JP7795779B2 - Waterproofing of portable medical devices - Google Patents

Description

The present invention relates to a drip-proof structure for a portable medical device in which a first structure and a second structure are detachably attached via a packing.

There has been a demand for portable medical devices, such as ultrasound diagnostic imaging devices used to diagnose livestock such as cows and pigs, to be waterproof. One method proposed for waterproofing portable medical devices is to seal the gap between a pair of structures that fit together with a packing (see, for example, Patent Documents 1 to 7).

JP 2004-287768 A (Fig. 1 etc.) JP 2009-30773 A (FIGS. 2, 5, 6, etc.) JP-A-9-18169 (claims 1 to 4, Figures 3 and 4, etc.) JP 2013-8844 A (Figs. 2, 3, etc.) JP 2013-26190 A (paragraphs [0045], [0046], FIG. 3, etc.) Japanese Patent Application Laid-Open No. 11-25940 (paragraphs [0010], [0011], Figure 3, etc.) JP 2008-288174 A (paragraph [0031], FIG. 7, etc.)

In order to maintain the water resistance of portable medical devices, it is necessary to apply a certain amount of pressure to the gasket, for example by screwing the structures together. However, if the pressure is too strong, the structure will deform. Potential ways to prevent deformation of the structure include screwing it in multiple places, reinforcing the structure with metal, or securing the structure with a mechanical locking mechanism, but all of these methods increase the cost of the product.

The present invention was made in consideration of the above-mentioned problems, and its purpose is to provide a drip-proof structure for portable medical devices that can be realized at low cost, while maintaining drip-proof properties while reducing the pressure on the structure.

In order to solve the above problem, the invention described in claim 1 is a drip-proof structure for a portable medical device in which a first structure having an opening and a second structure covering the opening are detachably attached via a packing, the gasket having a substantially circular cross-sectional shape when not pressed, a packing retaining portion having an annular groove in which the packing is received and retained and formed to surround the periphery of the opening, and a gasket retaining portion in the structure of the first structure or the second structure on which the packing retaining portion is not formed, positioned so as to be inserted into the packing retaining portion. The gist of the present invention is a drip-proof structure for a portable medical device, characterized in that the gasket has a pressure ridge formed on the annular groove and presses against the packing, the pressure ridge having a cross-sectional shape tapered at its tip and pressing against the packing by biting into the packing to about half its diameter, the packing retaining portion having an annular recess at the bottom of the annular groove at a position opposite the tip of the pressure ridge, and a pair of steps on the opening edge of the recess press against the packing placed in the annular groove, pressing the packing against the pressure ridge.

According to the invention described in claim 1, the pressure ridges penetrate into the packing to approximately half its diameter, pressing the packing toward the bottom of the annular groove. Furthermore, a pair of steps on the opening edge of the recess penetrate into the packing housed in the annular groove, pressing the packing toward the pressure ridges. This allows the packing to be efficiently compressed from two directions, maintaining the water resistance of the portable medical device without applying strong pressure to the packing or the structure. This eliminates the need for measures to prevent deformation of the structure, allowing for a low-cost water-resistant structure for the portable medical device. Furthermore, the packing's cross-sectional shape when unpressured is approximately circular, making it easy to form. Furthermore, because the annular groove has a recess at the bottom, the packing deforms when pressed toward the pressure ridges, and its outer periphery contacts the inner surfaces of the annular groove and the recess. As a result, the interface between the packing retainer and the packing becomes complex, lengthening the path for water infiltration, thereby reliably blocking water infiltration from outside the portable medical device.

The invention described in claim 2 is the same as claim 1, except that the pressing ridge is arranged so as to be inclined toward the center of the opening.

According to the invention described in claim 2, the pressure ridges are arranged at an angle, so that their tips bite into the packing at a position offset from its center. This reduces the pressure on the packing compared to when the tips bite into the center of the packing, preventing damage to the packing. Furthermore, because the pressure ridges are angled toward the center of the opening, i.e., toward the inside of the first structure, the packing deforms and escapes to the outside of the first structure (opening) as it is pressed by the pressure ridges, and is pressed more strongly against the outer periphery of the packing retaining portion of the first structure. This makes it possible to block water droplets entering from the outside of the first structure before their intrusion path.

The invention described in claim 3 is the same as claim 2, except that the annular groove is formed by an inner circumferential side wall provided on the first structure or the second structure in a state surrounding the opening, and an outer circumferential side wall provided on the first structure or the second structure in a state surrounding the inner circumferential side wall, and the height of the outer circumferential side wall is greater than the height of the inner circumferential side wall.

