U.S. patent application number 10/425813 was filed with the patent office on 2004-02-26 for needle insertion sensor.
Invention is credited to Christensen, Lars Hofmann, Poulsen, Jens Ulrik, Simonsen, Jan H..
Application Number | 20040039289 10/425813 |
Document ID | / |
Family ID | 31891732 |
Filed Date | 2004-02-26 |
United States Patent
Application |
20040039289 |
Kind Code |
A1 |
Christensen, Lars Hofmann ;
et al. |
February 26, 2004 |
Needle insertion sensor
Abstract
This invention relates to a doser comprising a syringe (2) with
a needle (3) which extends beyond the doser (1), which comprises an
engagement face (4) in the vicinity of the needle so that the
engagement face rests against the surface of the tissue into which
the needle is inserted. Detector means (5) are provided on said
engagement face to sample signals on the skin of the patient, said
means being arranged for providing heart rate signals. The
invention further provides means (13) for receiving information
related to health monitoring of a patient. This provides a doser
that may record heart rate, EKG, BGM and hypo-alarm administered
medicine. The doser may further be arranged to calculate an
appropriate dose of medication on the basis of a number of acquired
inputs.
Inventors: |
Christensen, Lars Hofmann;
(Jyllinge, DK) ; Poulsen, Jens Ulrik; (Virum,
DK) ; Simonsen, Jan H.; (Struer, DK) |
Correspondence
Address: |
Reza Green, Esq.
Novo Nordisk Pharmaceuticals, Inc.
100 College Road West
Princeton
NJ
08540
US
|
Family ID: |
31891732 |
Appl. No.: |
10/425813 |
Filed: |
April 29, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60389104 |
Jun 4, 2002 |
|
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Current U.S.
Class: |
600/485 |
Current CPC
Class: |
A61B 5/14532 20130101;
A61B 5/332 20210101 |
Class at
Publication: |
600/485 |
International
Class: |
A61B 005/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 30, 2002 |
DK |
2002 00650 |
Claims
1. A doser comprising a syringe with a needle, which extends beyond
the doser, which comprises, in the vicinity of the needle, an
engagement face for engaging a surface of a tissue into which the
needle is to be inserted, characterized in that detector means
capable of detecting heart rate are provided on said engagement
face.
2. A doser according to claim 1, characterized in that the doser
comprises additional electrode means capable of detecting heart
rate.
3. A doser according to claim 2, characterized in that the
additional electrode means are provided on the handle of the
doser.
4. A doser according to claim 1, characterized in that the needle
comprises electrode means.
5. A doser according to claim 2 characterized in that the electrode
means are sensitive to electrical signals.
6. A doser according to claim 2 characterized in that the electrode
means are sensitive to optical signals.
7. A doser according to claim 5, characterized in that the doser
comprises electrical circuits for generating and for receiving
electrical signals for measuring the impedance between
electrodes.
8. A doser according to claim 6, characterized in that the doser
comprises an emitter for generating and emitting light and detector
means for detecting light.
9. A doser according to claim 7 characterized in that the signals
are modulated.
10. A doser according to claim 7 characterized in that the doser
contains a calculating circuit and a storage circuit adapted to
process and store the value of said signals.
11. A doser according to claim 1 characterized in that the doser
has means for receiving external signals, and that the circuit in
the doser is adapted to combine the external signals with signals
from said detector means.
12. A doser according to claim 1 characterized in that the doser
contains means for wireless communication.
13. A doser according to claim 1 characterized in that the detector
means comprise a neural network program for signal processing.
14. A doser according to claim 13 characterized in that the neural
network program is executed on an external computer connected to
the doser via a wireless communication link.
15. A doser according to claim 1 characterized in that said
electrode means comprise a pair of mutually closely spaced
electrodes.
16. A doser according to claim 9 characterized in that the doser is
adapted to estimate electrocardiogram signals.
17. A doser according to claim 9 characterized in that the circuit
is adapted to recognize specific signal shapes.
