阅读说明：本技术 用于具有隔热的可灭菌手术工具的电池外壳 (Battery housing for sterilizable surgical tools with thermal insulation ) 是由 克里斯托弗·潘迪希倪 于 2016-01-28 设计创作，主要内容包括：本发明涉及用于具有隔热的可灭菌手术工具的电池外壳。具体地,一种电池组组件或外壳,包括一个或多个电池和外壳,该电池具有电化学单元,该外壳至少具有外壁,该外壁配置为生成充分围绕该电池的密封的体积空间。该体积空间的气氛包括热传导率低于0.018瓦特每米摄氏度的气体。这种具有气体的气氛在该外壁与这些电池之间提供了隔热层。具有此隔热层的该电池组组件可以承受高压灭菌而不会损害电池。该电池组组件可以用于向手术工具或其它能承受高压灭菌的装置提供电力。(The present invention relates to a battery housing for a sterilizable surgical tool having thermal insulation. A battery pack assembly or housing includes one or more batteries having an electrochemical cell and a housing having at least an outer wall configured to create a sealed volume substantially surrounding the battery. The atmosphere of the volume of space comprises a gas having a thermal conductivity of less than 0.018 watts per meter per degree celsius. This atmosphere with gas provides a thermal barrier between the outer wall and the cells. The battery pack assembly having such an insulating layer can withstand autoclaving without damaging the cells. The battery pack assembly may be used to provide power to surgical tools or other devices that can withstand autoclaving.)

1. A battery pack assembly comprising:

at least one battery;

a housing defining a sealed volume in which the at least one battery is located, the sealed volume comprising an atmosphere; and

a thermal conductivity sensor configured to detect a thermal conductivity of the atmosphere;

wherein the thermal conductivity of the atmosphere is in the range of 0.002 to 0.018 watts per meter per degree Celsius when the atmosphere is not breached.

2. The battery pack assembly of claim 1, wherein the atmosphere comprises at least one of:

partial vacuum; and

an inert gas selected from the group consisting of krypton, xenon, argon, and freon.

3. The battery pack assembly of claim 1 further comprising a communication terminal operatively connected to the thermal conductivity sensor and configured to communicate information about the sensed thermal conductivity.

4. The battery pack assembly of claim 3, wherein the information about the sensed thermal conductivity indicates at least one of a breach of the atmosphere and a defect of the at least one battery.

5. The battery pack assembly of claim 3, wherein the communication terminal is configured to be operatively connected to a display configured to display the information regarding the sensed thermal conductivity thereon.

6. The battery pack assembly of claim 1, further comprising a temperature sensor configured to sense a temperature within the housing; and

an indicator operatively connected to the temperature sensor and configured to convey information about the sensed temperature.

7. The battery pack assembly of claim 6, wherein the information about the sensed thermal conductivity indicates whether the temperature is at an acceptable level.

8. The battery pack assembly of claim 6, wherein the indicator is configured to communicate the information by light or sound.

9. The battery pack assembly of claim 1, wherein the at least one battery is exposed to an interior surface of an outer wall of the housing.

10. The battery pack assembly of claim 1, wherein an inner wall separates the at least one battery from an inner surface of an outer wall of the housing, and the volume is located between an outer surface of the inner wall and an inner surface of the outer wall.

11. The battery pack assembly of claim 1, further comprising a positive terminal and a negative terminal, each of the positive terminal and the negative terminal extending from the at least one battery to outside the housing; and

electrical contacts coupled to the positive and negative terminals outside the housing, the electrical contacts configured to connect to a surgical tool to provide power to the surgical tool via the at least one battery.

12. A battery pack assembly comprising:

at least one battery;

a housing in which the at least one battery is located, the housing having a sealed volume therein, the sealed volume comprising an atmosphere; and

a thermal conductivity sensor configured to detect a thermal conductivity of the atmosphere; and

a communication terminal operatively connected to the thermal conductivity sensor and configured to communicate information about the sensed thermal conductivity.