As the packing is pressed against the pressure ridge inclined toward the center of the opening, it deforms and escapes toward the outer periphery of the first structure or the second structure. Therefore, by making the height of the outer periphery side wall higher than the height of the inner periphery side wall, as in the invention described in claim 3, the packing contained within the annular groove can be securely held.

The invention described in claim 4 is the same as any one of claims 1 to 3, except that the packing is made of a material having closed cells. The invention described in claim 7 is the same as claim 6, except that the packing is made of a material having closed cells.

According to the inventions described in claims 4 and 7, the packing has closed cells, which makes it easier to compress, and therefore the waterproofing of the portable medical device can be maintained without applying strong pressure to the packing. Furthermore, because the cells in the packing are closed cells that do not communicate with other cells, water droplets can be prevented from passing through the packing via the cells.

The invention described in claim 5 is based on any one of claims 1 to 3, and is characterized in that the packing is pressed by the pressure ridges, thereby coming into surface contact and in close contact with the side and bottom surfaces of the annular groove and the side and bottom surfaces of the recess. Furthermore, the invention described in claim 8 is based on claim 6, and is characterized in that the packing is pressed by the pressure ridges, thereby coming into surface contact and in close contact with the side and bottom surfaces of the annular groove and the side and bottom surfaces of the recess.

According to the inventions described in claims 5 and 8, the packing is pressed against the pressure ridge, eliminating gaps between the outer surface of the packing and the inner surface (side and bottom) of the annular groove, and between the outer surface of the packing and the inner surface (side and bottom) of the recess. In this case, the interface between the packing and the packing retainer, which has the annular groove and recess, becomes complex, lengthening the path for water droplets to penetrate, thereby improving the sealing and drip-proofing properties of the portable medical device.

The invention described in claim 6 is based on claim 1 or 2, and is characterized in that the second structure is a lid that covers the opening, the pressure ridge is provided on the opening, and the packing retainer is provided on the inner surface of the lid.

According to the invention described in claim 6, the packing housed in the annular groove of the packing retainer is positioned on the lid (second structure) side. Therefore, if the packing deteriorates, it can be replaced simply by replacing the lid, making packing replacement easier than when the packing (packing retainer) is positioned on the first structure side.

As described above in detail, the inventions described in claims 1 to 8 make it possible to realize a structure that can maintain drip-proofing while reducing the pressure applied to the structure at low cost.

1 is a schematic perspective view showing a portable medical device according to an embodiment of the present invention; FIG. FIG. FIG. 10 is a cross-sectional view showing the relationship between the packing, the packing holding portion, and the pressing ridges before the lid is closed. FIG. 10 is a cross-sectional view showing the relationship between the packing, the packing holding portion, and the pressing ridges before the rear case is attached to the front case. 10 is a cross-sectional view showing the relationship between the packing, the packing holding portion, and the pressing ridge after the rear case is attached to the front case. FIG. FIG. 10 is a cross-sectional view showing the relationship between the packing, the packing holding portion, and the pressing ridges after the lid body is closed. FIG. 10 is a cross-sectional view showing the relationship between the packing, the packing holding portion, and the pressing ridge before the lid is closed in another embodiment. FIG. 10 is a cross-sectional view showing the relationship between the packing, the packing holding portion, and the pressing ridge after the lid body is closed in another embodiment.

An embodiment of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, the ultrasound diagnostic imaging device 11 (portable medical device) of this embodiment is an animal diagnostic device used to diagnose pregnancy in livestock such as cows and pigs. The ultrasound diagnostic imaging device 11 is connected to an ultrasound probe (not shown) via a signal transmission cable. The ultrasound probe is a component held by an operator and has multiple ultrasound transducers (not shown) at its tip. The ultrasound diagnostic imaging device 11 also houses a circuit board (not shown), on which a controller and multiple circuits are mounted. The controller is a microcomputer including a well-known central processing unit (CPU) and provides overall control of the ultrasound diagnostic imaging device 11. The ultrasound diagnostic imaging device 11 also includes a case body 13 (first structure) having a battery opening 12 and a cover 14 (second structure) that covers the battery opening 12. A battery 21 can be stored within the battery opening 12 to supply power to each circuit.

As shown in Figures 1 to 3, the lid 14 is constructed by integrally forming the main body 15, front wall 16, rear wall 17, and a pair of side walls 18. Five protrusions 31 protrude from one end surface 14a of the lid 14 (the outer surface of the rear wall 17), which can be inserted into holes (not shown) provided in the case body 13. Meanwhile, a pair of locking claws 32 are provided on the end (front wall 16) of the lid 14 opposite the side on which the protrusions 31 are provided, which can be engaged with locking holes 19 provided in the case body 13. By inserting each protrusion 31 into the holes and engaging both locking claws 32 with the locking holes 19, the lid 14 is removably engaged with the periphery of the battery opening 12 of the case body 13.

