U.S. patent application number 13/128355 was filed with the patent office on 2012-05-17 for method and system for heating and/or thawing blood products.
This patent application is currently assigned to RF DYNAMICS LTD.. Invention is credited to Daniella Atzmony, Eran Ben-Shmuel, Alexander Bilchinsky, Ohard Karnieli.
Application Number | 20120122072 13/128355 |
Document ID | / |
Family ID | 41665275 |
Filed Date | 2012-05-17 |
United States Patent
Application |
20120122072 |
Kind Code |
A1 |
Bilchinsky; Alexander ; et
al. |
May 17, 2012 |
METHOD AND SYSTEM FOR HEATING AND/OR THAWING BLOOD PRODUCTS
Abstract
A device for heating one or more blood product units using
electromagnetic (EM) energy is disclosed. The device comprises a
chamber sized and shaped for containing at least one frozen blood
product unit, a dielectric heating unit for applying
electromagnetic (EM) energy at a plurality of frequencies to the at
least one blood product unit, and a controller for operating the
dielectric heating unit to heat the at least one frozen blood
product unit to about a body temperature in less than 3 minutes
according to a heating pattern.
Inventors: |
Bilchinsky; Alexander;
(Monosson-Yahud, IL) ; Ben-Shmuel; Eran; (Savyon,
IL) ; Karnieli; Ohard; (Kiryat Tivon, IL) ;
Atzmony; Daniella; (Shoham, IL) |
Assignee: |
RF DYNAMICS LTD.
Hamilton
BM
|
Family ID: |
41665275 |
Appl. No.: |
13/128355 |
Filed: |
November 10, 2009 |
PCT Filed: |
November 10, 2009 |
PCT NO: |
PCT/IL2009/001059 |
371 Date: |
November 15, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61193248 |
Nov 10, 2008 |
|
|
|
61253893 |
Oct 22, 2009 |
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Current U.S.
Class: |
435/2 ;
422/44 |
Current CPC
Class: |
H05B 6/687 20130101;
H05B 6/705 20130101; H05B 6/68 20130101; H05B 6/70 20130101; H05B
6/688 20130101; H05B 6/6447 20130101; Y02B 40/00 20130101; H05B
6/664 20130101 |
Class at
Publication: |
435/2 ;
422/44 |
International
Class: |
A01N 1/02 20060101
A01N001/02 |
Claims
1-55. (canceled)
56. A device for heating at least one blood product unit using
electromagnetic (EM) energy, comprising: a chamber for containing
at least one frozen blood product unit; a dielectric heating unit
which applies electromagnetic (EM) energy to said at least one
frozen blood product unit; and a controller, which operates said
dielectric heating unit to heat said at least one frozen blood
product unit to about a body temperature according to a heating
pattern, at a plurality of radio frequencies.
57. The device of claim 56, wherein the controller is configured to
operate said dielectric heating unit to heat said at least one
frozen blood product unit to about a body temperature in less than
3 minute according to a heating pattern.
58. A device for heating a blood product unit by applying
electromagnetic (EM) energy, comprising: a chamber for containing
at least one cooled blood product unit having a temperature above
0.degree. C. and below 15.degree. C.; a dielectric heating unit for
applying electromagnetic (EM) energy to said at least one cooled
blood product unit; and a controller for operating said dielectric
heating unit to heat said at least one cooled blood product unit to
about a body temperature according to a heating pattern, at a
plurality of radio frequencies.
59. The device of claim 58, wherein said controller is configured
for operating said dielectric heating unit to heat said at least
one cooled blood product unit uniformly to about a body temperature
in 20 seconds or less according to a heating pattern.
60. The device of claim 56, wherein said device is sized for being
installed in a member of a group consisting of: an ambulance, an
operating room, and an emergency room.
61. A method of heating at least one frozen blood product unit
placed in a chamber by applying electromagnetic (EM) energy,
comprising: (a) thawing said at least one frozen blood product unit
by applying EM energy to said at least one blood product unit at a
plurality of different radio frequencies; and (b) heating said at
least one frozen blood product unit in said chamber to about a body
temperature by applying said EM energy.
62. The method of claim 61, wherein said thawing and said heating
are performed cumulatively in less than 3 minute.
63. The method of claim 61, wherein said EM energy is at a
plurality of frequencies.
64. The method of claim 63, comprising selecting a maximum power to
be dissipated in the at least one frozen blood product unit in a
manner which avoids overheating, wherein said EM energy is below
said maximum power at all said plurality of different
frequencies.
65. The method of claim 61, comprising gathering data pertaining to
at least one of said thawing, and said heating during at least one
of said thawing and said heating and scoring the quality of said at
least one frozen blood product unit according to said data.
66. The method of claim 61, comprising tagging each said at least
one frozen blood product unit with a respective quality score
according to said scoring.
67. The method of claim 61, comprising reading instructions from at
least one tag attached to said at least one frozen blood product
unit and performing at least one of said thawing and said heating
according to said instructions.
68. The method of claim 61, wherein said at least one frozen blood
product unit is a frozen plasma unit.
69. A method for heating a plurality of blood product units placed
in a chamber using electromagnetic (EM) energy, comprising:
applying EM energy to said plurality of blood product units;
measuring a temperature of each said blood product units; and
ending said applying when the temperature of each said blood
product unit is above a minimum threshold.
70. The method of claim 69, wherein said ending is performed
automatically.
71. The method of claim 69, wherein said minimum threshold is
25.degree. C. or more.
72. The method of claim 69, wherein said ending comprises ending
said applying when the temperature of any of said blood product
unit is above a maximum threshold.
73. A method for thawing a blood product unit placed in a chamber
using electromagnetic (EM) energy, comprising: applying EM energy
to said blood product unit at a time when said blood product unit
comprises frozen and thawed portions; and ending said applying when
the temperature of all portions of said blood product unit is
between 2.degree. C. and 15.degree. C.
74. The method of claim 73, wherein during the process the
temperature of no part of the blood product exceeds 40.degree.
C.
75. A method for managing blood product unit supply, comprising:
receiving a request for supply of at least one frozen plasma unit
and at least one cooled blood cells unit; heating one or more
cooled blood cells units and one or more frozen plasma units to
about a body temperature cumulatively in less than 3 minutes by
applying electromagnetic (EM) energy at a plurality of radio
frequencies; and jointly transferring at least one of the one or
more blood cells units and at least one of the one or more plasma
units according to the request.
76. The method of claim 75, comprising performing said heating in a
member of a group consisting of: an ambulance, an operating room,
and an emergency room.
77. The method of claim 75, wherein said heating comprises
automatically acquiring said frozen plasma unit and said cooled
blood cells unit from a freezing storage and automatically placing
said frozen plasma unit and said cooled blood cells unit in a
heating chamber, said applying being performed in said heating
chamber.
78. The device of claim 56, wherein the heating pattern is
determined by an analysis of absorption of different frequencies in
the blood product unit.
79. The device of claim 78, wherein analysis comprises defining
transmission frequencies and amount of energy to be transmitted at
each frequency, based on spectral information.
80. The device of claim 56, wherein power levels of transmitted
frequencies are inversely related to energy dissipation at the same
frequencies.
81. The device of claim 56, wherein said heating pattern is
dynamically determined according to absorption of different
frequencies in said blood product unit.
82. The method of claim 61, wherein heating is according to a
heating pattern determined by an analysis of absorption of
different frequencies in said blood product unit.
83. The method of claim 82, wherein the analysis comprises defining
transmission frequencies and amount of energy to be transmitted at
each frequency, based on spectral information.
84. The method of claim 61, wherein power levels of transmitted
frequencies are inversely related to energy dissipation at the same
frequencies.
85. The method of claim 61, wherein heating is according to a
heating pattern dynamically determined according to absorption of
different frequencies in said blood product unit.
86. The device of claim 56, wherein the controller is configured
for operating said dielectric heating unit to heat said at least
one frozen blood product unit to about a body temperature in less
than 3 minutes according to a heating pattern.
87. The device of claim 58, wherein said device is sized for being
installed in a member of a group consisting of: an ambulance, an
operating room, and an emergency room.
88. The method of claim 63, wherein the plurality of frequencies is
a plurality of radio frequencies.
Description
RELATED APPLICATIONS
[0001] The present application claims the benefit under 119(e) of
U.S. Provisional Patent Application No. 61/193,248 filed 10 Nov.
2008 and U.S. Provisional Patent Application No. 61/253,893 filed
22 Oct. 2009 and is related to two PCT applications Agent
References: 47408 and 46672 filed on 10 Nov. 2009, the disclosures
of which are incorporated herein by reference.
FIELD AND BACKGROUND OF THE INVENTION
[0002] The present invention, in some embodiments thereof, relates
to method and system for heating blood product units and, more
particularly, but not exclusively, to methods and systems for
heating blood product units using electromagnetic (EM) energy.
[0003] In hospitals and medical care centers, blood, blood products
and saline solution are use to transfuse patients in need. Saline,
a salt solution, is normally maintained at room temperature. Blood
products, such as red blood cells (RBC), platelets, and plasma, are
stored in frozen and/or cooled form in sealed bags for later use.
When frozen, the blood components are generally stored at
temperatures below -18.degree. C. Conventionally, fresh frozen
plasma is thawed by immersing it in a 37.degree. C. water bath.
This normally takes about half an hour. Alternatively, the bag of
frozen blood product may be thawed by heating it within a microwave
oven. Microwaves developed for the rapid warming of blood products
were introduced in the mid-1950s. After first trials in the 1960s
and 1970s, several reports of overheating appeared and their use
declined despite of their much shorter heating times; see Sherman L
A, Dorner I M. A new rapid method for thawing fresh frozen plasma.
Transfusion 1974; 14: 595-7; Arens J F, Leonard G L. Danger of
overwarming blood by microwave. Journal of the American Medical
Association 1971, 218: 1045-6 and Sohngen D, Kretschmer V, Franke
K, et al. Thawing of fresh-frozen plasma with a new microwave oven,
Transfusion 1988; 28: 576-80.
[0004] An example for a system for thawing blood product units is
provided in U.S. Pat. No. 5,374,811, filed on May 6, 1992 that
describes a method and apparatus for safely and rapidly rewarming
large quantities of frozen or refrigerated blood combines
microwave, or radio frequency radiation, heating with a forced air
system. Forced air is flowed over units of blood or tissue from
those units that will absorb the most microwave energy, generally
those units closest to the source of microwave energy, to those
units that will absorb the least microwave energy, generally those
units furthest from the source of microwave energy. The forced air
initially thaws the closest units so that they begin to absorb
significant microwave energy. The forced air, preferably chilled,
then prevents overheating of those closest units by transferring
heat to more distant units, beginning their thawing and
contributing to their rewarming. The microwave energy source is
turned off when the output temperature of the forced air reaches a
preselected temperature and the flow of forced air continues until
the output temperature stabilizes. The apparatus includes a
separated stack of perforated plates, each plate holding two units,
mounted inside a microwave oven. Forced air drives a turbine rotor
which rotates the plates while the air leaving the turbine flows
down among the stacked plates and out the microwave oven.
