomfortable. Further, the surface of the probe can be easily wiped with alcohol or the like, and the effect of preventing relative rotation between the finger and the probe is great because the rib extends in the longitudinal direction. In order to provide one rib on both sides of the light receiving portion and to exhibit such merit in a balanced manner, it is preferable to set each dimension of the rib as in claim 4.

As in the second aspect of the present invention, when a plurality of parallel ribs are provided on both sides of the light receiving part as the ribs provided on the surface of the concave part having the arc-shaped cross section, the contact part between the finger and the rib increases. Thus, relative movement can be suppressed more reliably. In addition, there are considerable individual differences in the thickness of the subject's fingers, etc. However, if multiple parallel ribs are provided, one of the ribs will be in an appropriate position to prevent relative movement. It is possible to deal with differences in finger dimensions. In the case where a plurality of parallel ribs are provided, it is preferable that the height of the rib is higher as the rib is farther from the center of the arc-shaped cross section where the light receiving unit is placed.
When the rib provided on the surface of the concave portion is a rib divided into a plurality of portions in the longitudinal direction as in the invention of claim 3, the lower skin of the finger enters the lower portion between the ribs, and the finger The relative movement in the longitudinal direction is more reliably suppressed.

  When the rib provided on the surface of the concave portion having the arc-shaped cross section is attached to the surface by adhesion as in the invention of claim 5, a rib manufactured separately is also applied to the existing pulse oximeter probe. The probe of the present invention can be easily installed. In this case, it is desirable to manufacture the rib with the same material as that of the existing probe.

  In the invention of claim 6, ribs (opposing ribs) extending in the longitudinal direction are also provided symmetrically on both sides of the light emitting unit in the concave part (opposing concave part) having an arcuate cross section formed in the light emitting unit side housing provided with the light emitting unit. Are provided at different positions. In this way, relative movement between the finger and the probe, particularly relative rotation, is more reliably suppressed.

  The invention of claim 7 is an application of the present invention to a pulse oximeter in which a main part of a pulse oximeter including a power source and a display unit is integrated with a probe, that is, an integrated pulse oximeter. Since the integrated pulse oximeter has a large mass and relative movement between the finger and the probe is likely to occur due to acceleration during body movement, it is clear that the usefulness of the rib of the present invention is high.

It is a figure which shows the structure of 1st Example which applied this invention to the probe of an integrated pulse oximeter. It is a figure which shows the effect | action etc. of 1st Example of FIG. It is a figure which shows the modification of 1st Example of this invention. It is a perspective view showing the 2nd example which applied the present invention to the probe of a separation type pulse oximeter. It is a perspective view which shows the probe of the conventional integrated pulse oximeter.

  Hereinafter, a probe for a pulse oximeter of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of a first embodiment in which the present invention is applied to an integrated pulse oximeter probe. Here, the basic structure of the integrated pulse oximeter of the present invention, that is, the light emitting unit side housing and the light receiving unit side housing are arranged to face each other, and the springs are arranged so that the front ends of both housings are close to each other. The structure to be energized is not different from the integrated pulse oximeter of FIG. 5, and in the first embodiment of FIG. 1, the parts corresponding to the parts in FIG. .

  The integrated pulse oximeter of the first embodiment shown in FIG. 1 includes a light emitting unit side housing 1 and a light receiving unit side housing 2 that also function as a probe. The light emitting unit side housing 1 includes a light emitting unit LD and a light receiving unit. The side housing 2 is provided with a light receiving part PD. Both housings arranged opposite to each other are urged in a direction in which the tips approach and come into contact with each other by a spring not shown in this figure, and the tips are closed as indicated by the solid line in the figure. If the other side is pinched with a finger, it will be in the open state like a two-dot chain line. A display unit 4 made of liquid crystal or the like is attached to the upper part of the light emitting unit side housing 1, and a power source battery (not shown) is stored inside the light receiving unit side housing 2.

  An upper concave portion 1R is formed on the lower surface of the light emitting portion side housing 1, and a lower concave portion 2R is also formed on the upper surface of the light receiving portion side housing 2. Both recesses extend from the distal end in the longitudinal direction of the housing, and the subject's finger is accommodated therebetween. The upper concave portion 1R and the lower concave portion 2R are formed in an arc-shaped cross section as shown in the upper right diagram of FIG. 1, and a light emitting portion LD and a light receiving portion PD are respectively installed at the center of the cross section to constitute a probe. Is done. On the surface of the lower recess 2R, ribs 5 extending in the longitudinal direction of the recess are provided one by one at symmetrical positions on both sides of the light receiving part PD.