As shown in Figures 3 and 4, a gasket retaining portion 41 having a substantially rectangular ring shape is provided on the inner surface 14b of the lid 14. The gasket retaining portion 41 is formed to surround the periphery of the battery opening 12 and has an annular groove 42 in which the gasket 40 is housed and held. The gasket 40 in this embodiment is made of a silicone resin (so-called silicone sponge) with numerous closed cells and has a hardness of approximately 10 to 20. The hardness described herein is measured using a durometer in accordance with JIS K6253-3. The gasket 40 in this embodiment is a columnar member whose overall length is slightly longer than the overall length of the annular groove 42 and whose cross-sectional shape when not pressed is substantially circular. In this case, if the gasket 40 is inserted into the annular groove 42 with a slight press fit, both ends of the gasket 40 are pressed against each other, eliminating any gaps, thereby maintaining drip-proofing. The packing 40 may also be a separate component, such as an O-ring.

Furthermore, the annular groove 42 is composed of an inner peripheral side wall 43 provided on the lid body 14 in a state surrounding the battery opening 12, and an outer peripheral side wall 44 provided on the lid body 14 in a state surrounding the inner peripheral side wall 43, and has a side surface 42a and a bottom surface 42b. The height of the inner peripheral side wall 43 is equal to the height of the outer peripheral side wall 44.

As shown in Figures 2 and 4, a pressing ridge 51 that presses against the packing 40 is formed in the structure (in this embodiment, the case body 13) on the side of the case body 13 and the lid body 14 where the packing retaining portion 41 is not formed. This pressing ridge 51 is located at a position that can be inserted into the packing retaining portion 41. The pressing ridge 51 protrudes from the upper surface 13a of the case body 13 so as to surround the battery opening 12. The width of the pressing ridge 51 is between one-third and two-thirds of the width of the annular groove 42, and the length (height) of the pressing ridge 51 is between one-third and two-thirds of the depth of the annular groove 42. The pressing ridge 51 has a cross-sectional shape that tapers toward the tip and is positioned so as to be inclined toward the center C1 (see Figure 2) of the battery opening 12. Therefore, the inclination angle θ1 of the inclined surface 51a on the inner circumferential side (the battery opening 12 side) of the pressing ridge 51 relative to the top surface 13a of the case body 13 is greater than the inclination angle θ2 of the inclined surface 51b on the outer circumferential side of the pressing ridge 51 relative to the top surface 13a. The angle θ3 formed by the inclined surfaces 51a and 51b is an acute angle, and in this embodiment is between 30° and 50°. The smaller the angle θ3, the smaller the pressure applied when crushing the packing 40. The tip of the pressing ridge 51 has a rounded cross-sectional shape.

As shown in Figures 4 and 7, the pressing ridge 51 presses the packing 40 toward the bottom of the annular groove 42 (upward in Figures 4 and 7) by engaging approximately half the diameter D1 of the packing 40, specifically, 30% to 70% of the diameter D1 of the packing 40. If the pressing ridge 51 penetrates more than 70% of the diameter D1 of the packing 40, strong pressure will be applied to the packing 40 to maintain the drip-proofing of the ultrasound imaging diagnostic device 11, which may cause deformation of the case body 13 or the lid 14. Furthermore, the force pressing the lid 14 toward the case body 13 will be too strong, making it difficult to engage the locking claw 32 of the lid 14 with the locking hole 19 of the case body 13. On the other hand, if the engagement of the pressure ridge 51 is less than 30% of the diameter D1 of the packing 40, the drip-proof performance will decrease, making it easier for water droplets to seep into the battery opening 12.

As shown in Figures 3 and 4, the packing retaining portion 41 has an annular recess 45 at a position facing the tip of the pressing ridge 51 at the bottom of the annular groove 42, i.e., at the center of the bottom of the annular groove 42. The width of the recess 45 is between one-third and one-half the width of the pressing ridge 51, and the depth of the recess 45 is between 10% and 30% of the depth of the annular groove 42. The recess 45 also has a side surface 45a and a bottom surface 45b. A pair of steps 46 on the opening edge of the recess 45 bite into the packing 40 accommodated in the annular groove 42, thereby pressing the packing 40 toward the pressing ridge 51. Both steps 46 (i.e., the connection between the side surface 45a of the recess 45 and the bottom surface 42b of the annular groove 42) have a rounded cross-sectional shape.