[0005] Another example is provided in U.S. Pat. No. 5,616,268,
filed on Jul. 7, 1994 that describes a microwave thawing system for
thawing bags of frozen blood products features non-invasively
monitoring the internal temperature of the blood product during
thawing, and controlling the level of warming energy applied to the
blood product based on the monitored temperature. The noninvasive
monitoring is performed with one or more antennas which receive
electromagnetic energy from the frozen blood product during
thawing. The inventors of U.S. Pat. No. 5,616,268 claim that
because the applied energy level is controlled based on the
temperature of the blood, the blood can be thawed rapidly with
little risk of damage from overheating. Pressure is applied to the
bag to maintain a uniform distribution of blood within the bag and
to separate the thawed blood from the still-frozen blood during
thawing; for example, the pressure moves the liquid blood to the
periphery of the bag and retains the frozen blood in the center of
the bag. As a result, the continued application of thawing energy
to the frozen blood poses little risk of overheating (and
contaminating) the liquid blood. The warming energy and the
electromagnetic energy are transmitted and received, respectively,
through receive waveguides configured to provide high isolation
between its transmit and receive ports.
SUMMARY OF THE INVENTION
[0006] According to some embodiments of the present invention there
is provided a device of heating a blood product unit using
electromagnetic (EM) energy. The device comprises a chamber for
containing at least one frozen blood product unit, a dielectric
heating unit which applies electromagnetic (EM) energy to the at
least one frozen blood product unit, and a controller which
operates the dielectric heating unit to heat the at least one
frozen blood product unit to about a body temperature in less than
3 minutes according to a heating pattern.
[0007] Optionally, the controller is configured for operating the
dielectric heating unit to heat the at least one frozen blood
product unit to about a body temperature in less than 1 minute
according to a heating pattern.
[0008] According to some embodiments of the present invention there
is provided a device of heating a blood product unit using
electromagnetic (EM) energy. The device comprises a chamber for
containing at least one frozen blood product unit, a dielectric
heating unit for applying electromagnetic (EM) energy to the at
least one frozen blood product unit, and a controller for operating
the dielectric heating unit to heat the at least one frozen blood
product unit. The device is configured to perform at least a
portion of the applying electromagnetic (EM) energy at a time when
the blood product unit being stationary.
[0009] Optionally, the at least portion is at least 50% of the
duration of the applying of electromagnetic (EM) energy.
[0010] Optionally, the at least portion is at comprises applying at
least 50% of the total amount of electromagnetic (EM) energy that
being applied to the frozen blood product unit.
[0011] Optionally, the device further comprises a freezing chamber
for freezing the at least one frozen blood product unit.
[0012] Optionally, the device further comprises a unit positioning
element sized and shaped to support the at least one frozen blood
product unit in the chamber.
[0013] More optionally, the unit positioning element is
automatically extracted when the chamber being opened.
[0014] More optionally, the unit positioning element comprises at
least one slot for placing the at least one frozen blood product
unit.
[0015] Optionally, the controller is configured for operating the
dielectric heating unit so as to allow substantially uniformly
heating the at least one frozen blood product unit regardless to
the position thereof in the in the chamber.
[0016] Optionally, the controller is configured for operating the
dielectric heating unit so as to allow substantially uniformly
heating the at least one frozen blood product unit without
receiving designated instructions from a human operator.
[0017] Optionally, each the frozen blood product unit is contained
in a bag having a maximal thickness between 2 cm and 6 cm.
[0018] Optionally, each the frozen blood product unit is contained
in a bag is of irregular thickness.
[0019] Optionally, the controller operates the dielectric heating
unit regardless of the shape of the frozen blood product unit.
[0020] According to some embodiments of the present invention there
is provided a device of heating a blood product unit using
electromagnetic (EM) energy. The device comprises a chamber for
containing at least one cooled blood product unit having a
temperature above 0.degree. C. and below 15.degree. C., a
dielectric heating unit for applying electromagnetic (EM) energy to
the at least one cooled blood product unit, and a controller for
operating the dielectric heating unit to heat the at least one
cooled blood product unit to about a body temperature in less than
1 minute according to a heating pattern.
[0021] According to some embodiments of the present invention there
is provided a device of heating a blood product unit using
electromagnetic (EM) energy. The device comprises a chamber for
containing at least one cooled blood product unit having a
temperature above 0.degree. C. and below 15.degree. C., a
dielectric heating unit for applying electromagnetic (EM) energy to
the at least one cooled blood product unit, and a controller for
operating the dielectric heating unit to heat the at least one
cooled blood product unit. The device is configured to perform at
least a portion of the applying electromagnetic (EM) energy at a
time when the blood product unit being stationary.
[0022] Optionally, the controller is configured for operating the
dielectric heating unit to heat the at least one cooled blood
product unit uniformly to about a body temperature in 20 seconds or
less according to a heating pattern.
[0023] Optionally, the at least portion is at least 50% of the
duration of the applying of electromagnetic (EM) energy.
[0024] More optionally, the at least portion is at comprises
applying at least 50% of the total amount of electromagnetic (EM)
energy that is applied to the cooled blood product unit.
[0025] More optionally, the chamber is sized and shaped for
containing the at least one cooled blood product unit.
[0026] Optionally, the device is sized for being installed in a
member of a group consisting of: an ambulance, an operating room,
and an emergency room.
[0027] Optionally, the EM energy is at a plurality of
frequencies.
[0028] According to some embodiments of the present invention there
is provided a method heating a blood product unit using
electromagnetic (EM) energy. The method comprises (a) placing at
least one frozen blood product unit in a chamber, (b) thawing the
at least one frozen blood product unit by applying EM energy to the
at least one frozen blood product unit at a plurality of different
frequencies, and (c) heating the at least one frozen blood product
unit in the chamber by applying the EM energy to about a body
temperature. The thawing and the heating are performed cumulatively
in less than 3 minutes.
[0029] According to some embodiments of the present invention there
is provided a method heating a blood product unit using
electromagnetic (EM) energy. The method comprises (a) placing at
least one frozen blood product unit in a chamber, (b) thawing the
at least one frozen blood product unit by applying EM energy to the
at least one frozen blood product unit, and (c) heating the at
least one frozen blood product unit in the chamber by applying the
EM energy to about a body temperature. The at least a portion of
the thawing and the heating is performed when the at least one
blood product is stationary.
[0030] Optionally, the thawing and the heating are performed
cumulatively in less than 1 minute.
[0031] Optionally, the EM energy is at a plurality of
frequencies.
[0032] More optionally, the method comprises selecting a maximum
power to be dissipated in the at least one frozen blood product
unit in a manner which avoids overheating, wherein the EM energy is
below the maximum power at all the plurality of different
frequencies.
[0033] More optionally, the method comprises gathering data
pertaining to at least one of the thawing, the heating and change
of at least one characteristic of the at least one frozen blood
product unit during at least one of the thawing and the heating and
scoring the quality of the at least one frozen blood product unit
according to the data.
[0034] More optionally, the method comprises tagging each the at
least one frozen blood product unit with a respective quality score
according to the scoring.
[0035] More optionally, the method comprises reading instructions
from at least one tag attached to the at least one frozen blood
product unit and performing at least one of the thawing and the
heating according to the instructions.
[0036] More optionally, the method comprises moving the at least
one frozen blood product unit during at least one of the heating
and the thawing.
[0037] More optionally, the method comprises storing the at least
one frozen blood product unit at a freezing temperature in the
chamber before performing the step (b).
[0038] More optionally, the at least one frozen blood product unit
is a frozen plasma unit.
[0039] According to some embodiments of the present invention there
is provided a method heating a cooled blood product unit using
electromagnetic (EM) energy. The method comprises (i) placing at
least one cooled blood product unit in a chamber, and (ii) heating
the at least one cooled blood product unit by applying EM energy to
the at least one cooled blood product unit to about a body
temperature. The heating is performed in less than 1 minute.
[0040] Optionally, the heating is performed in 20 seconds or
less.
[0041] According to some embodiments of the present invention there
is provided a method heating a cooled blood product unit using
electromagnetic (EM) energy. The method comprises (i) placing at
least one cooled blood product unit in a chamber, and (ii) heating
the at least one cooled blood product unit by applying EM energy to
the at least one cooled blood product unit to about a body
temperature. At least a portion of the heating is performed when
the at least one blood product is stationary.
[0042] Optionally, the at least one cooled blood product comprises
red blood cells.
[0043] According to some embodiments of the present invention there
is provided a method for heating a blood product unit using
electromagnetic (EM) energy. The method comprises placing a
plurality of blood product units in a chamber, applying EM energy
to the plurality of blood product units, measuring the temperature
of each the blood product units, and ending the applying when the
temperature of each the blood product unit is above a minimum
threshold.
[0044] Optionally, the ending is performed automatically.
[0045] Optionally, the minimum threshold is 25.degree. C. or
more.
[0046] Optionally, the ending comprises ending the applying when
the temperature of any of the blood product unit is above a maximum
threshold.
[0047] More optionally, the minimum threshold and the maximum
threshold are no more than 15.degree. C. apart.
[0048] More optionally, the minimum threshold and the maximum
threshold are about 2.degree. C. apart.
[0049] According to some embodiments of the present invention there
is provided a method for thawing a blood product unit using
electromagnetic (EM) energy. The method comprises placing at least
one blood product unit in a chamber, applying EM energy to the at
least one blood product units at a time when the at least one blood
product unit comprises frozen and thawed portions, and ending the
applying when the temperature of all portions of the at least one
blood product unit is between 2.degree. C. and 15.degree. C.
[0050] Optionally, during the process no part of the blood product
exceeds 40.degree. C. or 30.degree. C. or 20.degree. C.
[0051] Optionally, no material cooling is applied during the
process.
[0052] According to some embodiments of the present invention there
is provided a method for managing blood product unit supply. The
method comprises receiving a request for at least one frozen plasma
unit and at least one cooled blood cells unit, heating the at least
one cooled blood cells unit and the at least one frozen plasma unit
to about a body temperature cumulatively in less than 3 minutes by
applying electromagnetic (EM) energy, and jointly transferring at
least one of the at least one heated cooled blood cells unit and at
least one of the at least one frozen plasma unit to allow a
transfusion thereof.
