System for the remote monitoring of patients

• US 6,746,398 B2
• Filed: 09/30/2002
• Issued: 06/08/2004
• Est. Priority Date: 01/25/2000
• Status: Expired due to Fees

• Current Assignee: Centre National De La Recherche Scientifique
• Original Assignee: Centre National De La Recherche Scientifique
• Inventors: Pierrel, Jean-Marie, Hervy, Robert, Jeanpierre, Laurent, Chanliau, Jacques, Romary, Laurent, Charpillet, François, Thomesse, Jean-Pierre, PetitJean, Etienne, Durand, Pierre-Yves
• Primary Examiner(s): Marmor, Charles
• Assistant Examiner(s): ASTORINO, MICHAEL C
• Application Number:
  US10/262,291
• Publication Number:
  US 20030069481A1
• Time in Patent Office: 617 Days
• Field of Search: 600/300-301, 600/481-486, 600/500-508, 600/523, 600/529, 600/532, 600/538, 128/903-905, 128/920-925, 705/2-4, 706/924
• US Class Current: 600/300
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: Y10S 128/92 Computer assisted medical diagnostics

Abstract

System for monitoring patients at home comprising interface means at the patient'"'"'s home, interface means at a doctor'"'"'s surgery, a server linked by a network such as a telephone network to the interface means at the patient'"'"'s home and to the interface means at the doctor'"'"'s surgery, the said server receiving from the interface means at the patient'"'"'s home, values of physiological parameters measured by the patient or by sensors and comprising means for storing a history, corresponding to a certain period of time, regarding the values of physiological parameters which are transmitted thereto, the said server furthermore comprising means for implementing a processing on the values of physiological parameters transmitted by the patient with a view to their presentation and to the presentation of their changes on the interface means at the doctor'"'"'s surgery, characterized in that the said means implement on the latest values of physiological parameters which are transmitted to the server a processing comparing the state defined by these various values of physiological parameters with alert states defined as a function of the stored history of the patient and comprise means for transmitting the results of this processing to the interface means at the doctor'"'"'s surgery.

Claims

1. A system for monitoring patients subjected to dialysis at home comprising:

interface means at the patient'"'"'s home;

interface means at the doctor'"'"'surgery;

a server linked by a network to the interface means at the patient'"'"'s home and to the interface means at the doctor'"'"'surgery for receiving from the interface means at the patient'"'"'s home a value of physiological parameter measured by the patient or by sensors;

means for storing a history on the server, the history comprising values of the physiological parameter taken over a period of time;

means for implementing a processing on the server on the value of the physiological parameter for presentation and for presentation of their changes to the interface means at the doctor'"'"'s surgery, wherein the means for implementing a processing implements on the latest value of the physiological parameter which is transmitted to the server a processing comparing the latest value of the physiological parameter which is transmitted to the server a processing comparing the latest value with an alert state for generating a result;

means for transmitting the result to the interface means at the doctor'"'"'s surgery; and

wherein the means for implementing a processing calculate the probability for the patient to be in a given state among five possible states;

normal hydration, dehydration, hyper-hydration, underestimated dry weight and overestimated dry weight.

2. A system according to claim 1, wherein the means for implementing a processing compares the value of the physiological parameter or a modified physiological parameter with threshold values determined as a function of the history and, when such a threshold value is exceeded, transmits an alert message to the interface means at the doctor'"'"'s office and/or at the patient'"'"'s home.

3. A system according to claim 1, wherein the means for implementing a processing determines a trend parameter value, compares the trend parameter value with a threshold value and, when the threshold value is exceeded, indicates an alert message to the interface means at the doctor'"'"'s office and/or to the interface means at the patient'"'"'s home.

4. A system according to claim 3, wherein the means for implementing a processing compares more than one latest value with other threshold values which are independent of the history for modifying at least one trend parameter when one of the other threshold values is exceeded.

5. A system according to claim 4, wherein the means for implementing a processing determines the probability of occupying a given state as a function of a ratio between on the one hand a difference between the value of the physiological parameter and a normal reference value for the physiological parameter considering a tolerance.

6. A system according to claim 5, wherein the reference value is dependent on the history.

7. A system according to one of claim 1, wherein the interface means at the doctor'"'"'s office enables modification of the calculation of the probability of occupying a given state by the means for implementing a processing by means of modified calculation values proposed by the doctor.

8. A system according to claim 1, wherein the server comprises means to identifying the patient, interrupting the communication and then connecting up to the interface means at the patient'"'"'s home.

9. A system according to claim 1 wherein the interface means at the patient'"'"'s home requires the patient to fill in a chart of daily parameters prior to sending the physiological parameters.

10. A system according to claim 1 wherein the interface means at the patient'"'"'s home comprise means for checking the consistency of the physiological parameter values measured and transmitted by the patient.