As shown in FIG. 3, linear reinforcement ribs 61, 62 are provided at multiple locations on the inner surface 14b of the lid 14 in a front view. Specifically, the inner surface 14b of the lid 14 is provided with a plurality of first reinforcement ribs 61 extending in the depth direction of the lid 14 (vertical direction in FIG. 3) and a plurality of second reinforcement ribs 62 arranged perpendicular to the first reinforcement ribs 61 and extending in the width direction of the lid 14 (horizontal direction in FIG. 3). The reinforcement ribs 61, 62 intersect with each other within the inner region A1 surrounded by the packing retaining portion 41, forming a lattice pattern in a front view. Furthermore, the distance between adjacent first reinforcement ribs 61 in the inner region A1 is smaller than the distance between adjacent first reinforcement ribs 61 in the outer region A2 of the packing retaining portion 41. Similarly, the spacing between adjacent second reinforcing ribs 62 in the inner region A1 is smaller than the spacing between adjacent second reinforcing ribs 62 in the outer region A2. That is, the reinforcing ribs 61, 62 in the inner region A1 are arranged more densely than the reinforcing ribs 61, 62 in the outer region A2. Both ends of the reinforcing ribs 61, 62 in the inner region A1 are connected to the inner circumferential sidewall 43 that constitutes the annular groove 42. Meanwhile, one end of each of the reinforcing ribs 61, 62 in the outer region A2 (the end toward the center of the lid 14) is connected to the outer circumferential sidewall 44 that constitutes the annular groove 42. Most of the other ends of the reinforcing ribs 61, 62 in the outer region A2 (the end toward the outer periphery of the lid 14) are connected to the front wall 16, rear wall 17, and sidewall 18 of the lid 14.

As shown in Figures 1, 2, and 5, the case main body 13 comprises a front case 72 (first structure) having a case opening 71, and a rear case 73 (second structure) covering the case opening 71. The front case 72 is a rectangular box with a bottom, with the case opening 71 at its rear end (top end in Figure 5), and is configured with a concave cross-section by integrally forming a bottom (not shown) and four side walls 74. The front end (bottom end in Figure 5) of the rear case 73 is fitted into the interior of the front case 72. The rear case 73 is a rectangular box with a bottom that opens at its front end (bottom end in Figure 5), and is configured with a concave cross-section by integrally forming a ceiling 75 and four side walls 76.

As shown in FIG. 5, a gasket retaining portion 81 having a substantially rectangular ring shape is provided at the rear end (upper end in FIG. 5) of the side wall 74 of the front case 72. The gasket retaining portion 81 is formed to surround the periphery of the case-side opening 71 and has an annular groove 82 in which the gasket 80 is housed and held. Note that the gasket 80 in this embodiment is made of the same material as the gasket 40 (a silicone resin containing numerous closed cells). The gasket 80 in this embodiment is a columnar member whose overall length is slightly longer than the overall length of the annular groove 82, and its cross-sectional shape when not pressed is substantially circular. In this case, if the gasket 80 is inserted somewhat pressurized into the annular groove 82, both ends of the gasket 80 are pressed against each other, eliminating any gaps, thereby maintaining drip-proofing. Note that the gasket 80 may also be a separate component, such as an O-ring.

Furthermore, the annular groove 82 is composed of an inner peripheral side wall 83 provided on the front case 72 in a state surrounding the case-side opening 71, and an outer peripheral side wall 84 provided on the front case 72 in a state surrounding the inner peripheral side wall 83, and has a side surface 82a and a bottom surface 82b. The height of the outer peripheral side wall 84 is greater than the height of the inner peripheral side wall 83.

As shown in FIG. 5 , a pressing ridge 91 that presses the packing 80 is formed in the structure (in this embodiment, the rear case 73) on the side of the front case 72 or rear case 73 where the packing retaining portion 81 is not formed, at a position where it can be inserted into the packing retaining portion 81. The pressing ridge 91 protrudes from the front end surface 76a (the lower end surface in FIG. 5 ) of the side wall 76 of the rear case 73, surrounding the case-side opening 71. The width of the pressing ridge 91 is between one-third and two-thirds of the width of the annular groove 82, and the length (height) of the pressing ridge 91 is between one-third and two-thirds of the depth of the annular groove 82. The pressing ridge 91 has a cross-sectional shape that tapers toward the tip (the lower end in FIG. 5 ) and is positioned so as to be inclined toward the center of the case-side opening 71. Therefore, the inclination angle θ4 of the slope 91a on the outer periphery of the pressure ridge 91 relative to the front end face 76a of the side wall 76 is smaller than the inclination angle θ5 of the slope 91b on the inner periphery (towards the case-side opening 71) of the pressure ridge 91 relative to the front end face 76a. The angle θ6 formed by the slope 91a and the slope 91b is an acute angle, and in this embodiment, is between 30° and 50°. The smaller the angle θ6, the smaller the pressure applied when crushing the packing 80. The tip of the pressure ridge 91 (the lower end in FIG. 5) has a rounded cross-sectional shape.