[0053] Optionally, the method comprises performing the heating in a
member of a group consisting of: an ambulance, an operating room,
and an emergency room.
[0054] Optionally, the heating comprises automatically acquiring
the frozen plasma unit and the cooled blood cells unit from a
freezing storage and automatically placing the frozen plasma unit
and the cooled blood cells unit in a heating chamber, the applying
being performed in the heating chamber.
[0055] According to some embodiments of the present invention there
is provided a method for managing blood product unit supply. The
method comprises providing a dielectric heating device and a
freezing chamber in a member of a group consisting of: an
ambulance, an operating room, and an emergency room, storing at
least one frozen blood product unit in the freezing chamber at the
member, heating the at least one frozen blood product unit to about
a body temperature in less than 3 minutes by using the dielectric
heating device in the member, and providing the at least one heated
frozen blood product unit for transfusion in the member immediately
after the heating.
[0056] According to some embodiments of the present invention there
is provided a method for managing blood product unit supply. The
method comprises receiving a request for at least one frozen plasma
unit and at least one of one or more cooled blood product units and
one or more unheated saline units, placing both the at least one
frozen plasma and the at least one of one or more cooled blood
product units and one or more unheated saline units unit in a
chamber, and applying electromagnetic (EM) energy into the chamber
thereby thawing at least the at least one frozen plasma unit
without heating the at least one of one or more cooled blood
product units and one or more unheated saline units by more than
15.degree. C.
[0057] Optionally, the applying electromagnetic (EM) energy is
terminated when the at least one cooled blood product unit and the
at least one frozen plasma unit are heated to about a body
temperature.
[0058] Optionally, at least one of one or more cooled blood product
units and one or more unheated saline units consist of one or more
packed red blood cells unit.
[0059] According to some embodiments of the present invention there
is provided a vehicle for heating blood product units. The vehicle
comprises dielectric heating device having a chamber sized and
shaped for containing at least one frozen blood product unit and
configured for applying electromagnetic (EM) energy to the at least
one frozen blood product unit, and a chassis for supporting the
dielectric heating device. The dielectric heating device is
configured to perform at least a portion of the applying
electromagnetic (EM) energy when the vehicle is on a move.
[0060] According to some embodiments of the present invention there
is provided a method of managing blood product unit supply. The
method comprises receiving a request for at least one chilled or
frozen blood product unit at a storage site, placing the at least
one chilled or frozen blood product unit in a heating device, and
transporting the at least one chilled or frozen blood product unit
within the heating device to a use site being remote from the
storage site The heating device is operated such that the
temperature of at least one of the at least one chilled or frozen
blood product unit increases during the transporting by at least
10.degree. C. in all portions thereof.
[0061] Unless otherwise defined, all technical and/or scientific
terms used herein have the same meaning as commonly understood by
one of ordinary skill in the art to which the invention pertains.
Although methods and materials similar or equivalent to those
described herein can be used in the practice or testing of
embodiments of the invention, exemplary methods and/or materials
are described below. In case of conflict, the patent specification,
including definitions, will control. In addition, the materials,
methods, and examples are illustrative only and are not intended to
be necessarily limiting.
[0062] Implementation of the method and/or system of embodiments of
the invention can involve performing or completing selected tasks
manually, automatically, or a combination thereof. Moreover,
according to actual instrumentation and equipment of embodiments of
the method and/or system of the invention, several selected tasks
could be implemented by hardware, by software or by firmware or by
a combination thereof using an operating system.
[0063] For example, hardware for performing selected tasks
according to embodiments of the invention could be implemented as a
chip or a circuit. As software, selected tasks according to
embodiments of the invention could be implemented as a plurality of
software instructions being executed by a computer using any
suitable operating system. In an exemplary embodiment of the
invention, one or more tasks according to exemplary embodiments of
method and/or system as described herein are performed by a data
processor, such as a computing platform for executing a plurality
of instructions. Optionally, the data processor includes a volatile
memory for storing instructions and/or data and/or a non-volatile
storage, for example, a magnetic hard-disk and/or removable media,
for storing instructions and/or data. Optionally, a network
connection is provided as well. A display and/or a user input
device such as a keyboard or mouse are optionally provided as
well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0064] Some embodiments of the invention are herein described, by
way of example only, with reference to the accompanying drawings.
With specific reference now to the drawings in detail, it is
stressed that the particulars shown are by way of example and for
purposes of illustrative discussion of embodiments of the
invention. In this regard, the description taken with the drawings
makes apparent to those skilled in the art how embodiments of the
invention may be practiced.
[0065] In the drawings:
[0066] FIG. 1 is a schematic illustration of a blood product
heating device for thawing and/or heating one or more blood product
units, according to embodiments of the present invention;
[0067] FIG. 2A is a flowchart showing how a blood product heating
device such as the one depicted in FIG. 1 may be operated to thaw
one or more frozen blood product units, according to exemplary
embodiments of the invention;
[0068] FIG. 2B is a graph of frequency vs. time for an exemplary
decision function, according to exemplary embodiments of the
invention;
[0069] FIG. 2C is a simplified flow chart of a method of operation
of a device according to exemplary embodiments of the
invention;
[0070] FIGS. 3A-3H are schematic illustrations exemplary portable
blood product heating devices, according to some embodiments of the
present invention;
[0071] FIG. 3I is a schematic illustration of an exemplary portable
blood product heating device having a freezing chamber, according
to some embodiments of the present invention;
[0072] FIG. 4A is a flowchart of a method for managing the supply
of blood product units for transfusion, according to some
embodiments of the present invention;
[0073] FIG. 4B is a flowchart of a method for managing the supply
of blood product units for transfusion, according to some
embodiments of the present invention; and
[0074] FIG. 5 is a method for locally preparing and providing one
or more blood product units for transfusion, according to some
embodiments of the present invention.
[0075] FIG. 6 is a method for providing one or more blood product
units and/or saline solution units for transfusion together with
one or more thawed blood product units.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0076] The present invention, in some embodiments thereof, relates
to method and system for heating blood product units and, more
particularly, but not exclusively, to method and system for heating
blood product units using electromagnetic energy.
[0077] According to some embodiments of the present invention,
there is provided a device and a method for thawing and heating one
or more frozen and/or cooled blood product units, such as plasma,
with or without additives, for example cryoprecipitate, and blood
cells units, for example packed red blood cells and/or saline
units, to about a body temperature in less than three minutes, for
example in about a minute or less. A cryoprecipitate, is normally a
precipitate that results from cooling or even freezing of plasma,
and is often administered in a mixture with fresh frozen plasma.
The device includes a chamber that is sized and shaped for
containing blood product units, for example 1, 4, 7, 12, and/or any
intermediate number. Optionally, the blood product units are placed
on a unit positioning element, optionally detachable from the
chamber. It should be noted that as the heating pattern may be
determined by an analysis of the absorption of different
frequencies, the placement of the blood product units may not have
to be predefined and/or exact. The device further includes a
dielectric heating unit that applies electromagnetic (EM) energy at
a plurality of frequencies to the blood product units in the
chamber. The dielectric heating unit is operated by a controller.
Optionally, the operation is performed according to a heating
pattern that allows heating the blood product units to about a body
temperature in less than 3 minutes. Optionally, the thawing is
performed as described in U.S. 61/193,248 ('248), which is
incorporated herein by reference. Optionally, the device is a
portable device. Optionally, the device is sized and shaped for
being positioned in an ambulance, a trauma room, an operating room
(OR), and/or emergency room (ER) or any other location that is
remote from a blood bank (e.g. near or within an intensive care
unit or conventional hospital ward) without taking much space.
[0078] According to some embodiments of the present invention
there, is provided a method for managing a supply of blood product
units, optionally frozen. The ability to heat a blood product unit
to a body temperature in less than 3 minutes allows heating plasma
and red blood cells blood product units in a ratio of 1:1 upon
request and providing them for transfusion immediately. Optionally,
the blood product units are heated at a blood bank and provided,
optionally simultaneously, to a trauma room, an operating room
(OR), and/or emergency room (ER). In other embodiments the blood
product units are provided to the transfusion site, for example at
the trauma room, the operating room (OR), and/or the emergency room
in a frozen or cooled form and thawed and/or heated at the
transfusion site. In other embodiments the blood product units are
locally stored and heated at the transfusion site, for example at
the trauma room, the operating room (OR), and/or the emergency
room. In other embodiments, a portable device is capable of
completing the thawing and/or heating of the blood product units
during transit from the site of storage to the site of transfusion.
As the heating process is prompt and the size of the heating
device, and optionally a freezing chamber that is used for storing
the blood product units, is relatively limited, blood product units
may be locally stored at the transfusion site. Such storage reduces
the time needed for providing a blood product unit at a temperature
which is ready for transfusion.
[0079] According to some embodiments of the present invention,
there is provided a method for heating a plurality of frozen blood
product units. First, the frozen blood product units are placed in
a heating chamber. Then, EM energy is applied to thaw and heat the
frozen blood product units, optionally at a plurality of different
frequencies. Now, the temperature of each one of the frozen blood
product units is measured. This allows ending the EM energy thawing
and/or heating processes when the temperature of each one of the
frozen blood product units is above a minimum threshold (e.g.
25.degree. C. or more, 30.degree. C. or more, 35.degree. C. or more
or even 37.degree. C.). Such a method allows expediting the thawing
and/or heating processes while assuring that all the frozen blood
product units are in a requested temperature, such as about a body
temperature (e.g. between 30 and 37.degree. C. or between 35 and
38.degree. C.). Optionally, the thawing and/or heating processes
may be ended if any of the frozen blood product units is above a
maximum threshold (e.g. 25.degree. C. or more, 30.degree. C. or
more, 35.degree. C. or more or even 37.degree. C. or more). In such
an embodiment, the quality of the frozen blood product units cannot
be affected by overheating.
[0080] According to some embodiments of the present invention, a
device and a method are provided for thawing and/or heating one or
more frozen and/or cooled blood product units which remain
stationary during the thawing and/or heating. For brevity, a cooled
blood product unit means a frozen blood product unit, for example
in a temperature of -30.degree. C. or below and/or chilled or
cooled blood product unit, for example in a temperature between
about 0.01.degree. C. and about 10.degree. C.
[0081] According to some embodiments of the present invention,
there is provided a device and a method for thawing and/or heating
one or more frozen and/or cooled blood product units on a move, for
example during the transportation of the cooled blood product units
from a blood bank to a transfusion site. Optionally, the device is
a designated cart having a heating device integrated thereon.