11. A system according to claim 1, wherein the server links to the interface means at the patient'"'"'s home and the interface means at the doctor'"'"'s office via a telephone network.

12. A method for monitoring a patient subjected to dialysis at home comprising:

comparing a difference between a latest weight of the patient and an ideal body weight for the patient with a weight threshold and updating a weight trend in a server;

comparing a difference between a supine blood pressure of the patient and an upright blood pressure of the patient with a lying-standing blood pressure difference threshold and updating a lying-standing blood pressure trend in the server;

comparing a mean of the supine systolic pressure and a supine diastolic pressure with a supine pressure-lying-variation threshold calculated as the mean value over time of the mean of the supine systolic pressure and the supine diastolic pressure for the patient and updating a lying blood pressure trend in the server;

comparing the mean of the upright systolic and an upright diastolic pressure with a pressure-standing-variation threshold calculated as the mean value over time of the mean of the upright systolic pressure and the mean of the upright diastolic pressure for the patient and updating an upright blood pressure trend in the server;

determining a values of bags parameter based on volumes observed in a plurality of bags and updating a values of drainage volume of bags trend in the server;

transmitting an alert message from said server to an interface means at a doctor'"'"'s office and/or to an interface means at a patient'"'"'s home if a threshold value is exceeded; and

wherein threshold values are determined as a function of a stored history and are updated trend data received by the server.

13. A method according to claim 12, further comprising:

initializing a hydration trend to zero;

incrementing the hydration trend by a first given value when the weight of the patient exceeds his ideal body weight over a high weight threshold;

incrementing the hydration trend by a second given value when the weight of the patient goes below his ideal body weight under a low weight threshold;

incrementing the hydration trend by a third value when the difference between an upright blood pressure of the patient and a supine blood pressure of the patient exceeds a given lying-standing blood pressure difference threshold; and

attenuating the hydration trend daily by a factor and increasing the hydration trend daily by a value proportional to an ideal body weight deviation.

14. A method according to claim 12, whereby the value of a bag trend is determine as follows:

$\mathrm{Bag}=\left(\left({\mathrm{Bag}}_o-{\mathrm{Bag}}_i\right)-\frac{〈<br><br>\mathrm{Bag}〉<br><br>}{200}\right)\times <br><br>15$

where Bag is the new value of bag parameter, Bag_i is the volume that enters the bag, Bag₀ is the volume that goes out the bag, <

Bag>

is the mean value of the volume contained in this type of bag.

15. A method for monitoring a patient subjected to dialysis at home comprising:

calculating a probability of observing a given value v_i,t for a physiological parameter in a server from the following equation;

$P\left(V_{i,t}|S\right)=\underset{o\in <br><br>O<br><br>\left(i\right)}{\sum <br><br>}<br><br>f_{s,o}<br><br>\left(V_{i,t}\right)<br><br>p_i<br><br>\left(o|s\right)$

where

V_i,t is a value observed for a physiological parameter at the time t,

O(i) is a set of possible observations for the physiological parameter i, said set (O(i) comprising observations, including satisfactory, below a norm value, above a norm value;

f is a function of the type which gives a weighting of between 0 and 1, which is dependant on the value of the physiological parameter i for a given state s, and which parameters are defined by a doctor or depend on history,

p_i(o|s) is the probability of observing o for the parameter i assuming that the state of the patient is s; and

transmitting an alert message from said server to an interface means at a doctor'"'"'s surgery and/or to an interface means at a patient'"'"'s home if the norm value is likely to be exceeded;

wherein norm values are determined as a function of a stored history and are updated trend data received by the server.

16. A method according to claim 15, whereby the physiological parameter is selected from the group consisting of weight, blood pressure, orthostatic blood pressure, or balance sheet for the bags.

17. A method according to claim 16, further comprising:

comparing the difference between the weight of the patient and an ideal body weight with a lower and an upper weight threshold values;

comparing the difference between the blood pressure and a mean blood pressure calculated over a history of the patient with a blood pressure threshold value;

comparing the difference between the upright and supine blood pressures of the patient with a threshold value;

comparing the difference between a volume drained by the bags of the patient and a mean drained volume determined over a history of the patient with a normal value; and

deducing for each parameter i selected from the group consisting of weight, blood pressure, orthostatic blood pressure, or a balance sheet for the bags, a corresponding observation o in O(i).

18. A method according to claim 15, whereby the function f depends on a ratio defined by:

(measured value for i−

base value for i)/ tolerance, where the base value and the tolerance value for the parameter i are defined by a doctor or depend on a history.

19. A method according to claim 15, comprising modifying the values determined for the probabilities pⁱ(o|s), which modifications are calculated in such a way as to minimize the error between a new solution proposed by the doctor and the probability of observing a value for the physiological parameter calculated in the server.