When measuring the oxygen saturation, as shown in FIG. 2, when the light emitting unit side housing 1 and the light receiving unit side housing 2 are opened and the finger FG of the subject is sandwiched between them, the light emitting unit side biased by the spring The housing 1 presses the finger FG against the surface of the lower recess 2R. At this time, as shown in the right diagram of FIG. 2, the rib 5 protruding from the surface of the lower recess 2R slightly enters the skin of the elastic finger FG, and the finger FG is held in the lower recess 2R. The Therefore, even if an inertial force acts on the pulse oximeter due to the body movement of the subject, the relative movement between the lower concave portion 2R and the finger FG, in particular, the relative rotation is prevented, and the noise caused by the disturbance of the transmitted light And stable measurement without measurement error.
Further, when the finger FG is pressed against the surface of the lower concave portion 2R, the contact pressure of the portion where the rib 5 and the finger FG come into contact increases and the contact pressure of the other portion decreases, but the rib 5 Since it protrudes in two symmetrical places of the cross section across the PD, the contact pressure acting on the finger FG is weakened at the part facing the light receiving part PD in the center of the cross section. In other words, the portion that measures the transmitted light of the finger FG is not strongly compressed, and even a subject with a small blood flow does not stop the blood flow in the artery and cannot measure the pulse oximeter. .

As described above, the probe of the first embodiment of the present invention is provided with one rib 5 extending in the longitudinal direction at symmetrical positions on both sides of the light receiving portion PD in the lower concave portion 2R. Since the rib 5 is a linear protrusion having a certain length, there is almost no pain or discomfort given to the subject, such as when a plurality of point-like protrusions are pressed against a finger, and disinfection Therefore, it is easy to wipe the surface. And in order to exhibit the above-described effects while taking these points into consideration, it is preferable to set the dimensions of X, Y, and Z in the lower diagram of FIG. 1 such as the length and height of the rib 5 as follows. . Incidentally, the cross-sectional shape of the rib 5 is semicircular (kamaboko shape).
(1) The length X in the longitudinal direction is 10 mm or more and 15 mm or less.
(2) The mutual distance Y between the ribs sandwiching the light receiving portion is 6 mm or more and 12 mm or less.
(3) The height Z from the surface of the recess is 0.5 mm or more and 1.5 mm or less.

  Since the rib 5 has a simple shape, it can be formed simultaneously and easily when the lower recess 2R of the light receiving unit side housing 2 is manufactured. In general, the lower concave portion 2R is manufactured by injection molding, compression molding, or the like of a relatively hard synthetic resin having excellent biocompatibility. At this time, a slight process may be added to the mold. In addition, it is possible to manufacture only the rib 5 from a synthetic resin and adhere and fix it to the lower concave portion 2R. In this way, a rib that exhibits the effect of the present invention is provided to an existing probe. Can do.

FIG. 3 shows a modification of the first embodiment of the present invention. In these modified examples, the shape of the ribs in the longitudinal direction provided on both sides of the light receiving unit is changed. FIGS. 3A and 3B show the upper side of the lower concave portion 2R of the light receiving unit side housing. FIG. 2 is a view corresponding to the lower view of FIG.
In Modification 1 of FIG. 3A, two ribs 5A extending in parallel with each other in the longitudinal direction of the lower recess 2R are provided on both sides of the light receiving portion PD, respectively, as shown in the enlarged cross-sectional view along the line BB. Furthermore, the height of the rib away from the center of the arc-shaped cross section is high. Since the subject's fingers come into contact with a total of four ribs 5A installed on both sides of the light receiving portion PD, the area of the contact portion between the fingers and the ribs can be increased, and relative movement can be more reliably suppressed. it can. In addition, for example, even when the subject's finger is thin, it is possible to prevent relative movement by the finger coming into contact with the rib closer to the center of the cross section, such as the thickness of the finger. Appropriate measurement can be performed regardless of the difference.

  In the modification 2 of FIG.3 (b), each rib provided in the lower side recessed part 2R of the light-receiving part side housing is made into the rib 5B divided | segmented into two in the longitudinal direction. In this way, a low part without projections is formed between the divided ribs 5B, and the lower skin of the finger enters here, and the relative movement in the longitudinal direction of the finger is suppressed, and the light receiving part PD At the opposing finger portions, the degree of finger pressure that inhibits arterial blood flow is reduced.