[0082] Before explaining at least one embodiment of the invention
in detail, it is to be understood that the invention is not
necessarily limited in its application to the details of
construction and the arrangement of the components and/or methods
set forth in the following description and/or illustrated in the
drawings and/or the Examples. The invention is capable of other
embodiments or of being practiced or carried out in various
ways.
[0083] Reference is now made to FIG. 1, which is a schematic
illustration of a blood product heating device 100 for thawing
and/or heating one or more blood product units, according to an
embodiment of the present invention. The blood product heating
device 100 integrates a dielectric heating unit 11 for thawing
and/or heating one or more blood product units 12 which are placed
in a chamber 13. The dielectric heating unit 11 is constructed and
operated as described in one or more of the patent applications
which are included Table 1 below, with one or more of the changes
as detailed below. Optionally, the dielectric heating unit 11
includes one or more EM generators and one or more feeds for
dissipating EM energy in the chamber 13, optionally at a plurality
of frequencies. The chamber 13 is sized and shaped for containing
one or more blood product units 15. The blood product units 15 may
be simply placed at any position in the chamber, or alternatively
they may be placed in marked places or specially shaped recesses,
etc.
[0084] Optionally, the blood product heating device 100 is a
portable device sized and shaped to be easily or conveniently
transported. Optionally, the dimensions of the blood product
heating device 100 are similar to the dimensions of a conventional
desktop printer, for example about 25 cm wide, about 35 cm length,
and about 20 cm height. Such dimensions allow placing the blood
product heating device 100 in an ambulance, a trauma room, an
operating room (OR), and/or emergency room (ER) without taking much
space. As depicted in FIGS. 3A-3H, various housings may be designed
for containing the blood product units 15.
[0085] According to some embodiments of the present invention, the
power source of the EM energy is external to the blood product
heating device 100. For example, the power source may serve a
number of blood product heating devices 100 which are located in
different transfusion sites in a hospital and/or a medical center
and/or placed externally to the transfusion site, for example on
the roof and/or in a machine room, for saving space and/or
facilitate the maintenance and sterilization procedures. See '199,
which is incorporated herein by reference for similar embodiments
and implementations. At other times, the power source may be
portable and attached to the product heating device 100 such that
the device may be moved and operated at the same time. It should be
noted that when the energy source is attached to the blood product
heating device 100, a cart may be used for easier locomotion of the
device.
[0086] For clarity, as used herein, a dielectric heating unit 11
means a unit that uses radio frequency (RF) radiation for thawing,
heating and/or causing any change in the temperature to a saline
solution unit or a blood product unit that is placed in the chamber
13, such as a dose of plasma, a dose of red blood cells, and/or a
combination thereof. For clarity, a dose or a unit of red blood
cells may be a standard RBC unit or a standard saline solution unit
or a standard fresh frozen plasma unit. Normally, such blood
product units contained in bags and have a thickness of about 1-2
cm around the mid section. For example, the dielectric heating unit
may be defined as described in one or more of the documents listed
in Table 1 below, all of which are incorporated herein by
reference:
TABLE-US-00001 TABLE 1 hereinafter Ser. No. Country Title '235
IL2007/000235 PCT Electromagnetic heating '236 IL2007/000236 PCT
Electromagnetic heating '864 IL2007/000864 PCT Food preparation
'231 IL2008/000231 PCT Drying apparatus and methods and accessories
for use therewith '073 IL2007/001073 PCT RF controlled freezing
'201 61/064,201 USA A method and a system for a modular device '431
12/230,431 USA Dynamic impedance matching in RF resonator chamber
13 '592 12/153,592 USA Electromagnetic heating '248 61/193,248 USA
Device and method for thawing using RF energy '799 61/230,799 USA
Method and system for dielectric heating and cooking '199
IL2009/000199 PCT A method and a system for a modular device
[0087] As depicted in FIG. 1, the blood product heating device 100
includes a controller 14. Optionally, the controller 14 operates
the dielectric heating unit 11 according to thawing and heating
patterns which are adapted for the thawed and/or heated blood
product units, for example red blood cells (e.g. packed red blood
cells) and/or plasma. Optionally, the controller 14 operates the
dielectric heating unit 11 so that the blood product units 15 are
heated to about a room temperature in less than 3 minutes,
optionally in less than 1 minute. For brevity, thawing and heating
may be referred to herein as heating.
[0088] Exemplary Thawing
[0089] Attention is drawn to FIG. 2A, which depicts a flowchart 20
showing how the blood product heating device 100 may be operated to
thaw a frozen load, such as a frozen blood product unit, according
to exemplary embodiments of the invention. A more elaborated
discussion pertaining to this exemplary thawing may be found in
'248, which is incorporated herein by reference.
[0090] After the one or more blood product units 15 are placed in
chamber 13, a sweep 21 is performed. Sweep 21 may comprise one or
more sweeps, allowing the obtaining of an average of several
sweeps, thereby obtaining a more exact result. Additionally or
alternatively, sweep 21 may be repeated with different field
adjusting elements (FAE) properties or different load/plate
positions (optionally the sweep is performed several times at each
configuration). An FAE is any element within the chamber that may
affect the results of sweep 21. Accordingly, an FAE may include for
example, any object within the chamber, including one or more of
metal components within the chamber, an antenna, or even a blood
product unit. The position, orientation, shape and/or temperature
of an FAE are optionally controlled by controller 14. In some
embodiments of the invention, controller 14 is configured to
control several consecutive sweeps. Each sweep is performed with a
different FAE property (e.g., changing the position or orientation
of one or more FAE) such that a different spectral information may
be deduced. Controller 14 may then select the FAE property based on
the obtained spectral information.
[0091] In order to improve the accuracy of the analysis of the
sweep results, in an exemplary embodiment, the amount of power that
is actually transmitted (e.g. if the power transmitted at different
frequencies is not identical) at each frequency is included in the
calculation, in order to deduce the percent of transmitted energy
that is dissipated in the chamber 13.
[0092] Once one or more sweep results are obtained, an analysis 22
is performed. In analysis 22 a thawing algorithm is used to define
the transmission frequencies and the amount of energy to be
transmitted at each frequency, based on the spectral information
that was obtained at sweep 21. Consequently, energy 23 is
transmitted into the chamber 13, optionally as dictated by analysis
22. Optionally, the desired dissipated power is below the expected
power which is below the maximum power multiplied by the
dissipation ratio.
[0093] In an exemplary embodiment of the invention, the one or more
blood product units 15 are scanned 120 times in a minute. Higher
(e.g. 200/min, 300/min) or lower (e.g., 100/min, 20/min, 2/min,
10/thawing time, 3/thawing time) rates may be used, as well as
uneven sampling rates. In some cases, the information is provided
using other means, such as an RF/bar-code readable tag (e.g., with
previous scanning information or thawing presets) or using
temperature sensors.
[0094] In an exemplary embodiment of the invention, the rate of
sweeping depends on the rate of change in spectral information
between sweeps, for example, a threshold of change in dissipation
and/or frequencies (e.g., a 10% change in sum integral) may be
provided or different change rates associated with different sweep
rates, for example using a table. In another example, what is
determined is the rate of change between sweeps (e.g., if the
average of the changes between sweeps was less than the change
between the last two sweeps). Optionally or alternatively, changes
in the system (e.g. movement of the plate) may affect the sweep
rate (typically major changes increase the rate and minor or no
changes decrease it).
[0095] This process is optionally repeated for a predetermined
period of time or until termination by a user. Alternatively, the
thawing process may be terminated automatically 24. At 24, which
may be performed after each sweep, before each energy transmission
and/or at any other stage of the process, sweep results and/or a
sensor reading are used to decide whether or not thawing may be or
should be stopped. For example--if a phase change completion is
detected or if the object's temperature is measured to be above a
given temperature (e.g. outer temperature 5.degree. C. or more),
thawing may be terminated. In another example, if the total energy
dissipated into the one or more blood product units 15 reaches a
predetermined amount of energy that is needed for thawing to a
desired final temperature (e.g., taking into account the initial
temperature and composition of the one or more blood product units
15, thawing may be stopped.
[0096] The transmission parameters for thawing, comprising
(frequency/power) pairs, are optionally selected to increase (or
even maximize) energy dissipation in frequencies that have low
dissipation ratios in the one or more blood product units 15 (e.g.
predominantly solid or ice portions) and reduce (or even minimize)
energy dissipation at frequencies that have a relatively high
dissipation ratio (e.g. predominantly thawed portion, such as
liquid or water). For example, in low dissipation ratios, the
device will be set to produce efficient power dissipation (e.g., as
a factor of the possible maximal dissipation possible) while at the
high dissipation ratios, the device will be set to dissipate much
less energy than may be dissipated.
[0097] An exemplary thawing algorithm transmits zero power at
frequencies with dissipation ratio above a predetermined threshold
(e.g. 70% dissipation) of the maximum dissipation ratio in the
selected working frequency range [f.sub.1, f.sub.2] and non-zero
powers at other frequencies of that range. In some cases, the
powers are selected in a binary fashion--either maximal or minimal.
Alternatively, intermediate power levels are provided, for example
for portions with intermediate dissipation levels.
[0098] In an exemplary embodiment of the invention, the device
includes a memory having stored thereon a plurality of threshold
values, hpl values, dissipation/power ratios and/or parameters for
various properties of the one or more blood product units 15.
Optionally, the device and/or the user select between such stored
options as an initial setting or as a final setting for thawing.
For example, a fixed hpl of 80% (of the maximal power of the
amplifier at each frequency) may be used for frozen bovine meat of
a certain weight.
[0099] Exemplary Thawing Algorithm
[0100] An exemplary thawing algorithm is the following. In a
selected working range [f.sub.1, f.sub.2], high and low boundary
powers (hpl, lpl) are selected and any applied power is maintained
between these boundaries.
[0101] The boundary low power level (lpl) is the minimum power
level where dissipation in the one or more blood product units 15
is high enough to be useful. For example, if 15% is selected to be
the minimal useful dissipation, lpl will be set for each frequency
to be 15% of the maximal power that may be transmitted.
Alternatively it may be set at a pre-selected low power for all
frequencies (e.g., 60 Watts or less) or any combination of the
aforementioned; if the dissipation in the one or more blood product
units 15 at a given frequency is below lpl, the transmitted power
at that frequency will be set at zero.