As shown in Figures 5 and 6, the pressing ridges 91 press the packing 80 toward the bottom of the annular groove 82 (downward in Figures 5 and 6) by engaging approximately half the diameter D2 of the packing 80, specifically, 30% to 70% of the diameter D2 of the packing 80. If the pressing ridges 91 engage more than 70% of the diameter D2 of the packing 80, a strong force will be applied to the packing 80 to maintain the drip-proofing of the ultrasound imaging diagnostic device 11, which may result in deformation of the front case 72 or the rear case 73. Furthermore, the force pressing the rear case 73 toward the front case 72 will be too strong, making it difficult to screw the rear case 73 to the front case 72. On the other hand, if the pressing ridges 91 engage less than 30% of the diameter D2 of the packing 80, the drip-proofing performance will be reduced, making it easier for water droplets to enter the case body 13.

As shown in FIG. 5 , the packing retaining portion 81 has an annular recess 85 at a position facing the tip of the pressing ridge 91 at the bottom of the annular groove 82. In this embodiment, the recess 85 is located at a position offset toward the inner periphery of the bottom of the annular groove 82. The recess 85 has a side surface 85a and a bottom surface 85b. The width of the recess 85 is slightly smaller than the width of the pressing ridge 91, and the depth of the recess 85 is 10% to 30% of the depth of the annular groove 82 (i.e., the height from the bottom surface 85b to the upper end surface of the outer side wall 84). A pair of steps 86 on the opening edge of the recess 85 bite into the packing 80 accommodated in the annular groove 82, thereby pressing the packing 80 toward the pressing ridge 91. The outer step 86 (i.e., the connection between the outer peripheral side surface 85a of the recess 85 and the bottom surface 82b of the annular groove 82) has a rounded cross-sectional shape. Meanwhile, the inner side surface 82a of the annular groove 82 is inclined relative to the bottom surface 82b of the annular groove 82, and the area of the bottom surface 82b on the inner side of the recess 85 is significantly smaller than the area of the bottom surface 82b on the outer side of the recess 85. Furthermore, the inner step 86 (i.e., the connection between the inner side surface 85a of the recess 85 and the bottom surface 82b) has a non-rounded cross-sectional shape. The connection between the side surface 85a of the recess 85 and the bottom surface 85b also has a rounded cross-sectional shape.

Next, we will explain the examination method using the ultrasound imaging diagnostic device 11. Note that an examination using the ultrasound imaging diagnostic device 11 begins when gel is applied to the area to be examined of the livestock (the abdomen in the case of a pregnancy test), and then the power switch is operated with the ultrasound probe in contact with the area to be examined.

First, the controller starts transmitting and receiving ultrasound waves using the ultrasound probe. Specifically, it vibrates each ultrasound transducer in the ultrasound probe, irradiating the ultrasound waves generated there toward the examination area. Then, a portion of the ultrasound waves is reflected within the examination area, propagates toward the ultrasound probe, and is input (received) by the ultrasound transducer. The ultrasound waves (reflected waves) received by the ultrasound transducer are then converted into electrical signals (reflected wave signals). Furthermore, image display data for the ultrasound image is generated based on the converted reflected wave signals. The controller then transfers the image display data to the display device (not shown) of the ultrasound diagnostic imaging device 11, and the ultrasound image is displayed on the display device.

Next, we will explain how to assemble the ultrasound imaging diagnostic device 11.

First, prepare a front case 72 having a case-side opening 71, a rear case 73 covering the case-side opening 71, and a lid 14 covering the battery opening 12 in the case body 13 (rear case 73). Next, a packing 40 is press-fitted into the annular groove 42 of the packing retaining portion 41 provided in the lid 14. A packing 80 is also press-fitted into the annular groove 82 of the packing retaining portion 81 provided in the front case 72.

Next, the rear case 73 is attached to the front case 72 by screwing at multiple locations, thereby forming the case body 13. At this time, the tip of the pressing ridge 91 bites into a position offset from the center O2 of the packing 80 toward the inside of the case body 13 (to the left in Figures 5 and 6), pressing the packing 80 toward the bottom of the annular groove 82 (downward in Figures 5 and 6). As a result, the gap between the packing 80 and the pressing ridge 91 is closed. In addition, a pair of steps 86 on the opening edge of the recess 85 bite into the packing 80, pressing the packing 80 toward the pressing ridge 91 (upward in Figures 5 and 6). As a result, the outer peripheral surface of the packing 80 comes into surface contact with the side surface 82a and bottom surface 82b of the annular groove 82 and the side surface 85a and bottom surface 85b of the recess 85 (see Figure 6), closing the gap between the packing 80 and the annular groove 82 and the gap between the packing 80 and the recess 85. This allows the packing 80 to block water droplets from entering the case body 13 through the gap between the front case 72 and the rear case 73.