18. A doser according to claim 9 characterized in that the circuit
is adapted to determine pulse rates.
19. A doser according to claim 5, characterized in that the circuit
is adapted to calculate the blood glucose level.
20. A doser according to claim 19, characterized in that the
circuit is adapted to calculate doses in dependence on the
calculated blood glucose level.
21. A doser according to claim 20, characterized in that the
circuit is adapted to control the generation of control signals to
a pump in the doser.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a doser comprising a
syringe having a needle which extends outside the doser, which
comprises an engagement face in the vicinity of the needle so that
the engagement face rests against the tissue into which the
injection is inserted.
BACKGROUND OF THE INVENTION
[0002] Injection devices for multiple use having an exchangeable
insulin ampoule have been developed, which calculate an optimum
dose of medicine for a given patient (WO 00/32088). This
calculation can take the patient's health, food habits and
recordings of previously administered doses into consideration. For
this determination of dose it is necessary to know the patient's
received dose precisely to avoid overdosing or underdosing, as this
may have fatal consequences for the diabetic.
OBJECT OF THE INVENTION
[0003] The object of the invention is to utilize the known
sophisticated electronics for even better information of the user
on the basis of the provision of additional input signals to the
electronics, without the user having to do anything else than
he/she normally does.
[0004] This object is obtained in that measurements of the heart
rate are accomplished in that signal processing known per se is
used in combination with one or more electrode means for this
measurement being provided on said engagement face.
[0005] Thereby signals are obtained that are related to heart
activity and by expanding the doser with additional electrode means
provided on the handle, it is possible to obtain
electrocardiograms. Preferably additional electrode means are
provided that can be located elsewhere on the body and, either via
wires or wireless communication links, they are connected to the
doser.
[0006] Preferably electrical signals are used, but it is also an
option to use optical signals, like eg in connection with BGM
measurements (Blood Glucose Measurement).
[0007] Typically, the impedance is measured in the tissue touched
by the engagement face of the doser or, alternatively, light is
used. The signals may be modulated to avoid noise from the
surroundings.
[0008] An important feature of the invention is the finding that
merely by a very simple detection of heart signals, it is possible
to considerably improve the applicability. This is due to the fact
that the prior art calculating circuits are very sophisticated, ia
with self-learning software routines that can either be executed
within the doser as such or be executed in a large, external
computer connected to the doser via a wire or a wireless
communication link. In this manner the doser may have very large
signal-processing capacity and therefore the doser can
advantageously be provided with means for receiving external
signals.
[0009] By the provision of extra electrode means at the end
opposite that end of the doser which is in contact with the skin of
the stomach of the user, it is accomplished that the patient's hand
touches the additional electrode means, whereby the measurement
will take place through the patient's heart region. It is therefore
possible, by simple means, to considerably broaden the
applicability. By supplementing with light detection it is also
possible to perform a blood glucose measurement (BGM) in connection
with the doser that thus also lends itself for use as hypoglycemia
alarm.
[0010] A further advantageous use of the invention relates to
administering of the dosis which is injected. It is assumed in the
calculations that all the medicine discharged from the ampoule is
administered to the patient. When replacing the reservoir it is
essential to drain the injection doser needle as well as the
syringe for any possible air, as this might fill the patient's
veins. Consequently, the operator usually performs a first time
shot e.g. into a sponge after reservoir replacement to make sure
that there is no air left in the needle or eventual in the syringe.
This shot will inappropriately be recorded in the doser as an
injection shot into the patient, and it will therefore be necessary
to observe whether the needle is inserted into biological tissue,
e.g. a human body. This drawback is avoided by the doser according
to the invention that can very reliably detect whether dosis is
administered to biological tissue, since the decision can be taken
on the basis of the detection of heart rate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The accompanying drawings illustrate the present invention
by way of the embodiments in which:
[0012] FIG. 1 shows an embodiment of the doser according to the
present invention where the engagement face rests against skin.