[0102] The boundary high power level (hpl), determines the highest
allowed dissipated power. This means that the highest power
outputted is constrained to avoid undesired thermal effects. In
addition, the actual power outputted at a given frequency may be
selected according to spectral information, in particular, to
selectively target unthawed areas. Optionally, the power levels are
generally inversely related to dissipation. As may be noted,
reducing maximum oven power will generally lengthen thawing times.
In some cases, the power levels applied meet binary criteria: hpl
for low dissipating portions and some other value (such as zero)
for high dissipating areas.
[0103] Using an excessively high hpl may cause an unacceptable
uneven temperature distribution in the one or more blood product
units 15 and may result in thermal runaways. The more sensitive a
load is to transmitted power (e.g., at a certain working band), the
lower would be the power of an acceptable hpl. Optionally, the
working band is selected according to which working band better
distinguishes water from ice.
[0104] Generally, for sensitive blood product units 15, a low hpl
is set, but such hpl may be used also for less sensitive blood
product units 15, albeit at the cost of increasing the thawing
time. Nonetheless, at times it may be preferred to set for each
load the highest hpl that would provide an acceptable post thaw
temperature distribution in the load (e.g. .+-.15.degree. C.,
.+-.10.degree. C., .+-.5.degree. C., .+-.2.degree. C. or even more
uniform). The acceptable post thaw temperature distribution can
depend, for example, on one or more of the composition of the one
or more blood product units 15, and its sensitivity to overheating
(e.g. whether damage is caused; its extent and reversibility; and
to what extent the damage is material). It is noted that at times,
speed of thawing is preferred over quality, in which case a higher
hpl may be used, and the post thaw quality would be suboptimal.
These factors have an effect on the quality score of the heated
and/or thawed one or more blood product units 15, for example as
described below.
[0105] Optionally, the device is provided with a user selectable
tradeoff (e.g., knob or data input) between uniformity, maximum
temperature and/or rate of thawing.
[0106] It is noted that in accordance with some embodiments of the
invention, prevention of hot spots is actively preferred over
uniformity of thawing, heating and/or energy dissipation.
[0107] Optionally, hpl is set low enough so that a thawed section
will not be over heated before heating at its respective
frequencies is stopped or reduced.
[0108] Exemplary Methods of Determining hpl (High Power Level)
[0109] hpl may be determined in various manners, for example, by
trial and error. In an exemplary embodiment of the invention,
several hpl settings are tried to determine the maximal hpl which
would provide an acceptable temperature distribution in the one or
more blood product units 15, post thawing. Such trials may continue
during thawing, for example, being performed every scan, every
second or every minute or at intermediate time scales. In an
exemplary embodiment of the invention, hpl is started at low values
and increased gradually. Optionally, the hpl is set per item
type.
[0110] In an exemplary embodiment of the invention, preset hpl
values are provided for various combinations of properties of the
blood product units 15, such as one or two or more of shape,
weight, temperature, desired effect and/or bag's material type.
Optionally, a user selects properties and the device suggests
and/or uses an hpl accordingly.
[0111] Optionally, hpl is updated periodically during thawing.
[0112] In an exemplary embodiment of the invention, hpl is
estimated (initially or in an ongoing manner) with the assistance
of changing the blood product units 15 and/or chamber 13 so that
more useful spectral information is acquired. In general, if the
acquired spectral information is better, a better cut-off between
ice and water may be identified, allowing a higher hpl to be used
for the ice sections and a faster heating at a same quality (e.g.,
evenness) and/or a higher quality heating at same speed.
[0113] Alternatively, and while not wishing to be bound by theory,
it is proposed that the sensitivity of the blood product units 15
may be determined based on the relative dissipation of energy in
thawed and frozen portions of the blood product units 15. When the
dissipation in frozen portion and thawed portion is relatively
similar (e.g. 10-15% dissipation difference, such as between 40%
and 50% dissipation ratio) (e.g. due to low water content), the
sample is deemed to be of high sensitivity (e.g., the distinction
between ice and water requires a more sensitive determination). The
greater the disparity is between dissipations in thawed and frozen
parts, the lower the sensitivity of the blood product units 15.
Therefore, hpl may be determined by obtaining the spectral
information of the blood product units 15 and comparing the maximal
dissipation (d.sub.max) with the minimal dissipation (d.sub.min) in
a working frequency band. The greater the difference is between
d.sub.min and d.sub.max the lesser the sensitivity of the blood
product units 15, and higher the hpl that should optionally be
used.
[0114] It is noted that the hpl may be allowed to be higher if a
better selection of power to intermediate dissipation frequencies
is provided.
[0115] Also alternatively, and while not wishing to be bound by
theory, it is proposed that hpl may be determined based on the
maximum power that can be dissipated in the blood product units 15
at each frequency (ep(f)) and ldl. hpl may be set to be such that
the portion of the frequencies being used, for example all
frequencies within a working band (e.g. the band spanning 800-1000
MHz)) (or other set of frequencies) that are considered to
dissipate into the blood product units 15 and for which
lpl<ep(f)<hpl would be less than a preset threshold. For
example, this threshold may be selected to be 10% or 20% or 30% or
any value in-between. Optionally, this method is based on a
realization (and/or for cases that) that the device is typically
limited in maximum power and that practically, the closer the hpl
is to the maximum power, the less easy it may be to provide
different power levels at different, near, frequencies. Optionally,
the percentage depends on a desired tradeoff between quality and/or
speed.
[0116] Accordingly, a thawing protocol may use a single hpl value
(e.g. if dedicated to blood product units 15 having similar
sensitivity; or a low hpl that would be suitable for most
contemplated blood product units 15). Alternatively, the protocol
may use a selection between several possible hpl values (e.g. a
selection between a number of preset values or optionally setting
the value manually or automatically to correspond to a given load,
for example a certain blood product unit and/or acceptable post
thaw temperature distribution). Finally, the protocol may use any
value (e.g. calculated automatically or selected manually) within
the power capabilities of the device. An example of a relatively
high hpl may be 300 Watt or 80% of the maximal power from the
amplifier at that frequency. An example of a relatively low hpl may
be 120 Watts or 30% of the maximal power from the amplifier at that
frequency. Interim values are possible as well.
[0117] Exemplary Determination of Dissipation Function dr(f)
[0118] dr(f) denotes the dissipation ratio as a function of
frequency, namely the percentage of transmitted power through each
feed (e.g. feed j) that is dissipated in the blood product units
15. This function has potential values between 0 and 1, and is
optionally computed as shown in Equation 1, based on the measured
power and using measured spectral information. However, as noted
herein, a binary function or non-linear and/or non-monotonic
function may be used (e.g., and determined in a factory or during
calibration).
dr j ( f ) = P incident , watt j ( f ) - i P returned , watt ( i )
( f ) P incident , watt j ( f ) = 1 - i P returned , watt ( i ) ( f
) P incident , watt j ( f ) ( eq . 1 ) ##EQU00001##
[0119] Normalization of dr(f)
[0120] The dissipation ratio in frozen portions (e.g. ice) is
relatively lower than that of the thawed portions (e.g.
liquid/water), but a large amount of ice can show considerable
dissipation. In order to distinguish dissipation in at frequencies
having a low dissipation ratio (e.g. ice) from dissipation at
frequencies having a high dissipation ratio (e.g. liquid water),
while reducing the effect of relative mass, the dr(f) function is
optionally normalized to the whole range between 0 and 1; This
normalization may be useful also in other cases where the
difference between dissipation in frozen portions and thawed
portions is relatively small, regardless of the cause (e.g., low
water content). The normalized function--dr'(f)--may be used to
calculate the compensation factors, as shown below.
drh=min{dr(f)}.sub.f.di-elect cons.[f.sub.1.sub.,f.sub.2.sub.]
drl=max{dr(f)}.sub.f.di-elect cons.[f.sub.1.sub.,f.sub.2.sub.]
dr'(f)=(dr(f)-drl)/(drh-drl) (eq. 2)
[0121] In case of some blood product units, the use of dr'(f) is
optionally avoided, and in original dr(f) used instead. Optionally,
a device is configured to have both protocols for alternative use.
The choice between the protocols may be based on user input (e.g.
user interface or machine readable tags) or on a sensor reading
within the device (e.g. a weight sensor). Alternatively, dr'(f) may
be used for all blood product units 15.
[0122] The maximum power that can be dissipated in the blood
product units 15 at each frequency (depicted as ep(f)) is
optionally calculated as follows, given that P.sub.maximum j, watt
is a maximum power available from the amplifier at each
frequency.
ep.sub.j(f)=dr.sub.j(f)P.sub.maximum,j,watt(f) (eq. 3)
[0123] Using the above, the compensation function (coeff(f)) is
optionally calculated. This function is optionally used to
determine the relative amount of energy that should dissipate in
the blood product units 15
[0124] at each frequency, as a function of dr'(f), for example as
shown in eq. 4A:
coeff ( f ) = F ( dr ' ( f ) ) ( eq . 4 ) F ( dr ( f ) ' ) = { dr '
< 3 0 dr ' > 0.8 1 Else - 2 dr ' + 1.6 ( eq . 4 A )
##EQU00002##
[0125] In an exemplary embodiment of the invention, frequencies may
be classified as "ice", "water" and/or "mixed ice/water" according
to their dissipation ratio. Optionally, higher power is provided
into ice and mixed ice/water and plain water is provided with low
or no power.
[0126] Optionally, there is provided a dissipation threshold below
which the dissipation into the blood product units 15 is so low
that no power is transmitted, as the blood product units 15 portion
is assumed to not be ice. In an exemplary embodiment of the
invention, the device is designed to have a very low intrinsic
dissipation at any frequencies or a known dissipation at only some
frequencies (where the threshold may then be raised).
[0127] It is noted that large pieces of ice may have a relatively
high dissipation. Optionally, if there are no (or few, e.g., below
a threshold) low-dissipation frequencies and it is known that the
blood product units 15 is frozen, then it is assumed that the
lowest dissipation frequencies are ice and power (at regular or
somewhat reduced levels) is provided at such frequencies, until
lower dissipation frequencies appear, indicating the formation of
smaller frozen regions.
Example dr(f)
[0128] An example for a function according to Equation (4) is
depicted in FIG. 2B. As can be seen, two limits are set. At
frequencies that dissipate into the blood product units 15 less
than a pre-set threshold (e.g. dr'(f)<0.3 in the example of FIG.