Next, the battery 21 is placed in the battery opening 12 of the case body 13. The lid 14 is then attached to the case body 13. Specifically, the five protrusions 31 on the rear wall 17 of the lid 14 are first inserted into holes in the case body 13. Next, the front wall 16 of the lid 14 is rotated around the rear wall 17 to approach the case body 13, and then a pair of locking claws 32 on the front wall 16 are locked into the locking holes 19 in the case body 13. As a result, the lid 14 engages with the case body 13, covering the battery opening 12 and preventing the battery 21 placed in the battery opening 12 from falling out.

When the lid 14 is attached to the case 13, the tip of the pressure ridge 51 engages with the packing 40 at a position offset from the center O1 toward the inside of the battery opening 12 (to the right in Figures 4 and 7), thereby pressing the packing 40 toward the bottom of the annular groove 42 (upward in Figures 4 and 7). As a result, the gap between the packing 40 and the pressure ridge 51 is closed. Furthermore, a pair of steps 46 on the opening edge of the recess 45 engage with the packing 40, pressing the packing 40 toward the pressure ridge 51 (downward in Figures 4 and 7). As a result, the outer peripheral surface of the packing 40 comes into surface contact with the side surface 42a and bottom surface 42b of the annular groove 42 and the side surface 45a and bottom surface 45b of the recess 45, thereby tightly sealing the gap between the packing 40 and the annular groove 42 and the gap between the packing 40 and the recess 45 (see Figure 7). This allows the gasket 40 to block water droplets from seeping into the battery opening 12 through the gap between the case body 13 and the lid 14.

Therefore, this embodiment provides the following advantages:

(1) In the ultrasound imaging diagnostic device 11 of this embodiment, the pressing ridges 51 bite into the packing 40 to a depth of 30% to 70% of the diameter D1, thereby pressing the packing 40 toward the bottom of the annular groove 42 (upward in Figures 4 and 7). Furthermore, a pair of steps 46 on the opening edge of the recess 45 bite into the packing 40 housed in the annular groove 42, thereby pressing the packing 40 toward the pressing ridges 51 (downward in Figures 4 and 7). This allows the packing 40 to be efficiently compressed from two directions, thereby maintaining the drip-proof properties of the ultrasound imaging diagnostic device 11 without applying strong pressure to the packing 40 or the structure (case body 13 and lid 14).

In addition, in this embodiment, the pressing ridges 91 bite into the packing 80 to a depth of 30% to 70% of the diameter D2, thereby pressing the packing 80 toward the bottom of the annular groove 82 (downward in Figures 5 and 6). Furthermore, a pair of steps 86 on the opening edge of the recess 85 bite into the packing 80 housed in the annular groove 82, thereby pressing the packing 80 toward the pressing ridges 91 (upward in Figures 5 and 6). This allows the packing 80 to be efficiently compressed from two directions, maintaining the waterproof properties of the ultrasound diagnostic imaging device 11 without applying strong pressure to the packing 80 or the structure (front case 72 and rear case 73).

As a result of the above, there is no need to take measures to prevent deformation of the case body 13 (front case 72 and rear case 73) or the lid 14. Furthermore, because strong pressure is not applied to the case body 13 or the lid 14, a simple locking mechanism using the locking claws 32 can be used for the lid 14. Therefore, a drip-proof structure for the ultrasound diagnostic imaging device 11 can be achieved at low cost. Furthermore, the use of a simple locking mechanism makes it easier to open and close the lid 14, improving usability.

(2) The gaskets 40, 80 of this embodiment have closed cells and are easily deformed with a small force, so they fit securely into the recesses 45, 85 when compressed. This allows the ultrasound imaging diagnostic device 11 to achieve high sealing performance.

(3) In this embodiment, the tip of the pressure ridges 51, 91 has a rounded cross-sectional shape. Furthermore, in this embodiment, one of the pair of step portions 46 on the opening edge of the recess 45 and one of the pair of step portions 86 on the opening edge of the recess 85 also have a rounded cross-sectional shape. This reduces the pressure on the packings 40, 80 when they bite into the pressure ridges 51, 91 or step portions 46, 86, thereby preventing damage to the packings 40, 80.

(4) In this embodiment, vertically and horizontally extending reinforcing ribs 61, 62 are provided on the inner surface 14b of the lid 14 to prevent deformation of the lid 14. As a result, lifting of the lid 14 due to deformation is prevented, and gaps are less likely to form between the case body 13 and the lid 14. This allows the gasket 40 to reliably block water droplets that may seep into the battery opening 12 from between the case body 13 and the lid 14. Furthermore, the reinforcing ribs 61, 62 in the inner region A1 of the gasket holding portion 41 are arranged more densely than the reinforcing ribs 61, 62 in the outer region A2 of the gasket holding portion 41. This reinforces the inner region A1 directly above the battery 21, preventing a decrease in strength of the inner region A1 due to heat generation by the battery 21 and preventing deformation and lifting of the lid 14 due to a decrease in strength.