[0013] FIG. 2 illustrates an embodiment of the invention in detail
and with sensor means on the injection button.
[0014] FIG. 3 shows an embodiment of a sensor with two electrodes
according to the present invention.
[0015] FIG. 4 illustrates a QRS-pass as seen on a typical
electrocardiogram.
[0016] FIG. 1 shows detector means (5) on the engagement face (4)
of a doser that naturally contacts the skin (8) in normal use.
[0017] The doser (1) comprises a syringe (2) having a needle (3)
that generally extends outside the doser that comprises an
engagement face (4) in the vicinity of the needle, so that the
engagement face rests against the surface of the tissue (8) into
which the needle has been inserted. The engagement face has one or
more closely spaced electrodes connected to detector means for
measuring electrical pulses.
[0018] FIG. 3 shows an example of such a sensor (5) with two
closely spaced electrodes (5a, 5b).
[0019] In an embodiment, the electrical impedance between such two
electrodes is measured, and it can hereby be determined whether the
doser is in engagement with human tissue. The doser may thus be
adapted for specifically recording the amount of administered dose
to a tissue type having human characteristics.
[0020] According to the invention, the heart rate of the patient
can be determined by a continuous recording of the impedance of the
skin, which gives a further indication of live tissue not obtained
in prior art whereby a more safe decision can be made to determine
whether the insulin discharge takes place in a patient.
[0021] More importantly, the detector means according to the
invention can be used to determine the heart rate itself, even if a
person skilled in the art would expect that heart rate signals
obtained in a way according to the invention--at least to a certain
extent--would be of too low a quality to make a decision on
something as important as the heart rate.
[0022] By combining the detector means according to the invention
with modern signal shaping routines, e.g. comprising naural network
analysis (see WO 02/069798) reliable results can be obtained on the
basis of less reliable detector signals whereby the invention is
operable even under difficult conditions.
[0023] If the patient's skin is wet, the impedance between the
electrodes of the engagement face will be measured so low that it
is determined by the doser that human-like skin is not involved. In
this case it is therefore expedient that the needle can comprise a
sensor, e.g. an electrode, thereby allowing a measurement between
the sensor of the engagement face (5) and the sensor of the needle.
This provides an extra possibility of reliable measurement
results.
[0024] In a preferred embodiment a sensor is embedded also in the
handle of the doser (6). This allows for measurement between it and
the sensor of the engagement face (5) and/or the sensor of the
needle (3). According to the invention, this makes the heart rate
signals useable for obtaining electrocardiogram signals, as will be
described below.
[0025] Since an injection is typically made in the patient's thigh
or pit of the stomach, the current path between the sensors of the
doser at the end of the engagement face and the handle of the doser
will run through the patient's heart region and one arm, which
enables mapping of the heart rate as well as diastole and systole
of the patient's ventricles. This possibility allows diagnosis of
the patient's circulatory state, that is, if the patient himself
operates the doser.
[0026] In this embodiment, the doser may moreover be adapted for
calculating correlation between a sensor signal originating from
the engagement face (5) and the sensor signal of the handle (6) so
as to determine whether these pulse rates are consistent. If these
two signals do not resemble each other, it will mean that the
patient does not operate the apparatus himself, but that the
apparatus is operated by another person, e.g. a nurse. The doser
can thus determine on the basis of this correlation that it is not
possible to create a valid pseudo electrocardiogram (ECG).
[0027] The basics of the doser according to the present invention
are shown in FIG. 2. Signal processing/calculation means (10) is
connected with memory storage (11) containing e.g. user
information, operating system, executable program, etc.
[0028] The processing means may include a microprocessor, an
application-specific integrated circuit, or another integrated
circuit, a smart card, a general purpose computer adapted by
suitable software, or the like. The processing means may be
designed to acquire information from the internal
sensors/electrodes (3, 5 and 6) as well as from an external
communication link (13). The communication link (13) may be any
transmission line which may comprise wire and wire-less
communication links.