2B) the maximal allowed power which is a minimum between the
ep(f)/dr(f) and hpl(f)/dr(f) will be transmitted. At frequencies
that will at dissipate into the blood product units 15 more than a
pre-set value (e.g. dr'(f)>0.8 in the example of FIG. 2B) no
energy will be transmitted. At all other frequencies
(0.3<dr'(f)>0.8 in the example of FIG. 2B) the power
transmission will be calculated using the selected function. In the
case of FIG. 2B this was a generally linear function, but other
functions, optionally non-linear, may be used that provide an
inverse correlation between dr'(f) and coeff(f) (e.g. exponential,
step function, piecewise linear, polynomial and/or general look-up
table, optionally with interpolation). Optionally, the function
prefers applying power to low-dissipation areas to an extent
greater than a simple inverse function. Optionally, the function is
selected based on a perceived risk of damage to the blood product
units 15.
[0129] Exemplary Actual Power Calculation
[0130] gl(f) is the power to be dissipated in the object to be
heated, taking into consideration the maximum power that can be
dissipated in the blood product units 15 at each frequency (ep(f))
and hpl(f) and the compensation function (coeff(f)), as
follows:
gl ( f ) = { hpl < ep ( f ) hpl coeff ( f ) lpl < ep ( f )
< hpl ep ( f ) coeff ( f ) else 0 ( eq . 5 ) ##EQU00003##
[0131] Using gl(f) the power to be transmitted from the amplifier
(nopw(f)) in order to cause the desired dissipation in the blood
product units 15, at each frequency, is optionally calculated as
follows:
nopw(f)=gl(f)/dr(f) (eq. 6)
[0132] nopw(f) will always be lower than P.sub.maximum,j,watt(f),
which is the maximum power extractable from an amplifier at each
frequency for the following reason:
gl ( f ) = { hpl < ep ( f ) hpl coeff ( f ) lpl < ep ( f )
< hpl ep ( f ) coeff ( f ) else 0 max { gl ( f ) } = ep ( f )
coeff ( f ) = dr ( f ) P maximum , j , watt coeff ( f ) max { nopw
( f ) } = max { gl ( f ) } / dr ( f ) = P maximum , j , watt coeff
( f ) ( eq . 7 ) ##EQU00004##
[0133] Calculation of hpl Using Average Dissipation
[0134] FIG. 2C shows hpl being calculated as a function of the
average dissipation ratio within the working band or within the
selected frequencies. Optionally, this is based on the assumption
that a low average dissipation means a high sensitivity and vice
versa. Other functions may be used as well, for example, a table
matching hpl to average dissipation.
[0135] As seen in the graph, a low average dissipation ratio
indicates a high sensitivity of the blood product units 15 and
accordingly dictates a low hpl. The low value of hpl is optionally
selected to be slightly above lpl (to provide a minimal working
range). For example, the minimal hpl value may be between 70 and
120 Watts (e.g. 80 Watts). The maximal level of hpl may be chosen
to be as high as the maximal possible amplifier power or slightly
below that. As seen in FIG. 2C, when the average dissipation ratio
is below a preset lower limit, hpl is selected to be the lowest hpl
allowed, and when the average dissipation ratio is above a preset
upper limit, hpl is selected to be the highest hpl allowed. The
lower limit for average dissipation ratio may be, for example,
between 0.1 and 0.3 (e.g. 0.2) while the upper limit may be for
example between 0.5 and 0.9 (e.g. 0.6).
[0136] In-between values of average dissipation optionally dictate
an intermediate hpl value. It is to be appreciated that while FIG.
2C depicts a generally linear correlation for the intermediate
average dissipation ratio values, other functions, optionally
non-linear, may be used that provide a positive correlation between
the average dissipation ratio and hpl (e.g. exponential, step
function, polynomial, step-wise linear).
[0137] In some cases, the frequency distribution is in frequency
bands, so that one band can be recognized as matching ice (e.g.,
low dissipation) and another matches water (e.g., high
dissipation). Optionally, instead or in addition to calculating
hpl, gl(f) is set to be zero or at lpl (or any other preset low
value) for bands associated with water and at any preset high value
(e.g. hpl or a maximum available power or other setting) for
ice-associated bands. Optionally, the classification of bands as
water/ice is updated optionally periodically based on spectral
information that is periodically acquired.
[0138] While particular ways of calculating hpl and gl(f) are
described above, the methods can be combined, for example,
arithmetically or logically, for example, using an average value of
several methods or using a minimum or maximum or multiple methods.
For example--a Gaussian function of dr(f) (or of dr'(f)) may be
used to calculate gl(f).
[0139] According to some embodiments of the present invention, the
controller 14 collects data documenting thawing and/or heating
processes. Optionally, the collected data is stored in a
repository, such as a flash memory. The documented data is
collected using a measurement of the efficiency of absorption of
energy in one or more blood product units being heated as function
of frequency. Optionally, the controller 14 controls one or more
characteristics of the thawing process, for example the amount of
power absorbed in the heated one or more blood product units, based
on the collected measurement of energy absorption efficiency (for
example, by transmitting power to compensate for the variations of
energy absorption and/or variations of energy transmission). This
may be done by adjusting, for example, input power at each
transmitted frequency and/or choosing frequencies to be transmitted
and/or adjusting (for example, moving or rotating) one or more
field adjusting elements and/or moving the heated one or more blood
product units and/or changing antenna characteristics. This may be
done before operation, and/or at times also one or more times
during operation (for example, several times a second), based on
measurements of energy absorption during heating or during a short
hiatus in the heating.
[0140] Optionally, the controller 14 operates the dielectric
heating unit 11 according to reading of dielectric characteristics
of one or more blood heated units. Reading may be obtained one or
more times during heating (for example, several times a second).
For example, end of thawing process, when a phase change is sensed.
This can implement a cessation of heating. For brevity, heating of
a frozen blood product unit that contains plasma may include
thawing and heating of a cooled blood product unit that contains
red blood cells may include heating.
[0141] Reference is now also made to FIG. 3A, which is a schematic
illustration of an exemplary portable blood product heating device
100, according to some embodiments of the present invention.
Similarly to FIG. 1, the portable blood product heating device that
is depicted in FIG. 3, the blood product heating device 100
includes a chamber 205 and a controller and a dielectric heating
unit (not shown) that allows the thawing of one or more blood
product units (not shown). FIG. 3 further depicts an optional touch
screen 100 that allows controlling the thawing and/or heating
processes. It should be noted that any other man machine interface
(MMI) may be used for controlling the blood product heating device
100, for example a keypad, a keyboard, a set of buttons and the
like. In fact, in some embodiments, a dedicated device may be
operable with no MMI, whereby for example by closing the device
with a load in the device, the device will automatically perform a
predetermined protocol (thaw and/or warm) and terminate
automatically.
[0142] The blood product heating device 100 may further include a
unit positioning element, e.g. a tray, that is sized and shaped to
support a blood product unit, for example a bag containing 145-285
cubic centimeter (CC) of plasma. Alternatively, the bag may contain
between 40-500 ml of a blood product or even between 40-1,000 ml,
or a volume higher than 1 liter. Optionally, the bag may have
irregular shape and/or irregular width (being thicker at some
portions and thinner on others). Bag thickness may be for example
above 1 cm, above 3 cm or even 5 cm or 6 cm or more, or any
intermediate value or range. In thickness it is meant the minimum
dimension of the bag, between length width and thickness.
Optionally, a tray that is sized and shaped for supporting a number
of blood product units may be used, for example 2, 4, 6, 8, 10
and/or any intermediate number may be used. Optionally, the tray is
detachable, allowing replacing the tray that is placed in the
chamber 205 of the blood product heating device 100. For example, a
tray for 1 blood product unit may be replaced with a tray for a
plurality of blood product units and vice versa. Optionally, the
unit positioning element is extracted from the chamber so as to
ease the mounting and/or the dismounting of one or more blood
product units thereon and/or therefrom, for example as shown at
FIG. 3B.
[0143] It should be noted that other unit positioning elements may
be used, for example designated containers which are sized and
shaped to be placed in the chamber 13 and/or as depicted in FIGS.
3C-3H. As described above, the thawing and/or heating pattern may
be dynamically determined according to the absorption of different
frequencies. In such embodiments, the blood product units may not
have to be placed in exact locations. The heating pattern is
determined dynamically according to the properties of the blood
product units in the chamber 13 and therefore the operator does not
have to spent time on the exact positioning thereof in order to
achieve optimal outcomes.
[0144] In some embodiments of the present invention, the blood
product heating device 100 includes an actuation unit for
maneuvering the blood product units during the heating and/or the
thawing processes. Optionally, the actuation unit is connected to
the unit positioning element and configured for move it so as to
shake, stir, agitate spine, and/or vibrate, the blood product units
which are mounted thereon, repeatedly or intermittently.
[0145] Optionally, the vibrations are applied after the thawing of
the blood product units and/or during the heating of blood product
units, for example after a temperature of around 5.degree. C. is
detected in some or all of the blood product units. The vibrations
may be applied contentiously and/or intermittently. At times, the
device may be configured not to apply vibrations at least during a
portion of the time when EM energy is applied. This may in fact be
a significant portion of the heating (measured in time or energy).
For example--at least 25%, at least 50% or even at least 80% of the
irradiation may be performed at a time that the blood product
unit(s) remain stationary.
[0146] In some embodiments of the present invention, the blood
product heating device 100 integrates a temperature sensor for
measuring the temperature of the heated blood product units. Such a
temperature sensor may provide the base temperature and/or used for
monitoring the heated blood product units. Optionally, the
temperature sensor comprises a sensor, for example an infrared
temperature sensor, such as the OS101 Series Miniature Low-Cost
Non-Contact Infrared Temperature Sensor/Transmitter from NEWPORT
and an infrared temperature sensor such as the OS136 Series
Miniature Low-Cost Non-Contact Infrared Temperature
Sensor/Transmitter from OMEGA Engineering. The temperature sensor
may be used for monitoring and/or adjusting the heating process
and/or the heating pattern.
[0147] According to some embodiments of the present invention, the
controller 14 ends the heating process according to the temperature
of the one or more blood product units. The temperature may be
estimated according to the outputs of the aforementioned
temperature sensor and/or according to temperature sensing elements
which are attached to the blood product units, for example as
described below. When a number of blood product units are heated,
the controller 14 separately monitors the temperature of each one
of them.
[0148] Optionally, the controller 14 changes the dissipation of
electromagnetic (EM) energy in the chamber according to the
temperature of the blood product units. In such a manner, the
heating of the blood product units may be more uniform, for example
as described in the documents listed in Table 1. Optionally, the
dissipation is changed by one or more properties of one or more
FAEs in chamber 13.
[0149] Optionally, if the temperature of all the blood product
units is above a predefined range, the heating process ends. In
such a manner, all the blood product units are heated to the
predefined range during a certain heating session. Additionally or
alternatively, the heating process stops if the temperature of any
of the blood product units is increased above the predefined range
and/or any other threshold. For example, the heating stops as all
the blood product units are above a minimum threshold of 25.degree.