(5) In this embodiment, the lid 14 is attached to the case body 13 by inserting the protrusion 31 into the hole in the case body 13, rotating it around the rear wall 17 (protrusion 31), and then engaging the locking claw 32 with the locking hole 19 in the case body 13. In this way, the lid 14 can be rotated closer to the case body 13, while simultaneously compressing the packing 40, making it easier to attach the lid 14.

(6) Inspections using the ultrasound diagnostic imaging device 11 of this embodiment are performed with gel applied to the area of the livestock being examined. However, because gel is relatively expensive, vegetable oil may be used instead of gel, although this is not recommended. However, if the gasket were made of rubber, there is a risk that the oil would cause the gasket to deteriorate. Therefore, in this embodiment, the gaskets 40, 80 are made of silicone resin, which is resistant to chemicals. Therefore, even if vegetable oil adheres to the gaskets 40, 80, deterioration of the gaskets 40, 80 can be prevented.

The above embodiment may be modified as follows:

In the above embodiment, the packing retaining portion 41 was formed on the lid 14 (second structure) so as to surround the periphery of the battery opening 12, and the pressing ridge 51 was formed on the case main body 13 (first structure) at a position that could be inserted into the packing retaining portion 41 (see Figure 4). However, it is also possible to form the packing retaining portion 41 on the case main body 13 and form the pressing ridge 51 on the lid 14 at a position that can be inserted into the packing retaining portion 41.

In the above embodiment, the packing retaining portion 81 is formed on the front case 72 (first structure) so as to surround the periphery of the case-side opening 71, and the pressing ridge 91 is formed on the rear case 73 (second structure) at a position that can be inserted into the packing retaining portion 81 (see Figure 5). However, the packing retaining portion 81 may be formed on the rear case 73, and the pressing ridge 91 may be formed on the front case 72 at a position that can be inserted into the packing retaining portion 81.

- In the above embodiment, the pressing ridge 51 was positioned so as to be inclined toward the center C1 (see Figure 2) of the battery opening 12, and the pressing ridge 91 was positioned so as to be inclined toward the center of the case-side opening 71. However, as shown in Figures 8 and 9, the pressing ridge 101 may be positioned so as not to be inclined, and the tip of the pressing ridge 101 positioned so as not to be inclined may be inserted into the center O3 of the packing 102.

- In the above embodiment, the height of the outer peripheral side wall 84 of the annular groove 82 was higher than the height of the inner peripheral side wall 83 (see Figure 5). However, the height of the outer peripheral side wall 84 of the annular groove 82 may be lower than the height of the inner peripheral side wall 83, or the height of the outer peripheral side wall 84 may be equal to the height of the inner peripheral side wall 83.

In addition, in the above embodiment, the height of the outer peripheral side wall 44 of the annular groove 42 is equal to the height of the inner peripheral side wall 43 (see Figure 4). However, the height of the outer peripheral side wall 44 of the annular groove 42 may be higher than the height of the inner peripheral side wall 43, or the height of the outer peripheral side wall 44 may be lower than the height of the inner peripheral side wall 43.

- In the above embodiment, of the pair of steps 86 on the opening edge of the recess 85, only the step 86 on the outer periphery (the right side in Figure 5) had a rounded cross-sectional shape. However, the step 86 on the inner periphery (the left side in Figure 5) may also have a rounded cross-sectional shape. Also, in the above embodiment, the connection portion between the side surface 85a of the recess 85 and the bottom surface 85b of the recess 85 had a rounded cross-sectional shape (see Figure 5), but the connection portion between the side surface 45a of the recess 45 and the bottom surface 45b of the recess 45 (see Figure 4) may also have a rounded cross-sectional shape.

- In the above embodiment, the recesses 45, 85 have a generally rectangular cross section consisting of a bottom surface 45b, 82b and a pair of side surfaces 45a, 82a extending perpendicularly to the bottom surface 45b, 82b. However, the recesses may have other shapes, such as a generally trapezoidal cross section, a generally V-shaped cross section, or a generally semicircular cross section. Furthermore, the heights of the pair of side surfaces of the recesses may be different from each other.

- In the above embodiment, the packings 40, 80 were made of silicone resin with closed cells. However, the packings 40, 80 may also be made of other resin materials such as polytetrafluoroethylene (PTFE), polyamide (PA), polyethylene (PE), polyacetal (POM), or rubber materials such as nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluororubber (FKM), silicone rubber (VMQ), ethylene propylene diene rubber (EPDM), or urethane rubber (U).