13. The battery pack assembly of claim 12, wherein the thermal conductivity of the atmosphere is in the range of 0.002 to 0.018 watts per meter per degree celsius when the atmosphere is not breached.

14. The battery pack assembly of claim 12, wherein:

an outer surface of an outer wall of the housing is exposed to air outside the housing;

the atmosphere comprises a gas, a partial vacuum, or both; and

when the sealed volume is not breached, the thermal conductivity of the atmosphere is less than the thermal conductivity of the air.

15. The battery pack assembly of claim 12, wherein the information about the sensed thermal conductivity indicates at least one of a breach of the atmosphere and a defect of the at least one battery.

16. The battery pack assembly of claim 12, wherein the communication terminal is configured to be operatively connected to a display configured to display the information regarding the sensed thermal conductivity thereon.

17. The battery pack assembly of claim 12, wherein the atmosphere comprises at least one of a gas and a partial vacuum, and the at least one of the gas and the partial vacuum comprises at least 25% of the atmosphere.

18. The battery pack assembly of claim 12 further comprising a temperature sensor configured to sense a temperature within the housing; and

an indicator operatively connected to the temperature sensor and configured to convey information about the sensed temperature.

19. The battery pack assembly of claim 12, further comprising a positive terminal and a negative terminal, each of the positive terminal and the negative terminal extending from the at least one battery to outside the housing; and

electrical contacts coupled to the positive and negative terminals outside the housing, the electrical contacts configured to connect to a surgical tool to provide power to the surgical tool via the at least one battery.

20. A surgical tool, comprising:

at least one battery;

a housing defining a sealed volume in which the at least one battery is located, the sealed volume comprising an atmosphere; and

a thermal conductivity sensor configured to detect a thermal conductivity of the atmosphere;

a surgical tool configured to be operatively connected to the at least one battery, thereby allowing the at least one battery to provide power to the surgical tool;

wherein the thermal conductivity of the atmosphere is in the range of 0.002 to 0.018 watts per meter per degree Celsius when the atmosphere is not breached.

21. A method of sterilizing a surgical tool, comprising:

sterilizing a surgical tool using a sterilization process comprising an autoclave cycle, the surgical tool comprising:

an electrochemical cell; and

a housing enclosing a volume therein, the electrochemical cell being located in the volume; and

sensing thermal conductivity within the enclosure with a sensor during the autoclave cycle.

22. The method of claim 21, wherein the autoclaving cycle subjects the surgical tools to temperatures in a range of 121 ℃ to 132 ℃.

23. The method of claim 21, wherein the sterilization process subjects the surgical tool to a temperature greater than 80 ℃.

24. The method of claim 21, further comprising communicating the sensed thermal conductivity to an operator.

25. The method of claim 21, further comprising sensing a temperature within the enclosure with a second sensor during the autoclaving cycle; and

communicating the sensed temperature to an operator.

26. The method of claim 21, wherein the volume has an atmosphere comprising at least one of a partial vacuum and an inert gas.

27. The method of claim 26, wherein the atmosphere has a thermal conductivity in a range of 0.002 to 0.018 watts per meter per degree celsius at least prior to the autoclave cycle.

28. The method of claim 26, wherein the electrochemical cell is exposed to an atmosphere of the volume.

29. The method of claim 26, wherein an inner wall within the housing prevents exposure of the electrochemical cell to an atmosphere of the volume.

30. The method of claim 21, wherein the surgical tool is an orthopedic surgical tool.

31. A method of sterilizing a surgical tool, comprising:

sterilizing a surgical tool using a sterilization process comprising an autoclave cycle, the surgical tool comprising:

an electrochemical cell; and

a thermal insulation layer located between the electrochemical cell and air outside the surgical tool, the thermal insulation layer having a thermal conductivity in a range of 0.002 to 0.018 watts per meter per degree Celsius at least prior to the autoclave cycle; and

sensing the thermal conductivity of the thermal insulation layer with a sensor during the autoclave cycle.

32. The method of claim 31, wherein the autoclaving cycle subjects the surgical tools to temperatures in a range of 121 ℃ to 132 ℃.