C. or more, 30.degree. C. or more, 35.degree. C. or more or even
37.degree. C. or more. In such a manner, all the frozen blood
product units may be in a requested temperature, such as about a
body temperature, for example between 30 and 37.degree. C. or
between 35.degree. C. and 38.degree. C. Optionally, the thawing
and/or heating processes may be ended if any of the frozen blood
product units is above a maximum threshold, for example 25.degree.
C. or more, 30.degree. C. or more, 35.degree. C. or more or even
37.degree. C. or more. In such an embodiment, the quality of the
frozen blood product units cannot be affected by overheating.
[0150] As commonly known, blood product units, such as plasma
units, and at times also red blood cell units, are stored in
temperatures below -18.degree. C. For example, standardized fresh
frozen plasma units of 300 g can be stored for up to one year at
-30.degree. C. or below and are only thawed immediately prior to
use. In use, the blood product heating device 100 is designed for
thawing and heating the one or more frozen blood product units
which are placed in the chamber 205. As the blood product heating
device 100 may use a dielectric heating unit as described in one or
more of the documents listed in Table 1, the blood product unit may
be heated to a temperature of about 37.degree. C. in less than 3
minutes, for example 1 minute or less. Such heating allows rapidly
and safely thawing blood product units and raising their
temperature to about a body temperature, for example 30-37.degree.
C., without damaging the blood product unit or risking the blood
product unit and the blood bank or hospital staff with
contaminations which are a concern with warm water baths. It should
be noted that by increasing the temperature of the blood product
unit to about body temperature the blood product heating device 100
may allow the immediate transfusion thereof. A transfusion of blood
in lower temperatures may reduce the temperature of the recipient,
which is usually in a trauma situation. Such a temperature
reduction may cause hypothermia or worsen it. Hypothermia may
complicate a patient's condition, for example by inhibiting
coagulation and/or clot formation and/or result in blood loss.
[0151] Optionally, dielectric heating unit 11 allows heating one or
more blood product units 14 so that the temperature of each blood
product unit is uniform within 10.degree. C., 6.degree. C.,
4.degree. C. or 2.degree. C. when heating is completed, even if
each blood product unit has an irregular shape and/or composition
and/or is positioned at a random, irregular and/or non-exact
location or position in chamber 13. Exemplary embodiments may
provide this uniformity by directly RF thawing and/or heating each
blood product unit such that over 50% of the thawing and/or heating
are by direct RF heating and not by conduction from other portions
of the device. In some embodiments of the invention, such direct RF
thawing can reach 70, 80, or 90 or more percent.
[0152] Optionally, dielectric heating unit 11 transmits frequencies
and/or power via one or more feeds (e.g. antennae) that are
installed in the chamber. These frequencies and/or power are varied
in a controlled manner to produce a desired heating pattern (for
example, by more than 1, 2 or 5 MHz). This variation may occur
several times during operation (for example, several times a
second). In an embodiment of the invention, the desired pattern is
a uniform heating pattern.
[0153] Optionally, dielectric heating unit 11 includes multiple
inputs in which the frequencies of the inputs are different by more
than 5, 10 or 25 MHz. Optionally, dielectric heating unit 11
includes multiple inputs in which the frequencies of at least one
of the inputs changes dynamically during heating such that the
frequencies at the inputs vary by 5 MHz or more. Optionally,
dielectric heating unit 11 utilizes a wideband and high efficiency
(above 40%) solid state microwave amplifier to feed energy into the
chamber 13 and optionally utilize waste heat generated by the
generator to heat the air in the chamber 13. Optionally, the
dielectric heating unit 11 utilizes wasted heat generated by the RF
energy generator to heat a medium, for example air in the chamber
13, or water, as in a water heater. Optionally, the dielectric
heating unit 11 causes a resonance structure and/or designed
pattern, inside a resonator to radiate by (selectively or
generally) irradiating the resonance structure and/or designed
pattern thus using it as a radiation source (i.e. creating a
passive source).
[0154] Optionally, the dielectric heating unit 11 has a
high-efficiency (at least 50%, at times above 70% or even 80%) RF
heater. The efficiency is defined as power absorbed in one or more
heated blood product units versus power at the output of the power
source. This allows the possibility of a heater that operates using
a solar energy source. The power absorbed by one or more heated
blood product units may be calculated based on knowledge of power
input and efficiency of power transfer to the one or more heated
blood product units. This allows for the calculation of a current
temperature and/or a turn off-time based on actual heating rather
than some estimated heating time as presently used with microwave
cookers.
[0155] According to some embodiments of the present invention, the
blood product heating device 100 includes a freezing chamber (e.g.
for freezing blood product units) and/or a cooling chamber (e.g.
for storing cooled blood product units), for example as depicted in
FIG. 3I. An exemplary heating device that integrates a freezing
chamber that is also used for heating using irradiation is
described in '073, which is incorporated herein by reference. The
freezing chamber may allow storing the one or more blood product
units in a freezing temperature, for example below -18.degree. C.,
-30.degree. C., -40.degree. C. or any intermediate temperature. The
cooling chamber may allow storing the one or more blood product
units in a cooling temperature, for example any temperature being
above freezing and below one of 15.degree. C., 10.degree. C. or
8.degree. C., and any range in between. Exemplary cooling ranges
include between 2.degree. C. and 15.degree. C. or between 4.degree.
C. and 8.degree. C. Additionally or alternatively, the chamber 13
may be connected to one or more freezing elements that allow
freezing the blood product units in a freezing temperature, for
example below -18.degree. C., -30.degree. C., -40.degree. C. or any
intermediate temperature. In such an embodiment, frozen blood
product units are thawed and heated, for example as described
above, without having to open the chamber 13 and/or to relocate
them from their storage location. Additionally or alternatively,
the chamber 13 may be insulated such that temperature changes in
the blood product units due to the conditions outside the device
would be delayed.
[0156] According to some embodiments of the present invention, the
blood product heating device 100 is designed to maintain the thawed
and/or heated blood product units at a certain temperature, for
example about 37.degree. C. In such a manner, the heated blood
product units do not have to be used immediately after the heating
process. For instance, after the blood product units are heated,
for example as a preparation for a field operation, the physician
may postpone the blood transfusion and maintain the blood product
unit that is about to be used in a body temperature. In fact, the
temperature in which the blood product units may be maintained may
be any temperature above freezing (e.g. 4.degree. C. or more) and
the final heating step (which may at times take 10 seconds or less)
be performed upon demand.
[0157] Optionally, blood product units which are placed in chamber
13 are thawed and/or heated automatically to a body temperature at
a push of a button or in response to the mounting thereof the
chamber 13 and/or the closing of the chamber 13. In such a manner,
the operator of the blood product heating device 100 may receive a
blood product unit that is prepared for transfusion without having
to be familiar with complex heating protocols or any form of device
operation requirements.
[0158] Reference is now also made to FIG. 4A, which is a flowchart
of a method for managing the supply of blood product units for
transfusion, according to some embodiments of the present
invention.
[0159] As described above, the blood product heating device 100 is
designed for heating blood product units from frozen to about a
body temperature in less than 3 minutes, for example 1 minute or
less and from a temperature above freezing (e.g. between 2.degree.
C. and 10.degree. C.) to about a body temperature in less than 1
minute, for example 20 seconds or less (e.g. 10 seconds). Such a
prompt temperature increase allows a blood bank to prepare a blood
product unit for transfusion immediately upon request and not in
advance. This may reduce the need for pre-thawing blood product
units and therefore may respectively reduce the amount of thawed
blood product units which are disposed when remain unused.
[0160] It should be noted that currently plasma and red blood cells
units are stored at the blood bank respectively at about
-30.degree. C. and about 4.degree. C. Plasma is usually stored up
to one year and blood cell unit is stored up to one month. For
brevity, heating of a cooled blood product unit that contains
plasma may include thawing and heating of a cooled blood product
unit that contains red blood cells may include thawing and/or it
may be limited to heating a non-frozen blood product unit.
[0161] Normally frozen plasma is thawed upon need where the first
request is normally for O type (before a patient's blood is typed)
and then a second request may arrive for the proper blood type.
Blood cells unit are normally maintained as packed red blood cells
(pRBC) and is ready for immediate use, but given cold. As the
thawing of the plasma unit takes time, transfusions are delayed and
the proper ratio of 1 plasma unit for each blood cells unit is not
maintained. It should be noted that the quality of thawed plasma
units is reduced over time.
[0162] In some embodiments of the present invention frozen and
thawed blood products may be placed in a chamber and heated using
by irradiation, such that the frozen material would thaw but the
material that was thawed before operation would not over heat. This
allows for performing one or more of the following without
overheating a blood product unit or any portion thereof: (a)
thawing a blood product unit that comprises thawed and frozen
portions before heating; and (b) thawing a frozen blood product
unit in a chamber in the presence of a non-frozen blood product
unit. The latter option allows for example introducing into a
device frozen plasma units together with non-frozen (cooled) packed
red blood cell units and operating the device to heat all the units
to a desired final temperature (e.g. about body temperature) at the
same time. This also allows placing the different blood product
unit in the device at a ratio that is intended for use (e.g. 1
plasma unit:1 packed red blood cell unit) and optionally heating
them for transfusion temperature simultaneously or substantially
simultaneously.
[0163] As depicted in FIG. 4A, first, as shown at 301, a caretaker,
for example a physician, a nurse, and a medical assistant, orders
one or more blood product units, for example plasma and packed RBC
units, from the blood bank.
[0164] Then, as shown at 302, the blood bank heats and/or thaws the
requested blood product units according to the request, for example
using the blood product heating device 100. For example, blood
product units which contain blood cells may be heated at the same
ratio as blood product units which contain plasma which are thawed
and heated.
[0165] Optionally, the order sent as shown at 301 includes a set of
instructions that is sent to the blood product heating device 100
that automatically initiates one or more heating sessions
accordingly. In such an embodiment, the blood product heating
device 100 may be loaded by mechanical means, for example one or
more robotic arms and/or conveying belts, which load one or more
frozen and/or cooled blood product units from a blood storage, such
as a designated freezer. Optionally, blood product units are
preloaded to the blood product heating device 100 that maintains
them in a freezing temperature. In such an embodiment, the chamber
13 includes one or more cooling element. Optionally, a combination
of plasma and blood cells is prepared. Such a combination is
prepared for immediate transfusion.
[0166] Now, as shown at 303, the one or more heated and/or thawed
blood product units are transferred to the orderer thereof, for
example, the aforementioned thawed plasma and heated blood cells.