- In the above embodiment, an animal ultrasound imaging diagnostic device 11 was used as the portable medical device, but an ultrasound imaging diagnostic device for humans may also be used as the portable medical device. Also, a thermometer, blood pressure monitor, pulse oximeter, portable oxygen concentrator, pacemaker, AED (automated external defibrillator), etc. may also be used as the portable medical device.

Next, in addition to the technical ideas set forth in the claims, the technical ideas grasped by the above-described embodiments are listed below.

(1) A drip-proof structure for a portable medical device according to any one of claims 1 to 3, wherein the pressure ridge penetrates into the packing to a depth of 30% to 70% of the diameter of the packing.

(2) A waterproof structure for a portable medical device according to any one of claims 1 to 3, wherein the portable medical device is an ultrasonic diagnostic imaging device for animals.

(3) The drip-proof structure for a portable medical device according to claim 6, characterized in that a reinforcing rib protrudes from the inner surface of the lid.

(4) A drip-proof structure for a portable medical device according to technical concept (3), characterized in that the distance between adjacent reinforcing ribs in the inner region of the packing retaining portion is smaller than the distance between adjacent reinforcing ribs in the outer region of the packing retaining portion.

(5) In the technical concept (3), the reinforcing ribs are comprised of a plurality of first reinforcing ribs extending in the depth direction of the lid body and a plurality of second reinforcing ribs arranged perpendicular to the first reinforcing ribs and extending in the width direction of the lid body, and the first reinforcing ribs and the second reinforcing ribs intersect with each other within the inner region of the packing retaining portion, forming a lattice pattern.

11...ultrasound diagnostic imaging device as portable medical device 12...battery opening 13 as opening...case body 14 as first structure...lid body 14b as second structure...inner surface 40, 80, 102 of lid body...packing 41, 81...packing retaining portion 42, 82...annular groove 42a, 82a...side surface 42b, 82b of annular groove...bottom surface 45, 85 of annular groove...recess 45a, 85a...side surface 45b, 85b of recess...bottom surface 46, 86...step portion 51, 91, 101...pressure protrusion 71...case side opening 72 as opening...front case 73 as first structure...rear case 83 as second structure...inner side wall 84...outer side wall C1...center D1, D2 of opening...diameter of packing

Claims (8)

A drip-proof structure for a portable medical device, in which a first structure having an opening and a second structure covering the opening are detachably attached via a packing,
The packing has a substantially circular cross-sectional shape when not pressed;
a packing retaining portion having an annular groove in which the packing is accommodated and retained, the packing retaining portion being formed so as to surround the periphery of the opening;
a pressing protrusion formed in one of the first structure and the second structure on which the packing retaining portion is not formed, at a position where the protrusion can be inserted into the packing retaining portion and presses the packing,
the pressing protrusion has a cross-sectional shape tapered at a tip, and presses the packing toward the bottom of the annular groove by biting into the packing to about half its diameter,
the packing retaining portion has an annular recess at a position facing the tip of the pressing ridge at the bottom of the annular groove,
A drip-proof structure for a portable medical device, characterized in that a pair of steps on the opening edge of the recess bite into the gasket housed in the annular groove, thereby pressing the gasket toward the pressing ridge. The drip-proof structure for a portable medical device described in claim 1, characterized in that the pressure ridge is arranged so as to be inclined toward the center of the opening. the annular groove is configured by an inner circumferential side wall provided on the first structure or the second structure in a state surrounding the opening, and an outer circumferential side wall provided on the first structure or the second structure in a state surrounding the inner circumferential side wall,
3. The waterproof structure for a portable medical device according to claim 2, wherein the height of the outer peripheral side wall is greater than the height of the inner peripheral side wall. The drip-proof structure for a portable medical device described in any one of claims 1 to 3, characterized in that the packing is made of a material having closed cells. A drip-proof structure for a portable medical device according to any one of claims 1 to 3, characterized in that the gasket is pressed by the pressure ridge to come into surface contact and adhere closely to the side and bottom surfaces of the annular groove and the side and bottom surfaces of the recess. the second structure is a lid that covers the opening,
3. The drip-proof structure for a portable medical device according to claim 1, wherein the pressure ridge is provided at the opening, and the packing retaining portion is provided on the inner surface of the lid. The drip-proof structure for a portable medical device described in claim 6, characterized in that the packing is made of a material having closed cells. The drip-proof structure for a portable medical device described in claim 6, characterized in that the gasket is pressed by the pressure ridge to come into surface contact with and adhere to the side and bottom surfaces of the annular groove and the side and bottom surfaces of the recess.