[0029] Additionally, the processing means may comprise means to
control the generation of control signals to a pump (12), e.g. a
DC-driven motor, etc., which may enable an injection by way of
moving a piston rod (7) in the syringe (2). Further, a signal
device (9) may be present to generate measurement impulses, e.g. a
light emitter generator etc.
[0030] Creation of a standard ECG signal requires measurement on
three points on the patient's body. Even though the number of
acceptable sensor points in this embodiment will be three (handle,
needle, and engagement face), this method will not always be
sufficient to obtain a complete electrocardiogram. Since the needle
and engagement face sensor points are spaced closely together, the
measurement signal processing requires an unacceptable high
signal/noise ratio. To overcome this, it is therefore desirable to
ensure that at least one external sensor for this purpose can be
connected to the doser. In this embodiment, it will thus be
possible to generate a true balanced measuring signal. This
connection may be carried out by a physical wire and/or radio
communication. To screen noise from the surroundings, it is
necessary strongly to filter the resulting signal of especially the
50/60 HZ power supply frequency. The signal may then be chased for
a possible useful ECG signal where a QRS course is desired.
[0031] In this case, the doser is adapted to recognize the shape of
the QRS course of a human heart. To achieve a better noise/signal
ratio, the measuring signal may be modulated in frequency to a
range, which is discordant relative to the frequency of the power
supply, that is, at a frequency which is not a whole numbered
multiple of the power supply frequency.
[0032] If freedom of movement is desired, this sensor may consist
of a wireless electrode having a plurality of electrodes (U.S. Pat.
No. 6,073,046) adhered to the patient's chest. By implementation of
ECG monitoring by means of the doser, this can completely replace a
commonly used ECG apparatus.
[0033] It is also to be understood that the communication link 13
can be used to transmit information about the heart rate signals
measured to a separate computer. Especially when a neural network
is used to enhance the quality of the signal as disclosed in WO
02/069798, it may be expedient to use an external computer with
large processing power instead of building in an internal computer
having limited processing power.
[0034] It is moreover possible to replace the electrodes by an
emitter/detector or receiver/transducer so as to enable emission
and reception of optical signals and ultrasonic signals,
respectively.
[0035] The use of optical signals provides a new possibility for
the field of use of the doser for measuring physiological
parameters. For an effective treatment of diabetes, it is necessary
to know the patient's content of glucose in the blood (called BGM
below), since this quantity influences the determination of the
insulin dose amount. Currently, much research is focused on
intravenous measuring methods which can determine the BGM by means
of optics (U.S. Pat. No. 6,043,492) or by means of electrochemical
sensors (U.S. Pat. No. 5,954,685). These sensors measure on the
patient's skin and therefore eliminate the need for invasion.
[0036] The use of such sensors in the doser allows these methods to
be employed for carrying out glucometry during injection, without
the patient noticing this or performing any other actions. When
commencing an injection, the doser may record the BGM with a view
to determining the insulin amount and/or recommending an optimum
diet for the patient, as described in WO 00/32088.
[0037] Some times, however, the patient wants to check the glucose
state before he/she decides on insulin injection. If the patient
exclusively wants to know the BGM and therefore does not want to
insert the needle into the body, it will be desirable that the
doser is adapted to accommodate the entire needle so that the
needle may be pushed/pulled into the doser, whereby the needle will
be hidden at times when it is not needed. As long as the needle
does not extend outside the doser, a measurement may be performed
simply by keeping the doser with the engagement face against the
skin. This simple measuring method will motivate the patient to
check the BGM to a greater extent, which can contribute to a better
controlled treatment and therefore fewer sufferings because of
diabetes over a span of years.
[0038] In summary, when detector means are provided on a doser for
detecting of heart rate, a lot of new features can be obtained.
Obtaining partly or full-scale EKG signals and the option of BGM
measurements have been described. It will be understood that these
features could also be made use of for making a hand-held
hypo-alarm.
* * * * *