It should be noted that when a device, such as the blood product
heating device 100, is not available, a blood product unit of blood
cells is usually transferred while a respective blood product unit
of plasma is thawed. When such a treatment protocol is followed,
the plasma is infused after the blood cells. As the blood product
heating device 100 allows thawing the plasma in less than 3
minutes, for example 1 minute, it may be sent together with the
blood product unit that includes the blood cells, facilitating a
simultaneous transfusion thereof, as shown at 304. Alternatively,
the blood product unit may be supplied in frozen form to the site
of transfusion (or a place nearer to the site of transfusion than
the blood bank or site of storage) and heated therein (i.e.
performing step 303 before step 302).
[0167] Reference is now made to FIG. 4B, which is a flowchart of a
method for heating blood product units, according to some
embodiments of the present invention. First, as shown 311, the
blood product units in a heating chamber of a heating device, such
as the aforementioned blood product heating device 100, of
transportation means, such as a cart or an ambulance. Additionally
or alternatively, the device 100 together with its power source
(e.g. battery) may be sufficiently light weight, such that the
device may be operated when in transport (e.g. on a cart or when
being manually carried). Now, as shown at 312 the heating and/or
thawing process is initiated, for example as described above. The
heating and/or thawing process may be performed while the
transportation means is on a move, for example while the cart,
which is loaded with the blood products units, is conveyed to a
transfusion site and/or during a ride of the ambulance. In such
embodiments, the heating and/or thawing is performed without having
to delay the transfusion. Now, as shown at 313, the blood products
units are supplied at the transfusion site, for example at the
location to which the cart has been conveyed and/or in the
treatment comportment of the ambulance.
[0168] Reference is now made to FIG. 5, which is a method for
locally preparing and providing one or more blood product units for
transfusion, according to some embodiments of the present
invention. As described above and depicted in FIG. 3, the size of
the blood product heating device 100 may be limited, facilitating
the positioning thereof in an ambulance, a trauma room, an
operating room (OR), emergency room (ER), field OR, and/or field
ER. This allows immediate availability of blood/plasma at the
correct ratio and/or temperature.
[0169] In some such embodiments, as depicted in 401, frozen and/or
cooled blood product units, are stored on site, for example in the
ambulance, the trauma room, the OR, and/or the ER. For example, the
blood product units are stored frozen in a dual purpose device that
includes a freezing chamber for storing blood product units and a
heating chamber, such as the chamber indicated by numeral 14.
[0170] Now, as shown at 402, one or more blood product units are
heated and/or thaw on site. Optionally, the heating and/or thawing
is performed by the blood product heating device 100, similarly to
the described above in relation to 302.
[0171] Then, as shown at 403, the heated and/or thaw blood product
units are infused, optionally simultaneously, similarly to the
described above in relation to 304.
[0172] According to some embodiments of the present invention, the
blood product unit is tagged with data pertaining to the heating
and/or thawing process and/or the quality of the blood product
units. In such an embodiment, a heated blood product unit is tagged
with data that is gathered during the thawing and/or heating
thereof and/or with a quality score that is based on the gathered
data.
[0173] For example, the data may include the final temperature
and/or the launch temperature of the heated blood product unit, the
amount of EM energy that has been absorbed by the blood product
unit, the amount of EM energy that has dissipated in the chamber
during the heating process, data pertaining to the technical
qualification of the blood product heating device 100, the rate of
the blood product unit's temperature change and/or increase during
the heating process and/or the like. Optionally, the quality score
is based on some or all of the aforementioned gathered data.
[0174] Optionally, the tagging is performed by updating an
updatable memory element, such as an RFID tag or any other tag,
which is attached to the heated blood product unit. In another
embodiment, each blood product unit has a unique ID and the blood
product heating device 100 updates a record associated with the
unique ID with the gathered data and/or quality score. Optionally,
the unique ID is attached and/or printed to the package of the
blood product unit, for example as a barcode or a serial number.
The record is optionally stored in a storage device, such as a
flash drive, a memory card, and the like. Optionally, the blood
product heating device 100 comprises a communication interface that
allows forwarding records which are stored on the storage device to
a remote server, for example to a medical data center that monitors
the blood product unit supply and/or a client terminal of a
physician, such as a laptop, a personal digital assistant, and the
like.
[0175] Optionally, the controller 14 operates the dielectric
heating unit 11 according to data that is associated with the
heated blood product unit, for example instructions which are
stored on an RFID tag and/or coded on a sticker which is attached
thereto. The instructions may define a pattern that is adapted for
the content of the blood product unit, for example blood cells
and/or plasma, the amount of blood products in the heated blood
product unit, a number of blood product units that is placed in the
chamber 13 for heating and the like.
[0176] Attention is drawn to FIG. 6, depicting an exemplary method
for managing blood product unit supply, taking advantage of the
ability to heat frozen material without substantially heating the
liquid (e.g. without such thermal runaways as may damage a blood
product unit or render a saline unit too hot for immediate
use).
[0177] In step 601, at least one frozen plasma unit and said at
least one of one or more cooled blood product units and one or more
unheated saline units unit are placed together in a chamber. In
step 602 heating is performed comprising applying electromagnetic
(EM) energy into said chamber thereby thawing the frozen plasma
unit without heating the cooled blood product unit and/or the
saline solution unit to such an extent that might cause the unit to
be unusable at the end of thawing (e.g. due to damage or due to the
need to wait for it to cool). Examples for such overheating include
heating by more than 30.degree. C., by more than 15.degree. C., by
more than 10.degree. C. or by more than 5.degree. C.
[0178] This method may further include step 603, where the thawed
units are heated together with other units in the chamber, to reach
essentially the same temperature in all units (e.g. about a body
temperature).
[0179] A potential benefit of this method and of devices adapted
for performing it is that the different frozen and unfrozen units
may be heated in a single device such that they reach a desired
temperature at about the same time. Thus, the different units may
be heated for example in a proportion as they may need to be
used.
[0180] An additional potential benefit of the ability to thaw ice
without excessively heating non-frozen material (either when
present in a single blood product unit, such as a partially thawed
unit) or in different units (e.g. when one unit is stored in frozen
form, for example FFP) and another is provided in non-frozen form
(such as refrigerated pRBC).
[0181] It is expected that during the life of a patent maturing
from this application many relevant systems and methods will be
developed and the scope of the term an RFID tag, a dielectric
heating unit, a field adjusting element, and an MMI is intended to
include all such new technologies a priori.
[0182] Exemplary Heating of RBC
[0183] Blood was collected from healthy volunteers (male and
female) under the approval of the Rambam medical center human trail
committee. The blood donations (450 cc each) were separated using
the 2 bag system, as described in the American Association of Blood
Banks (AABB) guidelines, to pRBC and plasma by the medical center
staff. The blood was stored at 2-8.degree. C. at the blood bank in
Rambam and the plasma was rapidly frozen in a conventional
-80.degree. C. freezer. After 3 days, the FFP was transferred to
-20.degree. C.
[0184] Heating was performed in a device constructed according to
the present invention with a working RF band between 800-1000 MHz,
at either 600 Watts or 900 Watts.
[0185] The blood heated in either oven from 4.degree. C. to
37.degree. C. within 20 seconds or less. All pRBC units were tested
at the Rambam medical center for hemolysis index both before and
after heating. Furthermore, the samples were sent to pathology
expert lab for cell count. According to both tests there was no
significant change in the blood before and after heating.
[0186] As used herein the term "about" refers to .+-.10%.
[0187] The terms "comprises", "comprising", "includes",
"including", "having" and their conjugates mean "including but not
limited to". This term encompasses the terms "consisting of" and
"consisting essentially of".
[0188] The phrase "consisting essentially of" means that the
composition or method may include additional ingredients and/or
steps, but only if the additional ingredients and/or steps do not
materially alter the basic and novel characteristics of the claimed
composition or method.
[0189] As used herein, the singular form "a", "an" and "the"
include plural references unless the context clearly dictates
otherwise. For example, the term "a compound" or "at least one
compound" may include a plurality of compounds, including mixtures
thereof.
[0190] The word "exemplary" is used herein to mean "serving as an
example, instance or illustration". Any embodiment described as
"exemplary" is not necessarily to be construed as preferred or
advantageous over other embodiments and/or to exclude the
incorporation of features from other embodiments.
[0191] The word "optionally" is used herein to mean "is provided in
some embodiments and not provided in other embodiments". Any
particular embodiment of the invention may include a plurality of
"optional" features unless such features conflict.
[0192] Throughout this application, various embodiments of this
invention may be presented in a range format. It should be
understood that the description in range format is merely for
convenience and brevity and should not be construed as an
inflexible limitation on the scope of the invention. Accordingly,
the description of a range should be considered to have
specifically disclosed all the possible subranges as well as
individual numerical values within that range. For example,
description of a range such as from 1 to 6 should be considered to
have specifically disclosed subranges such as from 1 to 3, from 1
to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as
well as individual numbers within that range, for example, 1, 2, 3,
4, 5, and 6. This applies regardless of the breadth of the
range.
[0193] Whenever a numerical range is indicated herein, it is meant
to include any cited numeral (fractional or integral) within the
indicated range. The phrases "ranging/ranges between" a first
indicate number and a second indicate number and "ranging/ranges
from" a first indicate number "to" a second indicate number are
used herein interchangeably and are meant to include the first and
second indicated numbers and all the fractional and integral
numerals therebetween.
[0194] It is appreciated that certain features of the invention,
which are, for clarity, described in the context of separate
embodiments, may also be provided in combination in a single
embodiment. Conversely, various features of the invention, which
are, for brevity, described in the context of a single embodiment,
may also be provided separately or in any suitable subcombination
or as suitable in any other described embodiment of the invention.
Certain features described in the context of various embodiments
are not to be considered essential features of those embodiments,
unless the embodiment is inoperative without those elements.
[0195] Although the invention has been described in conjunction
with specific embodiments thereof, it is evident that many
alternatives, modifications and variations will be apparent to
those skilled in the art. Accordingly, it is intended to embrace
all such alternatives, modifications and variations that fall
within the spirit and broad scope of the appended claims.
[0196] All publications, patents and patent applications mentioned
in this specification are herein incorporated in their entirety by
reference into the specification, to the same extent as if each
individual publication, patent or patent application was
specifically and individually indicated to be incorporated herein
by reference. In addition, citation or identification of any
reference in this application shall not be construed as an
admission that such reference is available as prior art to the
present invention. To the extent that section headings are used,
they should not be construed as necessarily limiting.
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