33. The method of claim 31, wherein the sterilization process subjects the surgical tool to a temperature greater than 80 ℃.

34. The method of claim 31, further comprising communicating the sensed thermal conductivity to an operator.

35. The method of claim 31, further comprising sensing a temperature of the insulation layer with a second sensor during the autoclave cycle; and

communicating the sensed temperature to an operator.

36. The method of claim 31, wherein the thermal barrier layer comprises at least one of a partial vacuum and an inert gas.

37. The method of claim 31, wherein the surgical tool further comprises a housing having an atmosphere therein, the atmosphere providing the insulating layer.

38. The method of claim 37, wherein the electrochemical cell is exposed to the atmosphere.

39. The method of claim 37, wherein an inner wall within the housing prevents exposure of the electrochemical cell to the atmosphere.

40. An electrical power assembly comprising:

a power source;

an enclosure, the enclosure enclosing a volume therein, the power source being located in the volume, and the volume having an atmosphere providing a layer of insulation between the power source and air outside the enclosure; and

an interior wall within the housing that prevents the power source from being exposed to an atmosphere of the volume;

wherein the thermal conductivity of the atmosphere is less than the thermal conductivity of air outside the enclosure.

Background

The present invention relates to thermal insulation of battery cases, for example, to thermal insulation of cases containing battery cells exposed to high temperatures during surgery.

Battery powered tools have improved convenience and efficiency for medical workers in surgical settings. Such as in the sterile field of an operating room, where the surgical tools and their associated batteries are sterilized prior to use. Battery powered surgical tools are typically designed to withstand the temperatures associated with autoclaving for sterilization of the surgical tools or surgical instruments. These temperatures may be, for example, up to 132 ℃ for several minutes in a pre-vacuum sterilizer, or up to 121 ℃ for 30 minutes or more in a gravity displacement sterilizer.

Like surgical tools or instruments, the battery housing of such tools is also sterile. Such sterilization poses a problem in that the performance of the rechargeable battery cell may be degraded when exposed to temperatures exceeding 70 ℃. In addition to degrading performance, the cell itself is at risk of permanent damage once it is exposed to temperatures in excess of 80 ℃.

One way to prevent the battery cells from reaching such critical temperatures has been to sterilize the battery housing without the battery cells, and then the battery cells are added to the housing using a shield and a sealing cover to prevent the battery cells from being exposed to the sterilization zone. Another approach is to use thermal insulation materials to insulate the cells, such as microporous silicic acid (U.S. patent No. 6,756,766), silica (silicon dioxide), silicon carbonitride ceramics, and perforated silica gel (U.S. patent No. 8,486,560).

Yet another way is to sterilize the battery housing with the battery cells with chemicals or gases, such sterilization process avoiding the generation of temperatures that could damage the battery cells. However, the sterilization structure required for this approach is not typically available in hospitals, surgical centers, and other medical facilities.

Summary of The Invention

A simple, low-cost sealed battery housing and associated method of manufacture are provided. In an exemplary embodiment, the housing may be autoclaved with the rechargeable (electrochemical) cells enclosed within.

According to one aspect of an exemplary embodiment, a battery pack assembly includes at least one battery including an electrochemical cell and a housing having at least one exterior wall configured to create a sealed volume substantially surrounding the at least one battery. The atmosphere of the volume comprises a gas. The thermal conductivity of the gas in the volume of space is less than 0.018 watts per meter per degree celsius.

Drawings

Fig. 1 illustrates a perspective view of a battery pack assembly in accordance with an aspect of an exemplary embodiment of the present invention;

fig. 2 illustrates a perspective view of a battery pack assembly according to another aspect of an exemplary embodiment of the present invention;

FIG. 3 illustrates a perspective view of a battery pack assembly coupled to a charging station in accordance with an aspect of an exemplary embodiment of the present invention;

FIG. 4 illustrates a perspective view of a battery pack assembly coupled to a surgical device in accordance with an aspect of an exemplary embodiment of the present invention;

fig. 5 illustrates a perspective view of a battery pack assembly including a display according to an aspect of an exemplary embodiment of the present invention.