  FIG. 3C shows a modification of the cross-sectional shape of the rib provided in the recess of the light receiving unit side housing. The cross-sectional shape of the rib is not limited to the semicircular rib shown in FIG. 1 and the like, and a trapezoidal shape or a triangular shape with rounded corners may be appropriately employed. Although not shown, if a rib similar to the rib provided in the concave portion of the light receiving unit side housing is also installed in the concave portion of the light emitting unit side housing (in FIG. 1, the upper concave portion 1R of the light emitting unit side housing 1), The effect of suppressing the relative movement between the finger and the finger can be further enhanced.

FIG. 4 is a perspective view showing a second embodiment in which the present invention is applied to a separate pulse oximeter probe. Also in the sandwich type probe of the separation type pulse oximeter, the light emitting unit side housing 1 and the light receiving unit side housing 2 are arranged to face each other. However, since the main body provided with the battery for power supply and the display unit for displaying the measurement result is installed separately from the probe and the probe and the main body are connected by the cable CB, the probe itself is an integrated pulse. Compared to oximeters, it is smaller and lighter.
In the probe of the second embodiment shown in FIG. 4, basically, only the light receiving part PD is placed in the light receiving part side housing 2, which is formed by the lower recess 2 </ b> R extending in the longitudinal direction of the light receiving part side housing 2. It is installed at the center of the arc-shaped cross section. In the lower concave portion 2R, as in the pulse oximeter of FIG. 1, one rib 5 extending in the longitudinal direction of the concave portion is provided at one symmetrical position on both sides of the light receiving portion PD. As a result, the same effect as that of the first embodiment described above can be achieved with the probe of the second embodiment.

  As described in detail above, the present invention is such that ribs extending in the longitudinal direction are formed on both sides of the light receiving portion on the surface of the concave portion provided with the light receiving portion of the sandwiching probe of the pulse oximeter. The relative movement of the examiner's finger is suppressed. In the above-described embodiment, the present invention is applied to the sandwiching type probe in which both housings of the probe rotate around the fulcrum and the distal end side opens. However, the probe has a structure in which both housings open while keeping the parallel state. Needless to say, the present invention can be applied to such a probe as disclosed in Japanese Patent Application Laid-Open No. 11-188019 as an example. In addition, it is obvious that various modifications can be made to the above-described embodiment, such as giving a slight curvature to the rib extending linearly in the longitudinal direction, and forming an additional rib at the center of the cross section of the recess. is there.

DESCRIPTION OF SYMBOLS 1 Light emitting part side housing 1R Upper side recessed part 2 Light receiving part side housing 2R Lower side recessed part 3 Spring 4 Display part 5, 5A, 5B Rib LD Light emitting part PD Light receiving part

Claims (7)

A pulse oximeter probe in which a light emitting unit side housing provided with a light emitting unit and a light receiving unit side housing provided with a light receiving unit are arranged to face each other and are biased by a spring so that the front ends of both housings are close to each other Because
The light receiving unit side housing is formed with a concave part having an arcuate cross section extending from the tip part in the longitudinal direction of the light receiving unit side housing for accommodating a subject's finger, and the light receiving unit is formed in the circular shape. It is installed in the center of the cross-section of the recess of the arc-shaped cross section,
A probe characterized in that ribs extending in the longitudinal direction of the concave portion are provided on the surface of the concave portion of the arc-shaped cross section at symmetrical positions on both sides of the light receiving portion. The probe according to claim 1, wherein the rib provided on the surface of the concave portion having the arcuate cross section is a plurality of parallel ribs. The probe according to claim 1 or 2, wherein the rib provided on the surface of the concave portion having the arcuate cross section is a rib divided into a plurality of portions in the longitudinal direction of the concave portion. The rib provided on the surface of the concave portion of the arc-shaped cross section is one linear rib extending continuously in the longitudinal direction of the concave portion, and the height from the surface of the concave portion is 0.5 mm. 2. The probe according to claim 1, wherein the length is 1.5 mm or less, the length in the longitudinal direction is 10 mm or more and 15 mm or less, and the distance between the ribs sandwiching the light receiving portion is 6 mm or more and 12 mm or less. The probe according to any one of claims 1 to 4, wherein the rib provided on the surface of the concave portion having the arcuate cross section is attached to the surface by adhesion. In the light emitting unit side housing, an opposing concave part having an arc-shaped cross section is formed at a position facing the concave part of the light receiving unit side housing, and the light emitting part is installed in the central portion of the cross section of the opposing concave part, ,
The probe according to any one of claims 1 to 5, wherein opposed ribs extending in a longitudinal direction of the opposed recess are provided on the surface of the opposed recess at symmetrical positions on both sides of the light emitting unit. . The probe according to any one of claims 1 to 6, wherein a main part of a pulse oximeter including a power source and a display unit is integrally incorporated in the probe.

Images