SYSTEM FOR PROCESSING OF CONTINUOUS PRESSURE-RELATED SIGNALS FOR USE IN DRAINING FLUID FROM A BRAIN OR SPINAL FLUID CAVITY

• US 20090062625A1
• Filed: 10/24/2008
• Published: 03/05/2009
• Est. Priority Date: 07/21/2004
• Status: Abandoned Application

• Current Assignee: Dpcom As
• Original Assignee: Dpcom As
• Inventors: Eide, Per Kristian
• Application Number:
  US12/258,374
• Publication Number:
  US 20090062625A1
• Time in Patent Office: Days
• US Class Current: 600/300
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02108 from analysis of pulse wave characteristics
• CPC Class Codes: A61B 5/031 Intracranial pressure
• CPC Class Codes: A61M 27/006 Cerebrospinal drainage; Accessories therefor, e.g. valves

Abstract

This invention describes a method for processing pressure signals derivable from locations inside or outside a human or animal body or body cavity. Different aspects of the invention relate to a method for optimal differentiating between cardiac beat- and artifact-induced pressure waves, a method for obtaining new and improved information from said pressure signals, a method for obtaining signals predicting pressures inside a body or body cavity from pressure signals outside said body or body cavity, and a method for using said method for controlling an adjustable shunt vale. In particular this invention describes a system for draining fluid from a brain or spinal fluid cavity.

Claims

1. A system for processing continuous pressure-related signals derivable from one or more sensor(s) having location(s) inside or outside a body or body cavity of a human being, said system comprising:

a) means for on basis of said signals receivable from said sensor(s) via pressure transducer means to control drainage fluid flow rate from a first body cavity to a second body cavity in one said human,

b) a processing unit in said system having means for processing said signals, said processing means including sampling means for sampling said signals at specific intervals,

c) converter means for converting the sampled signals into pressure related digital data with a time reference,

d) means for during selectable time sequence windows identifying from said digital data single pressure waves related to cardiac beat-induced pressure waves, related to artifacts, or a combination of cardiac beat-induced waves and artifacts,

e) means for computing and analyzing said digital data during said selectable time sequence windows,

f) means for outputting to device terminal means one or more pressure parameter signals related to a selectable number of said time sequence windows;

f1) mean wave amplitude (TS.MeanWavedP),

f2) mean wave latency (TS.MeanWavedT),

f3) mean wave rise time coefficient (TS.MeanWaveRT),

f4) mean amplitude (TS.MeandP),

f5) mean latency (TS.MeandT),

f6) mean rise time coefficient (TS.MeanRT),

f7) mean single wave pressure (TS.Mean_SWP), and

g) a valve device controlling the drainage fluid flow rate and connectable to said body cavities,

h) regulator unit means connectable to said terminal means for receiving at least one of said parameter signals, said regulator unit means being capable of establishing a device performance modifying signal by means of one of said pressure parameter signals or a combination effect obtained from using at least two of said pressure parameter signals, wherein said performance modifying signal deliverable from said regulator unit being capable of controlling said drainage fluid flow rate through said valve device by input to a valve-opening regulator.

2. A system according to claim 1, wherein said sensor location provides for sensing pressure-related signals from a brain body cavity.

3. A system according to claim 1, wherein said sensor location provides for sensing pressure-related signals from a spinal body cavity.

4. A system according to claim 1, wherein said first body cavity relates to a brain body cavity.

5. A system according to claim 1, wherein said first body cavity relates to a spinal body cavity.

6. A system according to claim 1, wherein said second body cavity relates to a thoracic body cavity.

7. A system according to claim 1, wherein said second body cavity relates to an abdominal body cavity.

8. A system according to claim 1, wherein each of said selectable time sequence windows is a selected time frame of said pressure-related digital data with a time reference, said selected time frame lying in the range 5-15 seconds.

9. A system according to claim 1, wherein said identifying means d) exclude for further analysis pressure waves during said time sequence windows with single pressure wave (SW.x)-related parameters outside selected criteria for thresholds and ranges of said parameters, said parameters selected from the group of:

starting diastolic minimum pressure defining the start of the single pressure wave (SW.P_min1),

ending diastolic minimum pressure defining the end of the single pressure wave (SW.P_min2),

systolic maximum pressure of the single pressure wave (SW.P_max,),

amplitude of the single pressure wave (SW.dP),

latency of the single pressure wave (SW.dT),

rise time coefficient of the single pressure wave (SW.RT),

wave duration of the single pressure wave (SW.WD),

mean single wave pressure of the single pressure wave (SW.Mean_SWP), and

diastolic minimum pressure difference of the single pressure wave (SW.Diff_P_min).

