Lithium polymer battery powered intravenous fluid warmer
View Patent ↗A lithium polymer (LiPo) battery pack having LiPo battery cells is provided which includes battery protection circuitry, charging circuitry, cell balancing circuitry, and control and communication circuitry. The batteries can be charged while in use by an internal charger. Battery charging and discharging are accomplished in a controlled and protected manner to avoid overcharging and overdischarging conditions. The novel battery pack has built-in safeguards against dangerous LiPo battery conditions and is implemented in a small, portable unit which contains the battery cells, control and protection circuitry, internal charger and display gauge. The battery pack is useful for powering an intravenous fluid warmer or other medical or electrical devices and equipment.
1. An apparatus for use with a system for warming a fluid to be administered to a living body, which includes the system including a case through which a fluid line extends, the apparatus comprising:
a housing configured for attachment to the case, the housing including:
one or more lithium polymer cells;
a heater positioned to transfer heat to the case;
a fluid warmer microcontroller connected to the heater;
a first order battery protection circuit connected to elements selected from4hea group consisting of:
a battery condition indicator and controller,
at least one sensor connected to at least one of the one or more lithium polymer cells,
a cell balance circuit connected to the one or more lithium polymer cells, and
a battery disconnect switch;
a second order battery protection circuit connected to the one or more lithium polymer cells;
a fluid warmer over-temperature protection circuit to sense a temperature of the case during use; and
a thermal fuse coupled to the heater, the second order battery protection circuit, and the fluid warmer over-temperature protection circuit, wherein the second order battery protection circuit opens the thermal fuse in response to a predetermined condition, and wherein the fluid warmer over-temperature protection circuit opens the thermal fuse in response to sensing an excessive fluid temperature.
2. The apparatus of claim 1 , wherein the case includes a removable cartridge configured to permit fluid to flow through the removable cartridge during use.
3. The apparatus of claim 1 , wherein the at least one sensor is one or more of a plurality of temperature sensors, a voltage sensor, a current sensor connected to the battery condition indicator and controller, a stress sensor, or a strain sensor.
4. The apparatus of claim 1 , wherein the at least one sensor is a plurality of temperature sensors that are attached to the one or more lithium polymer cells in a distributed manner.
5. The apparatus of claim 1 , wherein the at least one sensor is one of a stress sensor or a strain sensor, and wherein the stress sensor or the strain sensor is connected to a diode to pull a temperature sensor low.
6. The apparatus of claim 1 , further comprising a power path controller logic circuit to control an external power switch and a battery discharge switch.
7. The apparatus of claim 1 , further comprising a heater control switch coupled between the fluid warmer microcontroller and the heater.
8. The apparatus of claim 1 , wherein the battery condition indicator and controller includes at least one of a display or an annunciator.
9. The apparatus of claim 1 , further comprising a charger connected to the one or more lithium polymer cells.
10. The apparatus of claim 9 , wherein an electric current to warm the case conducts in a circuit separate from the charger.
11. The apparatus of claim 1 , further including a fire and/or explosion resistant enclosure containing at least the one or more lithium polymer cells.
12. A battery back enclosure for a fluid warmer, the battery pack enclosure comprising:
one or more lithium polymer cells;
a first order battery protection circuit, coupled to at least one sensor and a battery disconnect switch, for disconnecting the one or more lithium polymer cells from a power source in response to a first predetermined condition;
a second order battery protection circuit, coupled to the at least one sensor, for disconnecting the one or more lithium polymer cells from the power source in response to a second predetermined condition;
a fluid warmer over-temperature protection circuit for disconnecting the one or more lithium polymer cells from the power source in response to sensing an excessive fluid temperature; and
a thermal fuse coupled to the second order battery protection circuit and the fluid warmer over-temperature protection circuit, wherein the second order battery protection circuit opens the thermal fuse in response to the second predetermined condition, and wherein the fluid warmer over-temperature protection circuit opens the thermal fuse in response to sensing the excessive fluid temperature.
13. The battery pack enclosure of claim 12 , wherein the at least one sensor is one or more of a plurality of temperature sensors, a voltage sensor, a current sensor, a stress sensor, or a strain sensor.
14. The battery pack enclosure of claim 12 , further including a battery condition indicator coupled to the first order battery protection circuit and having one or more of a display or an annunciator.
15. The battery pack enclosure of claim 12 , further comprising a charger connected to the one or more lithium polymer cells.
16. The battery pack enclosure of claim 15 , wherein the charger is coupled to the one or more lithium polymer cells such that the charger directs a discharge load current on a path partially separate from a path of charging current.
17. The battery pack enclosure of claim 15 , wherein an electric current output from the battery pack conducts in a circuit partially separate from the charger.
18. The battery pack enclosure of claim 12 , further including a fire and/or explosion resistant enclosure containing at least the one or more lithium polymer cells.