Detailed Description

The exemplary embodiments described herein are for illustrative purposes only and limit the scope of the invention. It should be understood that various omissions and substitutions of equivalents are contemplated as known to those skilled in the art due to environmental implications or convenience. Furthermore, although the following generally relates to exemplary embodiments of the physical design, it will be understood by those skilled in the art that variations in materials, component descriptions, and geometries may be made without departing from the spirit of the invention.

In one aspect of an exemplary embodiment of the invention, a battery pack assembly or housing includes one or more batteries having an electrochemical cell and a housing having an outer wall for creating a sealed volume substantially surrounding the batteries. The atmosphere of the volume of space comprises a gas having a thermal conductivity of less than 0.018 watts per meter per degree celsius. This gaseous atmosphere has a thermal insulation layer arranged between the outer wall and the cells. The battery pack assembly having such an insulating layer can withstand autoclaving without damaging the cells.

The thermal conductivity of the gas in the volume of space may be low, for example less than 0.016 watts per meter celsius. Further, the atmosphere of the volume of space may include a partial vacuum sufficient to cause the thermal conductivity of the gas in the volume of space to be less than 0.018 watts per meter per degree celsius. The gas comprised in the atmosphere of the volume of space may be at least 25% or at least 33% of an inert gas selected from the group consisting of krypton, xenon, argon and freon.

The battery pack assembly also includes a plurality of supports separating the batteries from the outer wall of the housing. In addition, an inner wall at least partially surrounding the battery is included. The outer wall of the enclosure is formed of a composite plastic that may be covered with a layer of metal, such as a metal layer that reduces the permeability of the outer wall.

To supply power, the battery pack assembly includes battery terminals extending from the batteries to the exterior of the outer wall. The battery terminals include positive and negative terminals coupled to the electrical contacts for connecting to and powering a surgical tool, and for connecting to and charging through a charging station.

As shown in fig. 1, a battery pack housing or assembly 100 includes a battery cell 110, a battery terminal 120, a first or outer wall 130, and a second or inner wall 140. The battery cells 110 may be rechargeable electrochemical cells, such as lead-acid batteries, nickel-chromium batteries (NiCd), nickel-metal hydride batteries (NiMH), lithium ion batteries (Li-ion), or lithium ion polymer batteries (Li-ion polymer).

The outer wall 130 forms a continuous sealed chamber around the inner wall 140 and the battery cell 110. The space between the inner surface of the inner wall 130 and the inner surface of the inner wall 140 presents a volume 160 having an atmosphere comprising a gas, a partial vacuum, or both. The inner wall 140 may be a continuous wall or a non-continuous wall surrounding the battery cell 110. When acting as a non-continuous wall, the inner wall 140 may partially or fully cover the battery cell 110 and separate the battery cell 110 from the inner surface of the outer wall 130. The cross-sectional area of the inner wall is preferably less than 25% of the outer surface area of the outer wall 130. Reducing the cross-sectional area of the inner wall 140 relative to the outer wall 130 facilitates reducing the thermal conduction from the outer wall 130 to the battery cells 110 through the battery enclosure 100.

To separate the outer wall 130 from the inner wall 140, the battery housing 100 includes supports, spacers or separators 150 that maintain the outer wall 130 separate from the inner wall 140. In the exemplary embodiment, the spacer material is formed from a plurality of individual supports 150 that prevent the battery cells 110 from contacting the outer wall 130. Of course, providing fillers or adjacent spacers rather than discrete structural "supports" is an alternative configuration that is contemplated.

Alternatively, as shown in fig. 2, the battery pack case 100 may be designed without the inner wall 140. In this configuration, the battery cell 110 is exposed to the atmosphere of the volume 160. Without the inner wall 140, as shown in fig. 2, the support 150 is configured to separate the outer wall 130 from the battery cell 110.