10. A system according to claim 1, wherein said identifying means d) exclude for further analysis pressure waves during said time sequence windows with delta single pressure wave (Δ

SW.x)-related parameters outside selected criteria for thresholds and ranges of said parameters, said parameters selected from the group of;

systolic maximum pressure difference between two subsequent single pressure waves (Δ

SW.Diff_P_max),

amplitude difference between two subsequent single pressure waves (Δ

SW.Diff_dP),

latency difference between two subsequent single pressure waves (Δ

SW.Diff_dT),

rise time coefficient difference between two subsequent single pressure waves (Δ

SW.Diff_RT),

wave duration difference between two subsequent single pressure waves (Δ

SW.Diff_WD), and

mean single wave pressure difference between two subsequent single pressure waves (Δ

SW.Diff_Mean_SWP).

11. A system according to claim 1, wherein said identifying means d) exclude for further analysis time sequence windows with time sequence (TS.x)-related parameters outside selected criteria for thresholds and ranges of said parameters, said parameters selected from the group of:

mean value of starting diastolic minimum pressures of a time sequence window (TS.MeanP_min1),

standard deviation of mean value of starting diastolic minimum pressures of a time sequence window (TS.MeanP_min1—

STD),

mean value of systolic maximum pressures of a time sequence window (TS.MeanP_max),

standard deviation of mean value of systolic maximum pressures of a time sequence window (TS.MeanP_max—

STD),

mean amplitude of a time sequence window (TS.MeandP),

standard deviation of mean amplitude of a time sequence window (TS.MeandP_STD),

mean latency of a time sequence window (TS.MeandT),

standard deviation of mean latency of a time sequence window (TS.MeandT_STD),

mean rise time coefficient of a time sequence window (TS.MeanRT),

standard deviation of mean rise time coefficient of a time sequence window (TS.MeanRT_STD),

mean wave duration of a time sequence window (TS.MeanWD),

standard deviation of mean wave duration of a time sequence window (TS.MeanWD_STD),

mean single wave pressure of a time sequence window (TS.Mean_SWP),

standard deviation of mean single wave pressure of a time sequence window (TS.Mean_SWP_STD),

mean of diastolic minimum pressure differences of a time sequence window (TS.MeanDiff_P_min),

standard deviation of mean of diastolic minimum pressure differences of a time sequence window (TS.MeanDiff_P_min—

STD),

mean of systolic maximum pressure differences of a time sequence window (TS.MeanDiff_P_max),

standard deviation of mean of systolic maximum pressure differences of a time sequence window (TS.MeanDiff_P_max—

STD),

mean amplitude difference of a time sequence window (TS.MeanDiff_dP),

standard deviation of mean amplitude difference of a time sequence window (TS.MeanDiff_dP_STD),

mean latency difference of a time sequence window (TS.MeanDiff_dT),

standard deviation of mean latency difference of a time sequence window (TS.MeanDiff_dT_STD),

mean rise time coefficient difference of a time sequence window (TS.MeanDiff_RT),

standard deviation of mean rise time coefficient difference of a time sequence window (TS.MeanDiff_RT_STD),

mean wave duration difference of a time sequence window (TS.MeanDiff_WD),

standard deviation of mean wave duration difference of a time sequence window (TS.MeanDiff_WD_STD),

mean single wave pressure difference of a time sequence window (TS.MeanDiff_Mean_SWP),

standard deviation of mean single wave pressure difference of a time sequence window (TS.MeanDiff_Mean_SWP_STD),

number of accepted single pressure waves of a time sequence window (TS.SWCount),

mean wave amplitude of a time sequence computed according to a first matrix (TS.MeanWavedP),

mean wave latency of a time sequence computed according to a first matrix (TS.MeanWavedT), and

mean wave rise time coefficient of a time sequence computed according to a second matrix (TS.MeanWaveRT).

12. A system according to claim 1, wherein said identifying means d) exclude for further analysis time sequence windows with delta time sequence (Δ

TS.x)-related parameters outside selected criteria for thresholds and ranges of said parameters, said parameters selected from the group of;

difference of mean values of starting diastolic minimum pressures between two subsequent time sequence windows (Δ

TS.MeanP_min1),

standard deviation of difference of mean values of starting diastolic minimum pressures of two subsequent time sequence windows (Δ

TS.MeanP_min1—

STD),

difference of mean values of systolic maximum pressure between two subsequent time sequence windows (Δ

TS.MeanP_max),

standard deviation of difference of mean values of systolic maximum pressure between two subsequent time sequence windows (Δ

TS.MeanP_max—

STD),

difference of mean amplitude values between two subsequent time sequence windows (Δ

TS.MeandP),

standard deviation of difference of mean amplitudes between two subsequent time sequence windows (Δ

TS.MeandP_STD),

difference of mean latency between two subsequent time sequence windows (Δ

TS.MeandT),

standard deviation of difference of mean latency between two subsequent time sequence windows (Δ

TS.MeandT_STD),

difference of mean rise time coefficient between two subsequent time sequence windows (Δ

TS.MeanRT),

standard deviation of difference of mean rise time coefficient between two subsequent time sequence windows (Δ

TS.MeanRT_STD),

difference of mean wave duration between two subsequent time sequence windows (Δ

TS.MeanWD),

standard deviation of difference of mean wave duration between two subsequent time sequence windows (Δ

TS.MeanWD_STD),

difference of mean single wave pressure between two subsequent time sequence windows (Δ

TS.Mean_SWP),

standard deviation of difference of mean single wave pressure of two subsequent time sequence windows (Δ

TS.Mean_SWP_STD),

difference of mean diastolic minimum pressure difference between two subsequent time sequence windows (Δ

TS.MeanDiff_P_min),

standard deviation of difference of mean diastolic minimum pressure difference between two subsequent time sequence windows (Δ

TS.MeanDiff_P_min—

STD),

difference of mean systolic maximum pressure difference between two subsequent time sequence windows (Δ

TS.MeanDiff_P_max),

standard deviation of difference of mean systolic maximum pressure difference between two subsequent time sequence windows (Δ

TS.MeanDiff_P_max—

STD),

difference of mean amplitude difference between two subsequent time sequence windows (Δ

TS.MeanDiff_dP),

standard deviation of difference of mean amplitude difference between two subsequent time sequence windows (Δ

TS.MeanDiff_dP_STD),

difference of mean latency difference between two subsequent time sequence windows (Δ

TS.MeanDiff_dT),

standard deviation of difference of mean latency difference between two subsequent time sequence windows (Δ

TS.MeanDiff_dT_STD),

difference of mean rise time coefficient difference between two subsequent time sequence windows (Δ

TS.MeanDiff_RT),

standard deviation of difference of mean rise time coefficient difference between two subsequent time sequence windows (Δ

TS.MeanDiff_RT_STD),

difference of mean wave duration difference between two subsequent time sequence windows (Δ

TS.MeanDiff_WD),

standard deviation of difference of mean wave duration difference between two subsequent time sequence windows (Δ

TS.MeanDiff_WD_STD),

difference of mean single wave pressure difference between two subsequent time sequence windows (Δ

TS.MeanDiff_Mean_SWP),

standard deviation of difference of mean SW pressure difference between two subsequent time sequence windows (Δ

TS.MeanDiff_Mean_SWP_STD),

difference of single wave count between two subsequent time sequence windows (Δ

TS.SWCount),

difference of mean wave amplitude between two subsequent time sequence windows (Δ

TS.MeanWavedP),

difference of mean wave latency between two subsequent time sequence windows (Δ

TS.MeanWavedT), and

difference of mean wave rise time coefficient between two subsequent time sequence windows (Δ

TS.MeanWaveRT).