The support 150 is preferably formed of a low thermal conductivity material that facilitates reducing heat transfer from the outer wall 130 to the inner wall 140 and the battery cell 110. In addition, it is preferable to minimize the cross-sectional area of the support 150. For example, the cross-sectional area may be a small fraction, e.g., less than 10%, of the surface area of the battery cell 110. The number of supports 150 included in the battery pack housing 100 depends on the particular configuration of the battery cells 110, but the number of supports 150 is preferably sufficient to maintain the position of the battery cells 110 (or the inner wall 140, if included) within the outer wall 130 and away from the outer wall 130.

Whereas the outer surface of the outer wall 130 is exposed to the environment, the inner surface of the outer wall 130 is exposed to the atmosphere of the volume 160 between the outer wall 130 and the inner wall 140 or the battery cell 110. The atmosphere provides a thermal barrier between the outer wall 130 and the battery cell 110. For example, the atmosphere of the gas may comprise at least 25% of a gas of low thermal conductivity. The low thermal conductivity gas may include a large proportion of an atmosphere, such as at least 33% atmosphere, 50% atmosphere, or all of the atmosphere in the volume 160. The low thermal conductivity gas is preferably an inert gas such as argon, krypton, xenon or freon.

In addition to or as an alternative to the low thermal conductivity gas, the atmosphere in the volume 160 may comprise a partial vacuum. The partial vacuum preferably amounts to 25% of the atmosphere in the volume 160. The partial vacuum may include a large proportion of an atmosphere, such as at least 33% atmosphere, 50% atmosphere, or all atmosphere in the volume 160.

Because heat transfer at atmospheric pressure is significantly affected by direct transfer or molecular motion convection during collisions of gas molecules with molecules, the partial vacuum facilitates reducing heat transfer from the outer wall 130 to the battery cell 110. If two objects, such as the outer wall 130 and the battery cell 110, are at different temperatures and placed in a chamber at atmospheric pressure, heat will begin to flow from the hotter side to the cooler side through the gas molecules. If this pressure is reduced by removing some of the gas molecules, for example by introducing a vacuum, the distance between the molecules will become larger and the number of molecular collisions will be reduced, resulting in a reduction in heat flow. Reducing the thermal conduction of the heat transfer medium (such as gas molecules) allows the hotter object to retain its heat. And, if the pressure is continuously reduced, the heat flow is also continuously reduced. Thus, introducing at least a partial vacuum between the hot object and the cold object (e.g., the outer wall 130 and the battery cell 110) creates a thermal insulator-the partial vacuum provides an amount of insulation that is dependent on the amount of vacuum (i.e., a very small number of molecules) between the hot object and the cold object.

Whether the atmosphere in the volume 160 includes a gas with low thermal conductivity, a partial vacuum, or a combination of the two, the thermal conductivity of the atmosphere is preferably configured to isolate the battery cell, thereby protecting the battery cell 110 from damage during autoclaving. The thermal conductivity of air is 0.024 watts per meter celsius. Using a low thermal conductivity gas and/or partial vacuum reduces the thermal conductivity of the atmosphere in the volume of gas 160 to below that of air. To protect the battery cell, it is preferable to provide sufficient gas and/or partial vacuum of low thermal conductivity in the atmosphere so that the thermal conductivity of the atmosphere ranges, for example, from 0.002 watts per meter degree celsius to 0.018 watts per meter degree celsius. More preferably, the thermal conductivity of the atmosphere is less than 0.018, less than 0.016, less than 0.012, less than 0.009, or less than 0.007 watts per meter per degree celsius. In an exemplary embodiment, the low thermal conductivity gas has a thermal conductivity of less than 0.012 watts per meter celsius, such as freon (having a thermal conductivity of 0.007) or krypton (having a thermal conductivity of 0.009). With the atmosphere of the volume 160 configured to have a low thermal conductivity, the battery enclosure 100, for example, prevents the inner wall 130 and the battery cells 120 from reaching 70 ℃ when the outer wall is exposed at 132 ℃ for 4 minutes or at 121 ℃ for 30 minutes.