13. A system according to claim 1, wherein said computing means e) incorporates determining time sequence (TS.x)-related parameters for included time sequence windows, said parameters selected from the group of:

mean value of starting diastolic minimum pressures of a time sequence window (TS.MeanP_min1),

standard deviation of mean value of starting diastolic minimum pressures of a time sequence window (TS.MeanP_min1—

STD),

mean value of systolic maximum pressures of a time sequence window (TS.MeanP_max),

standard deviation of mean value of systolic maximum pressures of a time sequence window (TS.MeanP_max—

STD),

mean amplitude of a time sequence window (TS.MeandP),

standard deviation of mean amplitude of a time sequence window (TS.MeandP_STD),

mean latency of a time sequence window (TS.MeandT),

standard deviation of mean latency of a time sequence window (TS.MeandT_STD),

mean rise time coefficient of a time sequence window (TS.MeanRT),

standard deviation of mean rise time coefficient of a time sequence window (TS.MeanRT_STD),

mean wave duration of a time sequence window (TS.MeanWD),

standard deviation of mean wave duration of a time sequence window (TS.MeanWD_STD),

mean single wave pressure of a time sequence window (TS.Mean_SWP),

standard deviation of mean single wave pressure of a time sequence window (TS.Mean_SWP_STD),

mean of diastolic minimum pressure differences of a time sequence window (TS.MeanDiff_P_min),

standard deviation of mean of diastolic minimum pressure differences of a time sequence window (TS.MeanDiff_P_min—

STD),

mean of systolic maximum pressure differences of a time sequence window (TS.MeanDiff_P_max),

standard deviation of mean of systolic maximum pressure differences of a time sequence window (TS.MeanDiff_P_max—

STD),

mean amplitude difference of a time sequence window (TS.MeanDiff_dP),

standard deviation of mean amplitude difference of a time sequence (TS.MeanDiff_dP_STD),

mean latency difference of a time sequence window (TS.MeanDiff_dT),

standard deviation of mean latency difference of a time sequence window (TS.MeanDiff_dT_STD),

mean rise time coefficient difference of a time sequence window (TS.MeanDiff_RT),

standard deviation of mean rise time coefficient difference of a time sequence window (TS.MeanDiff_RT_STD),

mean wave duration difference of a time sequence window (TS.MeanDiff_WD),

standard deviation of mean wave duration difference of a time sequence window (TS.MeanDiff_WD_STD),

mean single wave pressure difference of a time sequence window (TS.MeanDiff_Mean_SWP),

standard deviation of mean single wave pressure difference of a time sequence window (TS.MeanDiff_Mean_SWP_STD),

number of accepted single pressure waves of a time sequence window (TS.SWCount),

mean wave amplitude of a time sequence computed according to a first matrix (TS.MeanWavedP),

mean wave latency of a time sequence computed according to a first matrix (TS.MeanWavedT), and

mean wave rise time coefficient of a time sequence computed according to a second matrix (TS.MeanWaveRT).

14. A system according to claim 1, wherein said computing means e) yields output of analysis of parameters f1)-f7) during a selectable number of said time sequence windows, said analysis output providing for a pressure parameter signal.

15. A system according to claim 1, wherein selectable criteria relate to selectable thresholds for time sequence (TS.x)-related parameters, said parameters selected from the group of:

mean wave amplitude (TS.MeanWavedP), mean wave latency (TS.MeanWavedT), mean wave rise time coefficient (TS.MeanWaveRT), mean amplitude (TS.MeandP), mean latency (TS.MeandT), and mean rise time coefficient (TS.MeanRT).

16. A system according to claim 15, wherein said selectable criteria are determined on basis of analysis output of a selectable number of individual time sequence windows in a continuous series of said time sequence windows.

17. A system according to claim 1, wherein said performance modifying signal is a function of pressure parameter signals, said function being related to selectable criteria for said pressure parameter signals.

18. A system according to claim 14, wherein said selectable criteria for said pressure parameter signals are determined on basis of said analysis output.

19. A system according to claim 1, wherein features of said device performance modifying signal are selectable when said analysis output meets one or more of selectable criteria.

20. A system according to claim 1, wherein said computing means e) yields output of analysis of parameters f1)-f7) during a selectable number of said time sequence windows, said analysis output providing criteria for regulating a mode of function of a valve device.

21. A system according to claim 1, wherein said valve device controls the drainage fluid flow rate between said first and second body cavities.

22. A system according to claims 1, wherein said system incorporates a power supply locatable below skin surface of said human being.

23. A system according to claim 1, wherein said system incorporates transferable means enabling information transferal through skin of said human being, said information being deliverable to an external processing unit, said information including one or more of power supply power status, valve device performance data, parameter signals available or used.

24. A system according to claim 1, wherein said sensor(s), said pressure transducer, said processing unit, said valve device and said regulator unit together constitute a single physical unit.

25. A system according to claim 1, wherein said system is locatable below a skin surface of said human body in a thoracic or abdominal body area.