In addition to the thermal insulation provided by the atmosphere in the volume 160, to further protect the battery cell 110, the walls of the battery enclosure 100 may include materials with very low permeability to gases including nitrogen, oxygen, and other gases in the atmosphere. The material preferably has a very low permeability, e.g. 132 degrees celsius, both at room temperature and at a temperature at which it is autoclaved. For example, the material for the outer wall 130 and the inner wall 140 may be a composite plastic with different webs and layers to reduce permeability. The thickness of the outer wall 130 is preferably sufficient to withstand damage such as dropping onto a floor, as well as to take into account the impact and molding properties of the materials used, such as plastics.

In addition to the materials used for the walls of the battery enclosure 100, a film, coating, coextrusion, or plating may be disposed on the interior or exterior of the outer wall 130, and preferably to the inner wall 140. The coating is preferably located on the inside of the outer wall 130 to protect damage such as from scratches. The coating may for example be a metal layer which advantageously reduces the permeability of the wall, preferably by at least 90%. The desirably low permeability is generally a function of the "free gas volume" within the outer wall 130 of the battery enclosure 100. In a preferred embodiment, the material and coating of the outer wall 130, for example, are preferably designed such that the free volume transfer within the atmosphere of the volume 160 does not exceed 10% when stored at 23 ℃ for one year. With such a low permeability, the atmosphere within volume 160 does not dissipate from battery enclosure 100 over time.

The battery terminal 120 may include a positive lead and a negative lead that may be connected to the electrical contact 170. The electrical contacts 170 are configured to connect to and provide power to a device, such as a surgical tool, for example, as shown in fig. 4. The surgical tool may be, for example, an orthopedic power tool as described in U.S. patent No. 8,936,106. The electrical contacts 170 may also be connected to a charger to charge the battery cells 110, for example, as shown in fig. 3. The cell terminal 120 passes through the outer wall 130 and inner wall 140 and is preferably sealed by a low permeability potting compound, O-ring or other sealing method to reduce gas leakage. The sealing material may be, for example, 20-2350 polyurethane. In addition, the cross-sectional area of the electrical contacts 170 is kept to a minimum level, thereby reducing conductive heat transfer to the battery cells 110.

The battery terminals 120 may include one or more communication terminals in addition to the positive and negative leads. These communication terminals may be configured to provide information about atmospheric damage, the temperature of the battery cell, the battery level of the battery cell, and other information related to the use or condition of the battery pack case 100 including the battery cell 110. To provide such information via the communication terminals, the battery enclosure 100 may include circuitry, detectors, and sensors configured to detect conditions and parameters related to the use of the battery enclosure 100 and the battery cells 110. The communication terminals may be coupled to a display 180, such as shown in FIG. 5, which is configured to display information provided by the communication terminals. The electrochemical cell may also be replaced by a fuel cell.

To detect temperature, the battery pack enclosure 100 may include a thermocouple that monitors the temperature of the battery cell 1120 or the area surrounding the battery cell 110. The status of the temperature, e.g., the temperature remaining at an acceptable level, having reached a point near a critical level, or having reached a critical level, may be indicated using an indicator light visible on the outer surface of the outer wall 130 or the sound of a speaker mounted on the outer surface of the outer wall. The indicator light and sound may also be used to indicate whether the battery is ready for use. Thermochromic strips may also be used to indicate that the battery cell 110 is at a safe use temperature by a color or other change.

In addition to sensing and providing an indication of temperature, the battery enclosure 100 may include fault protection that prevents use of the battery when it is activated. This fault protection can be achieved, for example, by blowing fuses in the connection. Additional safety devices, such as PTC elements, commonly used in the industry, may be introduced into the battery pack case 100 to prevent the battery cells 110 from discharging until they are sufficiently cool. The battery enclosure 100 may include a sensor for detecting thermal conduction in the internal gas chamber region and a sensor for detecting the peak temperature reached by the battery cells 110 within the battery enclosure 100 during an autoclave cycle. Based on the detected information, the sensor communicates information to the operator, such as damage to the thermal system or a defect such as the battery cell 110 not being charged.

While various specific embodiments of the disclosure have been described, such references should not be considered as limitations on the scope of the disclosure.